Question: Vascular invasion is a characteristic feature of

Mucormycosis occurs as a systemic infection following dissemination from a primary focus in the upper respiratory tract or nasal cavity. When the lung is the primary site of infection the fungi may invade the aeries to cause thrombosis and infraction. Ref: Textbook of Microbiology, Ananthanarayan and Paniker; 9th edition


Question: CSF Chloride is decreased in

CSF from tuberculous meningitis often develops a spider web clot on standing Other CSF findings are increased lymphocytes, decreased chloride. The use of PCR and DNA probes may help detect the bacilli speedily and more often.

Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli)


Question: Prions are best killed by

Ans. is 'c' i.e., Sodium hydroxide Incineration is apparently the only way of disinfecting prion-contaminated materials or tissues. Boiling or irradiation have no effect and even routine autoclaving (at 121degC) is not reliable. Therefore, where there is a risk of exposure, surgeons use disposable instruments. To sterilize reusable instruments, WHO currently recommends combined use of a strong solution of sodium hydroxide and extended autoclaving at 134degC. "Autoclaving at 134degC for 5 hrs or treatment with 2 N NaOH for several hours is recommended for sterilization ofprions". Harrison


Question: Best indicator for monitoring of syphilis treatment

Ans. (a) VDRL Serological test of syphilis Most sensitive test FTA-ABS Most specific test TPI (not used now) Test of choice for rapid diagnosis RPR Test of choice for evaluation of therapy VDRL Test of choice for diagnosis of congenital syphilis IgM FTA-ABS Now, TPPA has supplanted FTA-ABS as definitive diagnosis test for syphilis.


Question: Wasserman test is

Ref: Ananthanarayana textbook of Microbiology 9th edition Pgno : 120 Complement fixation test Direct complement fixation test Wasserman test Syphilis Indirect complement fixation test T.pallidum immobilization test Syphilis Sabin Feldman dye test Toxoplasmosis Cytocidal test Vibrio Immunoadherence Vibrio , T.pallidum


Question: N.K. Cell provides immunity against

Ans. is 'a' i.e., Virus . NK cells are considered to be impoant in immune surveillance and natural defence against virus infected cells and malignant mutant cells.


Question: Transfer of DNA from one bacterium to other by a bacteriophage is known as

Ans. c (Transduction). (Ref. Textbook of Microbiology by Anantanarayan, 6th/53)TRANSMISSION OF GENETIC MATERIAL IN BACTERIA IS BY:# Transformation:- Transfer of genetic information through agency of free DNA.# Transduction:- Transfer of a portion of DNA from one bacteria to another by transduction phase.- It is not confined to transfer of chromosomal DNA.- It transduces epizomes & plasmids also.- B'phages are viruses that parasitise bacteria & consist of nucleic acid core & a protein coat.- It is excellent tool for gene mapping of bacteria.# Lysogenic conversion:- Phage DNA becomes integrated with bacterial chromosome as prophage, which multiplies synchronously with host DNA & is transferred to daughter cells. This is lysogeny & bacteria harbouring prophages are lysogenic bacteria.- In transduction phage acts as vehicle carrying bacteria genes from one cell to another but in lysogenic conversion phage DNA itself is new genetic element.# Conjugation:- Process where by 'male' or 'donor' bacterial mates or makes physical contact with female or recipient bacteria & transfer genetic element into it.# Sexduction:- Process of transfer of host genes through F factor resembles transduction known as sexduction.


Question: Giemsa stain yeast cells in HIV are associated with

(C) Cryptococcosis # Cryptococcus neoformans is an encapsulated yeast that causes cryptococcosis.> Cryptococcosis has changed from a relatively obscure fungal pathogen that infects immunocompetent patients to a leading cause of central nervous system infection in the world's enlarging immunocompromised populations.> Infection with C. neoformans is termed cryptococcosis.> Most infections with C. neoformans occur in the lungs.> Fungal meningitis and encephalitis, especially as a secondary infection for AIDS patients, are often caused by C. neoformans, making it a particularly dangerous fungus.> Infections with this fungus are rare in those with fully functioning immune systems.


Question: Gas gangrene is due to

The alpha-toxin is produced by all types of Clostridium perfringens and most abundantly by type A strains. This is the most impoant toxin biologically and is responsible for the profound toxemia of gas gangrene. It is lethal, dermonecrotic and hemolytic. It is phospholipids which, in the presence of calcium and magnesium ions, splits lecithin into phosphorylcholine and diglyceride. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 259


Question: Hepatitis A virus is best diagnosed by

Ans. is 'a' i.e., IgM antibodies in serum Lab diagnosis of HAV . "Detection of IgM - specific anti-HAV in the blood of an acutely infected patient confirms the diagnosis of hepatitis A" . IgM appears in acute phase, peaking about 2 weeks after elevation of liver enzymes and becomes undetectable within 3-6 months. . ELISA is the method of choice for measuring antibodies. Diagnosis can also be established by detection of virus in the stool from about 2 weeks prior to the onset of jaundice up to 2 weeks after. "But these tests for detection of HAV, are not widely available or useful in practice".


Question: Pasteurella multocida is transmitted by

Pasteurella multocida:Francisella tularensis--Gram-negative bacilli, non-motile,--zoonotic disease--Catalase, oxidase, and indole positive--Wound infection followed by the bite of humans, dogs & cats; bacteremia and sepsis--Gram-negative bacilli, non-motile--Causative agent of Tularemia--Tick-borne disease, Rabbit-bite fever--Capsulated, intracellular--Divided by budding & binary fission --Local ulceration with lymphadenitis, typhoid-like fever with glandular enlargement--Influenza-like respiratory illness--Media - Francis blood dextrose cysteine agar for isolation(Ref: Ananthanarayan 9th edition, p401-402)


Question: Actinomycosis is a


Question: A patient has prosthetic valve replacement and he develops endocarditis 8 months later. Organism responsible is

Staphylococcus epidermidis is invariably present on the normal human skin. It is non-pathogenic ordinarily but can cause disease when the host defences are breached. It is a common cause of stitch abscess. It has a predilection for growth on implanted foreign bodies such as aificial hea valves, shunts, intravascular catheters and prosthetic appliances, leading to bacteremia. Hospital strains are multi-drug resistant. It can cause cystitis and central line-associated BSI. Biofilm formation is an impoant factor in the pathogenesis. It is an extracellular polysaccharide matrix which protects bacteria from antibacterial agents and helping colonisation and resistance to infection. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 208


Question: Condyloma accminatum is caused by HPV types of

Ans. is 'c' i.e., 6,11 . High risk HPV: HPV-16, 18, 31, 33 & 45 ---> associated with cervical cancer. . Low risk HPV: HPV- 6 & 11 --> associated with precursor lesions CM and condyloma accuminatum . HPV-5 & 8 associated with squamous cell cancer in patients with epidermodysplasia verruciformis


Question: Rice grains appearance with passage of proglottids in stool is seen in

(T. saginata) (144-Panikar 6th)* Most common presenting finding is the passage of proglottids in the stool in T. saginata (1315-CMDT-08).* T. solium - Autoinfection with eggs can progress to cysticercosis.* T. saginata - Commonly lives in Jejunum (Unarmed tapeworm).* The larva of T. saginata (cysticercus bovis) is not found in humans.* Niclosamide and praziquantel are effective treatment.


Question: The Generation time in coliform bacilli is

Population doubling time or the generation time of

E.coli is 20 mins
MTB is 20 hours
M. leprae is 20 days.


Question: Chagas disease is caused by

Trypanosoma cruzi causes Chagas diseaseThey are introduced when infected kissing bug feces are rubbed into conjunctiva, bite site or a break in the skin.Unilateral swelling of the eyelids (Romana&;s sign) is characteristic.Interstitial myocarditis is the most common serious condition.Invasion or toxic destruction of nerve plexuses in the alimentary tract wall leads to megaesophagus and megacolon (Brazilian Chagas disease)Jawetz 27e pg: 715


Question: Stalactite growth in a ghee broth culture is characteristic of

Yersinia pestis:The plague bacillus is a sho, plump, ovoid gram-negative bacillus.It is aerobic and facultatively anaerobicIt is not nutritionally exacting and grows on ordinary mediaIf grown in a flask of broth with oil or ghee floating on top, a characteristic growth occurs which hangs down into the broth from the surface, resembling stalactites .Ref: Ananthanarayan; 7th edition; Page no: 324


Question: Example for Live vaccine is

<img class="fr-dib" style="width: 300px;" src=" /> Live vaccines They initiate infection without causing any injury or disease. The immunity following live Vaccine administration therefore parallels that following natural infection though it may be of a lower order. The immunity lasts for several years but booster doses may be necessary. Live vaccines may be administered orally (as in with the sabin Vaccine for poliomyelitis) or parenteral (as with the Measles Vaccine) other examples are Rubella and yellow fever Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 83


Question: Recent noble prize is for

The Nobel prize in Physiology or Medicine 2006 was awarded jointly to Andrew Z Fire and Craig C Mello for their discovery of RNA interference, gene silencing by double-stranded RNA. Ref: Ananthanarayanan and Paniker's textbook of microbiology 9th edition.


Question: Pneumococcal vaccine is prepared from

Pneumococcal vaccine: A polyvalent polysaccharide vaccine representing the capsular antigens of the 23 most prevalent serotypes have been stated to give 80-90% protection. Given in patients with enhanced risk of pneumococcal infection, absent or dysfunctional spleen, sickle cell disease, immunodeficiency etc. It is not recommended in children under the age of two years and those with lymphoreticular malignancies and immunosuppressive therapy A 7 valent conjugate vaccine (conjugated to the CRM197 protein of C.diptheriae) is now available which can be used in children from two months to two years. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 228


Question: A gardener has multiple vesicles on hand and multiple eruptions along the lymphatics. Most common fungus responsible is

Sporotrichosis is a chronic infection involving cutaneous, subcutaneous and lymphatic tissue. It is caused by Sporothrix schenckii. pathogenesis- 1. lesion on the exposed pa of skin follow minor trauma. Nodules are first formed, followed by ulceration and necrosis of nodules. 2. From lesions on the skin and subcutaneous tissue, infection spread by lymphatic channels to the lymph node, and lymphatics are hardened and cord-like. Ref: Textbook of Microbiology, Ananthanarayan and Paniker; 9th edition


Question: Immunoglobulin transpoed through the placenta is

IgG is the only immunoglobulin class to cross the placenta and therefore is the most abundant immunoglobulin in newborns. Isotype-specific transpo of IgG across the placenta occurs with a preference for IgG1 and IgG3 subclasses.IgG also mediates opsonization of antigen through binding of antigen-antibody complexes to Fc receptors on macrophages and other cells.IgM is a Millionaire molecule, largest. IgA - Secretory Ig. IgE - AnaphylaxisJawetz 27e pg: 137


Question: Fiber optic instruments like endoscopes should be disinfected by

2% Glutaraldehyde for 20 minutes is active against bacteria, viruses and fungi. Latest 0.5% Ohophthaldehyde is used with 5min Contact period. Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 33


Question: EAC rosettes are formed by


Question: Markers of acute viral hepatitis caused by HBV

In acute hepatitis following serological markers are present:

HBs Ag
Ig M anti HBc Ag (in recent infection) or IgG anti HBc Ag (in remote infection).
Hbe Ag (with high infectivity) or Anti Hbe Ag (with low infectivity).


Question: The most common mechanism of resistance to the drug in staphylococcus is

b-Lactamase production is common, is under plasmid control, and makes the organisms resistant to many penicillins (penicillin G, ampicillin, ticarcillin, piperacillin,and similar drugs). The plasmids are transmitted by transduction.Jawetx 27e pg:204


Question: The beta haemolytic streptococcus commonly implicated in neonatal meningitis is


Question: HLA is the major histocompatibility antigen determining homograft rejection. This comes under

HLA and blood groups come under iso-specificity in which antigens are present in ceain group of subjects in same species Ref: Textbook of Microbiology Baveja 5th ed Pg 94


Question: Injection abscesses due to use of contaminated vaccines occurs in infections caused by


Question: Virulence factors for meningococci

Meningococci are capsulated, unlike Neisseria. Based on their capsular polysaccharide antigens, they are classified into 13 subgroups, of which groups A, B, C, X, Y and W-135 are the most impoant Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 231


Question: Among the infectious diseases transmitted by food, one is


Question: The endotoxin of the following gram negative bacteria does not play any part in the pathogenesis of the natural disease.

Cholera Vibrios also possess lipopolysaccharide O antigen (LPS, endotoxin) as in other gram-negative intestinal bacilli. But unlike other gram-negative bacilli like E.coli, Klebsiella and Pseudomonas, etc. (where endotoxin is the principle virulence factor), LPS apparently plays no role in pathogenesis of cholera but is responsible for the immunity induced by killed vaccine.
For Vibrio cholerae the principle virulence factor is the exotoxin, i.e. cholera toxin.


Question: Most sensitive test for Treponema

FTA-ABS test Most sensitive test in Syphilis The non specific tests (VDRL / RPR) test can be easily ruled out:? Their sensitivity is comparable to that of specific tests in primary and secondary syphilis but in latent or late syphilis they have quite low sensitivity. Specific Tests TPI In its time TPI was the most specific test available .for diagnosis of syphilis and was considered "gold standard" in .syphilis serology. However because of its extreme complexity it was available only in. few laboratories. The TP1 test has now been supplanted by other tests such as FTA-ABS and TPHA which are quite as specific and much simpler. FTA-ABS test FTA-ABS test is as specific as the TPI test and is now accepted as the standard reference test. However it can be done only in suitably equipped laboratories, it is not available for routine testing. TPHA test TPHA test is just as specific as FTA-ABS and almost as sensitive except in the primary stage. It is also much simple and more economical. These advantages have made TPHA a standard confirmations test. TPPA test The TPHA test has been replaced by the serodia TP-PA test which is more sensitive for primary syphilis. TPHA is widely available in Europe but not used in U.S.A. From the discussion above, and from the table reproduced from Harrison, it seems, the TPPA is the most sensitive test far syphilis. - Both FTA-ABS and TP-PA are equally sensitive in secondary and latent syphilis. - TP-PA has higher sensitivity in Primary syphilis. - The problem is that enough datas for TP-PA are not available. Test Primary Secondary Latent Teiary * VDRL/RPR 78 (74-87) 100 95(88-100) 71 (37-94) * FTA-ABS 84 (70-100) 100 100 96 * TP-PA 89 100 100 NA Diagnosis of syphilis:- Treponema pallidum cannot be isolated by routine culture methods therefore detection is either by direct visualization of the organisms in material .from the lesion or indirectly by immunological/serological methods. Each stage of the treponematoses requires a paicular testing modality. Absolute diagnosis during the first and second stages can be made by direct examination under dark field microscopy of a specimen from primary chancre, the maculopapular rash, or the condyloma Tatum. Since the direct visualization of spirochetes is effective only during the active stages of primary and secondary syphilis, serologic tests were developed. Serological tests in syphilis are of two types - Non specific treponemal tests - Specific treponemal tests Nonspecific treponemal tests :? Infection with syphilis results in cellular damage and the release into the serum of a number of lipids including cardiolipin and lecithin. The body produces antibodies against these antigens. - Non specific treponemal tests detects the presence of these antibodies to lipoprotein material from damged cells and cardiolipin from treponemes and as a consequence are not specific for Treponema. (Reactivity in these tests indicates host tissue damage). - If the patient has these antibodies it is assumed that he or she has syphilis. These tests are used for screening of syphilis. - If these tests are positive presence of the disease should be confirmed by specific tests. The tests commonly employed are: ? - Veneral disease Research laboratory test (VDRL TEST) - Rapid plasma Regain Test (RPR test) Why are these tests nonspeciic?? - These tests measure antibodies directed against cardiolipin antigen that results ,from interaction of host tissues with treponema pallidum or spirochete itself. (They do not detect the antibodies against Treponena itself). - Cardiolipin is a phospholipid and it is possible that a similar substance present in the treponemal cell or released. from damage host cells damaged by the stimulate antibody production. - Assays for nonspecific antibody, because of their low cost and technical simplicity have routinely been used as screening test .for evidence of syphilis since these tests have relatively low specificity positive results are confinned by detection of specific anti Treponemal antibody. Antibody develops in 70% of patients within 2 weeks of developing chancre and in 100% of patients with secondary syphilis. The impoant point about nonspecific treponemal tests is that they can be used quantitatively: ? - Quantitative result of these tests tends to correlate with disease activity thus they are very helpful .for screening. A four, fold or greater rise in the titre may be seen during the evolution of early syphilis. in secondary syphilis, test results are always positive and often at a high titre. The nonspecific treponemal tests should become nonreactive one year after successful therapy in primary syphilis and 2 years after successful therapy in late syphilis. - There fore these tests can be used to monitor response to treatment. -After successful treatment there would be sustained four fold decrease in antibody titre. - Similarly a four fold increase in titre following therapy suggests reinfection or relapse and necessitates reevaluation. Non specific Treponemal tests for syphilis VDRL Test The VDRL test is a non specific serological test for syphilis. It uses a mixture of cardiolipin, cholesterol and lecithin as antien. With the use of these antigens, IgG or 1gM antibodies present in the serum or C.S.F. (in case of neurosyphilis) are detected. This test can be used quantitatively and increase in VDRL titre with time can be used to confirm a diagnosis of syphilis. R.P.R. It is also a nonspecific test which uses cardiolipin as antigen. Treponemal specific tests While the nonspecific tests look for antilipoidal antibodies the specific treponemal tests look for antibodies against the spirochete itself The tests included in this category are: ? - Indirect immunoflorescence treponemal antibody-absorption test (FTA-ABS) test. -Treponema pallidum hemagglutination assay (TPHA) or microhemagglutination test (MHA-TP) - Treponema pallidum immnobilisation test (TPI). - Enzyme immune assay (ELISA). - TPPA test These tests are used to confirm a positive nontreponemal reaginic test. Treponema specific tests are not completely specific for syphilis because false positive reactions can occur with other spirochetal diseases (e.g., Yaws, pinta leptospirosis, rat bite fever, relapsing degfever, lyme disease). An impoant point about these tests is that they do not correlate with disease activity. - These test findings become positive soon after infection and typically remain positive for life despite adequate treatment.


Question: Ochratoxin is the mycotoxin produced by

Ochratoxin- Aspergillus ochraceus Fusarium- sciepenols Amanita-muscarine Aspergillus-aflatoxin Ref: Baveja 5th ed pg: 562


Question: The most sensitive test for the diagnosis of herpes simplex (HSV) meningitis in a newborn infant is

HSV meningitis or encephalitis is difficult to diagnose by laboratory tests as there is a low titer of virus present in the CSF. Neonatal HSV infects the child during the birth process. While culture, Tzanck smear, and even antibody tests may be useful in adults, particularly those with HSV-rich lesions, they are not useful for CSF testing. Only PCR is sensitive enough to detect HSV DNA in the CSF. Once diagnosed rapidly, HSV encephalitis or meningitis can be treated with acyclovir.


Question: Streptococcal toxic shock syndrome is due to liberation of

Pyrogenic exotoxin ( erythrogenic, Dick, scarlatinal toxin): the toxin was named erythrogenic because it's intradermal injection into susceptible individuals produced an erythematous reaction. The primary effect of the toxin is induction of fever and so it was renamed streptococcal pyrogenic exotoxin. 3 types of SPE have been identified: A, B, and C, types A and C are coded by bacteriophage genes while type B gene is chromosomal. SPE are superantigens, T cell mitogens that induce a massive release of inflammatory cytokines, causing fever, shock and tissue damage. Soft tissue infections with some eM types 0f S.pyogenes (1, 3, 12, 28) may sometimes cause a toxic shock syndrome resembling staphylococcal TSS. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 214, 215


Question: Reduction rhinoplasty is done for

An operation called Reduction Rhinoplasty reduces the size of the framework of the nose over which the skin is draped. The skin itself is not touched.The frame of the nose which is made up of bone in its upper half and gristle(cailage) in its lower half is approached from underneath the skin.


Question: Coccobacillus grown in BYCE medium is

Coccobacllus which have fatidious requirements and grow on complex media such as buffered charcoal,yeast extract (BYCE) agar,with L_cysteine and antibiotic supplements with 5%CO2 at PH_6.9, temperature 35degC and 90% humidity is legionella. Ref: anantnarayan and panikers 10 th edition


Question: Syphilis was first identified by

Treponema pallidum is the causative agent of syphilis, was first discovered by Schaudinn and Hoffmann in the chancers and inguinal lymph nodes of syphilitic patients. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th edition; Pg: 378


Question: Dimorphic fungi grow as molds at


Question: In the Eijkman test, mac Conkey broth tubes are incubated at

At 44 degree centigrade, Mac Conkey broth tubes are incubated Ref: Textbook of Microbiology Baveja 4th ed Pg 691


Question: Coincidental malignancy in the upper respiratory tract with inveed papillomas seen in

Coincidental malignancy in the upper respiratory tract with inveed papilloma is seen in 4%Malignant transformation of the tumor itself is seen in 8%


Question: Submandibular salivary gland is divided into superficial and deep lobes by

The submandibular salivary gland is a large salivary gland situated in the anterior pa of the digastrics triangle.The gland is about the size of a walnut.It is roughly J-shaped being indented by the posterior border of the mylohyoid which divides it into a larger pa superficial to the muscle and a small pa lying deep to the muscle.


Question: The optimal time and temperature required for sterilization in an autoclave is


Question: Simplest and most effective method to prevent nosocomial infection

As hand contact is the most common mode of transmission,
the best preventive measure of nosocomial infection is proper hand hygiene


Question: Double stranded RNA is

genome of reovirus consist of double stranded RNA


Question: Latex card agglutination test is done for

Latex card agglutination test to detect cryptococcal anitgen in CSF.


Question: Most common organism responsible for pseudomembranous colitis is

Clostridium difficile: long, slender, gram-positive bacilli. Non-hemolytic, saccharolytic and weakly proteolytic. Causes: bloody diarrhea, pseudomembranous colitis, a common cause of nosocomial diarrhea. Pathogenesis: high molecular weight exotoxin A and B Toxin A is a potent enterotoxin, Toxin B is a cytotoxin. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 270


Question: Category A bioterrorism agents are

Category A bioterrorism agents include - 1. Smallpox- various virus 2. Tularemia- Francisella tularensis 3. Anthrax- bacillus anthracis 4. Botulinum toxin- Clostridium botulinum 5. Bubonic plague- yersinia pedis 6. Viral haemorrhage fever- filoviridae (Marburg virus and Ebola virus) Ref: Baveja textbook of microbiology; 4th edition


Question: The culture media for fungus is

Tellurite and chocolate agar are bacterial culture media. NNN media used for culture of the parasite (Leishmania). Reference: Textbook of Microbiology; Baveja; 4th edition


Question: The dengue fever virus is

Dengue (breakbone fever) is a mosquito-borne infection caused by a flavivirus that is characterized by fever, severe headache, muscle and joint pain, nausea and vomiting, eye pain, and rash.Ref: Jawetz, Melnick, & Adelberg's Medical Microbiology; Twenty-Seventh Edition; Chapter 38; Ahropod-Borne and Rodent-Borne Viral Diseases


Question: Toxigenicity of tetanus is done on

In vivo: In vivo toxigenicity of tetanus is tested in a mouse. A 2-4 day old cooked meat culture is inoculated into the root of the tail of a mouse. A second mouse that has received the tetanus antitoxin an hour earlier serves as the control. Symptoms develop in the test animal in 12-24 hours, beginning with the stiffness in the tail. The animal dies within two days. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 267


Question: Culture medium for Corynebacterium diphtheria is

Loeffler's serum slope: diphtheria bacilli grow on this media very rapidly and colonies can be seen in 6-8 hours, long before other bacteria grow. Colonies are the first small, circular white opaque disc but enlarge on continued incubation and may acquire a distinctly yellow tint. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 242


Question: Presence of budding capsulated yeast in CSF is

(C) Cryptococcus neoformans # Cryptococcus neoformans is round or ovoid budding cell, 4-30 mm in diameter with polysaccharide capsule,> Infection is acquired by inhalation causes pulmonary cryptococcosis, (cryptococcal meningitis is most serious type of infection seen in AIDS patients.)> Diagnosis is established by demonstration of capsulated budding yeast cells in the lesion or culture from CSR> Blastomyces is dimorphic fungus (lung and cutaneous lesion)> Histoplasma is a dimorphic fungus involving pulmonary and reticuloendothelial sys.> Coccidioides imitis is dimorphic fungus producing respiratory infection only.> Cryptococcus causes CNS infection, so can be isolated from CSR


Question: Travellers diarrhoea is caused by

Enterotoxigenic E.coli (ETEC): Diarrhea caused by ETEC is of two epidemiological types Endemic in developing countries causing watery diarrhea to fatal disease. Traveller's diarrhea seen in persons from non-endemic areas visiting endemic areas. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg:285


Question: Red pigment producing bacteria is

Serratia forms characteristic pink,red or magenta non diffusible pigment called prodigosin which is optimally formed at room temperature. Ref: anantnarayan and panikers 10 th edition


Question: A tangled mass of hyphae is

Mycelium-a tangled mass of hyphae.
Fungi which form mycelia are called moulds.


Question: Causative agent of Favus is

Favus - scutula formation over scalp caused by T. Shoenleii
Kerion - Painfull boggy swelling caused by

T. Mentagrophytes
T. Verrucossum.


Question: VDRL test for diagnosis of syphilis is an example for

VDRL- Flocculation test Though flocculation also is a type of precipitation, flocculation is ideal for VDRL In which floccules are suspended after formation of antigen-antibody complex Ref: Textbook of Microbiology Baveja 5th ed Pg 120


Question: In myocardial infarction, the infarct acquires hyperemic rim with a yellow center at

Findings of infarct at 3 - 7 days: Gross examinationHyperemia borderSoftening yellow-tan center Histopathology (light microscopy)The beginning of the disintegration of dead muscle fibersNecrosis of neutrophilsThe beginning of macrophage removal of dead cells at the border


Question: The sterilization method for catgut suture

Ans. (b) Radiation Sterlisation of Materials Impoant Materials Methods of sterilisation and disinfection 1 Glasswares-syringes, Petri dishes, test tubes, flasks, surgical instrument; oily fluids and powders Hot air oven 2. Serum, body fluids, bacterial vaccines Waterbath, vaccine bath 3. Milk Pasteurisation, 63degC x 30 min. or 72degC x 20 sec 4. Cystoscope and endoscope Glutaraldehyde (Cidex-2%) or ethylene oxide 5. Most of the culture media Autoclaving 6. Culture media containing egg, serum or sugar Tyndallisation 7. Rubber, plastic and polythene tubes, disposable syringes Glutaradehyde, ethylene oxide gas 8. Dressings, aprons, gloves, catheters surgical instruments except sharp instruments. Autoclaving 9. Sharp instruments 5% cresol 10.Suture materials except catgut Autoclaving 11.Catgut Ionising radiation 12. Rubber or plastic disposable goods, disposable syringes, bone and tissue graft, adhesive dressings Ionising radiation 13. Faeces and urine, vomitus sputum Bleaching powder, cresols, formatin, burning, autoclaving, boiling 14.Sterilisation of operation theatre Formaldehyde gas 15. Wards and laboratory or operation theatre floor space Formaldehyde gas and cresols (Lysol) 16. Skin Tincture iodine, spirit (70% ethanol), Savlon (phenol derivative).


Question: Selective culture medium to grow leptospira

CULTURE MEDIA ORGANISM 1. EMJH(Ellinghausen McLlaugh Johnson and Harris) Leptospira 2. Thayer Main medium Gonocoocus and meningococcus 3. MacConkey's agar Enterobacteriacae 4. Chocolate agar Gonocoocus , meningococcus and hemophilus


Question: Near double stranded DNA among the following

(B) Hepatitis B # Genome of HBV is made of circular DNA, but it is unusual because the DNA is not fully double-stranded.> One end of the full length strand is linked to the viral DNA polymerase.> The genome is 3020-3320 nucleotides long.


Question: The bursa communicating with knee joint is

The suprapatellar bursa communicates with the cavity of the knee joint.Inflammation of the infrapatellar bursa is known as Clergyman&;s knee and prepatellar bursa is known as Housemaid&;s knee.The Anserine bursa separates the inseions of Semitendinosus, Saorius and Gracialis from tibia.


Question: Saccharolytic reaction in cooked meat broth is produced by

CMB also called Robesons cooked meat -contains nutrient broth and cooked meat of ox hea Saccharolytic reaction positive for cl.perfringes Proteolytic reaction positive for cl.tetani Ref: CP Baveja 4th ed Pg:51


Question: Common host of Balantidium coli is

Ans: d (Pig)Ref: C K Jayaram Panicker's Textbook of Medical Parasitology, 6th ed. Pg. 111-112Balantidium coli* Only ciliate protozoan parasite of humans* Largest protozoan parasite in humans* It is a zoonosis, the principal reservoir being pigs, monkeys and rats.* It occurs in 2 stages -- trophozoite and cyst form.* Trophozoite lives in the large intestine* Infective form is the cyst in food and water.* Clinically resembles amoebiasis -- diarrhoea or dysentery, abdominal colic, nausea, vomiting* Treatment is with tetracycline metronidazole is also useful.


Question: Complement binding immunoglobin via the classical pathway is


Question: Streptokinase is produced from

S.equisimilis produces streptolysin O, streptokinase (antigenically distinct from that produced by S.pyogenes) and other extracellular substances. S.equisimilis is the source of streptokinase used for thrombolytic therapy in patients. Group C streptococci are predominantly animal pathogens. Group C strains isolated from human sources usually belong to the S.equisimilis species. It can cause upper respiratory infections, as well as deep infections such as endocarditis, osteomyelitis, brain abscess, pneumonia and puerperal sepsis. Strains are tolerant to penicillin and serious infections may not respond to penicillin treatment. The addition of gentamycin is recommended in serious cases. Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg: 219


Question: The following is a diploid cell strain

HL-8 (Rhesus embryo cell strain ) and WI-38 (human embryonic lung cell strain) are diploid cell lines Primary cell strains include- chick embryo fibroblast cell culture, human amnion cell culture etc Ref: Baveja 5th ed Pg: 417


Question: Transfer of a poion of the DNA from one bacterium to another by the bacteriophage is known as

In transduction, donor DNA is carried by a phage coat and is transferred into the recipient by the mechanism used for phage infection.Reference: Jawetz, Melnick, & Adelberg's Medical Microbiology; 27th edition; Chapter 7; Microbial Genetics


Question: Acid maltase deficiency occurs in

Pompe DiseaseAcid maltase (acid a-glucosidase) deficiency, also called Pompe disease, is a glycogen and lysosomal storage disease with autosomal recessive inheritance.The classic severe infantile form presents with hypotonia, myocardiopathy, and hepatosplenomegaly.This variant is rapidly progressive and generally results in death in the first year of life. However, as with other lysosomal diseases, there are early- and late-onset forms of this disorder.The late-onset patients typically present with a slowly progressive myopathy that may resemble a limb-girdle muscular dystrophy. Respiratory insufficiency may develop with advancing disease.In late stages of the disease, patients may require mechanical ventilation, repo swallowing difficulties, and experience loss of bowel and bladder control.Myocardiopathy is not usually seen in late-onset variants of Pompe disease.


Question: The active component of Bleaching powder is


Question: Example of type 1 hypersensitivity


Question: Enterovirus 72 is

Hepatitis A virus belongs to Enterovirus (picomavirus family) and was originally designated as “enterovirus-72”

Hepatitis ‘A' virus

 HAV is a non enveloped RNA virus.
 It is classified in genus Hepatovirus under family picomavirus.
 Originally called as enterovirus 72.
 It is the only human hepatitis virus which can be cultivated in vitro. It can be grown in some human and simian cell

cultures.

 Most common cause of acute hepatitis in children.
 Transmission is by the fecal-oral route.
The virus is shed in feces during the late incubation period and the prodromal phase of the illness.
Maybe present occasionally in the saliva and urine of patients, but this is not relevant in the spread.

Prophylaxis
Both passive and active prophylaxis are available.
Passive prophylaxis by pooled normal human immunoglobulin is given IM before exposure or in the early incubation period.
Active prophylaxis is by a conjugate vaccine containing HAV (inactivated by formalin) grown in human diploid cell culture.


Question: A patient presents with fever, uicaria, itching and swelling followed by injection of Penicillin. It is due to

There are two clinical pictures that can result from penicillin allergy, namely acute (Type I) and sub-acute reactions (Type II) mediated by IgE and IgG antibodies respectively. The acute allergic reaction arises immediately or rapidly within minutes to an hour or two and includes sudden anaphylaxis with hypotension, bronchospasm, angioedema and uicaria. Acute reactions result from reaction with preformed IgE to penicillin as a result of previous exposure. A less dramatic picture may occur 7 to 10 days after penicillin treatment stas or 1-2 days after repeat therapy. In this setting, the picture is sub-acute and can include uicaria, fever and ahralgias or ahritis. The sub-acute reaction is caused by preformed IgG to penicillin as a result of previous penicillin treatment. The IgG antibody results in the activation of the complement reactions producing inflammation resulting in the symptoms. Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 166,167


Question: From one of the following He la cells are derived

(C) Carcinoma cervix > Cell lines derived from most virus induced cancers contain path of all of the virus genome. The most famous of these-- He la cell line was established from cervical cancers.


Question: A patient has an increased antibody titer to delta agent. You would most likely suspect

Delta agent is a recently discovered antigen associated with HBsAg. Its presence usually correlates with HBsAg chronic carriers who have chronic active hepatitis. EIA and radioimmunoassay (RIA) tests are available to detect antibodies to delta agent. Fifth disease is a viral exanthem commonly seen in children 8 to 12 years old. Children are ill for a few days but recover without incident. Unfounately, if a pregnant female acquires the disease in the first trimester of pregnancy, the fetus is at risk. The causative agent is thought to be a parvovirus (parvovirus B 19). Adults with no titer to varicella (VZV) are at risk for acquisition of chickenpox. If they are health care workers, there is additional risk in transmitting VZV to immunodeficient children. Antibodies to VZV are readily detected by both enzyme immunoassay (EIA) and fluorescent-antibody (FA) techniques. SSPE is thought to be caused by a measles-related virus present in the central nervous system. Most SSPE patients show elevated measles virus antibodies in serum and CSF. In patients with multiple sclerosis (MS), lower CSF antibody titers have been observed, suggesting a possible etiologic role for measles virus in MS. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition

Possible subacute sclerosing panencephalitis (SSPE)


Question: Investigation of choice for neurosyphilis

* Sample of diagnosis for neurosyphilis is CSF * Only tests that can be done for neurosyphilis are: * VDRL * FTA-ABS * The diagnosis of asymptomatic neurosyphilis is made in patients who lack neurologic symptoms and signs but who have CSF abnormalities including mononuclear pleocytosis, increased protein concentrations, or CSF reactivity in the VDRL test. * When VDRL is negative, FTA-ABS is done to confirm the test. * Ideally both tests here are used in diagnosis; But when you have to choose single best option - best is VDRL according to CDC site and Mandells ID book. Ref:- Harrisons T.B of internal medicine 19th edition; pg num:- 1136


Question: Most common complication of chicken pox

M/c - secondary bacterial pneumonia(strept > staph)
Most dangerous - Varicella pneumonia.


Question: Atrophy of intrinsic muscles of the hand, sensory deficit on medial side of forearm and hand, and diminished radial pulse on turning the head on the affected side could be because of

Cervical ribs (present in up to 1% of people) aiculate with the C7 veebra are clinically significant because they may compress spinal nerves C8 and T1 or the inferior trunk of the brachial plexus supplying the upper limb. Tingling and numbness may occur along the medial border of the forearm. They may also compress the subclan aery, resulting in ischemic muscle pain (caused by poor blood supply) in the upper limb.


Question: The Dane particle is the


Question: Coconut cake rectum is seen in

T. trichura also known as whipworm causes coconut cake rectum in children.


Question: Contaminant in home canned vegetables and smoked fish includes

Clostridium botulinum: strict anaerobic, cause botulism. Source of botulism is preserved food, meat and meat products, canned foods. Proteolytic varieties can digest food, which appears spoiled. The cans are often inflated and show bubbles on opening. Non-proteolytic varieties have food unchanged. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 269


Question: Diagonal conjugate is defined as the distance between

The diagonal conjugate is clinically estimated by measuring the distance from the sacral promontory to the lower margin of the symphysis pubis.

Upper border of symphysis pubis and the sacral promontory

Lower border of symphysis pubis and the sacral promontory

Lower border of symphysis pubis and the third piece of sacrum

Lower border of symphysis pubis and tip of sacrum


Question: Immunoglobulins present in milk


Question: Most common site for Amebic liver abscess

It involves posterior superior surface of right lobe of liver.

Posterior inferior surface of Right lobe of  liver

Posterior inferior surface of left lobe of liver

Posterior superior surface of right lobe of liver

Posterior superior surface of left lobe of liver


Question: Anaerobic bacteria can be cultured in


Question: Lesions caused by Entamoeba histolytica predominantly involve

Trophozoites generally infect the large intestinal mucosa but under certain conditions they may perforate the gut and invade other organs (especially liver, lungs and brain).
In many cases, the trophozoites remain confined to the intestinal lumen (noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool.
In some patients the trophozoites invade the intestinal mucosa (intestinal disease), or, through the bloodstream, extraintestinal sites such as the liver, brain, and lungs (extra-intestinal disease), with resultant pathologic manifestations.

Ref :
https://www.cdc.gov/parasites/amebiasis/pathogen.html
http://parasite.org.au/para-site/text/entamoeba-text.html#:~:text=Host%20range%3A%20Entamoeba%20histolytica%20is,in%20tropical%20and%20subtropical%20countries.


Question: Stuart's medium is a transport media for

Stuart's and Amies medium are transport media for Neisseria.


Question: Staphylococcus can cause

Staphylococcal infections are the most common bacterial infections and range from tril to fatal. The common pyogenic staphylococcal infections are: Skin and soft tissue infections: Folliculitis, furuncle, abscess, wound infections, carbuncle, impetigo, paronychia and less often cellulitis. 2. Musculoskeletal: Osteomyelitis, ahritis, bursitis and pyomyositis. 3. Respiratory: Tonsillitis, pharyngitis, sinusitis, otitis, bronchopneumonia, lung abscess, empyema and rarely pneumonia 4. CNS: Abscess, meningitis and intracranial thrombophlebitis 5. Endovascular: Bacteremia, septicemia, pyemia, endocarditis Ref: Textbook of Microbiology; Ananthanarayan and Paniker's; 10th Edition; Page No: 204


Question: The best diagnostic procedure of M.tuberculosis

Ans. is 'c' i.e., Sputum culture "Definitive diagnosis depends on isolation (culture) and identification of M. tuberculosis from a diagnostic sepcimen (most common specimen in sputum)".


Question: Heat labile immunoglobulin

Ans. is 'c' i.e., IgE Only heat labile Ig Inactivated at 56 degrees C in one hour.


Question: The granules discharged in mycetoma contains

Granules composed of broader filaments and often shows septa and chlamydospores in mycotic mycetoma. Ref: Textbook of Microbiology, Ananthanarayan and Paniker; 9th edition


Question: Citron bodies are seen in

Citron bodies - Boat or leaf shaped bodies seen in clostridium septicum.


Question: Culture of streptococcus viridans resemble

Streptococcus viridans and Streptococcus pneumoniae are alpha hemolytic. On blood agar, after incubation for 18 hours, the colonies are small (0.5-1mm), dome-shaped and glistening, with an area of green discolouration around them, resembling colonies of viridans streptococci. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 224


Question: HDV is


Question: Helper cells belong to

1. CD4+ T cells: CD4 cells are also known as helper T (Th) cells. They constitute about 65% of peripheral T cells and are found mainly in the thymic medulla, tonsils, and blood. CD4 displayed on the surfaces of these T cells recognize a nonpeptide-binding poion of MHC class II molecules. Hence, CD4+ T cells are restricted to the recognition of MHC class II complexes. Helper T lymphocytes are involved in the induction and regulation of immune responses. 2. Main function of helper T cells: 1. Help in the antigen-specific activation of B cells and effector T cells. 2. Th-1 cytokines activate cytotoxic inflammatory and delayed hypersensitivity reactions. 3. Th-2 cells help in the production of interleukins which encourage production of antibodies especially IgE. 4. Th-2 cytokines are associated with regulation of strong antibody and allergic responses.

Immunology Pa 2 ( Hybridoma Technology, Complement Pathways, Interferon, Structure and Functions of Immune Cells )


Question: The usefulness of a 'screening test' in a community depends on its

Predictive value of a test signifies the diagnostic power of the test.An attribute of an idea screening test is its repeatability or reliability or reproducibility.Sensitivity has been defined as the ability of the test to identify correctly all those who have the disease, that is truly positive (Hence determines the usefulness of the screening test).Specificity is not as impoant. After screening, we can apply a confirmatory test with high specificity.


Question: The following immunoglobulin is not known to fix complement


Question: Selective medium for Gonococci rpt


Question: Keroin is caused by

kerion - severe boggy lesions with a marked inflammatory reaction that sometimes develops in scalp infection due to dermatophytes. Reference: Textbook of Microbiology; Baveja; 4th edition


Question: Flavivirus associated with congenital microcephaly is

Ref: Ananthanarayana textbook of Microbiology 9th edition Pgno : 520 FLAVIVIRIDAEFamily Characteristics* Enveloped, icosahedral* Positive-sense ssRNA* Ahropod-borne (arboviruses) Virus Disease St. Louis encephalitis virus Encephalitis West Nile encephalitis virus Encephalitis Dengue Break bone fever (rash, muscle and joint pain), reinfection, can result in dengue hemorrhagic shock Yellow Fever virus Yellow fever: liver, kidney, hea, and GI(black vomit) damage Zika Mild - febrile illness of rash and ahralgiaCongenital: microcephaly and fetal demise


Question: Diene's phenomenon is seen in

Diene's phenomenon - proteus
Diene's method of staining → mycoplasma


Question: Causative organism of SARS


Question: Phospholipid used to investigate syphilis by the regain test is

Ans. a (Cardiolipin). (Ref. Ananthanarayan, Microbiology, 6th/pg.378; 7th ed. pg. 381)SEROLOGICAL TESTS FOR SYPHILISThese tests form the mainstay of laboratory' diagnosis.A Large number of tests have been described, of which only a few are now employed.These are follows:1. Tests for antibodies reacting with cardiolipin antigen (Non-specific reagin tests; standard tests for syphilis; STS)2. Tests for antibodies reacting with group specific treponemal antigen3. Tests for specific antibodies to pathogenic treponema (T. pallidum).Reagin antibody testsThese tests use the lipoid or cardiolipin antigens and are known as 'standard tests for syphilis' or STS.The first of the reagin antibody tests was the Wassermann complement fixation test (1906).It is no longer in use now.# The first flocculation test used widely was tube flocculation test of Kahn.# The Kahn test has been replaced by the simpler and more rapid VDRL test., which gives more quantitative result.# VDRL test can be used for testing CSF also, but not plasma. CSF need not be heated prior to test.# A number of modifications of the VDRL have been developed, of which the Rapid Plasma Reagin (RPR) test is the most popular.Sensitivity of Serodiagnostic Tests in Untreated SyphilisMean Percentage Positive (Range) at Indicated Stage of DiseaseTestPrimarySecondaryLatentTertiaryVDRL, RPR78 (74-87)10095 (88-100)71 (37-94)FTA-ABS84 (70-100)10010096TP-PA89100100NA


Question: Japanese B encephalitis virus is transmitted by the following vector

(A) Culex tritaeniorhynchus # Japanese encephalitis:> The virus was first isolated in Japan during an epidemic in 1935. Several large epidemics have occurred since then. Epidemics show a seasonal incidence (summer-autumn) in the temperate regions, though this is not evident in the tropical areas.> Culex tritaeniorhynchus, a rural mosquito that breeds n rice fields, is the principal vector.> In India, Japanese encephalitis was first recognised in 1955 when the virus was isolated from mosquitoes of the Culex vishnui complex from Vellore during an outbreak of encephalitis in Tamiinadu.


Question: Oudin procedure is a immunodiffusion by

Single diffusion in one dimension (Oudin Procedure).


Question: Widal test is a type of

Tube dilution agglutination test (Widal test): Serum agglutinins rise sharply during the second and third weeks of S serotype Typhi infection. The Widal test to detect these antibodies against the O and H antigens has been in use for decades. At least two serum specimens, obtained at intervals of 7-10 days, are needed to prove a rise in antibody titer. Serial dilutions of unknown sera are tested against antigens from representative salmonellae. The interpretive criteria when single serum specimens are tested vary, but a titer against the O antigen of greater than 1:320 and against the H antigen of greater than 1:640 is considered positive.Ref: Jawetz Medical Microbiology; Chapter15 Enteric Gram-Negative Rods (Enterobacteriaceae); Page no: 241


Question: Toxin production by Corynebacterium diphtheriae is due to

The toxigenicity of diphtheria bacilli depends on the presence in it of corynephages, which act as the genetic determinant controlling toxin production. Non-toxigenic strains Kay be rendered toxigenic by infecting them with the beta or some other phage. This is known as lysogenic or phage conversion. The toxigenicity remains only as long as the bacilli are lysogenic. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; page no 240


Question: The segment of DNA between chromosomal and extrachromosomal DNA molecules within the cells are


Question: Type of diarrhea in Vibrio cholera is

cholera is an acute diarrheal disease caused by V.cholera. In its most severe form, it presents as profuse painless, watery diarrhea and copious effoless vomiting; this may lead to hypovolemic shock and death. The cholera stool is typically a colorless watery fluid with flecks of mucus, said to resemble water in which rice has been washed (hence called 'rice-water stools') Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg:313


Question: Selective media for Naegleria fowleri is

Ans. c (Non-nutrient agar with with E.coli) (Ref Jawetz's Microbiology 24th/ Chapter 46)# Amebas can be readily cultured on nonnutrient agar plates seeded with Escherichia coli.FREE-LIVING AMOEBAS (CAUSING PRIMARY AMOEBIC MENINGOENCEPHALITIS)# Primary amebic meningoencephalitis: free-living soil amebas implicated are:- Naegleria fowleri,- Acanthamoeba castellanii,- Balamuthia mandrillaris, and- Hartmanella# Entry of Acanthamoeba into the CNS occurs from skin ulcers or traumatic penetration, such as keratitis from puncture of the corneal surface or ulceration from contaminated saline used with contact lenses.# Diagnosis is by microscopic examination of the CSF, which contains the trophozoites and red cells but no bacteria.# These soil amebas are distinguished by a large, distinct nucleus; by presence of contractile vacuoles and mitochondria (absent in Entamoeba); and by cysts that have a single nucleus and lack glycogen or chromatoidal bodies.# Acanthamoeba may encyst in invaded tissues, whereas Naegleria does not.# Rx with amphotericin B has been successful in a few cases, especaially diagnosis can be made quickly.Primary amebic meningoencephalitis (Naegleria Infections)# Primary amebic meningoencephalitis caused by Naegleria fowleri# Follows the aspiration of water contaminated with trophozoites or cysts or the inhalation of contaminated dust, leading to invasion of the olfactory neuroepithelium.# After an incubation period of 2-15 days# C/f: severe headache, high fever, nausea, vomiting, and meningismus develop. Photophobia and palsies of the third, fourth, and sixth cranial nerves are common.# The prognosis is uniformly poor: most patients die within a week.# Infection is most common in otherwise-healthy children or young adults, who often report recent swimming in lakes or heated swimming pools.# Diagnosis depends on the detection of motile trophozoites in wet mounts of fresh spinal fluid.# Antibodies to Naegleria spp. have been detected in normal adults; serologic testing is not useful in the diagnosis of acute infection.# Only a few survivors, treated with high-dose amphotericin B and rifampin, have been reported.Additional Educational Points:Common Culture Media in Mycology are:1. Sabouraud's glucose agar pH 5.42. Czapek-Dox medium3. Com meal agarNNN or Tobie's medium# In NNN only the promastigotes are found. L donovani usually grows slowly, the promastigotes forming tangled clumps in the fluid.# L tropica grows more quickly, promastigotes forming small rosettes attached by their flagella in the fluid, while# L braziliensis may produce a wax-like surface with fewer, smaller promastigotes.# In contrast, L mexicana produces rapid growth of large organisms in simple blood agar medium. In tissue cultures, intracellular amastigotes may occur in addition to the extracellular promastigotes.


Question: Among the following, T cell independent antigen acts through—


Question: Hemolytic uremic syndrome is caused by

Shigella dysenteriae type 1 causes toxemia due to the production of exotoxin.the complication includes polyneuritis, ahritis, conjunctivitis, parotitis and hemolytic uremic syndrome. Ref: Textbook of microbiology; Ananthanarayan and paniker's;10th edition; Pg:293


Question: The causative agent for duodenal ulcer is;

H. Pylori is gram negative bacteria, non-spore forming, micro aerophilic, extra cellular bacteria. H. pylori causes Peptic ulcer disease (80% of duodenal ulcer and 60% of gastric ulcer) It acts by decreasing Somatostatin - producing D cells. Other diseases caused by it are - Chronic atrophic gastritis and Autoimmune gastritis Adenocarcinoma of stomach (non cardiac) and non-Hodgkin's gastric lymphoma H. pyloriinfection increases the risk of gastric malignancies such asgastric adenocarcinomaandMALToma's


Question: The Most common fungus to cause meningitis is


Question: Paul Bunnel test is done for

(B) EBV # Heterophil antibodies, which is an antibody against EBV cross reacts with red blood cells of different animal species.> This can be used as a rapid screening test for mononucleosis (Monospot test and Paul Bunnell tests)> The Paul-Bunnell test uses sheep erythrocytes; the Monospot test, horse red cells, blood cells.> In infectious mononucleosis, IgM heterophil antibodies are usually detectable for the first 3 months of infection.


Question: A lady presented with fever and rashes, she returned from the USA gives a history of exposure to ticks. Most probable diagnosis is

Rocky mountain spotted fever caused by R.ricketsii is most serious type of spotted fever.it is prevalent in n.america and South America,transmitted by dermacabtor Andersoni and related sps of ticks Anantnarayan and paniker's 10th edition


Question: Streptococcus causing rheumatic hea disease is

Streptococcus pyogenes infection leads to two impoant non-suppurative post-streptococcal sequelae - acute rheumatic fever and acute glomerulonephritis. This complication ensues 1-3 weeks after the acute infection so that the organism may not be detectable when sequelae set in. In rheumatic fever, carditis, including connective tissue degeneration of the hea valves and inflammatory myocardial lesions characterized by Aschoff nodules is seen. Occurs due to an antigenic cross-reaction between group A carbohydrate of Streptococcus pyogenes and cardiac valves Streptococcal antigens cross-reactive with human tissues Streptococcal antigen Human antigen Disease Hyaluronic acid Synol fluid Reactive ahritis Cell Wall M protein Myocardium ARF(Acute rheumatic fever) Cell Wall C carbohydrate Cardiac Valves ARF(Acute rheumatic fever) Peptidoglycan Skin antigens Guttate psoriasis Cytoplasmic membrane Glomerular vascular intima Acute glomerulonephritis (AGN) Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 215


Question: Toxin involved in the streptococcal toxic shock syndrome is

Streptococcal toxic shock syndrome is caused by pyrogenic exotoxin. Pyrogenic exotoxin (erythrogenic, shock, scarlatinal toxin): the primary effect of the toxin is induction of fever and so it was renamed streptococcal pyrogenic exotoxin (SPE). 3 types of SPE are identified- A, B, C. Types A and C are coded by bacteriophage genes while type B gene is chromosomal. SPE is superantigens, T cell mitogens that induce a massive release of inflammatory cytokines, causing fever, shock and tissue damage. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 213


Question: Non Halophilic vibrio is

Except for V. cholera and V. mimicus all vibrios are halophilic.


Question: Definitive host of ascariasis

Ref: Harrisons, 19th ed. pg. 1413* Ascaris lumbricoidesis the largest intestinal nematode parasite of humans, reaching up to 40cm in length.* Humans are definitive host of ascaris* Clinical disease arises from larval migration in the lungs or effects of the adult worms in the intestines.* Clinical Features:# Around, 9-12 days after egg ingestion, patients may develop an irritating non-productive cough and burning substernal discomfort that is aggravated by coughing or deep inspiration.# Eosinophilia develops during this symptomatic phase and subsides slowly over weeks.# Chest x-rays may reveal evidence of eosinophilic pneumonitis (Loffler's syndrome), with rounded infiltrates a few millimeters to several centimeters in size.* Treatment: Mebendazole (DOC)


Question: Friedlander&;s bacillus is the eponym of

K.pneumoniae is also known as Friedlander's bacillus. Klebsiella causes pneumoniae which is a serious disease with high case fatality. K.pneumoniae is a frequent cause of urinary tract infection, often causing catheter-associated UTI (CAUTI) Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg:287


Question: A preterm, LBW infant delivered by LSCS after IVF was put on ventilator in NICU for severe RDS. The respiratory distress subsided on day 7 and TPN with lipid formulation was staed from day 10. The neonate developed signs of sepsis on day 15.The most likely causative agent is

Malassezia furfur is a lipophilic fungus that is found on skin. It causes fungemia, primarily in premature infants on high-lipid intravenous supplements. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition


Question: SARS is a type of

The SARS coronavirus (SARS-CoV):*Virus that causes severe acute respiratory syndrome (SARS)*It belongs to coronaviridae*November 2002, Guangdong province in south China experienced an outbreak of an unusual respiratory infection, with many deaths (Ref: Ananthanarayan 9th edition, p559-560)


Question: Job syndrome is due to

The autosomal dominant hyper-IgE syndrome also known as Job syndrome, characterized by the clinical triad of high serum IgE, recurring staphylococcal skin abscesses, and recurrent pneumonia with the formation of pneumatoceles.There is a defective immune response involving T lymphocytes, neutrophils and the cytokines they produce, especially interferon-gamma. Excessive levels of interferon-gamma result in marked elevation of immunoglobulin E.Disorders of phagocytosis:1.Chronic granulomatous disease2.Myeloperoxidase deficiency3.Chediak-Higashi syndrome4.Leukocyte G6PD deficiency5.Job's syndrome6.Tuftsin deficiency7.Lazy leukocyte syndrome8.Hyper- IgE syndrome9.Actin-binding protein deficiency10. Shwachman's diseaseRef: Ananthanarayan 9th edition, p172


Question: Possible source of “SECOND SIGNAL” to a bound Bcell by specific antigen include


Question: Newborn is presented with microcephaly, Chorioretinitis, Limb hypoplasia  & Cicatrising lesion of hands. Most probable diagnosis is

Congenital varicella syndrome

Microcephaly
Chorioretinitis
Limb hypoplasia
Cicatrizing lesion


Question: The antibiotic of choice for streptococcal pharyngitis is

There are few bacteria for which antimicrobial susceptibility is highly predictable. However, some agents are the drug of choice because of their relative effectiveness. Among the three antibiotics that have been shown to treat legionellosis effectively (erythromycin, rifampin, and minocycline), erythromycin is clearly superior, even though in vitro studies show the organism to be susceptible to other antibiotics.Penicillin remains the drug of choice for S. pneumoniae and the group A streptococci, although a few isolates of penicillin-resistant pneumococci have been observed. Resistance among the pneumococci is either chromosomally mediated, in which case the minimal inhibitory concentrations (MICs) are relatively low, or plasmid-mediated, which results in highly resistant bacteria. The same is generally true for H. influenzae. Until the mid-1970s, virtually all isolates of H. influenzae were susceptible to ampicillin. There has been a rapidly increasing incidence of ampicillin-resistant isolates, almost 35 to 40% in some areas of the United States. Resistance is ordinarily mediated by b-lactamase, although ampicillin-resistant, b-lactamase-negative isolates have been seen. No resistance to penicillin has been seen in group A streptococci.C. difficile causes toxin-mediated pseudomembranous enterocolitis as well as antibiotic-associated diarrhea. Pseudomembranous enterocolitis is normally seen during or after administration of antibiotics. One of the few agents effective against C. difficile is vancomycin. Alternatively, bacitracin can be used.Lyme disease, caused by B. burgdorferi, has been treated with penicillin, erythromycin, and tetracycline. Treatment failures have been observed. Ceftriaxone has become the drug of choice, particularly in the advanced stages of Lyme disease.


Question: Sporulation occurs at

Lag phase - maximum cell size.
Stationary phase - sporulation.


Question: Complements produced by spleen

C1 -Intestinal epithelium
C2, C4 - Macrophages
C5, C8 - Spleen
C3, C6, C9 - Liver.


Question: Vascular invasion is a prominent feature of

Vascular invasion is a feature of Mucormycosis causing thrombosis, infarction.


Question: Infection with Sporothrix schenckii (formerly Sporotrichum schenckii) is an occupational hazard for gardeners. The portal of entry for this organism is the

Cutaneous sporotrichosis, caused by S. schenckii, begins at the site of inoculation, usually on an extremity or the face. The organism often is found on thorns of rose bushes. Ulceration is common and new lesions appear along paths of lymphatic channels. Extracutaneous sporotrichosis is seen primarily in bones and joints. There is no evidence to suggest that any portal of entry besides skin is important.


Question: Dimorphic fungus rpt

candida- yeast like fungi. rhizopus and mucor are mould. REF:Baveja textbook of microbiology 4th edition


Question: The organism that can resist  temperature of 50° C  for minutes, grows in presence of >6.5% NaCl is

Enterococcus resist

pH of 9.4
40% of bile
Temperature of >45-55oC for minutes
6.5% of NaCl


Question: T. trichuria maintains its position in the intestinal tract by

Trichuris trichiura also called whip tapeworm lie embedded in the cecal wall, with the thread-like anterior poion piercing the mucosa and the thick posterior end projecting out.The infection is diagnosed by demonstrating the adult worm or the egg in the stool. Freshly passed eggs are bile stained, barrel-shaped and unembryonated.Panicker 7e pg: 172


Question: Job's syndrome is the following type of immunonodeficiency disease

Ans. is 'd' i.e., Disorder of phagocytosis Jobs syndrome is defect in phagocytic function. It is characterized by cold staphylococcal abscess, atopic eczema, otitis media; serum immunoglobulins are normal except IgE that is elevated


Question: Recurrent Neisseria infections are predisposed ina) Early complement component deficiencyb) Late complement component deficiencyc) C1 esterase deficiencyd) Properdin deficiency


Question: Staphylococcus aureus causes

The exfoliative toxin produced by staphylococci is responsible for staphylococcal scalded skin syndrome(SSSS). The severe form of SSSS is known as Reitter's disease in the newborn and toxic epidermal necrolysis in older patients. Milder forms are pemphigus neonatorum and bullous impetigo. Ref: Textbook of Microbiology; Ananthanarayan and Paniker's; 10th Edition; Page No: 204


Question: Drug of choice for MRSA

Methicillin was the first compound developed to combat resistance due to Penicillinase production by staphylococci. MRSA become common nowadays resistant not only to Penicillin but to all other beta-lactam antibiotics. vancomycin is the drug of choice for MRSA. Strains resistant to vancomycin and teicoplanin are still not common. Ref: Textbook of Microbiology; Ananthanarayanan and Panicker; 10th Edition; Page no: 208


Question: Northern blot technique is used in the detection of

Explanation: Southern Blotting: o Highly sensitive technique for identifying DNA fragments by DNA- DNA hybridization.
o This technique has very wide applications in DNA analysis. Northern Blotting: o Used for the analysis of RNA.
o Procedure is analogous to southern blotting, hence the name northern blotting.
o Here the RNA mixture is separated by gel electrophoresis, blotted and identified using labelled DNA or RNA probes. Western Blotting:
o A similar technique for the identification of proteins {antigens) is called immunoblotting {or, in conformity with other blotting techniques, western blotting).
o Here the protein antigen mixture is separated by SDS-PAGE (sodium dodecylsulfatepolyacrylamide gel electrophoresis),
blotted on to nitrocellulose strips and identified by radiolabeled or enzyme-labeled antibodies as probes. o E.g. Western blot test for detection of antibodies directed against different antigens of
HIV.


Question: B cells are processed in

Ans. a (Bone marrow). (Ref: Ananthnarayan, Microbiology/6th ed., 116)# B lymphocytes precursors, pro-B cells develop in the fetal liver during embryonic life and in bone marrow afterwards continuously throughout life.# Rearrangement of Ig genes takes place on their becoming preB cell, which synthesize cytoplasmic IgM.# T-cell precursors from yolk sac, fetal liver, BM, migrates to thymus during embryonic and post- natal stages.# Earliest identifiable cells of T-lineage and CD7 + pro T cells, on entering thymus became preT cells (immature).# These cells mature in extrathymic tissue and become helper/inducer T-cells, cytotoxic supressor cells.


Question: Stain used in electron microscopy

Phosphotungstic acid is electron dense, opaque for electrons. It is a common negative stain for viruses, nerves, polysaccharides and other biological tissue materials for imaging by an Electron microscope.

General Microbiology Pa 1 (History, Microscopy, Stains and Structure and Physiology of Bacteria)


Question: Classification of shigella is on the basis of fermentation of

Classification of shigella is done on the basis of fermentation of mannitol Exceptiom-Non mannitol fermenter i.e Shigella dysenteriae which is also catalase negative. The most common cause of bacillary dysentery in India is Shigella flexneri and in world is Shigella sonnei which is late lactose fermenter.

Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli)


Question: Infection occurring after man&;s bite is

Staphylococcus infection - human patients and carriers are the commonest sources of infection. About 10- 30% healthy person carry bacterial in the nose, skin, axilla, perineum and throat. Ref: Textbook of microbiology; Ananthanarayan and paniker's 10th edition; Pg:205


Question: One of the following is NOT a protozoal infection


Question: Most pathogenic species of candida is

C. albicans is most common and most pathogenic.


Question: Abdominal pain, fat malabsorption and frothy stools suggests of

Giardia lamblia is an intestinal flagellate , infection acquired by ingestion of contaminated water and food and also by ano- oral sexual practice The parasite attaches itself to the epithelial surface of duodenum and jejunum causes a disturbance of intestinal function , leading to malabsorption of fat .patient complaints of loose stool and steatorroea. Baveja textbook of parasitology , 3rd edition.


Question: Fungal meningitis in an immunocompromised individual is most commonly caused by

(D) Cryptococcus neoformans # Fungal Infections in the immunocompramised i.e. in AIDS patients:> Candidiasis (esophageal, tracheal, or pulmonary)> Crypttococcosis (CNS infection)> Coccidioidomycosis (disseminated)> Histoplasmosis (disseminated)


Question: Elevated IgG and IgM antibody titers to parvovirus suggest a diagnosis of

Fifth disease is a viral exanthem commonly seen in children 8 to 12 years old. Children are ill for a few days but recover without incident. Unfortunately, if a pregnant female acquires the disease in the first trimester of pregnancy, the fetus is at risk. The causative agent is thought to be a parvovirus (parvovirus B 19).

Possible subacute sclerosing panencephalitis (SSPE)


Question: The "string of pearl" colonies on nutrient agar is produced by

When Bacillus anthracis is grown on the surface of a solid medium containing 0.05-0.5 units of Penicillin/ml, in 3-6hours the cells grow large, spherical and in chains on the surface of the agar resembling a string of pearls. This string of pearls reaction clearly differentiates bacillus anthracis from Bacillus cereus and other aerobic bearers. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 252


Question: Quellung reaction is due to

Quellung reaction: a specific test of Streptococcus pneumoniae. A suspension of Streptococcus pneumoniae is mixed with a drop of the type-specific antiserum and a spoonful of methylene blue solution. In the presence of the homologous antiserum, the capsule becomes apparently swollen, sharply delineated and refractile. The Quellung test can be done directly with sputum from acute pneumonia cases. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 225


Question: The single most common cause of pyrexia of unknown origin is

Tuberculosis is an ancient disease, infection is common in India. So it is the most common cause of Pyrexia of Unknown origin, compared to others. Ref: Baveja textbook of microbiology; 4th edition


Question: Resistance to isoniazid, the likely mechanism for resistance is

Strains of M. tuberculosis resistant to individual drugs arise by spontaneous point mutations in the mycobacterial genome that occur at low but predictable rates (10-7-10-10for the key drugs). Resistance to rifampin is associated with mutations in the rpoB gene in 95% of cases; That to isoniazid with mutations mainly in the katG (50-95% of cases) and inhA (up to 45%) genes; That to pyrazinamide in the pncAgene (up to 98%); That to ethambutol in the embB gene (50-65%). Because there is no cross-resistance among the commonly used drugs, the probability that a strain will be resistant to two drugs is the product of the probabilities of resistance to each drug and thus is low.

Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli)


Question: Poached egg colony on potassium tellurite agar is characteristic of

Daisy head - Gravis
Frog's egg colony - Intermedius
Poached egg - Mitis.


Question: The temperature required for cultivating mycobacterium


Question: F plasmid of high frequency recombination is

Hfr Conjugation: F factor being a plasmid, is always Extra-chromosomal It may integrate with bacterial chromosome and behave as episome. Such donor cells are able to transfer chromosomal DNA to recipient cells with high frequency in comparison to F+ cells, therefore, named as Hfr cells (high frequency of recombination). During conjugation of Hfr cell with an F- cell, only few chromosomal genes along with only a pa of the F factor get transferred. Hence, F- recipient cells do not become F+ cells.

General Microbiology Pa 1 (History, Microscopy, Stains and Structure and Physiology of Bacteria)


Question: Thymus has

Interstitial dendritic cells - Lungs, liver, spleen
Interdigitating dendritic cells - Thymus
Circulating dendritic cells - Blood & lymph
Follicular dendritic cells - Lymph nodes.


Question: Malabsorption caused by A/E aEUR'

Ascaris lumbricoides Intestinal parasites not only cause diarrhoeal disease but also cause significant malabsorption. Capillaria phillipinensis The parasite is small : Males measures 2.3 mm to 3.2 mm and females measure 2.5 mm to 4.3 mm long. The male &Ay small caudal alae and a spineless spicule sheath. Pathology in capillaria infection Worms repeatedly penetrate mucosa of the small intestine and reenter the lumen especially jejunum leading to progressive degeneration of mucosa and submucosu. Infected people usually experience diarrhoea and abdominal pain progressing to weight loss, weakness malaise, anorexia and emaciation. Protein and electrolytes are lost and there is malabsorption of fats and sugars. Patients die from loss of electrolytes, hea .failure and sometimes secondary bacterial infection.


Question: Visceral Larva migrans is a feature of

Visceral Larva Migrans Seen in:-

Toxocara canis - m/c
Toxocara catis
Ascaris suum
Angiostrongylus cantonensis
Gnathostoma spinigerum.


Question: Most sensitive investigation for preoperative localization of abnormal parathyroid glands is

Neck ultrasound locates glands in approximately 75% of cases. (99mTc) labelled Sestamibi isotope scans identify approximately 80% of abnormal parathyroid glands.CT & MRI is not indicated prior to first-time neck exploration.


Question: Sterilization control used in membrane filters is

Sterilization control for membrane filters is Brevundimonas diminuta and sarratia marcescens.


Question: Lyophilization means

Freeze-drying--technically known as lyophilization or cryodesiccation--is a dehydration process typically used to preserve a perishable material or make the material more convenient for transpo.Viruses can be preserved by storage at subfreezing temperatures, and some may withstand lyophilization and can thus be preserved in the dry state at 4degC or even at room temperature


Question: Secondary immune response is mediated by

Secondary immune response is mediated by IgG, IgM - Primary Immune response, IgA - Secretory Immunoglobulin found in glandular secretions and serum, IgE - Type I HS Reactions Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 96-98


Question: Most common presentation of Cryptococcosis is

Pulmonary Cryptococcosis is the first & Most common presentation.


Question: Toxin of emetic strain of bacillus cereus resembles in action of

It is a preformed toxin similar to S.aureus enterotoxin.


Question: Hansen’s bacillus is cultured in

Hansen’s bacillus is M. leprae and can be grown in Armadillo and Foot pad of mice.


Question: Flagellated amoeba is

Naegleria fowleri also called brain eating amoeba is flagellated.


Question: Stages seen in peripheral smear of falciparuma) Schizontsb) Gametocytesc) Accoled) Ring forme) Trophozite

Mature, compact trophozoites in a thin blood smear. Compact trophozoites in a thinblood smear.
P. falciparum schizonts are seldom seen in peripheral blood. Mature schizonts have 8 to 24 small merozoites;
dark pigment, clumped in one mass


Question: Common inhabitant of throat and tonsils is

Alpha hemolytic streptococci (S. viridans)


Question: CD4 cells recognize the antigens in association with


Question: Most common cause of Genital Herpes

Both HSV-1 and 2 can cause genital and oral - facial infection but reaction at oral - facial site is more common with HSV-1 and at the genital site with HSV-2


Question: Continuous cell culture of bacteria

Ans. is 'c' i.e., Chemostat device Bacterial cultures can be maintained in a state of exponentional growth over long periods of time using a system of continuous culture. Continuous culture, in a device called chemostat, can be used to maintain a bacterial population at a constant density, a situation that is, in many ways, more similar to bacterial growth in natural environments. In a chemostat microbial cells are grown at a steady state where cell biomass production, substrates and products concentrations remains constant, and growth occurs at a constant rate. These features make a chemostat unique and powerful tool for biological and physiological research.


Question: A child is presenting with vomiting and abdominal pain after 5 hours of eating some food. The most likely causative organism

→ Food poisoning presenting within 6 hours is seen:

Staph aureus and
B. cereus.

→ Cl. Botulinum causes constipation (not diarrhea) and the incubation period is about 18-24 hours.
→ V. cholerare has incubation period > 16 hours.


Question: Xenodiagnosis is used in the diagnosis of a disease that is transmitted by the bite of a

Xenodiagnosis is used in the diagnosis of Chagas disease, which is caused by Trypanosoma cruzi, a hemoflagellate. There are four morphologic forms of hemoflagellates. In man, they may be intracellular, in which they are called leishmanial forms; or, they may be located extracellularly in the blood, in which they are called trypanosomes. The insect vectors may have leptomonads (promastigotes) or crithidial (epimastigote) forms. Leishmaniasis (cutaneous, mucocutaneous/and visceral) only has the leishmania, intracellular forms present in man. In Mrican trypanosomiasis, only the extracellular, or trypanosomal form, is present in man. Chagas disease has both the intracellular (leishmanial) and extracellular (trypanosomal) forms. Chagas disease is rampant in South America and is the major cause of progressive hea failure and death in that area. T cruzi is a flagellated protozoan that is transmitted to man by the bite of the Reduviid bug, or kissing bug, which usually occurs during the night. Sholy after the bite, the bug defecates on the wound site and the sleeping host rubs the organisms into the wound. Periorbital inflammation develops, which is called Romana's sign. Trypanosomes circulate in the blood and leishmanial forms invade (1) the reticuloendothelial cells, producing hepatosplenomegaly; (2) the hea muscle, causing myocarditis and arrhythmias; (3) the brain, producing a meningoencephalitis; and (4) into the gastrointestinal tract, where the leishmania destroy the ganglion cells in the distal esophagus and rectum to produce acquired achalasia and Hirschsprung disease, respectively. Laboratory diagnosis is made by (1) finding trypanosomes in the blood, (2) finding leishmanial forms in tissue, (3) culture, (4) serology, and (5) xenodiagnosis. Xenodiagnosis is a method of inoculation in which sterile Reduviid bugs are fed or offered the blood of an infected patient. After a few weeks, the bug's intestinal contents are examined for presence or absence of the organism. Only 5% of patients die in the acute stage of hea failure, whereas in chronic disease, hea failure is a common cause of death. Nifuimox is the drug of choice.


Question: Synergohymenotropic toxins of Staphylococcus consists of

The toxins of Staphylococcus are: Cytolytic toxins: which include alpha-hemolysin, beta-hemolysin, gamma hemolysin, delta hemolysin and leucocidin Leucocidin (called the Panton-Valentine toxin or PVL after its discoverers) is a two-component toxin like gamma lysin, being composed of S and F components. Such bi-component, membrane active toxins have been grouped as synergohymenotropic toxins. Ref: Textbook of Microbiology; Ananthanarayanan and Panicker; 10th Edition; Page No: 203, 204


Question: The most frequent cause of scalded skin syndrome is

Scalded skin syndrome is caused by Staphylococcus aureus. It is an exfoliative disease in which the outer layer of epidermis gets separated from the underlying tissues. The severe form of SSSS is known as Ritter's disease in newborn and toxic epidermal necrolysis in older patients. Ref: Textbook of Microbiology; Ananthanarayanan and Panicker; 10th Edition; pg:204


Question: 52 yrs male presented with muscular stiffness and painful cramps. The face was drawn into a forced grimace ("sardonic grin," or risus sardonicus). Strychnine Poisoning was suspected; Strychnine is supposed to antagonize competitively

STRYCHNINE POISONINGMechanism of toxicity: Strychnine competitively antagonizes glycine, an inhibitory neurotransmitter released by post-synaptic inhibitory neurons in the spinal cord. Clinical presentation: Muscular stiffness and painful cramps precede generalized muscle contractions and opisthotonos.The face may be drawn into a forced grimace ("sardonic grin," or risus sardonicus).Repeated and prolonged muscle contractions often result in hypehermia, rhabdomyolysis, myoglobinuria, and renal failure.Hyperacusis, hyperalgesia, and increased visual stimulation.Death is usually caused by respiratory arrest owing to the intense contraction of the respiratory muscles.


Question: Mycoplasmas differ from chlamydiae in that they are

Mycoplasmas lack a rigid cell wall and are bound by a triple-layer unit membrane. For this reason, they are completely resistant to the action of penicillins. Unlike the chlamydiae, they can replicate in cell-free media.

Able to grow on artificial cell-free media


Question: Virulence determinant implicated in pathogenesis of scarlet fever is

Streptococcal Pyrogenic exotoxin ( erythrogenic, Dick, scarlatinal toxin): the toxin was named erythrogenic because it's intradermal injection into susceptible individuals produced an erythematous reaction. This test was used to identify children susceptible to scarlet fever, a type of acute pharyngitis with extensive erythematous rash, caused by Streptococcus pyogenes strains producing this toxin. The primary effect of the toxin is an induction of fever and so it was renamed streptococcal pyrogenic exotoxin. 3 types of SPE have been identified: A, B and C. Types A and C are coded for by bacteriophage genes while type B gene is chromosomal. SPE are superantigens, T cell mitogens that induce a massive release of inflammatory cytokines, causing fever, shock and tissue damage. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 213


Question: Dark ground microscopy is used for

Treponema pallidum immobilization (TPI) test Serum of patient with complement and T. pallidum are maintained in a complex medium anaerobically If the antibodies are present, the Treponemes are immobilized when examined under dark ground illumination.

General Microbiology Pa 1 (History, Microscopy, Stains and Structure and Physiology of Bacteria)


Question: The following drug acts by blocking reverse transcriptase

Zidovudine acts by inhibiting the conversion of RNA to DNA by blocking the enzyme reverse transcriptase. It is a prodrug which has to be conveed to triphosphate form to be active Baveja 5th ed Pg.: 519


Question: Metachromatic granules can be stained by

Ref: Ananthnarayan, 9th ed. MedPub* Albert stain is a type of differential stain used for staining the volutin granules also known as Metachromatic granules found in Corynebacterium diphtheriae.* The name metachromatic is because of its property of changing color, i.e. when stained with blue stain they appear red in colour. When grown in Loffler's slopes, C. diphtheriae produces large number of granules.* Stains used for C. Diphtheriae:# Ponders stain# Albert stain# Neisser stain# Loeffler methylene blue


Question: Tinea capitis (endothrix) is caused by

Tinea capitis (endothrix) is caused by T.schoenleinii, T.violaceum and T.tonsurans.


Question: A patient of RHD developed infective endocarditis after dental extraction. Most likely organism causing this is

Streptococcus viridans is a group which normally resides in the mouth and upper respiratory tract and is alpha hemolytic. In persons with pre-existing cardiac lesions, they may cause bacterial endocarditis, Streptococcus sanguis being most often responsible. Following the tooth extraction or dental procedures, they cause transient bacteremia and get implanted on damaged or prosthetic valves or in congenitally diseased hea and grow to form vegetation. Streptococcus mutans is also a member of viridans group which causes endocarditis in individuals with risk factors ( dental extraction in people with damaged valves). The bacterium has a polysaccharide coat that allows it to stick to teeth and also to damaged hea valves, it can invade the bloodstream. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 220, 221


Question: In type I hypersensitivity, the mediators is

(IgE) (161-AN 7th) (202-206-CP)Types of hypersensitivity reactions and their featuresType of reactionClinical syndromeMediatorsType I: IgE1. Anaphylaxis2. Atopy P. K. reactionIgE, histamine and other pharmacological agentsType II: Cytolytic and CytotoxicAntibody-mediated damage- thrombocytopenia-agranulocytosis, hemolytic anemiaIgG: IgM, CType III: Immune complex1. Arthrus reaction2. Serum sickness3. Glomerulonephritis, rheumatic fever and rheumatoid arthritisIgG: IgM C Leucocytes.Type IV: Delayed hypersensitivity1. Tuberculin test - Lepromin test, Frei-test, Histoplasmin and toxoplasmin tests viral infections such as herpes simplex and mumps2. Contact dermatitis - drugs, metal (Nickle, chromium), chemicals3. Granulomatous type TB, Leprosy, Schistosomiasis, sarcoidosis and Crohn's diseaseT. cells, Lymphokines, macrophages


Question: Given cystogram appearance is a feature of

A pine cone bladder or Christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with the thickened trabeculated wall.It is typically seen in the severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4).Extra Edge: Fetal skull like extensively calcified bladder in SchistosomiasisThimble bladder: TBAdder Head appearance: ureteroceleTeardrop bladder: Pelvic Lipomatosis, perivesical extraperitoneal hematomaMolar tooth bladder: Extraperitoneal bladder tear

Congenital anomalies of the genitourinary tract


Question: Strawberry cervix is seen in

FeatureNormal Vaginal ExaminationVulvovaginal CandidiasisTrichomonal VaginitisBacterial VaginosisEtiologyUninfected; lactobacilli predominantCandida albicansTrichomonas vaginalis (strawberry cervix)Associated with Gardnerella vaginalis, various anaerobic and/or noncultured bacteria, and mycoplasmas Typical symptomsNoneVulvar itching and/or irritationProfuse purulent discharge; vulvar itchingMalodorous, slightly increased dischargeDischarge AmountVariable; usually scantScantOften profuseModerate ColoraClear or translucentWhiteWhite or yellowWhite or grey ConsistencyNonhomogeneous, floccularClumped; adherent plaquesHomogeneousHomogeneous, low viscosity; uniformly coats vaginal wallsInflammation of vulvar or vaginal epitheliumNoneErythema of vaginal epithelium, introitus; vulvar dermatitis, fissures commonErythema of vaginal and vulvar epithelium; colpitis macularisNonepH of vaginal fluidbUsually 4.5Usually 4.5Usually 5Usually >4.5Amine ("fishy") odor with 10% KOHNoneNoneMay be presentPresentMicroscopycNormal epithelial cells; lactobacilli predominantLeukocytes, epithelial cells; mycelia or pseudomycelia in up to 80% of C. albicans culture-positive persons with typical symptoms Leukocytes; motile trichomonads seen in 80-90% of symptomatic patients, less often in the absence of symptomsClue cells; few leukocytes; no lactobacilli or only a few outnumbered by profuse mixed microbiota, nearly always including G.vaginalis plus anaerobic species on Gram&;s stain (Nugent&;s score 7) Other laboratory findingsIsolation of Candida spp. Isolation of T. vaginalis or positive NAATdUsual treatmentNoneAzole cream, tablet or suppository--e.g., miconazole or clotrimazole once daily for 7 days Fluconazole single doseMetronidazole or tinidazole single dose Metronidazole 7 daysMetronidazole for 7 daysMetronidazole gel once daily for 5 days Clindamycin, 2% cream vaginally each night for 7 daysUsual management of sexual panerNoneNone; topical treatment if candidal dermatitis of penis is detectedExamination for STD; treatment with metronidazole, 2 g PO (single dose)None (Ref: K.D Chatterjee 13th edition, p49)


Question: Dimorphic fungus in the following is

Blastomyces is a dimorphic fungus, shows filamentous and yeast form. Candida and Cryptococcus show yeast form. Aspergillus shows filamentous form. Reference: Textbook of Microbiology; Baveja; 4th edition


Question: Mad Cow disease (Bovine Spongioform Encephalopathy) is similar in man to

(B) Creutzfeldt Jakob Disease # Group B (Prion Diseases) -caused by slow viruses:> The subacute spongiform viral encephalopathies are chronic progressive degenerative diseases of the CNS> Prion diseases of animals: Scrapie is the prototype prion disease. Mink encephalopathy is a scrapie-like disease of mink. It is believed to have spread to mink by feeding them on scrapie infected sheep meat.> Bovine spongiform encephalopathy (BSE, 'mad cow disease) has been enzootic in Britain from 1986. The infection is presumed to have spread to cattle by the practice of feeding them with abattoir waste and offal which may have contained scrapie infected neat> Human prion diseases: These include Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker (GSS) syndro me, Kuru and fatal familial insomnia.> CJD is a subacute presenile encephalopathy, with progressive incoordination and dementia, ending fatally in about a year. The appearance of a new variant of CJD affecting younger persons (below 45 years) in Britain in 1996 raised fears of infection through eating BSE infected beef.> Kuru (meaning tremor) was identified in 1957 as a mysterious disease seen only in the Fore tribe inhabiting the eastern highlands of New Guinea.> Group B (Prion Diseases) -caused by slow viruses


Question: Fried egg colony is seen in culture of

Fried egg colonies are seen in culture of Mycoplasma. Mycoplasma- Culture media- PPLO Agar Colonies can examined by- Hand lens or Diene's staining

Systemic Bacteriology (Haemophilus, Yersinia, Spirochaetes, Ricketssia, Chlamydia, Mycoplasma and Miscellaneous Bacteria)


Question: The most common organism causing acute osteomyelitis is

Microorganisms that Cause OsteomyelitisOrganismCommentFrequently Encountered BacteriaStaphylococcus aureusMost likely bacterial pathogen. Aggressive, invasive. Often metastatic foci with bacteremia Consider surgery earlyStaphylococci other than S. aureus (coagulase-negative) Usually associated with foreign material or implantsBiofilm productionStreptococciMay spread rapidly through soft tissuesEnterobacteriaceae (Escherichia coli, Klebsiella spp., others) Considerable variation in antibiotic susceptibility Increasing antibiotic resistance with overuse May become resistant to antibiotics during therapyPseudomonas aeruginosaIncreasingly resistant to the antibiotics. The frequent successor to other bacteria when initial therapy fails. Maybe related to contaminationUnusual OrganismsAnaerobic bacteriaUsually mixed with aerobic bacteriaMay be synergisticSurvival dependent on devitalized tissue Baonella henselaeAssociated with cat scratches and probably with fleasBrucella speciesProminent in developing countries, especially with unpasteurized milkFungiCandida the most likely genusConsiderable variation in susceptibility, depending on species Surgery may be helpful if the infection is invasiveMycobacterium tuberculosisMay involve any boneVeebral osteomyelitis common in some countriesMycobacteria other than M. tuberculosisNeed special culture media to recoverVirusesAssociated with some viral infections, including varicella and variolaRef: Harrison's infectious disease 2nd edition, p260


Question: The commonest organism causing cellulitis is

Streptococcus pyogenes causes a variety of suppurative infection of the skin, including infection of the wound or burns, with a predilection to produce cellulitis and lymphangitis. Streptococcal subcutaneous infection ranges from cellulitis to Necrotising fasciitis. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 215


Question: Graft Versus host reaction is mediated by

In GVHD, the donated bone marrow or peripheral blood stem cells view the recipient's body as foreign. The donated T cells present in the graft, attack the tissues of the transplant recipient after perceiving host tissues as antigenically foreign. There are two forms of GVHD: Acute graft versus host disease (aGvHD). Chronic graft versus host disease (cGvHD). Ref: Ananthanarayana textbook of Microbiology 9th edition Pgno : 186


Question: A common source of Staphylococcus in the hospital is

Staphylococci are the primary parasites of human beings and animals, colonizing the skin, skin glands and mucous membranes. The most common source of infection in human patients and carriers, animals and inanimate objects being less important. Patients with superficial infections and respiratory infection disseminate large numbers of staphylococci into the environment. About 10-30 percent of healthy persons carry staphylococci in the nose and about 10 percent in the perineum and also on the hair. The vaginal carriage is about 5-10 percent.


Question: The tapeworm that can be transmitted directly from human to human is

The adult Hymenolepis nana worm is very small, at perhaps 4 cm in length. The so-called "dwarf tapeworm" is the only tapeworm that can be transmitted directly from human to human.Eggs are ingested the fecal-oral route. They then release embryos that penetrate the intestinal wall. The resulting cysts mature in the intestinal wall, then reenter the gut lumen to develop into adult worms again.Ref: Sherris microbiology; 6th edition; Page no: 893


Question: 30 year old man has mitral valve vegetation. Patient is a iv drug abuser. Culture media used to isolate the organism responsible for this is

Left sided endocarditis in iv drug abuser.

M/c organism responsible is Enterococcus


Question: Meningitis is characterized by the acute onset of fever and stiff neck. Aseptic meningitis may be caused by a variety of microbial agents. During the initial 24 h of the course of aseptic meningitis, an affected person's cerebrospinal fluid is characterized by

Aseptic meningitis is characterized by a pleocytosis of mononuclear cells in the cerebrospinal fluid; polymorphonuclear cells predominate during the first 24 h, but a shift to lymphocytes occurs thereafter. The cerebrospinal fluid of affected persons is free of culturable bacteria and contains normal glucose and slightly elevated protein levels. Peripheral white blood cell counts usually are normal. Although viruses are the most common cause of aseptic meningitis, spirochetes, chlamydiae, and other microorganisms also can produce the disease. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition


Question: Most common cause of meningitis in alcoholics is

Meningitis results only when host resistance is lowered by contributory factors such as respiratory viral infections, pulmonary congestion, stress, malnutrition, immunodeficiency or alcoholism. Splenectomy and sickle cell disease are impoant predisposing conditions. Ref: Textbook of microbiology; Ananthanarayan and paniker's; Pg:227


Question: Penicillium marneffei is seen in

Penicillium marneffei has been repoed to be an impoant oppounist pathogen in the HIV infected. It causes disseminated infection with multiple organ involvement. Ref: Baveja textbook of microbiology; 4th edition


Question: A person has received complete immunization against tetanus 10 years ago. Now he presents with a clean wound without any lacerations from an injury sustained 2.5 hours ago. He should now be given

Active immunisation is not only the most effective method of prophylaxis but also the only means whereby tetanus following unnoticed injuries can be prevented. This is achieved by spaced injection of formol toxoid, which is available either as plain toxoid or adsorbed on aluminium hydroxide or phosphate. A full course of immunisation confers immunity for a period of at least ten years. A booster dose of toxoid is recommended after 10 years. A booster dose of toxoid is given if wounding occurs three years or more after a full course of immunisation. Reference: Textbook of Microbiology; Anathanarayan and paniker&;s; 9th edition; Page no: 262, 263

Human tet globulin and single dose of toxoid


Question: Cancer not associated with Human Papilloma virus

Cancer associated with HPV are cervical cancer, Anal cancer, Vulval cancer, Vaginal cancer, Penile cancer, Oropharyngeal SCC.


Question: Muriform cells are seen in

Muriform cells also called medlar bodies, sclerotic bodies are seen in chromoblastomycosis.


Question: Fastest microbiocidal agent against M.leprae


Question: Tinea faciei is

Tinea barbae - Infection of beard & moustache area of face.
Tinea faciei - Infection of non - bearded area of face.


Question: Group A carbohydrate of Str. pyogenes cross reacts with human


Question: Rideal Walker test is used to determine the efficiency of the


Question: Minimum number of people for a group discussion are

For effective group discussion, the group should not be less than 6 and more than 12 members.


Question: Griffith typing is done for

Griffith typing is used for fuher classification of S.pyogenes, belonging to Lancefield's group A. Based on the M proteins on the cell surface, they are subdivided into M types. About 80 types of Streptococcus pyogenes have been recognized so far (types M1, M2, M3 and so on). Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg: 211