• E-strip method (antibiotic gradient diffusion) is used for--> Minimum inhibitory concentration for antibiotic seneitivity.

E.Coli 1. NNS(Neonatal septicemia)2. Acute cystitis and pyelonephritis3. Spontaneous bacterial peritonitis in alcoholics*4. Traveller's diarrhoea(enterotoxigenic strain)5. HUS in children d/t eating undercooked hamburgers(enterohemorrhagic

toxin O157:H7)6. Enterotoxic shock7. Acute cholecystitis

Gonococcal urethritis Non-specific urethritis

Caused by gonococcus Caused by chlamydia trachomatis

Present within first week of sexual exposure IP- *2-3 wks following sexual exposure

Thick and creamy exudate Thin and watery exudate

Gram -ve diplococci visible on gram staining Chlamydia not visible on routine gram stains

• Mycoplasma pneumoniae- produces primary atyical pneumonia. Acute interstitial pneumoniae is characterised by lymphocytes and plasma cells within the interstitium i.e. the alveolar septal walls (In contrast typical pneumonias are characterised by acute inflammation with neutrophils within the alveoli). Mycoplasma pneumoniae causes *agglutination (not cotting) of RBCs. This agglutination goes away if you warm up the blood.

• In Neisseria gonorrhoea structure responsible for adherence- Pilli(Fimriae)--> not F-pilli (GT 88 Q-26)• To differentiate Streptococcus and Listeria: do Catalase test

o Streptococcus: -veo Listeria: +ve

• H influenzae: G -ve and pleomorphic• Potential agents for biological terrorism-

o Anthraxo Plagueo Smallpoxo Tularemia

• Taq polymerase: T. aquaticus is a bacterium that lives in hot springs and hydrothermal vents, and Taq polymerase was identified as an enzyme able to withstand the protein-denaturing conditions (high temperature) required during PCR. Therefore it replaced the DNA polymerase from E.coli originally used in PCR. Taq's optimum temperature for activity is 75-80°C, with a half-life of 9 minutes at 97.5°C

• Attest- Raoid read out ethylene oxide biological indicator producing fluorescent change on failure.• Bacteroides fragilis- anerobic G -ve uniformly resistant to aminoglycosides and usually to penicillin as well.

Wound are foul smelling.o Black exudates or a black pigment(heme) in the isolated colony is charatcteristic of B. Melaninogenicus.

• Picornavirus: features PICO-RNAvirus(Positive sense, ICOsahedral, RNA virus)

RNA Viruses• Picornaviridae, Caliciviridae , Togaviridae, Flaviviridae, Coronaviridae, Rhabdoviridae, Filoviridae,

Paramyxoviridae, Orthomyxoviridae, Bunyaviridae, Arenaviridae, Reoviridae, Retroviridae

Some general rules for all DNA viruses:

• Are HHAPPPPy viruses: Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polvoma• Are double stranded EXCEPT parvo (single stranded).• Are linear : EXCEPT papilloma, polyoma(circular, supercoiled) and hepadna (circular, incomplete).• Are icosahedral except pox (complex)• Replicate in nucleus except pox (carries own dna dependent rna polymerase)

• Phagocytosis does not involve creation of memory cells• Leptospiral meningitis resembles aseptic or viral meningitis with CSF having normal glucose concentration and

moderately elevated WBCs.• In simulataneous acute HBV and HDV infections, IgM anti Hbc will be detectable, while in acute HDV infection

superimposed on chronic HBV infection, anti-Hbc will be of the IgG class

Q. A bacterium has a lag phase of 40 minutes and a generation time of 20 minutes. How many cells will there be at the end of 120 minutes, if there are 4000 cells to begin with and there is no stationary phase-

1. 4 x10 to power 122. 2.56 x 10 to power 53. 6.4 x 10 to power 4----ans(key)4. 3.2 x 10 to power 4

Explanation- 40 min(lag phase)--> 4x10 to the power 360(1st generation time)--> 8x10 to the power 380(2nd generation time)--> 16x10 to the power 3100(3rd generation time)--> 32x10 to the power 3120(4th generation time)--> 64x10 to the power 3.

• Hepatitis A does not infect infant or neonates

• Quorum sensing- Phenomenon whereby accumulation of a duffusible low molecular weight signal molecule enables individual bacterial cells to sense when the minimum number of bacteria has been achieved.

• TYPHOID DIAGNOSIS (BASU):◦ BLOOD CULTURE ON 1ST WEEK ◦ ANTIBODIES(WIDAL) ON 2ND WEEK ◦ STOOL CULTURE ON 3RD WEEK ◦ URINE CULTURE ON 4TH WEEK

• Burkholderia pseudomallei is the causative agent of melioidosis. It also causes chronic pulmonary infection mimicking TUBERCULOSIS. The other principal form of B. pseudomallei infection is skin ulceration with associated lymphangitis and regional lyphadenopathy. Spread from the lungs or skin, which is most often documented in debilitated individuals give rise to septicemic forms of meliodosis that carry a high mortality rate.

• H1N1 influenza--> incubation period--> 3-7 days. Prompt initiation of antiviral agents (oseltamivir or zanamivir) within 48 hours of symptom onset is imperative for providing treatment efficacy against influenza virus.

• Lambda phage will remain in lysogenic state if cl proteins predominate, but will be transformed into the lytic cycle if cro proteins predominate

• Prion- In mammals prions reproduce by binding to normal, cellular isoform of the prion protein(PrPC) and stimulating conversion of PrPC into the disease causing isoform(PrPSc). PrPC is rich in alpha-helix and has little beta-structure, while PrPSc has less alpha-helix and a high amount of beta-structure. This alpha-to-beta structural transition in the prion protein(PrP) is the fundamental event underlying prion diseases. All known prions induce the formation of an amyloid fold, in which the protein polymerises into an aggregate consisting of tightly packed beta sheets. This altered structure is extremely stable and accumulates in infected tissue, causing cell death and tissue damage. This stability means that prions are resistant to denaturation by chemical and physical agents, making disposal and containment of these particles difficult.

➢ Interferon are proteins and are the first cytokine to be recognized➢ Malachite green inhibits gram positive and negative organisms and has no activity against tubercle bacilli. Hence

it is used as a selective agent in LJ medium. Listeria monocytogenes-

o Gram +ve bacillus which has the unusual ability to multiply at low temperatures. It is typically spread via contaminated food typically unpasteurized dairy products. Infection is particularly dangerous to the unborn child where it can lead to miscarriage.

o C/F- Diarrhoea, flu like illness Pneumonia, meningoencephalitis Ataxia and seizures

o Suspected listeria infection should be investigated by taking blood cultures. CSF may reveal Pleocytosis, with tumbling motility on wet mounts

o Rx- IV ampicillin + gentamicin

Q. A premature neonate suffers pneumonia and sepsis. Sputum culture on blood agar plate yields pin pointed beta-hemolytic colonies. Which of the following is a simple test to determine whether the organism is streptococcus agalactiae or L. monocytogenes-

1. Bacitracin sensitivity test2. Catalase test-------------------ans3. Coagulase test4. PCR

Discussion- Group B streptococci do not produce catalase while Listeria are catalase +ve

1. Biological indicator for Ethylene oxide is-1. B.Strearothermophilus2. B.subtilis globogi---------------ans3. B.subtilis niger4. Serratia marsecences

Discussion- Others-• Bacillus subtilis niger--> Hot air owen• B.Strearothermophilus--> Autoclaving• S erratia marsecences--> Filteration

2. All the temperature & duration of autoclave are recommended except-1. 121 C for 15 min.2. 126 C for 10 min.3. 129 C for 7 min.-------------------ans4. 134 C for 3 min.

Discussion-

All have equal effect

Autoclaving 121 C x 15 min (M/C)

126 C x 10 min

134 C x 3 min

Hot air oven 170 C x 18 min

180 C x 7.5 min

190 C x 1.5 min

3. Category no.6 biomedical waste in India include-1. Human anatomical waste2. Animal waste3. Soiled waste-------------------ans(Park-648)4. Liquid waste

Discussion- 1. Human anatomical waste2. Animal waste3. Microbioogy and Biotechnology waste4. Sharps5. Cyto-toxic drugs6. Soiled waste7. Solid waste8. Liquid waste9. Incineration ash10. Chemical waste

Yellow bag 1,2,3,6 Incinerated

Red 3,6,7 Autoclaving/Microwaving/Chemical treatment

Blue bag 4,7 First disinfect with 1% bleach

Sharps-->Mutiltion, Secured landfill

Plastic-->Shredding-->recycle

Black bag 5,9,10(Solid) Used for general waste Secured landfill

4. Sugar and gelatin containing media are sterilized by-1. Autoclaving2. Hot air oven3. Tyndallization------------ans4. Inspissation

Discussion- Done at 100 degree C x 20 min for 3 consequetive days. Useful for sugar and gelatin.80-88 degree C x 30 min x 30 days--> Egg and serum--> like LJ medium/Loffler's serum slope

Ethylene oxide--> Heart lung machineSharps--> Hot air owen(not autoclave--> will lose sharpness)Plastics--> Sterlised by radiation

6. Amikacin inhibit the bacteria growth by-1. Inhibit 30s ribososme--------ans2. Inhibit 50s ribososme3. Inactivate DNA dependant RNA polymerase4. Inhibit DNA gyrase

Discussion- Aminoglycoside(ROAMS P=270)

7. Polypeptide capsule seen in-1. Pneumococci2. Streptococci3. B.anthracis----------ans4. H.influenza

Discussion- Demonstration of capsule--> Diagnostic of animal anthrax-->Mcfedyen Rxn

Capsule--> Pneumococcus-->Polysaccharide also k/a SSS(Specific Soluble Substrate--> Named since it diffuses into tissue):

• makes CSF cloudy• responsible for early toxemia• exacerbation of COPD

Capsule--> H. Influenzae--> Type B--> highly virulent (vacccine available for this variant)--> highly invasive because of PRP(Polyripitol PO4)

• The major determinant of virulance with H. Influenzae is the presence of capsule.• Cause epiglottitis, meningitis

41. Which of the following virulence factors is generally absent in the stains of the causative organism that produce otitis media, compared with those that produce epiglottitis or meningitis-

1. IgA protease2. Pili3. Pneumolysin4. Polyribitol phosphate-------ans

8. Bacteria utilizes which of the following source for the synthesis of nucleic acid-1. Nitrogen2. Carbon3. Metal and ions4. Phosphate-------------ans

Discussion-

Nucleic acid synthesis Phosphate needed

Protein snthesis Nitrogen needed

Carbon synthesis Used for cellular constituents

Metal ions Needed for enzymatic activity

9. Bacyeriocin production is common in which phase of bacterial growth curve in a closed system-1. Lag phase2. Log phase3. Phase of decline

4. Stationary phase-------------ansDiscussion-

10. V. cholera classical can be differentiated from V.cholera Eltor by all except-1. Haemolysis2. VP test3. Indole test-----------------------------ans4. Chick RBC agglutination tests

Discussion-

Classical ELTor

Polymyxin sensitive Hemolysis +ve

Sensitive to Mukherjee type IV Phage VP +ve

Agglutinate chick RBCs

11. The presence of catalase and superoxide dismutase enzymes in a bacterium indicates that-1. It can grow under aerobic conditions------------ans2. It is an anaerobic organism3. It will not degrade hydrogen peroxide4. Its growth will be inhibited by a lowered oxygen concentration

12. Which of the following statement is false about fimbriae-1. Present on non motile organism also2. More numerous than flagella3. Mannose sensitive fimbriac are non pathogenic4. Not essential for the survival of bacteria in host---------ans(It is essential)

Discussion- (Ananthanarayan P=15). Fimbriae=Pilli. Unrelated to motility.Fimbriae can agglutinate RBC--> Haemagglutination(Inhibited by mannose)-

• Mannose resistant fimbiae- Less nunber, Plasmid mediated, Pathogenic• Mannose sensitive fimbriae- Large number, Chromosomally mediated, Non-pathogenic

13. High concentration of calcium and dipicolinic acid is present in which of the foloowing-1. Cell wall of bacteria2. Capsule 3. Fimbriae4. Spore------------------ans

14. The rationale for giving prophylactic antibiotics at the beginning of a surgical procedure can be thought of as an attempt to prevent the becteria from entering which of the following growth phases-

1. Death phase2. Lag phase

3. Log phase-------------------ans4. Phase of decline

15. Which of the following is high level chemical disinfectant-1. Iodophore2. Phenol3. 3% H2O24. Paracetic acid----------ans

Discussion- Chemical disinfectant-

• High level - Sporicidal, Kill Myc. TB, Fungicidal, Viricidal, Bactericidal. Eg. Glutaraldehyde, Formaldehyde(Sterlisation of wards), 6% H2O2, Na hypochloride, Paracetic acid

• Intermediate level - not sporicidal. Myc. TB may or may not be killed eg. Alcohol, phenol, 3% H2O2, Chlorine releasing compond like 1% bleaching powder

• Mainly bactericidal - eg. Ionophores, Ordinary ammonium compunds

16. Culture method used for antibiotic sensitivity test is-1. Streak culture2. Stroke culture3. Lawn culture-----------ans4. Stab culture

Discussion- Carpet/Lawn culture- Homogenous growth in surface. Amount of growth is required on solid media as for instance in the preparation of bacterial antigens and vaccines.

Streak culture- Isolation of bacteria from clinical specimen

Stab culture- B. anthraxis(Inverted fir tree appearence)

18. A microbiologist wants to develop a vaccine for prevention of attachment of diarrheogenic E.coli to the specific receptors in gastro-intestinal tract. All of the following fimbrial adhesions would be appropriate vaccine candidates except-

1. CFA-12. P1-Pili--------------ans3. CFA-24. K 88

Discussion-

Diarrhoea causing E.Coli CFA(Colony Forming Antigen)--> I, IV, K88, K99

Uropathogenic E.Coli P1-Pilli

19. If transportation is delayed, which clinical specimen is never refrigerated-1. Blood2. CSF----------------------ans3. Peritoneal fluid4. Pericardial fluid

Discussion- Because H. Influenzae is very sensitive to cold. It causes meningitis in 6mth-2yrs of age. Always incubated at 37 degree C.

20. Which of the following is incorrect about Vibrio parahaemolyticus-1. Capsulated, Bipolar staining2. Lactose and sucrose fermentor-------------ans3. Cause invasive diarrhea4. Halophilic

Discussion- Vibrio parahemolyticus-

• Pleomorphic• Take bipolar staining• Unipolar flagella- in liquid medium• Peritrichous flagella--> Solid media• Halophilic• Non lactose and sucrose fermentor• Invasive diarrhoea a/w food poisoning specially sea food

21. Kauffman white scheme of salmonella is based on-1. H & O antigen---------------ans2. Culture characteristic3. Biochemical characteristic4. Clinical picture

Discussion- Kauffman white Grp-D,O-9,H-d => Sal. typhi

22. PLET medium used for isolation of bacillus anthracis consists of-1. Polymyxin, lactose, EDTA & thallous acetate2. Polymyxin, Iysozyme, EDTA & Tetracycline3. Polymyxine, Lactose, EDTA & Tetracycline4. Polymyxin, lysozyme, EDTA & thallous acetate--------ans

24. Which of the following deficiency leads to cell mediated immune deficiency-1. Transcobalamin2. Purine Nucleoside Phosphorylase-----------ans3. Myeloperoxidase4. Tuftsin

Discussion- Transcobalamin deficiency--> deficiency of humoral immune deficiencyDeficiency of 1+3 => disorder of phagocytosis

25. False about M. ulcerans is-1. Cause buruli’s ulcer2. Produce toxin3. Grow at 37 degree C & 25 degree C----------------ans4. Non chromogen

Discussion-

Atypical mycobacteria(Ananthanarayan P= 365):• Photochromogens - Produce no pigment in dark eg. Myc cansasii, Myc. Marinum• Scotochromogens - Produce pigment in light and also dark eg. Myc. scrofulaceum(cause scrofula--> Cerviacal

adenitis in children)• Non-photochromogens - M. Avium; M. Ulcerans--> Only mycobacterium to produce toxin• Rapid-growers - Important cases of abscess after mass vaccination programmes eg. M. fortuitum*, M.

chelonei

26. Which of the following is associated with vascular atheromatous disease-1. Chlamydia trachomatis2. Chlamydia pneumoniae-------------ans3. Chlamydia psittacosis4. Chlamydia serotypes D-K

Discussion- Because it secretes atherogenic factor--> atherogenesis of coronary and cerebral artery.C. pneumoniae-

• Difficult to culture• Resistant to tetracycline--> so macrolides are used• Diagnosed by immunofluorescence test• Only one strain--> TWAR (TaiWan Acute Respiratory)

27. Zoonotic tetrad is required for transmission of which of the following-1. Endemic typhus2. Epidemic typhus3. Scrub typhus--------------------------ans4. Rocky mountain spotted fever

Discussion- Transmitted by Mite larva--> Chigger. Grows only when there is(Zoonotic tetrad)-

1. Transitional vegetation2. Increased humidity3. Co-existance of man and chigger4. Rodents--> Carriers of Mites--> Rickettsia transmitted transovarially to chigger

28. Which species of shigella does not ferment mannitol-1. Sh.flexneri2. Sh.boydii3. Sh.Sonnei4. Sh.dysentery------------------ans

29. In patients of pre-existing cardiac lesions which of the following is the most responsible for bacterial endocarditis-

1. Streptococci mutans2. Streptococci mitis3. Streptococci sanguis--------------ans (P=212)4. Streptococci salivaris

30. A 43 year male presents to you with chronic, symmetric polyarthritis involving the knees. The man gives a history of having developed an extensive rash after a deer hunting trip several years earlier. He recalls that he felt “sick” at that time, and developed knee pain that prevented him from climbing stairs for several months, but then partially resolved.Organism most likely related to the patient’s arthritis is-

1. Fungus2. Gram-negative cocci3. Gram-positive cocci4. Spirochete--------------------ans(MK-I P=567)

Discussion- Lyme's d/e--> transmitted by ticks(deer is resorvoir host)• Stage I- Rash--> called Erythema migrans chronicum (remember Erythema infectiosum---> Parvo-virus)

• Stage II- Arthralgia, Lymphadenopathy, Fever• Stage III- Polyneuropathy, Arthritis and encephalopathy

32. A 22 year woman presents with a 1 week history of mild lower abdominal pain and a yellowish vaginal discharge. Examination reveals a red, swollen cervix without motion and tenderness. The mucosa is friable. KOH mount is negative, and wet mount does not reveal clue cells. Grams stain of the following exudates reveals gram-negative cocci. Which procedure would most likely lead to the correct diagnosis-

1. Culture the blood on Thayer-Martin agar2. Order DNA probe assays of endocervical exudates--------------------ans3. Order serologic tests to identify specific capsular antigens4. Order the germ tube test

Discussion- Ac. Gonorrhoea--> Urethritis, CervicitisSelective medium--> Thyer-Martin agar(also in N.meningitis). Contains vancomycin, Colistin, Nystatin. Specimen--> a sample from vagina(and not a blood sample).

33. A 16 year old high school cheerleader presents with low-grade fever, pleuritic pain and a non-productive cough. Her serum agglutinates Streptococcus salivarius strain MG. Therapy should include which of the following-

1. Ampicillin2. Erythromycin--------------------------ans3. Oxygen and external cooling4. Penicillin G

34. All of the following are mode of transmission of leprosy except-1. Transplacental spread------------ans(not yet documented)2. Insect bite3. Breast milk4. Droplet infection

Discussion- Others have been documented

35. All of the following statements regarding botulism is correct except- 1. Detection of exotoxin in blood in diagnostic-------------------ans2. Honey is associated with infant botulism3. Constipation can occur4. Detection of antitoxin in serum can acid in the diagnosis

Discussion- C.botulinium- Exotoxin 8 types--> acts at NM junction--> blocks Ach--> symptoms of parasympathetic block. It is implicated in-

• Food poisoning--> Canned food• Infant--> Honey• Wound

Diagnosis- Demonstration of toxin in stool specimen either by ELISA or Rapid Agglutination Test. Toxin rarely appear in blood(but in later stages anti-toxin may be found in blood--> helps in retrograde diagnosis.

36. Oroya fever is caused by-1. Bartonella----------ans(P=420)2. Ehrlichia3. Rickettsia4. Orientia

Discussion- also k/a carrison's disease-->Scientist who died. Characteristic lesion--> Verruga peruana.

37. Magnente red pigment produced by-1. Staph aureus2. Serratia--------------ans(psudohemoptysis)3. Pseudomonas4. Acinetobacter

38. XDR TB is mycobacterium tuberculosis that is resistant to-1. INH, Rifampicin & pyrazinamide2. INH, Rifampicin, pyrazinamide, any Fluoroquinolones & streptomycin3. INH, Rifampicin, any Fluoroquinolones 4. INH, Rifampicin, any Fluoroquinolones and kanamycin-------ans

Discussion- MDR--> Resistant to INH+R2nd line(commonly used): FQ, Aminoglycosides, Macrolide dervativesMDR+FQ+Aminoglycoside resistant--> XDRNot option 2 since streptomycin is 1st line drug.

39. Gram negative, nonmotile, lactose ferments, oxidase negative, catalase positive, bacteria was isolated from urine sample most probable diagnosis is-

1. E.coli2. Klebsiella----------------ans3. Shigella4. Citrobacter

Discussion- Enterobacteriacae family--> G-ve bacilli, Cat +ve, Oxidase -ve.McConky agar:

• Lactose fermenter-▪ Motile: E. Coli, Citrobactor▪ Non-motile: Klebsiella

• Non-Lactose fermenter-▪ Motile- Salmonella, Proteus, Serratia▪ Non-motile: Shigella

Pseudomonas- Oxidase +veH. aegypticus- Acute contagious conjunctivitis--> Pink eyeEpisomes--> Plasmid+Chromosome

40. A 16 year old girl presents to you complaining of redness and a yellowish discharge from her left eye for the past 2 days. Upon examination, there is diffuse conjuctival hyperemia associated with a mucoid discharge. Gram’s stain of the exudates shows pleomorphic, gram-negative bacilli. To culture this organism with whole blood agar, which of the following must be used-

1. Cold temperature 2. Egg yolk cholesterol3. Reduced oxygen tension4. Staphylococcus aureus-----------ans

Discussion- Pleomorphic bacteria-

• Proteus• Vib. Parahemolyticus• Haemophilus(P=333)

◦ X and V factors(from lysed RBCs)◦ Staph aureus--> beta hemolytic--> releases X and V factor◦ Satellitism-

42. Which of the following is sexduction-1. F+F-2. F’F- -------------------ans3. HfrF-4. HfrF’

Discussion-

43. Which of the following antigenic variation leads to loss of virulence in salmonella-1. HO variation2. SR variation----------ans(P=293)3. VW variation

4. Phase variation

44. Reverse CAMP test reaction is seen in-1. Cl.tetani2. Cl.botulinum3. Cl.difficile4. Cl.welchii---------------ans

Discussion- CAMP test--> Positive in gp. B streptococcus(S.Agalactiae)

Clostridium perfringens/welchii--> Reverse

45. Filamentous shape virus:1. Calicivirus2. Ebola------------ans3. Adeno4. Tobacco-Mosaic virus

Discussion- Ck all

TMV Rod shaped

Adeno Satellite, Saucer shaped

Calicivirus Cup shaped

Arena Appear as Sand

Rotavirus Appearence of Wheel

Coronavirus Crown

46. Best source of complement is-1. Horse2. Guinea pig-----------ans3. Man4. Dog

47. Staph aureus can be differentiated from staph epidermidis by:1. Phosphate test2. Novobiocin sensitivity test3. Gram stain4. Mannitol fermentation------------ans(P=200)

Discussion- Staph aureus-

• Coagulase +ve• Mannitol fermentation• Gelatin liquification• Tollurite reduced to metallic tollurin• Golden yellow pigment• beta-Hemolysis

48. True about Hapten are all except-1. Incapable of inducing antibody formation2. Do not react with antibody----------------------------------------------------ans3. Become immunogenic when combine with large carrier molecule4. Simple hapten are monovalent

Discussion- Can not induce Ab formation but reacts with it

49. True about carbohydrate antigen is all exept-1. Has low immunogenicity2. Memory response present----------------ans3. Cause polyclonal B cell activation4. T cell independent pathway

Discussion-

Carbohydrate Antigen Protein Antigen

T-Cell independent T-Cell dependent

Mainly B-Cell activation-->Secretes Ig(IgG/IgM) Stimulation of T,B cell--> Secretes Immnoglobulins-->IgG/IgA/Ig/M/IgE/IgD

Non-specific/Irrelevant Immunoglobulins Specific

Memory response absent Present

50. Secondary immune response is characterized by all except-1. Prompt2. Long lag phase---------------------ans(P=75)3. High titre IgG4. Negative phase may occur

51. Contrast agent induced reactions like edema, urticaria, rash and hypotension are mediated due to-1. IgG mediated reaction2. Anaphylactoid reaction-----------ans3. Type-I allergic reaction4. Ig E mediated reaction

Discussison- Anphylactoid--> separate entity--> not type I

Hyper-Sensitivity Reaction

B-Cell Type I--> IgE

Type II--> IgG

Type III--> Ag+Ab

T-Cell Type IV--> T-Cells

52. All are tube agglutination test except-1. Paul Bunnel test2. Widal test3. Well felix reaction4. Kahn test--------------------ans(Tube flocculation--> Used in syphilis)

53. IgM is most potent than IgG is all except-1. Immune hemolysis2. Opsonization3. Bacterial agglutination4. Neutralization of toxin & viruses--------------ans

Discussion- IgG is most potent in neutralisation of toxins and viruses

54. Administration of the transfer factor for treatment of malignant melanoma would stimulate which of the following types of immunity-

1. Artificial active2. Adoptive-----------------------ans3. Artificial passive4. Natural active

Discussion- Immunity:(P=70)

• Innate • Acquired -

▪ Passive- ◦ Natural- IgG(Mother to foetus), IgA◦ Artificial- ATS, Anti Diptheric Serum, Ig

▪ Active-◦ Natural--> Exposure to infection◦ Artificial--> Vaccines

55. Human embryonic lung cell strain is-1. Primary cell culture2. Explant culture3. Continues cell line4. Diploid cell strain-----------ans

Discussion-

Cell Culture

Primary N freshly prepared cells eg. Human amnion cells, Monkey kidney

Diploid Fibroblast, Human embronic lung cell, Rh monkey

Continuous Hela--> CaCx

McCoy--> Ca Synovium

Hep2--> Ca larynx

56. Heat labile toxin of E.coli is expressed in-1. Rabbit small bowel culture

2. CHO(Chinese Hamster Ovary) culture-------------ans3. HELA cell line culture4. VERO cell line culture

Discussion- ETEC-

• Heat labile - Increased adenyl cyclase--> Increases cAMP-->detected by-▪ Cell culture-

• CHO• Mouse adrenal cell line

▪ Rabbit ileal loop test• Heat sensitive - Increased cGMP--> detected by-

◦ ELISA◦ Mouse(Ig)◦ Intra gastric test

Answer is not 1 because 'culture' is written, it is not culture only a test.

57. Grape like clustering of cells on cell culture is characteristic of-1. Measles2. Herpes3. Adeno-----------------ans4. Enterovenous

Discussion- Measles--> syncytial formation(features of paramyxovial virus: also in Mumps, RSV*)Herpes--> Focal degenerationEnterovirus--> Degeneration of entire cell line

58. Reynolds braude phenomenon is-1. Formation of chlamydospores on corn meal agar2. Hypersensitivity reaction to dermatophyte3. Formation of germ tube by C albicans on human serum--------ans4. Inhibition of candida growth by specific antiserum

59. Which of he following is not caused by Cox A virus-1. Herpangina2. Hand foot & mouth disease3. Mycocarditis--------------------ans4. Hemorrhagic conjunctivitis

60. Which of the following enterovirus causes bronchitis and pneumonia-1. Enterovirus 702. COX A virus3. Enterovirus 68--------------ans4. Echo virus

Discussion- Enteroviruses-

Virus Serotypes

Polio 3 Total 67 serotypes. Aseptic meningitis/encephalitis is caused by allCox A 24 Ac. hemorrhagic conjunctivitis

Herpangia

Hand foot mouth d/e

Cox B 6 Myocarditis/Pericarditis

Juveline DM

Bornholm's d/e

Echo 34 Mainly infect CNS

64. Echoviruses are cytopathogenic human virus that mainly infect the-1. Respiratory system2. CNS---------------------------ans3. Blood & lymphatics4. Intestinal tract

61. A 39 year old man presents with complaints of dark urine, and upper abdominal discomfort. On examination, the patient has a temp of 100.2*F and jaundice. LFT results are totally bilirubin 12.4%, SGOT 980 units, SGPT 1200 units anti-hepatitis A IgM negative, HBeAg positive, anti-HbsAb negative, hepatitis C negative. When this patient enters the window period, what would likely be the first change in his serologic findings-

1. He will become HBcAg positive2. He will become HBc IgG positive3. He will become HBsAb positive4. He will become HBsAg negative-------------ans(P=555)

Discussion-

HBsAg Epidemiological Ab

HBeAg Infectivity

Anti-HBcAb Chronicity

Anti-HBsAb Chronicity

Anti-HBeAb Low infectivity

After Hep B Vaccine--> Anti HbsAb is found. • If >10 i.u./ml* of blood--> Protected against Hep B• If < 10 i.u./ml of blood--> repeat the schedule 0,1,6

◦ But If antibody is still not raised--> Such people are called non-responders--> Everytime he has to take immnunoglobulins whenever he comes with infected blood--> It's mandatory

62. All are urease test positive except-1. S.Typhi--------------ans2. Cryptococcus neoformans3. Proteus mirabilis4. Klebsiella

63. Natural reservoir of Nipah virus is-1. Man2. Bat3. Pig-----------ans4. Duck

Discussion- Causes outbreak of diarrhoea(also handravirus)

Nipah virus Pig reservoir Now included in Paramyxovirus

Handra virus Cat reservoir

65. Which of the following is done to differentiate pasteurization & sterilized Milk-1. Methylene blue reduction test2. Eijkman tests3. Phosphatase tests4. Turbidity test---------------ans(P=606)

Discussion- Raw milk is sterlised(all proteins are coagulated)--> 100 degree C--> 5minPhosphatase test--> To Check Pasteurisation. In pasteurisation phosphatase is completely destroyedDegree of contamination of milk--> Methylene blue reduction testEijkaman test--> E.coli found in water

66. True about Rabies is all except-1. Negri bodies most abundant in cerebellum and hippocampus2. Antigen is detected in corneal smear & skin3. Rise in antibody tire in CSF4. Hydrophobiophobia is a characteristic feature--------ans

Discussion- Fear of Hydrophobia/Rabies--> Hydrophobiophobia/Lysaphobia

67. Which of the following antigen can be used as Rabies vaccine-1. Lipoprotein envelop2. Glycoprotein G-----------ans3. Unsegmented RNA4. A+C

Discussion- Rabies attaches to ach receptors on neurons with glycoprotein G.

68. Respiratory suncytial virus (RSV) is differentiated from other paramyxoviruses by all except-1. Absence of hemolysin2. Absence of hemadsorption3. Presence of fusion protein------------ans(Absence)4. Absence of neuraminidase

69. A 9 month infant is brought to the Health Department to receive the second dose of OPV (oral polio vaccine) 2 weeks after the first vaccination. The child has mild diarrhea, so the decision is made to defer further immunizations. Bacteriologic examination of stool culture is unremarkable; however, a small, single-stranded, positive RNA virus is isolated from the specimen. This same agent was isolated from sewage effluent the preceding week. The viral isolate was not inactivated by heat at 56*C for 1 hour. Which of the following viruses was most likely isolated-

1. Rotavirus2. Parvovirus B193. Hepatitis A----------------ans4. Poliovirus

Discussion- 1--> Double stranded2--> DNA

3--> more heat resistant4--> heat labile(both heat and cold) --> hence can-not lyophalise polio (-70 degree C)

70. Hepatitis C virus belongs to which of the following genus-1. Hepatovirus2. HEPES virus3. Hepacivirus------------ans4. Calicivirus

Discussion- Hepatitis E--> Calcivirus

72. True statement about rabies is-1. Rabies vaccine provides life long immunity2. Rabies vaccine is always live attenuated]Rabies has single serotype3. Rabies has single serotype4. Rabies can be diagnosed by immunoflurescence test------------------ans

Discussion- Antemortem--> Skin, Cornea, Saliva

73. An AIDS patient complains of headaches and disorientation. A clinical diagnosis of toxoplasma encephalitis is made and toxoplasma cysts are observed in the brain section. Which of the following antibody results would be most likely in this patients-

1. IgM nonreactive,IgG nonreactive2. IgM nonreactive,IgG reactive(low titre)3. IgM reactive(low titre),IgG reactive(high titre)---------ans4. IgM reactive(high titre),IgG reactive(high titre)

Discussion- Toxoplasma-

• Pseudocyst- Found early in infection--> Tachyzoites• Tissue cyst(found late)-

▪ Sporozoites--> multiply slow--> Bradyzoides▪ CNS and Muscles

74. The presumptive coliform count is 3 and E.coli count is 0, what would be the quality of water-1. Excellent2. Un satisfactory3. Satisfactory-----------ans4. Suspicious

Discussion-

Coliform count E. coli count

Excellant 0 0

Satisfactory* 1-->3 0

Suspician 4-->10 0

Unsatisfactory >10 0,1 or more

75. R. Seeberi is a-1. Bacteria2. Dermatophyte3. Protozoa---------ans(Rhinosporidium seeberri--> Now reclassified as protozoa)4. Yeast

76. Niger seed Agar is used for-1. T.gondii2. C.neoformans--------------ans

3. Acanthamoeba4. P.Jerovecii

77. Culture from corneal ulcer shows septate hyphae. Most likely organism is-1. Aspergillus-----------------ans(P=227 ROAMS)2. candida3. Toxoplasmosis4. Trachoma

Discussion- After aspergillus--> Fusarium

78. All are involve in ectothrix infection except-1. T.mentagrophytes2. M.canis3. M.audouinii4. T.tonsurans-------------ans

Discussion- Ectothrix

• Trichophyton rubrum• Microsporum audomini• Microsporum canis

Endothrix-• T. tonsurans• T. violaceum

Favus--> a type of endothrix but has air-pockets

Dermatophytes-• Geophilic- Myc. Glypsium• Zoophilic-

▪ M. canis▪ T. verrucosum

• Anthrophilic-▪ T. meni(ck)▪ M. audomini▪ E. floccosum

79. Which of the following is a zoophilic dermatophyte-1. M.gypseum2. T.verrucosum----------ans3. T.rubrum4. E.Floccosum

80. A Brazilian immigrant is hired at a meat-packing plant, and undergoes a physical examination. Chest x-ray demonstrates a patchy, bilateral pneumonia and a lung mass, and he is referred to a specialist. Biopsy of mass demonstrates fungal organisms with a few very distinctive “pilot’s wheel” yeast forms. Which of the following is the most likely diagnosis-

1. Blastomycosis2. Coccidioidomycosis3. Histoplasmosis4. Paracoccidioidomycosis------------ans

Discussion- Yeast cell with multiple buds--> pilots wheel appearence--> 4Coccidiomycosis--> 1 bud only

81. The formation of granulomas is seen in major systemic fungal infections. Which of the following groups of

fungi is most likely to cause granulomas1. Aspergillums, Coccidioides, Cryptococcus2. Epidermophyton, Blastomyces, Trichophyton3. Cladosporium, Aspergillus, Microsporum4. Coccidioides, Blastomyces, Histoplasma-----------and

82. Which of the following best describes an infection with Coccidioides immitis-1. A negative complement – fixing (CF) antibody test2. Clavate macroconidia3. “Fungus ball” formation4. Inhaled arthrospores form thick- walled spherules filled with endospores----ans

94. True about Widal test is all except-1. O agglutination forms compact granular clumps2. Fimbrial antigen gives false +ve reaction3. Anamnestic reaction seen in immuno compromised patient--------ans4. Rising O antibody indicated recent infection

Discussion- Seen in person who has previous exposure of typhoidH- Highly immunogenicO- Rises early--> recent infection

98. As per NACO guidelines, all the drugs are used for post exposure prophylaxis of HIV infection except-1. Zidovudine2. Lamivudine3. Nevirapine---------ans4. Indinavir

Discussion- Used in prevention of transmission from mother to child

100. All are true about free coagulase except-1. Require CRF for its action2. Heat labile3. Detected by slide agglutination test-----------ans4. Secreted into the medium

Discussion- Staph-

• Bound coagulase• Free coagulase--> detected by tube agglutination test

89. The air bacterial count permitted in surgical operation theater is-1. 1/cub ft2. 10/cub ft-------------ans3. 20 /cub ft4. 50/cub ft

Discussion- Special Sx--> NSx, Transplants--> not more than 1Offices not more than 50