E Coli NNS Neonatal septicemia Acute cystitis and

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E Coli NNS Neonatal septicemia Acute cystitis and Powered By Docstoc
					•   E-strip method (antibiotic gradient diffusion) is used for--> Minimum inhibitory concentration for antibiotic

E.Coli                   1. NNS(Neonatal septicemia)
                         2. Acute cystitis and pyelonephritis
                         3. 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 shock
                         7. 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: -ve
        o Listeria: +ve
•   H influenzae: G -ve and pleomorphic
•   Potential agents for biological terrorism-
        o Anthrax
        o Plague
        o Smallpox
        o 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 12
    2. 2.56 x 10 to power 5
    3. 6.4 x 10 to power 4----ans(key)
    4. 3.2 x 10 to power 4
40 min(lag phase)--> 4x10 to the power 3
60(1st generation time)--> 8x10 to the power 3
80(2nd generation time)--> 16x10 to the power 3
100(3rd generation time)--> 32x10 to the power 3
120(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.

• 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 test
    2. Catalase test-------------------ans
    3. Coagulase test
    4. PCR
Discussion- Group B streptococci do not produce catalase while Listeria are catalase +ve

1. Biological indicator for Ethylene oxide is-
    1. B.Strearothermophilus
    2. B.subtilis globogi---------------ans
    3. B.subtilis niger
    4. Serratia marsecences
Discussion- Others-
    • Bacillus subtilis niger--> Hot air owen
    • B.Strearothermophilus--> Autoclaving
    • Serratia 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.-------------------ans
    4. 134 C for 3 min.

                          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 waste
    2. Animal waste
    3. Soiled waste-------------------ans(Park-648)
    4. Liquid waste
    1. Human anatomical waste
    2. Animal waste
    3. Microbioogy and Biotechnology waste
    4. Sharps
    5. Cyto-toxic drugs
    6. Soiled waste
    7. Solid waste
    8. Liquid waste
    9. Incineration ash
    10. 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%      Sharps-->Mutiltion, Secured landfill
Black bag       5,9,10(Solid)       Used for general waste       Secured landfill

4. Sugar and gelatin containing media are sterilized by-
    1. Autoclaving
    2. Hot air oven
    3. Tyndallization------------ans
    4. 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 machine
Sharps--> Hot air owen(not autoclave--> will lose sharpness)
Plastics--> Sterlised by radiation

6. Amikacin inhibit the bacteria growth by-
    1. Inhibit 30s ribososme--------ans
    2. Inhibit 50s ribososme
    3. Inactivate DNA dependant RNA polymerase
    4. Inhibit DNA gyrase
Discussion- Aminoglycoside(ROAMS P=270)

7. Polypeptide capsule seen in-
    1. Pneumococci
    2. Streptococci
    3. B.anthracis----------ans
    4. 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
     • 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 protease
    2. Pili
    3. Pneumolysin
    4. Polyribitol phosphate-------ans

8. Bacteria utilizes which of the following source for the synthesis of nucleic acid-
    1. Nitrogen
    2. Carbon
    3. Metal and ions
    4. Phosphate-------------ans

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 phase
    2. Log phase
    3. Phase of decline
    4. Stationary phase-------------ans

10. V. cholera classical can be differentiated from V.cholera Eltor by all except-
    1. Haemolysis
    2. VP test
    3. Indole test-----------------------------ans
    4. Chick RBC agglutination tests

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------------ans
    2. It is an anaerobic organism
    3. It will not degrade hydrogen peroxide
    4. 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 also
    2. More numerous than flagella
    3. Mannose sensitive fimbriac are non pathogenic
    4. 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 bacteria
    2. Capsule
    3. Fimbriae
    4. 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 phase
    2. Lag phase
    3. Log phase-------------------ans
    4. Phase of decline

15. Which of the following is high level chemical disinfectant-
    1. Iodophore
    2. Phenol
    3. 3% H2O2
    4. Paracetic acid----------ans
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 culture
     2. Stroke culture
     3. Lawn culture-----------ans
     4. Stab culture
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-1
    2. P1-Pili--------------ans
    3. CFA-2
    4. K 88
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. Blood
     2. CSF----------------------ans
     3. Peritoneal fluid
     4. 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 staining
    2. Lactose and sucrose fermentor-------------ans
    3. Cause invasive diarrhea
    4. Halophilic
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---------------ans
    2. Culture characteristic
    3. Biochemical characteristic
    4. 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 acetate
    2. Polymyxin, Iysozyme, EDTA & Tetracycline
    3. Polymyxine, Lactose, EDTA & Tetracycline
    4. Polymyxin, lysozyme, EDTA & thallous acetate--------ans

24. Which of the following deficiency leads to cell mediated immune deficiency-
    1. Transcobalamin
    2. Purine Nucleoside Phosphorylase-----------ans
    3. Myeloperoxidase
    4. Tuftsin
Transcobalamin deficiency--> deficiency of humoral immune deficiency
Deficiency of 1+3 => disorder of phagocytosis

25. False about M. ulcerans is-
    1. Cause buruli’s ulcer
    2. Produce toxin
    3. Grow at 37 degree C & 25 degree C----------------ans
    4. Non chromogen
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.

26. Which of the following is associated with vascular atheromatous disease-
    1. Chlamydia trachomatis
    2. Chlamydia pneumoniae-------------ans
    3. Chlamydia psittacosis
    4. 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 typhus
    2. Epidemic typhus
    3. Scrub typhus--------------------------ans
    4. Rocky mountain spotted fever
Discussion- Transmitted by Mite larva--> Chigger.
Grows only when there is(Zoonotic tetrad)-
    1. Transitional vegetation
    2. Increased humidity
    3. Co-existance of man and chigger
    4. Rodents--> Carriers of Mites--> Rickettsia transmitted transovarially to chigger

28. Which species of shigella does not ferment mannitol-
    1. Sh.flexneri
    2. Sh.boydii
    3. Sh.Sonnei
    4. Sh.dysentery------------------ans

29. In patients of pre-existing cardiac lesions which of the following is the most responsible for bacterial
     1. Streptococci mutans
     2. Streptococci mitis
     3. 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. Fungus
        2. Gram-negative cocci
        3. Gram-positive cocci
        4. 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 agar
     2. Order DNA probe assays of endocervical exudates--------------------ans
     3. Order serologic tests to identify specific capsular antigens
     4. Order the germ tube test
Discussion- Ac. Gonorrhoea--> Urethritis, Cervicitis
Selective 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
     1. Ampicillin
     2. Erythromycin--------------------------ans
     3. Oxygen and external cooling
     4. Penicillin G

34. All of the following are mode of transmission of leprosy except-
    1. Transplacental spread------------ans(not yet documented)
    2. Insect bite
    3. Breast milk
    4. 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-------------------ans
    2. Honey is associated with infant botulism
    3. Constipation can occur
    4. 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. Ehrlichia
    3. Rickettsia
    4. Orientia
Discussion- also k/a carrison's disease-->Scientist who died. Characteristic lesion--> Verruga peruana.

37. Magnente red pigment produced by-
    1. Staph aureus
    2. Serratia--------------ans(psudohemoptysis)
    3. Pseudomonas
    4. Acinetobacter
38. XDR TB is mycobacterium tuberculosis that is resistant to-
     1. INH, Rifampicin & pyrazinamide
     2. INH, Rifampicin, pyrazinamide, any Fluoroquinolones & streptomycin
     3. INH, Rifampicin, any Fluoroquinolones
     4. INH, Rifampicin, any Fluoroquinolones and kanamycin-------ans
MDR--> Resistant to INH+R
2nd line(commonly used): FQ, Aminoglycosides, Macrolide dervatives
MDR+FQ+Aminoglycoside resistant--> XDR
Not 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.coli
     2. Klebsiella----------------ans
     3. Shigella
     4. 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 +ve
 H. aegypticus- Acute contagious conjunctivitis--> Pink eye
 Episomes--> 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 cholesterol
    3. Reduced oxygen tension
    4. Staphylococcus aureus-----------ans
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- -------------------ans
    3. HfrF-
    4. HfrF’

43. Which of the following antigenic variation leads to loss of virulence in salmonella-
    1. HO variation
    2. SR variation----------ans(P=293)
    3. VW variation
    4. Phase variation

44. Reverse CAMP test reaction is seen in-
    1. Cl.tetani
    2. Cl.botulinum
    3. Cl.difficile
    4. Cl.welchii---------------ans
CAMP test--> Positive in gp. B streptococcus(S.Agalactiae)

Clostridium perfringens/welchii--> Reverse

45. Filamentous shape virus:
    1. Calicivirus
    2. Ebola------------ans
    3. Adeno
    4. 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. Horse
    2. Guinea pig-----------ans
    3. Man
    4. Dog

47. Staph aureus can be differentiated from staph epidermidis by:
    1. Phosphate test
    2. Novobiocin sensitivity test
    3. Gram stain
    4. Mannitol fermentation------------ans(P=200)
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 formation
    2. Do not react with antibody----------------------------------------------------ans
    3. Become immunogenic when combine with large carrier molecule
    4. 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 immunogenicity
    2. Memory response present----------------ans
    3. Cause polyclonal B cell activation
    4. T cell independent pathway

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--
Non-specific/Irrelevant Immunoglobulins                       Specific
Memory response absent                                        Present

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

51. Contrast agent induced reactions like edema, urticaria, rash and hypotension are mediated due to-
    1. IgG mediated reaction
    2. Anaphylactoid reaction-----------ans
    3. Type-I allergic reaction
    4. 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 test
    2. Widal test
    3. Well felix reaction
    4. Kahn test--------------------ans(Tube flocculation--> Used in syphilis)

53. IgM is most potent than IgG is all except-
     1. Immune hemolysis
     2. Opsonization
     3. Bacterial agglutination
     4. 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 active
     2. Adoptive-----------------------ans
     3. Artificial passive
     4. Natural active
     • 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 culture
    2. Explant culture
    3. Continues cell line
    4. Diploid cell strain-----------ans

                    Primary         N freshly prepared cells eg. Human amnion cells, Monkey kidney
                    Diploid         Fibroblast, Human embronic lung cell, Rh monkey
Cell Culture
                    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-------------ans
    3. HELA cell line culture
    4. VERO cell line culture
    • 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. Measles
    2. Herpes
    3. Adeno-----------------ans
    4. Enterovenous
Measles--> syncytial formation(features of paramyxovial virus: also in Mumps, RSV*)
Herpes--> Focal degeneration
Enterovirus--> Degeneration of entire cell line

58. Reynolds braude phenomenon is-
    1. Formation of chlamydospores on corn meal agar
    2. Hypersensitivity reaction to dermatophyte
    3. Formation of germ tube by C albicans on human serum--------ans
    4. Inhibition of candida growth by specific antiserum

59. Which of he following is not caused by Cox A virus-
    1. Herpangina
    2. Hand foot & mouth disease
    3. Mycocarditis--------------------ans
    4. Hemorrhagic conjunctivitis

60. Which of the following enterovirus causes bronchitis and pneumonia-
    1. Enterovirus 70
    2. COX A virus
    3. Enterovirus 68--------------ans
    4. Echo virus
 Virus     Serotypes
Polio     3                                                     Total 67 serotypes. Aseptic
                                                                meningitis/encephalitis is caused by all
Cox A     24            Ac. hemorrhagic conjunctivitis
                        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 system
    2. CNS---------------------------ans
    3. Blood & lymphatics
    4. 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
    1. He will become HBcAg positive
    2. He will become HBc IgG positive
    3. He will become HBsAb positive
    4. He will become HBsAg negative-------------ans(P=555)

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--------------ans
    2. Cryptococcus neoformans
    3. Proteus mirabilis
    4. Klebsiella
63. Natural reservoir of Nipah virus is-
    1. Man
    2. Bat
    3. Pig-----------ans
    4. 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 test
    2. Eijkman tests
    3. Phosphatase tests
    4. Turbidity test---------------ans(P=606)
Raw milk is sterlised(all proteins are coagulated)--> 100 degree C--> 5min
Phosphatase test--> To Check Pasteurisation. In pasteurisation phosphatase is completely destroyed
Degree of contamination of milk--> Methylene blue reduction test
Eijkaman test--> E.coli found in water

66. True about Rabies is all except-
    1. Negri bodies most abundant in cerebellum and hippocampus
    2. Antigen is detected in corneal smear & skin
    3. Rise in antibody tire in CSF
    4. Hydrophobiophobia is a characteristic feature--------ans
Fear of Hydrophobia/Rabies--> Hydrophobiophobia/Lysaphobia

67. Which of the following antigen can be used as Rabies vaccine-
    1. Lipoprotein envelop
    2. Glycoprotein G-----------ans
    3. Unsegmented RNA
    4. 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 hemolysin
    2. Absence of hemadsorption
    3. 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. Rotavirus
    2. Parvovirus B19
    3. Hepatitis A----------------ans
    4. Poliovirus
1--> Double stranded
2--> DNA
3--> more heat resistant
4--> 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. Hepatovirus
    2. HEPES virus
    3. Hepacivirus------------ans
    4. Calicivirus
Discussion- Hepatitis E--> Calcivirus

72. True statement about rabies is-
    1. Rabies vaccine provides life long immunity
    2. Rabies vaccine is always live attenuated]Rabies has single serotype
    3. Rabies has single serotype
    4. 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 nonreactive
    2. IgM nonreactive,IgG reactive(low titre)
    3. IgM reactive(low titre),IgG reactive(high titre)---------ans
    4. IgM reactive(high titre),IgG reactive(high titre)
    • 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. Excellent
    2. Un satisfactory
    3. Satisfactory-----------ans
    4. Suspicious

                                        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. Bacteria
    2. Dermatophyte
    3. Protozoa---------ans(Rhinosporidium seeberri--> Now reclassified as protozoa)
    4. Yeast

76. Niger seed Agar is used for-
    1. T.gondii
    2. C.neoformans--------------ans
    3. Acanthamoeba
    4. P.Jerovecii

77. Culture from corneal ulcer shows septate hyphae. Most likely organism is-
    1. Aspergillus-----------------ans(P=227 ROAMS)
    2. candida
    3. Toxoplasmosis
    4. Trachoma
Discussion- After aspergillus--> Fusarium

78. All are involve in ectothrix infection except-
    1. T.mentagrophytes
    2. M.canis
    3. M.audouinii
    4. T.tonsurans-------------ans
    • Trichophyton rubrum
    • Microsporum audomini
    • Microsporum canis
    • T. tonsurans
    • T. violaceum

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

   • 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.gypseum
    2. T.verrucosum----------ans
    3. T.rubrum
    4. 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. Blastomycosis
     2. Coccidioidomycosis
     3. Histoplasmosis
     4. Paracoccidioidomycosis------------ans
Discussion- Yeast cell with multiple buds--> pilots wheel appearence--> 4
Coccidiomycosis--> 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 granulomas
    1. Aspergillums, Coccidioides, Cryptococcus
    2. Epidermophyton, Blastomyces, Trichophyton
    3. Cladosporium, Aspergillus, Microsporum
    4. Coccidioides, Blastomyces, Histoplasma-----------and

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

94. True about Widal test is all except-
    1. O agglutination forms compact granular clumps
    2. Fimbrial antigen gives false +ve reaction
    3. Anamnestic reaction seen in immuno compromised patient--------ans
    4. Rising O antibody indicated recent infection
Discussion- Seen in person who has previous exposure of typhoid
H- Highly immunogenic
O- Rises early--> recent infection

98. As per NACO guidelines, all the drugs are used for post exposure prophylaxis of HIV infection except-
    1. Zidovudine
    2. Lamivudine
    3. Nevirapine---------ans
    4. Indinavir
Discussion- Used in prevention of transmission from mother to child

100. All are true about free coagulase except-
    1. Require CRF for its action
    2. Heat labile
    3. Detected by slide agglutination test-----------ans
    4. Secreted into the medium
    • Bound coagulase
    • Free coagulase--> detected by tube agglutination test

89. The air bacterial count permitted in surgical operation theater is-
    1. 1/cub ft
    2. 10/cub ft-------------ans
    3. 20 /cub ft
    4. 50/cub ft
Special Sx--> NSx, Transplants--> not more than 1
Offices not more than 50

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