Question: An abattoir worker presented with a malignant pustule on his hand that progressed to form an ulcer. Smear was taken from the ulcer and sent to laboratory for investigation. The diagnosis

Ans. a. Cutaneous anthrax Anthrax Anthrax is a zoonoses, caused by Bacillus anthracisdeg, that occurs primarily in herbivores Routes of Infection: Humans become infected when B. anthracis spores are introduced into the body by the following routes: Contact with infected animals or contaminated animal productsdeg Insect bitesdeg Ingestiondeg Inhalationdeg Three major clinical forms in Humans: Cutaneousdeg (MC) Gastrointestinal (rare) Inhalational or pulmonary (it causes hemorrhagic pneumonia) Woolsoers' disease Occupational hazard for people who soed wooldeg Most dangerous form of inhalational anthrax Hide poer's disease Caused by contact with contaminated hair, wool, hides or products Malignant pustule Commonly seen in head and neckdeg Eschar stage that appears 2-6 days after the hemorrhagic vesicle dries to become a depressed black scabdeg surrounded by redness Diagnosis: Presumptive diagnosis of the anthrax is made by staining it with polychrome methylene blue stain, called as Mc-Fadyean's reaction Anthrax Mc-Fadyean's Reaction When blood films containing anthrax bacilli are stained with polychrome methylene blue stain for few seconds and examined under microscope, an amorphous purplish materialdeg is noticed around bacilli. This represents the capsular material and is characteristic of anthrax bacilliQ Culture Characteristics of Bacillus anthracis On agar plate: Frosted glass appearancedeg On gelatin stab culture: Inveed fir tree appearancedeg


Question: Stain for premalignant lesions

Toluidine blue is the stain for premalignant lesions.


Question: Infraclavicular lesion in tuberculosis is


Question: The typical temperature of an autoclave (operating at 30 psi of pressure is)

Two types of autoclave are used in laboratories and hospitals. * Moist heat at 121 degree Celsius X 15-20 minutes (Pressure-15 psi) * Moist heat at 134 degree Celsius X 3 minutes (Pressure-30 psi)

General Microbiology (Sterilization and Bacterial Genetics)


Question: Viral infection not transmitted by blood transfusion is

Dengue fever is transmitted by the bite of Aedes aegypti mosquito. Parvovirus transmission through respiratory route and blood. Hepatitis by parental, sexual and perinatal. Cytomegalovirus - transmitted by transplacental route, postnatal infection by sexual intercourse, blood transfusion and organ transplantation. Ref: Baveja textbook of microbiology; 4th edition.


Question: Amplifier host in Japanese Encephalitis is;

Japanese encephalitis: Option 1: Humans, cattle, buffaloes, and pigs are the veebrate hosts. Option 2: Culex tritaeniorhynchus is a major vector but has predilection for cattle instead of humans or pigs. Since the cattle does not develop viremia, this does not contribute to the spread of the disease. The high cattle to pig ratio in India is a major factor which has been suggested to control infections in India. Natural infection occurs in Ardeid birds, such as herons and egrets, and the virus is transmitted from bird to bird by C. tritaeniorhynchus. Bird acts as a reservoir host. Option 3: Pigs are usually the amplifier host of Japanese encephalitis. Option 4:Horse is dead end host in Eastern equine encephalitis virus (EEEV).

Virology Pa-2 (RNA Virus Pa-1,2 & Miscellaneous Viruses)


Question: Main cytokine involved in erythema nodosum leprosum reaction is

Erythema nodosum leprosum rection is type II lepra rection .In this modules over skin are seen This is a type III hypersensitivity reaction . Main cytokine involve is TNF -alpha DOC - gluco-coicoids

Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli)


Question: The capsule of Cryptococcus neoformans in a CSF sample is seen by

(B) India ink preparation > In unstained, wet preparation of CSF with a drop of Indian ink or nigrosine, the capsule can be seen as a clear halo around the yeast cell. This is an example of negative staining.# Diagnosis of cryptococcus is established by demonstration of capsulated, budding yeast cells in the lesions and by culture.> Capsules stand out in India ink preparations.> Fungus grows readily on Sabouraud's agar forming smooth, mucoid, cream coloured colonies.


Question: THUMB PRINT APPEARANCE in culture film smear is seen in


Question: Skin penetration not seen in


Question: Type E adverse reaction is

Ans. is 'd' i.e., Withdrawal reaction Type A (Augmented) reaction Excess of normal, predictable, dose related pharmacodynamic effect. May occur in everyone eg - Postural hypotension, hypoglycemia Type B (Bizzare) reaction Due to unusual attributes of the patient interaction with the drug. Not dose related Not a pa of normal pharmacological effect of a drug. Occurs only in some people. eg - Idiosyncracy and drug allergy. Type C (chronic) reaction Due to long term exposure eg; Analgesic nephropathy, dyskinesia by levodopa, immunosuppression by coicosteroids. Type D (Delayed) effects eg; Carcinogenesis or teratogenesis. Type E (Ending of use) reaction 3 eg; withdrawl reactions with clonidine.


Question: Holding time for Hot air oven with a temperature of 1600C

<img class="fr-dib" style="width: 300px;" src=" /> Hot air oven This is most widely used method of sterilization by dry heat. A holding period of 160degC for two hours is used to sterilise glassware, forceps, scissors, scalpels, all-glass syringes, swabs and some pharmaceutical products such as liquid paraffin, dusting powder, fats and grease. Hot air is a bad conductor of heat and its penetrating power is low The Owen is usually heated by electricity, with heating elements in the wall of the chamber. It must be fitted with a fan to ensure even distribution of air and elimination of air pockets. It should not be overloaded Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 30


Question: The ratio of anaerobe to aerobes in stool is

The mean number of bacteria in colon exceeds 10^11 bacteria/ gram of faecal matter. Approximately 99.9% of these bacteria are anaerobic in the colon. 300 to 400 different species or types of bacteria can be found. So the ratio of anaerobes to aerobes in the stool is 1000:01. Ref: Baveja textbook of microbiology; 4th edition.


Question: The efficacy of the moist heat sterilization technique commonly used to sterilize laboratory ware and culture media is tested by using (OR) Sterilisation control for moist heat is

using non-pathogenic strain of clostridium tetani


Question: Runt disease is due to

Runt disease is graft versus host disease produced experimentally in Laboratory animals.


Question: Lyme disease is caused by

Ans, c (Borrelia burgdorferi). (Microbiology by Anantanaray an, 6th/359; Harrison 18th/Table 17-1)LYME DISEASE is caused by Borrelia burgdorferi.3 Stages:1) Skin manifestation - *ECM = Erythema chronicum migrans (common over back), LNP, fever.2) Neuroboriliasis, meningoencephalopathy, neuropathy, Myocarditis.3) Arthitis -Late sequelaEtiologyDescriptionEpidemiologyClinical SyndromeMgtBorrelia burgdor feri causes Lyme diseasePapule expanding to erythematous annular lesion with central clearing (erythema migrans; average diameter, 15 cm), sometimes with concentric rings, sometimes with indurated or vesicular center; multiple secondary erythema migrans lesions in some casesBite of tick vector (Ixodes dammini)Headache, myalgias, chills, photophobia occurring acutely; CNS disease, myocardial disease, arthritis weeks to months later in some* Media for growth - Modified Kesley's media.* Treatment-- cefuroxone, penicillin, tetracycline.Zoonotic bacteriaSpeciesDiseaseTransmission and sourceBartonella henselaeCat scratch feverCat scratchBorrelia burgdorferiLyme diseaseTick bite; Ixodes ticks that live on deer and miceBrucella spp.Brucellosis/Undulant feverDairy products, contact with animalsFrancisella tularensisTularemiaTick bite; rabbits, deerYersinia pestisPasteurella multocidaPlagueCellulitisFlea bite; rodents, especially prairie dogsAnimal bite; cats, dogs


Question: Most sensitive test for HIV infection


Question: A man with chills, fever, and headache is thought to have "atypical" pneumonia. History reveals that he raises chickens and that approximately 3 weeks ago he lost many them to an undiagnosed disease. The most likely diagnosis of this man's condition is

Ornithosis (psittacosis) is caused by Chlamydia psittaci. Humans usually contract the disease from infected birds kept as pets or from infected poultry, including poultry in dressing plants. Although ornithosis may be asymptomatic in humans, severe pneumonia can develop. The disease is cured easily with tetracycline

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


Question: Antibody in cold agglutin disease is

Cold agglutinin disease (CAD): This designation is used for a form of chronic AIHA that usually affects the elderly. First, the term cold refers to the fact that the autoantibody involved reacts with red cells poorly or not at all at 37degC, whereas it reacts strongly at lower temperatures. As a result, hemolysis is more prominent the more the body is exposed to the cold. The antibody is usually IgM; usually, it has an anti-I specificity (the I antigen is present on the red cells of almost everybody)Harrison 19e pg: 659


Question: Nagglers reaction is used in the diagnosis of


Question: Reservoir of tetanus bacilli is

Ans. b (Soil). (Ref. Ananthanarayan, Microbiology, 4th/pg.245)TETANUS# Caused by Clostridium tetani# Seen following deep or penetrating wound in relatively avascular areas# More prevalent in developing countries# Seen in neonate (tetanus neonaturum) following the use of cow dung on the umbilicus# Microbiology- Gram-positive spore forming rod (Clostridium tetani is a gram-positive anaerobic bacillus)- Typical 'drum-stick' appearance with terminal spore- Widely found in the environment and soil- A Strict anaerobe that produces a powerful exotoxin- The neurotoxin is a powerful exotoxin- Exotoxin is resistant to autoclaving- Exotoxin is not antigenic and repeat infection can occur- Infection produces few signs of local inflammation# Pathogenesis- Germination of spores releases the exotoxin- Toxin affects nervous system and reaches CNS via the peripheral nerves- Acts on presynaptic terminals of inhibitor nerves- Reduces the release of inhibitory neurotransmitters (e.g., glycine)- Excess activity of motor neurons produces muscle spasm# Clinical features- Facial muscle spasm produces trismus- Typical facial appearance = 'risus sardonicus'- Back muscle spasm produces opisthotonous- Eventually exhaustion and respiratory failure leads to death- The diagnosis is essentially clinical- Differentiating between contamination and infection on wound swabs is difficult# Prevention:- Tetanus can be prevented by- Active immunisation with tetanus toxoid with booster every 5-10 years- Adequate wound toilet of contaminated wounds- Consider passive immunisation with hyperimmune immunoglobulin# Treatment (of suspected cases)- Passive immunisation with anti-tetanus immunoglobulin- Adequate wound debridement- Intravenous benzyl penicillin- Intensive care support- Despite the use of ITU mortality is about 50%


Question: Toxic shock syndrome is due to

TSST-1 antibody is seen in convalescents. This is protective and its absence is a factor in the pathogenesis of the condition. Though tampon-related TSS is now rare, the syndrome occurs in other infections of the skin, mucosa, and other sites and also in some surgical wounds. Ref: Textbook of microbiology Anantha Narayan and panickers; tenth edition; pg no:204


Question: Zonula of Zinn is

The lens is held in position by the suspensory ligament called zonules of Zinn. A ligament composed of straight fibrils radiating from the ciliary body of the eye to the crystalline lens, holding the lens in place and relaxing by the contraction of the ciliary muscle. - Relaxation of the ligament allows the lens to become more convex.


Question: The term 'virus' was coined by


Question: Black water fever is caused by

Ans. b (Plasmodium falciparum). (Ref. Harrison, Principle of Medicine, 18th ed./Chapter 210. Malaria)Black water fever is caused by Plasmodium falciparum. Bloody urine (hemoglobinuria) occurs as a complication of falciparum malaria infection. It results from destraction of RBCs & release of hemoglobin. It occurs most commonly in patients who have been treated with drugs derived from gunine. It is characterized by high fever, dark urine, epigastric pain, vomits, jaundice & shock. Hepatosplenomegaly occurs. Severe anemia is the hallmark & renal failure can ocur.


Question: Type V hypersensitivity is a type of

Type V reactions - Modification of type II HSN, also called Jones - mote reaction or cutaneous basophil hypersentitivity.


Question: Colorado tick fever is the only known human infection caused by

Coltiviruses form another species within the Reoviridae. The virus paicle is 80 nm in diameter with a genome consisting of 12 segments of double-stranded RNA, totaling about 29 kbp. Colorado tick fever virus, transmitted by ticks, is able to infect humans.Reference:Jawetz, Melnick, & Adelberg's Medical Microbiology; 27th edition; Chapter 37; Reoviruses, Rotaviruses, and Caliciviruses


Question: Common name for Trichuris trichura


Question: Man is the only reservoir of

In Japanese encephalitis Heron act as the reservoir, host and pig act as the amplifier host. Humans are the only natural host of measles. Monkeys are often infected but they seem to acquire the infection from the human. * All warm-blooded animals including man are susceptible to rabies infection though some may be highly susceptible and another intermediate (man and dog). Ref: Textbook of Microbiology, Ananthanarayan and Paniker; 9th edition


Question: Tube agglutination test is used for serological diagnosis for

Tube agglutination test is useful for serological diagnosis of enteric fever, typhus fever, infectious mononucleosis Ref: Textbook of Microbiology Baveja 5th ed Pg 120


Question: Jerne's hypothesis is for

Ans. b (Idiotypic network) (Ref. Anantanarayan, Microbiology, 6th ed., 91)Sequential anti-idiotypic antibody formation is the basis of Jeme's network hypothesis of immune regulation.IMMUNOGLOBULIN SPECIFICITIES# The immunoglobulin specificity of the greatest biological importances is idiotypic specificity pertaining to the nature of the antigen binding sites (paratopes); the specific antigenic determinants on the paratope are called idiotopes.# The sum total of idiotopes on an Ig molecule constitutes its idiotype.# By immunisation with Fab fragments, anti-idiotypic antibodies can be produced. These resemble the epitopes of the original antigen.# Used as a vaccine, these show protection against the original antigen (pathogen or tumor) in experimental animals.# Sequential anti-idiotypic antibody formation is the basis of Jerne's network hypothesis of immune regulation.# The antigenic specificities which distinguish between the different classes and subclasses of immunoglobulins present in all normal individuals of a given species are termed isotypic Specificities.# Antigenic specificities which distinguish immunoglobulins of the same class, between different groups of individuals in the same species, are called allotypic specificities.# Immunoglobulin allotypes have been studied in detail in the rabit and guinea pig by using type-specific immune sera.# Antiallotype antibodies are also found in sera containing 'rheumatoid arthritis factor'.# Two allotypic systems are known in humans - the Gm system (for gamma marker) and the InV system (abbreviation of patent's name). The Gm is associated with the Fc portion of the IgG heavy chain. More than 25 Gm types have been identified so far the InV system is associated with the Kappa light chain and so has been renamed Km. Three Km allotypes have been identified.# Genetic markers associated with IgA are called 'Am'.# To date, in the human system no allotypic markers have been found for lambda light chains or m, d or e heavy chains.


Question: The arrangement of flagella in lophotrichous is

Bacterial flagella are thread-like appendages composed entirely of protein, 12-30 nm in diameter. They are the organs of locomotion for the forms that possess them. Three types of arrangement are known: monotrichous (single polar flagellum), lophotrichous (multiple polar flagella), and peritrichous (flagella distributed over the entire cell).Ref: Jawetz; 27th edition; Page no: 32


Question: Restriction enzyme Type II

Restriction enzyme type II identifies the palindromic sequences on the DNA and cuts the DNA strand at a ceain specific site. Types of Restriction EnzymesRestriction enzymes are traditionally classified into four types on the basis of subunit composition, cleavage position, sequence specificity and cofactor requirements. Type I enzymes are complex, multisubunit, combination restriction-and-modification enzymes that cut DNA at random far from their recognition sequences.Type II enzymes cut DNA at defined positions close to or within their recognition sequences. They produce discrete restriction fragments and distinct gel banding patterns, and they are the only class used in the laboratory for DNA analysis and gene cloning. Type III enzymes are also large combination restriction-and-modification enzymes. They cleave outside of their recognition sequences and require two such sequences in opposite orientations within the same DNA molecule to accomplish cleavage; they rarely give complete digests.Type IV enzymes recognize modified, typically methylated DNA and are exemplified by the McrBC and Mrr systems of E. coli.

Cleaves specific palindromic DNA sequences

Helps in keeping the nascent protein unfolded


Question: Seal finger and whale finger is seen with

Erysipeloid skin lesion is caused by Erysipelothrix. M/c site is finger causing seal finger and whale finger.


Question: Effector binding region of the antibody is

Within the variable regions of both the Light and Heavy chains are subregions consisting of extremely variable amino acid sequences, called hypervariable, that cooperate in space to form the antigen-binding siteReference: Jawetz, Melnick, & Adelberg's Medical Microbiology; 27th edition; Chapter 8; Immunology

Constant region of heavy and light chain

Variable region of heavy and light chain


Question: The capsule of Streptococcus pyogenes is made up of

Virulence factors of Streptococcus pyogenes: Cell wall associated factors: Capsule Carbohydrate antigen Protein antigen A carbohydrate-based streptococcal capsule composed of hyaluronic acid surrounds the bacterium, protecting it from phagocytosis by neutrophils. It is not antigenic in human beings. The cell wall is composed of an outer layer of protein and lipoteichoic acid, a middle layer of group-specific carbohydrate and an inner layer of peptidoglycan. The peptidoglycan is responsible for cell wall rigidity. It also has some biological propeies such as pyrogenic and thrombolytic activities. Reference: Textbook of Microbiology; Anathanarayan and panicker's;10th edition; Page no: 212


Question: The following is a killed vaccine

Peussis, meningococcal, Salk, cholera, rabies, influenza are killed vaccines BCG OPV are live attenuated vaccines Ref: Textbook of Microbiology Baveja 4th ed Pg 617


Question: Analysis of protein antigen is by

The western blot is a widely used analytical technique used in molecular biology, immunogenetics and other molecular biology disciplines to detect specific proteins in a sample of tissue homogenate or extract. Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 579


Question: Paul Bunnell Test is the standard diagnostic procedure for

(A) Infectious mononucleosis # Standard diagnostic procedure for Infections mononucleosis is the Paul-Bunnel test.> During infectious mononucleosis, heterophile antibodies agglutinate sheep erythrocytes> However, such antibodies may also occur after injections of sera & sometimes even in normal individuals> Infectious mononucleosis antibodies may be differentiated by absorption tests.> The Paul-Bunnel antibody develops early during the course of infectious mononucleosis, and disappears within about two months.


Question: Negative staining technique is used for

Negative StainingThis procedure involves staining the background with an acidic dye, leaving the cells contrastingly colorless. The black dye nigrosin is commonly used. This method is used for cells or structures that are difficult to stain directly. Used for BacillusRef: Javetz Medical Microbiology; 27th edition; Page no: Page no: 38


Question: Herpangina is seen in with

Generalized myositis, herpangina-coxsackie A Focal myositis, myocarditis, pericarditis, born holms disease or epidemic myalgia-coxsackie B Ref: Baveja 5th ed Pg: 459


Question: Burkitt's lymphoma is characterized by elevated "early antigen" tests with a restricted pattern of fluorescence. This disease is caused by

Epstein-Barr virus (EBV) is a herpesvirus that causes a number of syndromes; the most common is infectious mononucleosis. It is a ubiquitous enveloped DNA virus. Only one serotype of EBV has been recognized, although molecular methods have reorganized a number of genotypes of EBV.Infectious mononucleosis is an acute disease most commonly seen in younger people. It is characterized by a proliferation of lymphocytes, lymph node enlargement, pharyngitis, fatigue, and fever. Infection in young children is usually either asymptomatic or characteristic of an acute upper respiratory infection. Diagnosis is usually made by a positive heterophil test. Heterophil antibodies are those that occur in one species (human) and react with antigens of a different species. The heterophil test may be insensitive (30 to 60%) in children. Definitive diagnosis is made by detection of antibodies to EBV components.EBV causes a variety of other syndromes including Burkitt's lymphoma, the most common childhood cancer in Africa, and nasopharyngeal carcinoma, commonly seen in China.Similar mononucleosis-like diseases are caused by cytomegalovirus (CMV) and Toxoplasma gondii, a parasite. CMV causes fewer than 10% of infectious mononucleosis-like diseases. CMV "mono" is primarily characterized by fatigue. Congenital infection with CMV almost always causes serious sequelae, such as retardation and hearing loss. T. gondii also causes a variety of clinical problems, among them encephalitis in AIDS patients and food poisoning from the ingestion of raw meat. Although CMV and T. gondii are relatively rare causes of infectious mononucleosis, they must be ruled out, particularly when EBV tests are nonreactive.


Question: Micro organism motile at 25° C but not motile at 37° C


Question: A person presents with headache, fever, stiff neck. Most likely organism responsible is

It is case of meningitis. M/c organism responsible for meningitis is S.pneumoniae.


Question: ”CACHECTIN” is produced by

Tumor necrosis factor (TNF, cachexin, or cachectin, and formerly known as tumor necrosis factor alpha or TNFα) is an adipokine involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction. It is produced chiefly by activated macrophages
The primary role of TNF is in the regulation of immune cells. TNF, being an endogenous pyrogen, is able to induce fever,apoptotic cell death, cachexia, inflammation and to inhibit tumorigenesis and viral replication and respond to sepsis via IL1& IL6 producing cells. Dysregulation of TNF production has been implicated in a variety of human diseases including Alzheimer's disease, cancer, major depression and inflammatory bowel disease (IBD)


Question: Lysogenic conversion is

Ref: PubMed* Lysogenic conversion is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome.* Once the genetic material of phage bacteria is introduced, the host bacterium continues to live and reproduce normally.* The genetic material of the bacteriophage, called a prophage, can be transmitted to daughter cells at each subsequent cell division, and a later event (such as UV radiation or the presence of certain chemicals) can release it, causing proliferation of new phages via the lytic cycle.* For example, a number of strains of the diphtheria bacillus acquire the capacity to form diphtheria toxin immediately after penetration of the phage into the cell and retain that capacity until the moment of the cells dissolution (lysis).

Integration of host bacterial nucleic acid to phage

Integration of phage nucleic acid to host bacteria genome

Bacterial mechanism to cause antigenic shift


Question: The most common mechanism of drug resistance in staphylococci is

The most common mechanism of drug resistance in staphylococci is through production of beta lactamase or penicillinase, which inactivates penicillin by splitting the beta lactum ring. These are inducible enzymes which are plamid mediated. They can be transmitted by transduction or conjugation. Ref: Textbook of Microbiology; Ananthanarayanan and Panicker; 10th Edition; Page No: 202


Question: Citrate as a sole source of carbon is utilized by

Citrate is used by salmonella as sole source of carbon But citrate test positive: Salmonella Typhimurium Salmonella Paratyphi A is citrate negative Ref: Elmer W Koneman 5th ed Pg 186


Question: PK reaction detects

The Prausnitz-Kustner test is an immunologic test formerly used by physicians to determine if a patient has an allergic reaction to a specific antigen. IgE is homocytotropic i.e. species specific. Only human IgE can fix to the surface of human cells. This is the basis of Prautnitz- Kustner reaction, which was the original method of detecting atopic antibody. Examples of Type I Hypersensitivity Reaction.

Immunology Pa 1 (Immune Response, Antigen-Antibody Reactions, Hypersensitivity, Structure of Immune System, Immunodeficiency Disorders)


Question: Drug resistance in MTB is due to

Mutational drug resistance plays a major role in Mycobacterium tuberculosis.


Question: Commonest cause of nosocomial infection

Controversial MCQ, no where there is clear cut reference for MC agent of HAI
Initially hospital outbreaks were caused by Gram positive organisms like Streptococcus pyogenes and the methicillin resistant Staphylococcus aureus (MRSA)
Presently Gram negative enteric pathogens (Enterobacteriaceae) including Escherichia coli, Klebsiella and Enterobacter species have emerged as an important cause
Pseudomonas and Acinetobacter species are also common nosocomial pathogens and are extremely resistant to common antibiotics and antiseptics.


Question: Kolmer test is a screening test done for


Question: Diluent for trimethoprim in antibiotic disc for sensitivity testing is

Diluent for trimethoprim in antibiotic sensitivity testing is acetic acid Sod bicarbonate for amoxicillin and ceftazidime Ref: Textbook of Microbiology Baveja 4th ed Pg 629


Question: Most effective method of sterilization by heat is

Most effective method of sterilization by heat is by using moist heat (steam) above atmospheric pressure Autoclave is a classical example. Principle of autoclave- when water boils under pressure, instead of boiling at 100 degrees, it boils at a higher temperature. Hence the steam generated is at higher temperature.

General Microbiology (Sterilization and Bacterial Genetics)


Question: Hemolytic uraemic syndrome associate with

EHEC Entero haemorrhagic E.coli Cause HUS Shiga like toxin or Verotoxin (VT-1& VT-2) Aka verotoxigenic E.coli Culture media is Sorbitol mac-Conkey agar (SMAC) and Rainbow agar used Diarrhoea causing E coli EPEC - Entero Pathogenic Attaching/Effacing lesions to villi EIEC - Entero Invasive resemble shigellosis & sereny test +ve 3. ETEC - Traveller's diarrhoea CFA (colonisation factor antigen 4. EAEC - Aggregative persistent type of diarrhoea (EAST-1 Toxin) Parvo Virus B19: Single standard DNA Virus cause Aplastic Crisis


Question: Duffy antigen is associated with

The Duffy glycoprotein is a receptor for chemicals that are secreted by blood cells during inflammation. It also happens to be a receptor for Plasmodium vivax, a parasite that invades red blood cells (RBCs) and causes malaria. Ref ananthnarayana and panikers microbiology textbook 8/e


Question: 25 years old male presented with diarrhea for 6 months. On examination the causative agent was found to be acid fast with 12 micro meter diameter. The most likely agent is aEUR'

Cyclospora [Ref : Harrison 171)* p. 1313, 13141 All the parasites mentioned in the question cause chronic diarrhoea (mostly in immunocompromised patients). All of them reveal oocyst on stool examination. In Giardiasis, parasite is also seen along with oocyst stool examination. Oocyst of all the organisms except giardia are acid fast. The diagnosis rests on the size of the oocyst. DIAGNOSIS OF INTESTINAL PROTOZOAL INFECTION Parasite Stool Fecal acid fast stain Size of the oocyst Giardia Oocyst + Parasite 4 nuclei - 8-12 x 7 x 10 [tm Cryptospo- riclium Oocyst + Small, 4-5 inn in diameter Isospora Oocyst + Large 25 1.tm in diameter Cyclospora Oocyst + Medium 8-101_tm diameter Microsporidia Spores Special fecal stains, tissue biopsies More on this topic Parasites causing chronic diarrhoea Giardia Cryptosporidiosis Isospora Cyclospora Hookworm Amoebiasis Strongyloides Acid fast organisms are ? Mycobacterium Lepra bacilli Nocardia Isospora Bacterial spores Rhodococcus Sinegma bacilli Spermatic head Cryptosporidium Cyclospora


Question: Bacteria implicated in dental caries is

Streptococcus mutans is an alpha Hemolytic streptococcus which is a pa of the normal flora of the oral cavity. This gram-positive coccus is commonly found in the mouth from where it can spread to cause dental caries or endocarditis in individuals with risk factors(dental extraction in individuals with damaged hea valves). The bacterium has a polysaccharide coat that allows it to stick to teeth and also to the damaged hea valves. It produces acid from sugar in saliva and this promotes erosion of tooth enamel. Normal body defenses are usually adequate to prevent disease. Disease due to this bacterium can be prevented by mainataince of good oral hygeine and by regular dental checkup Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 221


Question: A 20 year old male patient complaints of  a genital discharge resembling flow of seed. He has h/o sexual intercourse with a commercial sex worker 5 days back. Culture media used for the organism is

Flow of seed genital discharge suggests gonococcal urethritis.


Question: Diagnostic of Rabies aEUR'

Negri bodies "Negri bodies are pathognomonic for Rabies". - Negri bodies are eosinophilic cytoplasmic inclusion bodies in brain neurons and are composed of randomly oriented rabies virus, nucleocapsids embedded in an amorphous substance or matrix. These inclusions are seen in:? - Purkinje cells of cerebellum - Pyramidal cells of hippocampus Also know:- In Measles Both nuclear and intracytoplasmic bodies can be seen.


Question: Primary atypical pneumonia is caused by

Ans. c (Mycoplasma). (Textbook of Microbiology by Anantanarayan 6th/365)MYCOPLASMA# Bacteria devoid of cell walls# Highly pleomorphic# Eaton agent# Pleuropneumonia like organisms. Smallest free living micro-organisms.# Do not produce spores, flagella or fibria.# Gliding motility present.# 'Fried egg' appearance of colonies positive.# Colonies best studied by staining with Diene's method.# Cold agglutination test (streptococcus MG).# Pathogenicity- M. pneumonia -Primary atypical pneumonia.- Ureaplasma urealyticum and M.hominis -genital infection# Treatment--tetracycline & erythromycin.


Question: Most immunogenic Typhoid antigen


Question: A "parasite" that may be a fungus is the initial clinical manifestation in up to 60% of patients with AIDS. This organism is

One of the multiple criteria for classification of AIDS is the development of P. carinii pneumonia (PCP). Pneumocystis is a fungus formerly thought to be a parasite that was classified with the sporozoa. PCP may also be seen in patients with congenital or another acquired cellular immune dysfunction. Most patients with AIDS are given prophylactic aerosolized pentamidine or SXT-TMP for PCP. PCP is easily diagnosed in respiratory secretions by a direct fluorescent antibody test. Both the microsporidia and Cryptosporidium are intestinal parasites that also infect patients with AIDS, but these microorganisms cause protracted diarrhea. Blastocystis and Blastomyces are both yeasts and should not be confused with Pneumocystis or each other.


Question: Selective medium for Gonococci is

Selective media for gonococci is Thayer - Main media. It contains vancomycin, colistin and nystatin. These antimicrobials will suppress the growth of other organisms which inhibits the growth of Meningococci. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 231


Question: Differential expression of the same gene depending on parent of origin is referred to as

The phenomenon referred to as genomic imprinting leads to preferential expression of an allele depending on the parental origin.Genomic imprintingHuman inherits two copies of each gene, i.e. two alleles, from homologous maternal and paternal chromosomes.There is no functional difference between the genes derives from mother or the father. But, with respect to some genes, there are functional differences between the paternal gene and maternal gene. These differences result from an epigenetic process, called genomic imprinting. In most cases, genomic imprinting selectively inactivates either the maternal or paternal allele. Maternal genomic imprinting:Selective inactivation of maternal allele.Example: Angelman syndrome.Paternal genomic imprinting:Selective inactivation of paternal allele.Example: Prader-Willi syndrome.


Question: Biological indicator for Autoclave is

Autoclave  - Geobacillus stearothermophilus
Hot air oven - CL tetani or bacillus subtilis
Ionizing radiation - Bacillus pumilus.


Question: Best laboratory test to diagnose HIV infection March 2007


Question: Maternal to child transmission of HIV is prevented by

HIV infected mother can transmit the virus to fetus''infant during pregnancy, during delivery or by breastfeeding,
Early diagnosis and antiretroviral therapy to mother and infant significantly decrease the rate of intrapartum and perinatal transmission (Vertical transmission) of HIV infection.
Zidovudine treatment of HIV infected pregnant women from the beginning of the second trimester through delivery and of infant for 6 weeks following birth decreases the rate of transmission from 22.6 % to < 5%
A single dose of nevirapine given to the mother at the onset of labor followed by a single dose to the newborn within 72 hours of birth decreased transmission by 50%. This is the preferred regimen now in developing countries


Question: Rice watery stools are Characteristic of

About 50% of infections with classic V cholerae are asymptomatic, as are about 75% of infections with the El Tor biotype. The incubation period is 12 hours-3 days. There is a sudden onset of nausea and vomiting and profuse diarrhea with abdominal cramps. Stools, which resemble "rice water," contain mucus, epithelial cells, and large numbers of vibrios. There is a rapid loss of fluid and electrolytes, which leads to profound dehydration, circulatory collapse, and anuria. The moality rate without treatment is between 25% and 50%.Ref: Jawetz; 27th edition; Page no: 255


Question: Most common manifestation of congenital toxoplasmosis

Most common - Chorioretinitis
In adults - Cervical lymphadenopathy.


Question: Raynaud Braude phenomenon is seen in

Candida species:General characteristicsCultural characteristics*Gram positive ovoid, elongated budding yeast-like fungi*Major pathogenic species: C.albicans, C.tropicalis, C.glabrata, C.parapsilosis, C.krusei*Non capsulated*Candida is a human commensal so infection is mostly endogenous*Impoant Oppounistic pathogen*Blood agar and SDA - creamy white, some are pasty and few are rough colonies*Preferred media - Sabouraud dextrose agar with or without antibiotics (Gentamicin, chloramphenicol and cycloheximide) Virulence factorsClinical features*Adhesins*Urease activity*Extracellular proteinases*Phospholipases*Lipases*Hydrolytic enzymes*Phenotypic switching: from budding yeasts- Pseodohyphae-true hyphae*Superficial infections: Cutaneous (interigo, diaper rash), nail (paronychia and onychomycosis) and mucosal infections (oral thrush, stomatitis and vaginal candidiasis)*Deep infections (esophagitis, GIT candidiasis, endocarditis, UTIs, Meningitis, Ocular candidiasis)*Disseminated candidiasis and candidaemiaDiagnosisTreatment*Microscopy: Direct Gram stain and KOH mount, Calcofluor white stain and LPCB*Culture: Blood agar and SDA*Germ tube test: Reynauds-Braud phenomenon positive*Corn meal agar with Tween 80: identification of species*CHROM agar inoculation: different colour by Candida species*Sugar fermentation and assimilation test*DOC - Amphotericin B*Alternative - Echinocandins and Azoles (Ref: Ananthanarayan 9th edition, p611-612)


Question: Rapid diagnostic test for gram negative bacterial Meningitis is

Limulus amebocyte lysate reacts with bacterial endotoxin lipopolysaccharide, which is a membrane component of gram - negative bacteria.


Question: Herpes zoster ophthalmicus is

It is due to reactivation of herpes in ophthalmic branch of trigeminal nerve.

Reactivation of herpes in trigeminal nerve

Reactivation of herpes in occulomotor nerve


Question: This test is positive in

Test is quellung reaction quellung reaction: a small amount of growth is mixed with saline, antisera against the capsule polysaccharide, and methylene blue stain. After incubation at room temperature for 1 hour, the reaction is observed under the microscope.The organisms are outlined in light blue. A positive reaction shows clumping because of cross-linking of the antibodies and pneumococci. The halo effect around the pneumococci is apparent capsular swelling.Jawetz 7e pg 224


Question: Hereditary angioneurotic edema is due to deficiency of

C1 esterase inhibitor causes Hereditary angioneurotic edema.


Question: Sereny test is positive for

Sereny's test is positive in EIEC (Enteroinvasive E.coli). Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg: 285


Question: Toxic shock syndrome is Staphylococcus infection is due to

Toxic shock syndrome is a potentially fatal multisystem disease caused by TTST type 1(formerly known as enterotoxin type F or pyrogenic exotoxin C) is most often responsible, though enterotoxins B or C may also cause the syndrome. Staphylococcal enterotoxins and TSST-1 are superantigens which are potent activators of T lymphocytes. Being V beta-restricted T cell mitogens, such superantigens stimulate very large numbers of T cells, without relation to their epitope specificity. This leads to an excessive and dysregulated immune response, with the release of cytokines interleukins 1 and 2, tumor necrosis factor and interferon gamma. This explains the multisystem involvement and florid manifestations in staphylococcal food poisoning and TSS. Ref: Textbook of Microbiology; Ananthanarayanan and Panicker; 10th Edition; Page No: 204


Question: Staphylococcus aureus virulence is due to

Staphylococcus produces two types of diseases: infections and intoxications. The virulence factors of Staphylococcus are: Cell-associated polymers Cell surface proteins Extracellular enzymes Toxins Extracellular enzymes include Coagulase, lipid hydrolase, hyaluronidase, and nuclease. Ref: Textbook of Microbiology; Ananthanarayanan and Panicker; 10th Edition; Page No: 203, 204


Question: Selective media for Vibrio cholerae

TCBS medium- Thiosulfate, Citrate, Bile salt & Sucrose Repeat .from May 2008


Question: The components of Innate immunity that are active against viral cells include

Natural killer (NK) cells are large, granular lymphocytes morphologically related to T cells, which make up 10-15% of blood leukocytes. NK cells contribute to innate immunity by providing protection against viruses and other intracellular pathogens. NK cells have the ability to recognize andkill virus-infected cells and tumour cells. Cytotoxic T cells - Phagocytosis. B cells - Antibody production. Memory T cells - Cell-mediated immunity. Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno: 137


Question: Most fatal complication of measles is

SUBACUTE SCLEROSING PANENCEPHALITIS It is a slowly progressive disease characterised by seizures and progressive deterioration of cognitive and motor function. SSPE belongs to group C slow virus infection, caused by a defective measles virus . Age: SSPE typically develops if the primary measles virus infection in childres less than 2 years of age SSPE usually develops after 7-13 years after primary measles infection. High titer antibody to measles virus in CSF is diagnostic Ref : essentials of Medical microbiology apurba sastry 1st edition page 468


Question: The bacterium that is most commonly used in genetic engineering is

GENETIC ENGINEERINGEngineering is the application of science to social needs. Recombinant plasmids may be introduced into a bacterial host, frequently E coli, by forced transformation. Alternatively, electroporation is a procedure that introduces DNA into bacteria using an electrical gradient.Ref: Jawetz, Melnick, & Adelberg's Medical Microbiology; Twenty-Seventh Edition; Chapter 7; Microbial Genetics


Question: Warthin Finkeldey giant cells

(C) Measles[?]MEASLES:oGiant multinucleate cell found in hyperplastic lymph nodes early in the course of measlesoNecrosis of the Respiratory tract epithelium with lymphocytic infiltrateoSmall vessel vasculitis on the skin and oral mucosaoHistological Findings: Two types of Multinucleated giant cells in both epidermis & oral epithelium by 7-11 days.1. Warthin Finkeldey cells of reticuloendothelial system2. Epithelial giant cells of respiratory & other epithelia.-Rash reveals intracellular edema and dyskeratosis-Epidermal syncytial giant cells with up to 26 nuclei-Lymphoid hyperplasia-Fusion of infected cells - multinucleated giant cells-Warthin-Finkeldey giant cells: Pathognomonic for measles, up to 100 nuclei-Also with HIV-infected individuals and Kimura disease-Rarely in neoplastic (e.g. lymphoma) & non-neoplastic lymph node disorders.OTHER GIANT CELLS AT A GLANCE![?]Classification based on functional characteristics:oDamaged striated muscle fibres-Regenerating sacrolemmal cells in damaged voluntary muscle.-Aschoff giant cells in heart muscle (fused myocardial macrophages).oFused fibroblasts (as in giant cell fibroma)oThe osteoclastoTumor giant cells-Reed-stern berg cells in Hodgkin's lymphomas-Giant cells in central giant cell granuloma-Giant cells in other tumors E.g. CarcinomaoFused cells due to viral infections.-Epithelial giant cells as in HSV infection.-Connective tissue cells as in Measles (Warthin Finkeldey cells).oFused macrophages-Due to reaction to foreign bodies (exogenous or endogenous materials) e.g. foreign body giant cell with scattered nuclei-Due to reaction to organism as in tuberculosis (Langhans' giant cell) and fungal infections-Touton giant cells of xanthoma.oGiant Cells In Inflammation:-Foreign Body giant cells (b) Langhan's giant cells (c) Touton giant cells (d) Aschoff giant cellsoGiant Cells In Tumor:-Tumor giant cells (b) Reed-Stern berg cells (c) Giant cell tumor of bone[?]Other Classification:oMicrobial Lesions: a. Tuberculosis (b) Leprosy (c) Actinomycosis (d) SarcoidosisoTumor & Tumor Like Lesions:-Central giant cell granuloma (b) Peripheral giant cell garnuloma (c) Giant cell fibroma (d) Giant cell tumor (e) Osteo- sarcomaa (f) Rhabdomyosarcoma (g) Hodgkin's lymphomaoCystic Lesions: a) Traumatic bone cyst (b) Aneurysmal bone cystoMetabolic Lesions: a) HyperparathyrpoidismoOsteodystrophic Lesions: a) Noonan like multiple giant cell lesion syndromeoMiscellaneous Lesions: a) Cherubism (b) Paget's disease (c) Fibrous dysplasia


Question: Infective dose of S.typhi is

Infective dose is 103-106 colony forming units.


Question: Spore rorming anaerobic gram positive bacilli


Question: Flupiine is

Flupiine is a centrally acting non-opioid analgesic. It is unique as a non-opioid, non-NSAID, Nonsteroidal analgesic. It is a centrally acting, non-opioid analgesic with N-methyl D aspaate (NMDA) receptor antagonist propey which has been shown to be effective in the management of postoperative pain.


Question: The following organism is motile with NO external flagella

(D) Spirochetes # Spirochetes: Elongated, motile, flexible bacteria twisted spirally along the long axis are termed 'spirochetes' (from Speira, meaning coil and chaite, meaning hair). They are structurally more complex than other bacteria. A characteristic feature is the presence of varying numbers of endoflagella, which are polar fiagella wound along the helical protoplasmic cylinder, and situated between the outer membrane and cell wall. Endoflagella are believed to be responsible for motility but the exact mechanisms of locomotion are not understood.> Brucellae are coccobacilli or short rods 0.5-0.7 urn x 0.6-1.5 pm in size, arranged singly or in short chains. The cells are so small that they may be mistaken for cocci, as was done by Bruce who called them Micrococcus melitensis. In older cultures, irregular forms appear. They are nonmotile, noncapsulated and nonsporing. They are Gram negative and nonacid fast. Bipolar staining is not uncommon.> Mycoplasmas are the smallest free-living microorganisms, and one of the most pleomorphic.They occur as granules and filaments of various sizes. The granules may be coccoid, balloon, disc, ring or star forms. The filaments are slender, of varying lengths and show true branching. Multiplication is by binary fission, but as genomic.> Chlamydiae occur in two forms, the elementary body and the reticulate body (formerly also called the 'initial body'). The elementary body is the extracellular, infective form. It is a spherical particle, 200-300 nm in diameter, with a rigid trilamirar cell wall similar to the cell walls of Gram negative bacteria, and an electron dense nucleoid. The reticulate body is the intracellular growing and replicative form, 500- 1000 nm in size. Its cell wall is fragile and pliable, leading to pleomorphism.


Question: Most common agent responsible for bronchiolitis is


Question: The maculopapular, copper coloured rash is characteristic of

This "primary lesion" always heals spontaneously, but 2-10 weeks later, the "secondary" lesions appear. These consist of a copper-colored or red maculopapular rash anywhere on the body, including the hands and feet, and moist, pale papules(condylomas) in the anogenital region, axillae, and mouth. The patient may also have syphilitic meningitis, chorioretinitis, hepatitis, nephritis (immune complex type), or periostitis. The secondary lesions also subside spontaneously. Bothprimary and secondary lesions are rich in spirochetes and are highly infectious. Contagious lesions may recur within 3-5 years after infection, but thereafter the individual is not infectious.Ref: Jawetz; 27th edition; Page no: 324


Question: Madura foot is caused by

(Fungal infectiuons): (618 Anant narayan 7th edition; 626-27-Chakraborty 2nd/ caused by)Madura foot or Maduramycosis caused by filamentous fungiImportant Causative agents of mycetoma (557- Baveja 4th)Causative agentColour of the grainsA. Eumycetoma Acremonium falciformeWhite - yellowMadurella mycetomiBlackM. griseaBlackPseudo allescheria boydiiWhite - yellowExophiala jeanselmeiBlackB. Actinomycetoma Actinomadura maduraeWhite -yellowA.pelletieriRedNocardia brasiliensisWhiteStreptomyces somaliensisYellow* Presence of grains in pus or biopsy material is diagnostic*** Mycetoma granules often elicit an immunologic response in tissue called Splendore-Hoeppli reaction"Sulphur granules" section of tissue showing an actinomycotic colony. The clubs at the periphery giving a"sun ray appearance"***


Question: Best way to differentiate Entero hemorrhagic E.coli from other E.coli is

EHEC does not ferments sorbitol thus Sorbitol Macconkey agar is used to differeniate EHEC from other E.coli.


Question: Mad Cow disease (Spongiform disease) occurs due to

Mad cow disease or bovine spongiform encephalopathy i.e. Caused by “prions”
“PRIONS” are unconventional transmissible agents, proteinaceous in nature.”
Diseases caused by prions are
Kuru
Creutzfeldt Jakob Disease.
Gerstmann Straussler Scheinker Syndrome
Fatal Familial Insomnia.
Scrapie Of Sheep
Transmissible Encephalopathy of Mink.
Bovine Spongiform Encephalopathy (Mad Cow Disease)


Question: A patient with neurological problems has an elevated cerebrospinal fluid (CSF) antibody titer to measles virus. You would most likely suspect

(C) Possible subacute sclerosing panencephalitis (SSPE) # 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 CSE In patients with multiple sclerosis (MS), lower CSF antibody titers have been observed, suggesting a possible etiologic role for measles virus in MS.


Question: Ehrlichia effects

Ehrlichia are small gram negative,obligate intrcintracellular bacteria which have affinity towards bloodcells.Ehrichia chaffeensis cause human monocyte ehrlichiosis and E.phagocytophilia cause human granulocytic ehrlichiosis which effects granulocytes (neutrophils) Ref:ananthnarayan and paniker's microbiology 10th edition


Question: Urine sample examinations is a useful investigation in infestation of

Ans. a (S. hematobium) (Ref. H - 18th/ ch. 219)SCHISTOSOMIASIS (BILHARZIA)Distribution and important species of Schistosoma are:# S. japonica is found in Central and Eastern China, and the Philippines and nearby islands; and primarily affects the liver and intestines.# 5. mansoni is found in Africa, the Eastern Mediterranean, the Caribbean, and South America and primarily affects the liver and intestines.# S. haematobium is found in Africa, the Middle East, and Eastern Mediterranean and primarily affects the urinary tract.# S. mekongi is found in Southeast Asia and primarily affects the liver and intestines.Incubation:# Symptoms of acute schistosomiasis begin about a month after infection.Signs and Symptoms# Acute schistosomiasis ->>Katayama fever.Q# The last (chronic) stage varies according to species, i.e., S. japonica, 5. mansoni, and S. mekongi primarily affect liver and intestines; while S. haematobium primarily affects the urinary tract.# In general, patients with chronic schistosomiasis tend to present in developed countries with lethargy, colicky abdominal pain, mucoid/bloody diarrhea, or dysuria and hematuria.# Chronic hepatosplenic schistosomiasis is a consequence of eggs retained in tissue and prolonged infection - usually of > 10 years duration.# Fibrosis may cause portal hypertension, splenomegaly, or esophageal or gastric varices.Q# Chronic genitourinary schistosomiasis is associated with chronic 5. haematobium infection.# Hematuria and dysuria are common from the acute through chronic stages. Bladder cancer rates are increased in endemic areas. Salmonella infection concurrent with schistosomiasis is common and is resistant to treatment unless the schistosomiasis is also treated.Diagnosis# Diagnosis of S. japonicum and S. mansoni is by the presence of ova in feces or tissue. Diagnosis of S. haematobium is by the presence of ova in urine or tissue. However, ova loads are not always sufficient for diagnosis, especially in long-standing chronic illness. Immunofluorescent antibody tests and antigen detection assays are increasingly used.# "Fetal head" bladder calcification may be shown in X-rays in chronic S. haematobium infection. QTreatment# For S. haematobium and S. mansoni, praziquantel 20/kg po bid for one day; for S. japonica and S. mekongi, praziquantel 20/kg po tid for one day are the treatments of choice.# S. mansoni may also be treated with oxamniquine in a single po dose (with food) of 15 mg/kg. S. haematobium in North and East Africa may be treated with metrifonate 7.5-10 mg/kg every other week for a total of 3 doses.Also Know:# The second most common urologic cancer and the most frequent malignant tumor of the urinary tract is bladder cancer. Usually a transitional cell carcinoma. Most prevalent in men during the sixth and seventh decades. Risk factors include smoking, diets rich in meat and fat, schistosomiasis, chronic treatment with cyclophosphamide, and exposure to aniline dye (a benzene derivative).# Causes of portal hypertesnion are as follows: 1. Presinusoidal: Splenic or portal vein thrombosis, schistosomiasis. granulomatous disease. 2. Sinusoidal: Cirrhosis, granulomatous disease. 3. Postsinusoidal: Right heart failure, constrictive pericarditis, hepatic vein thrombosis.


Question: Lipschutz bodies are seen in

Lipschutz bodies are inclusion bodies seen in herpes simplex.


Question: Bacterial adherence to epithelium is mediated through

Explanation: Fimbriae Certain (Gram-negative bacilli carry very fine, hair-like surface appendages called fimbriae or pili.
They are shorter and thinner than flagella Fimbriae can be seen only under the electron microscope.
Fimbriae function as organs of adhesion, helping the cells to adhere firmly to particles of various kinds Fimbriated bacteria form surface pellicles in liquid media.
Many fimbriated cells (for example Escherichia, Klebsiella) agglutinate red blood cells. Hemagglutination provides a simple method of detecting the presence of such fimbriae.
The hemagglutination is specifically inhibited by D- mannose (mannose sensitive) A special type of fimbria is the sex pili.
They are found on ‘male’ bacteria and help in the attachment of those cells to ‘female’ bacteria.
They do not mediate attachment to epithelium Flagella Flagella are the organs of locomotion.
Flagellum consists of three distinct parts the filament, the hook and the basal Flagella are made up of a protein (flagellin) Flagella are less than 0.02 Jim in thickness and hence beyond the limit of resolution of the light microscope.
They may, in some instances, be seen under dark ground illumination.
They can be visualised by special staining techniques in which their thickness is increased by mordanting, or by electron microscopy Mesosoxnes Mesosomes (chondroid) are vesicular,
convoluted or niultilaniinated structures formed as invaginations of the plasma membrane into the cytoplasm.
They are more prominent in Gram-positive bacteria. They are the principal sites of respiratory enzymes in bacteria and are analogous to the mitochondria of eukaryotes.
Mesosomes are often seen in relation to the nuclear body and the site of synthesis of crosswall septa,
suggesting that they coordinate nuclear and cytoplasmic division during binary fission


Question: Intermediate host for hydatid disease aEUR'

Man Hydatid disease of the liver is caused by Echinococcus granulosus: Ecchinococcus granulosus:- Also known as dog tapeworm, hydatid worm Habitat Small intestine of dog and other canine animals Definitive host --> Dog, wolf, fox, jackal (canine animals) Intermediate host Sheep, pig, cattle, horse, goat, man (dead end) Infective form .- Egg Mode of infection Ingestion of eggs Also know Man is the definitive host in most of the parasitic infection except the following parasites where it is an intermediate host. Echinococcus granulosus (Hydatid worm) Plasmodium (Malaria) Taenia solium (Man is both definitive an intermediate host) Toxoplasma gondii Sarocysts lindemanii


Question: Intracellular inclusion bodies in rabies are

Ans. d (Negri bodies) (Ref. Q. 75 of MH-2005)Pathologic FeatureClinical ConditionAschoff bodiesRheumatic feverAsteroid bodiesSporotrichosisBunina bodiesAmyotrophic lateral sclerosisBollinger bodiesFowl pox (intracytoplasmic acidophilic)Call-Exner bodiesGranulosa cell tumor of ovaryCivatte (Colloid) bodieslichen planusCowdry bodiesHerpes (type A bodies)Polio and Adeno viral infection (type B bodies)Councilman bodiesToxic hepatitis,Viral hepatitis,Yellow feverDonovan bodiesGranuloma inguinaleDohle bodiesSepsis or severe inflammatory disordersDonath-Landsteiner antibodiesParoxysmal cold hemoglobinuriaFerruginous bodiesAsbestosisGamna-Gandy bodiesCongestive splenomegalyGlomeruloid bodies'GlioblastomaGaurnieri bodiesVacciniaHirano bodiesAlzheimer's diseaseHeinz bodiesG6PD deficiencyHematoxylin bodiesSLEHowell-Jolly bodiesAspleniaHalberstaeder-Prowazek (HP) bodiesTrachomaHX bodies (Berbeck's granules)Langerhan cell histiocytosis XLipschutz bodiesHerpes simplexLevinthal-Cole-Lillie bodiesPsittacosisLewy bodiesParkinsonismLD bodiesLeishmaniasisLafora bodiesMyoclonic epilepsyMallory hyaline bodiesAlcoholic liver diseaseIndian childhood cirrhosisPrimary Billiary CirrhosisMichaelis-Gutmann bodiesMalakoplakiaMiyagawa bodiesLGVMasson bodiesCryptogenic organizing pneumoniaNegri bodiesRabiesPsammoma bodiesTransitional meningiomaPapillary carcinoma thyroidSerous cystadenocarcinoma of ovaryMesotheliomaPick bodiesPick's disease and contain 3 repeat tauRussell bodiesMultiple myelomaReinke's crystalsHilus cell tumor (Leydig cell tumor)Sclerotic bodiesChromoblastomycosisSchaumann, residual & asteroid bodiesSarcoidosisSpironolactone bodiesAldesterone-producing adrenal adenomasSchiller-Duval bodiesYolk sac tumor (endodermal sinus tumor)Tuberculate sporesHistoplasmosisVerocay bodiesNeurilemmoma (Schwannoma)Weibel-Palade bodiesNormal intracellular stores of P-selectinZebra bodiesNiemann-Pick's diseaseEducational Table:Diagnostic Pathologic FeatureDisease1Flexner and Wintersteriner rosettes# Retinoblastoma2Necrosis and vascular or endothelial cell proliferation and pseudo-palisading nuclei# Astrocytoma3Perivascular pseudo-rosettes# Ependymoma4"Floating neurons" in the pools of mucopolysaccharide-rich fluid of the myxoid background# Dysembryoplastic neuroepithelial tumor5Extremely cellular, with sheets of anaplastic ("small blue") cells# Medulloblastomas7Calcification, present in as many as 90% of these tumors, ranges from microscopic foci to massive depositions# Oligodendroglioma8Cystic, with a mural nodule & if solid, it is usually well circumscribed.The tumor is composed of areas with bipolar cells with long, thin "hairlike" processes that are GFAP positive. Rosenthal fibers, eosinophilic granular bodies, and microcysts are often present# Pilocytic astrocytoma9Verocay bodies; Antoni A and B pattern of growth# Schwannoma10.'Onion bulb' appearance.# Relapsing polyneuropathy


Question: Virulence factor helpful for entamoeba histolytica to adhere to intestinal mucosa is

Amoebic Lectin antigen helps in adhesion.


Question: Subacute bacterial endocarditis is caused by


Question: "Genital elephantiasis" is caused by

(Lymphogranuloma venereum) (428-A7th)LYMPHOGRANULOMA - VENEREUM (Lymphogranuloma inguinale, poradenitis, climatic or tropical bubo)- Caused by chlamydia -trachomatis - L2 (Most commonly)- Preferred site - regional lymphnodes- Primary lesions - painless papulovesicular lesion ** on the external genitalia- Women - hemorrhagic proctitis with regional lymphadenitis- Late sequelae in women leading to rectal strictures and elephantiasis of the vulva (esthiomene)**Chancroid or soft sore is caused by Haemophilus - ducryi "School of fish" or rail rod track" appearance- Tender nonindurated irregular ulcers on the genitalia


Question: Compared to breastmilk colostrum is rich with

Colostrum:Colostrum is the first stage of breast milk that occurs during pregnancy and lasts for several days after the bih of the baby.It is either yellowish or creamy in colour. It is also much thicker than the milk that is produced later in breastfeeding.Colostrums is high in protein, fat-soluble vitamins, minerals, and immunoglobulins. Immunoglobulins are antibodies that pass from the mother to the baby and provide passive immunity for the baby.Passive immunity protects the baby from a wide variety of bacterial and viral illnesses. 2-4 days after bih, colostrums will be replaced by transitional milk.


Question: Clostridium tetani is

Clostridium tetani is a gram-positive, slender bacillus. It occurs singly and occasionally in chains. The spores are spherical, terminal and bulging, giving the bacillus the characteristic 'drumstick' appearance. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 264


Question: Verocytotoxin has been isolated in individual suffering from Hemolytic uraemic syndrome in their

Verocytotoxin or SHIGA LIKE TOXIN is produced by Enterohemorrhagic E coli which invades vascular endothelial cell and causes diarrhoea so show the presence of verocytotoxin is confirmed in the specimen of faeces. The toxin is produced by specific strain of ETEC O157 H7

Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli)


Question: Oval bulging terminal spores are seen in

Clostridium teium produces oval and terminal spores. It resembles tennis racket Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 258


Question: Aspergilloma has

Aspergillus has non pigmented septate hyphae with characteristic dichotomous branching at an angle of approximately 45degrees. Ref: Textbook of Microbiology, Ananthanarayan and Paniker; 9th edition


Question: The operating temperature in an ethylene oxide sterilization during a warm cycle is

Ethylene Oxide sterilization (High level disinfectant) Cold cycle stas at 37 + 5 oC Warm cycle stas at 54 + 5 oC ETO is Highly penetrating gas It is used for sterilizing plastic ,rubber paicles , Respirators, Hea lung machine , disposable plastic syringes , petri dishes Bacillus Globigi used as biological indicator for ethylene oxide sterilizer

General Microbiology Pa-2 and Pa-3 (Sterilization and Bacterial Genetics)


Question: Gonococcus does not involve

In men, the disease caused by gonococci stas as an acute urethritis with a mucopurulent discharge containing gonococci in large numbers. Infection extends along the urethra to prostrate, seminal vesicles and epididymis. Chronic urethritis may lead to stricture formation. The infection may spread to periurethral tissues, causing abscess and multiple discharging sinuses (water can perineum) Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 235


Question: Stool specimen is transported in

Transport media for stool specimen are
a. Cary-Blair medium
b. Buffered glycerol saline
c. Stuart medium

 Inoculate media for routine stool culture are

a. Blood agar
b. MacConkey agar
c. Hektoen enteric HE (agar)
d. Selective media for campylobacter: Campy BAP, skirrow
e. Selenite F broth or GN Broth
f. Xylose-lysine deoxycholate agar (XLD agar)

 For specific situations, selective media are used

i. Vibrio: TCBS agar or alkaline peptone broth.
ii. Yersinia: Cefsulodin-Irgasan-Novobiocin (CIN) agar or Phosphate Buffered Saline (PBS) broth.
iii. E.coli 0157: H7 Sorbitol-MacConkey agar


Question: Louse borne is


Question: Vascular involvement and thrombosis is seen in

Mucormycosis occurs as a systemic infection following dissemination from a primary focus in the upper respiratory tract or nasal cavity, where the spores germinate and the mycelia invade the adjacent tissues- orbit, sinuses and the brain. 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: The process of transfer of cell mediated immunity from one individual to other is

Adoptive immunity occurs following injection of immunologically competent T-Lymphocytes known as transfer factor.


Question: Typhoid in 1st week is best diagnosed by

Ans. a (Blood culture). (Ref. Harrison, Medicine, 18th/ Chapter 153. Salmonellosis )# In typhoid, blood cultures are positive in approximately 90% cases in 1st week of fever, 75% of 2nd week, 60% of 3rd week and 25% thereafter (MacConkey, DCA and Wilson Blair media).# Faeces culture is almost as valuable as blood culture, as viruses shed during the disease and in convalescence, but they are also positive in carrier state is a drawback. But this is particularly valuable in patients on antibiotics, as they are not eliminated from faeces.# Widal test is negative in 1st week; titres start rising after 1st week, peaks at 3rd to 4th week and then starts falling. Urine culture can be positive in 2nd and 3rd week, that too only in 25% cases.# Bone marrow culture is positive in most of the cases, when even blood cultures are negative.Note: The diagnostic 'gold standard' for diagnosis of typhoid is culture, for salmonella typhi or paratyphi. The mnemonicBASU is very vague and not advisable to remember, because the fact is...B-Blood culturepositive in any week, however 90% positive 1st week.A-Agglutinationpositive in 3rd, 4th week.S-Stool culturepositive in any week, but can also be positive in carriers.U-Urine culturepositive in 2nd and 3rd week.


Question: Mycobacterium tuberculosis is best demonstrated by


Question: Wakana disease is caused by

Wakana disease seen in Ancyclostoma.
Both GIT & pulmonary symptoms seen.


Question: In Toxoplasmosis the oocyst seen in and pseudocyst is seen in respectively.

C i.e. Cats, human (cat faeces and human tissue)Ref: Paniker's Textbook of Parasitology, 6th edition, page 96-103Explanation:Human ingesting either tissue cysts or oocysts-- rupture of cyst wall and release of organisms-- invade the small intestinal epithelium-- via mesenteric lymph nodes-- disseminates throughout the body and multiplies intracellularly.Pseudocyst (tachyzoites)Tissue cyst (bradyzoites)Placenta, liver, L.N, spleen, skeletal muscles, lungs, heart, retina and choroid.Brain and skeletal muscles.


Question: Carotid body contains islands of two types of cells, type I and type II cells, surrounded by fenestrated sinusoidal capillaries. Type I cells are excited by hypoxia, and the principal transmitter appears to be

Carotid & Aoic Bodies There is a carotid body near the carotid bifurcation on each side, and there are usually two or more aoic bodies near the arch of the aoa.Each carotid and aoic body (glomus) contains islands of two types of cells, type I and type II cells, surrounded by fenestrated sinusoidal capillaries.Type I cellsThe type I or glomus cells are closely associated with cup-like endings of the afferent nerves.The glomus cells resemble adrenal chromaffin cells and have dense-core granules containing catecholamines that are released upon exposure to hypoxia and cyanide.The cells are excited by hypoxia, and the principal transmitter appears to be dopamine, which excites the nerve endings by way of D2 receptors.Type II cellsThe type II cells are glia-like, and each surrounds four to six type I cells. Their function is probably sustentacular.


Question: Most dominant colonic bacteria is

Bacteroids are the normal inhabitants of the intestine, respiratory, female genital tract. the normal flora of adult colon contains 96 to99% of anaerobes and only 1 to 4% of aerobes. Anaerobes - Bacteroides species, bifidobacteria, anaerobic lactobacilli, anaerobic streptococci. Ref: Baveja textbook of microbiology; 4th edition.


Question: Ideal dose of Diptheria antitoxin given for treatment is

* Specific treatment of diphtheria consists of antitoxic and antibiotic therapy. * Antitoxin should be given immediately when diphtheria is suspected, as the fatality rate increases with delay in staing antitoxic treatment. * Antibiotic treatment only supplements and does not replace antitoxic therapy. * Diphtheria antitoxin should be given in respiratory diphtheria - 20,000 to 1,00,000 units. Ref:- Ananthanarayan and Paniker's Textbook of Microbiology 10th ed; Pg num:- 245


Question: Most common cause of UTI in neonate is


Question: An inhibitor was designed to block a biologic function in H. influenzae. If the goal of the experiment was to reduce the virulence of H. influenzae, the most likely target would be

The major determinant of virulence in H. influenzae is the presence of a capsule. There is no demonstrable exotoxin and the role of endotoxin is unclear. While one would expect that IgA protease would inhibit local immunity, the role of this enzyme in pathogenesis is as yet unclear.


Question: The unit of measurement used in bacteriology is

Unit of measurement used in bacteriology is the micron Ref: Anantanarayan; 7th edition; Page no: 7


Question: Median weight of 100 children was 16 kgs. The standard detion was 8.calculate the percentage coefficient of variance

Coefficient of Variation (COV)* COV = SD x 100 Mean or Median SD is expressed as a percentage of mean or median. CV=SD/MEAN x 100= 8/16 x 100= 50%


Question: Mycotic abscess are due to


Question: Selective media for N. gonorrhoeael

Ans. a (Thayer-Martin media). (Ref Anantanarayan, Microbiology, 8th/ p. 226).# A popular selective medium for N. gonorrhoeae (gonococci) is Thayer-Martin medium containing vancomycin, colistin, and nystatin.# They also grow well on chocolate agar and Mueller Hinton agar.Bacteria and their growth mediaOrganismMedium usedStaphylococcusLudlam's mediumStreptococcusBlood Agar, Pikes medium (transport)NeisseriaBlood agar, Chocolate agarMueller-Hinton star caesin hydrolysate agar, Modified Thayer-MartinGonococciStuart Transport MediumCorynebacterium diphtheriaeLoeffler's serum slope, Tellurite blood agar, MacLeod and Hoyle's mediaLactose and nonlactose fermentersMacConkey mediumShigellaDeoxycholate citrate agarShigella Inhibited byWilson and Blair's bismuth sulphite mediumSalmonellaWilson and Blair's bismuth sulphate mediumHaemophilusFactor X Hemin, Factor V NADP, Levinthal's Medium, Filde's agarVibrio CholeraHolding or Transport Media1) VR-Venkatraman RamaKrishnan Medium2) Cary-Blair Medium3) Autoclaved Sea WaterEnrichment-Media1) Alkaline peptone water at pH 8.62) Monsur's taurocholate tellurite peptone water at pH 9.2, Plating Media3) TCBS medium contains thiosulfate, citrate, bile salts and sucroseHaemophilusStalactite growthBordetellaBordet-Gengou glycerine-potato-blood agarBrucellaCastaneda's method of blood cultureListeriaTryptose phosphate or thioglycollate broth at 4degCCalymmatobacteriumLevinthal agarCampylobacterMicroaerophilic 5% oxygen, Cary BlairSkirrow's, Butzler's or campy BAP Selective mediaLegionellaBCYE Agar (Buffered Charcoal yeast extract)TuberculosisEgg containing: 1) Lowenstein-Jensen (LJ), 2) Petragnini, 3) DorsetContain Blood: 1) TarshisContaining Serum:l) LoefflerContaining Potato: 1.) PawolowskyLiquid Media: 1). Dubo's Medium, 2) Middlebrook's Medium, 4) Sula's Medium 3) Pros Kauer and Beck's Medium, 5) Sauton's MediumSpirochetesComplex MediaLeptospirosis1) Korthoff's media2) Stuart and Fletcher's media3) EMJH (Ellinghausen, McCullough, Johnson, Harris)Bacillus anthracisPLET mediumClostridiaRobertson's cooked meat brothClostridium tetaniFilde's techniqueAnaerobic bacteriaGaspakMycoplasmaLipids/Cholestrol enhances their growth; Diene's methodRickettsiaVolk sac of developing chick embryoChlamydiaCell culture (McCoy & Hela Cells commonly used)


Question: For early diagnosis of corynebacteria diphtheria medium used is

For early diagnosis - LSS (6-8hours).
For defenitive diagnosis - Potassium tellurite agar.


Question: A child upon ingestion of shellfish , developed tingling sensation in the mouth, swelling of the face, lips and tongue and also complained of abdominal pain and dizziness. This is an example of _

This is an example of an IgE mediated type of hypersensitivity reaction. The primary mediators are histamine and serotonin. The secondary mediators are prostaglandins and leukotrienes. The clinical manifestations may be local or systemic and range from mild rhinitis to fatal anaphylaxis. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition


Question: A Carrier of Neisseria Meningiditis can be detected by

Specimen for cases - Blood and CSF
Specimen for carriers - Nasopharyngeal swab.


Question: Molluscum contagiosum is caused by

Ans: a) Pox virusMolluscum contagiosum is seen in children and adults. It is characterised by pink o pearly white wart like nodules on the skin. Eosinophilic hyaline inclusion bodies called molluscum bodies are present Humans are the only susceptible hosts.Extra points:Certain inclusion bodies* Vaccinia - Guamieri bodies* Fowl pox - Bollinger bodies* Herpes, Yellow fever - Cowdry type A* Adeno, Polio - Cowdry type B


Question: Adjuvant given along with antigens are going to


Question: Infective form for mosquito in Plasmodium falciparum is aEUR'

Gametocytes "Infective stage of plasmodium for mosquito ----)Gametocytes". The gametocytes do not cause any clinical illness in the human host but are essential for transmission of the infection. The gametocytes do not develop .fuher or divide in the veebrate host & unless taken up by the vector mosquito they die in a few days. A gametocyte concentration of 12 or more per cmm of blood in the human host is necessary for mosquitoes to become infected. Remember Infective stage of plasmodium for mosquito --) Gametocytes Infective stage of plasmodium for man --) Sporozoite Plasmodium passes its life cycle in two different hosts Man --) Intermediate host Female anopheles mosquito --) Definitive host Human infection begins when a female anopheles mosquito inoculates sporozoites from its salivary gland into blood i.e. sporozoites are infective to man. In man sporozoites undergo multiple asexual reproduction and develops into gametocytes. Gametocytes are transferred to the insect. In the insects gametocytes develops into sporozoites after multiple sexual divisions.