Medical Micro-Apmc Questions

MICROBIOLOGY 1. Which is true about the bacterial cell? A. Prokaryotic, unicellular B. Gram positive bacteria have outer membrane C. Gram negative bacteria have thicker cell wall than gram positive bacteria D. Eukaryotic, muliticellular Answer: A 2. Which structure is found in gram-negative bacteria but not in gram positive bacteria? A. outer membrane C. nucleoid B. peptidoglycan D. plasma membrane Answer: A 3. True about transfer of genes from one bacterium to another. A. Gram negative bacteria that have sex pill transfer plasmids by conjugation B. Free DNA fragments are transferred by transformation C. Bacteriophages are involved in transduction D. Involves participation of flagella Answer: A 4. Which of the following bacteria is gram negative A. Staphylococcus C. Corynebacterium B. Vibrio D. Lactobacillus Answer: B 5. True about obligate anaerobes A. Use sugars by oxidative pathway B. Infections are limited to muscle tissues C. Lack superoxide dismutase D. Can use oxygen in small amounts Answer: C 6. Which structure is associated with virulence of a bacterium A. Cell wall C. Flagella B. Lipopolysaccharide D. Endospores Answer: B 7. This mechanism of gene transfer is characterized by the requirement for cell-tocell contact A. Conjugation C. Transformation B. Transduction D. Transfection Answer: A 8. Action of lysozyme

A. Involved in the formation of peptide bond between two peptidoglycan subunits B. Hydrolyzes peptidoglycan by cleaving the glycosyl bonds between N-acetylmuramic acid and N-acetyl glucosamine C. An enxyme that dissolves the peptidoglycan layer D. Located in the periplasmic space and is involved in the hydrolysis of foreign DNA Answer: B 9. True about gram negative bacteria A. Have simpler but thicker cell wall than gram positive bacteria B. Has an outer membrane located outside the peptidoglycan layer C. Contains teichoic acid polymers dispersed throughout the peptidoglycan D. Removal of the cell wall results in the formation of protoplasis Answer: B 10. This type of antibiotic should be used with caution because of renal and ototoxicity. A. Penicillins C. Aminoglycosides B. Macrolides D. Tetracycyclines Answer: C 11. Lack/s the ability to develop catalase and superoxide dismutase: A. Obligate aerobes C. Facultative anaerobes B. Obligate anaerobes D. Aerotolerant anaerobes Answer: B 12. Which bacterial structures is not essential for growth but may confer survival advantage under certain conditions? A. Cell wall C. Endospore B. Outer membrane D. Flagella Answer: D 13. Serves as an anchor to bind and pull apart daughter chromosomes during cell division A. Pill C. Flagella B. Mesosome D. Outer membrane Answer: B 14. Responsible for the endotoxin activity of lipopolysaccharide A. Somatic O polysaccharide C. Lipid A

B. Core polysaccharide D. protein A Answer: C

A. Chromomycosis Lobomycosis B. Mycetoma Sporotrichosis Answer: B

15. Use organic compounds as carbon source and chemical reactions as energy source A. Chemolithotrophs C. photoorganotrophs B. Chemoorganotrophs D. photolithotrophs Answer: B

C. D.

23. Cave explorers who develop pneumonia following such explorations are likely to have acquired A. Blastomycosis C. Histoplasmosis B. Candidiasis D. Cryptococcosis Answer: C

16. A mutant bacterium lacks the ability to produce the amino acid leucine and grows only in a culture medium containing leucine. This bacterium was exposed to a preparation of DNA from Pseudomonas aeruginosa and was able to grow in a medium without leucine. What mechanism or event may have taken place? A. Transduction C. Conjugation B. Transformation D. Chromosomal mutation Answer: B

24. A diver in a deep stagnant water develops polypoid masses in his nostrils. He is likely to have acquired A. Chromomycosis C. Lobomycosis B. Rhinosporidiosis D. Sporotrichosis Answer: B 25. A farmer developed verrucous and warty lesions on his legs. Upon examination of sample of skin crusting by KOH preparation, dark colored sclerotic bodies were seen. The most likely diagnosis is A. Chromomycosis B. mycetoma C. lobomycosis D. sporotrichosis Answer: A

17. Normally sterile site in the body A. Mouth C. Vagina B. Anus D. CSF Answer: D 18. A strain of Streptococcus pyogenes is able to produce pyrogenic exotoxin encoded by a prophage is an example of: A. Transposition C. Conjugation B. Lysogeny D. Chromosomal mutation Answer: B

26. A gardener developed multiple subcutaneous nodules on his forearm. A biopsy material did not show any fungus on direct microscopic examination. However, in culture, white, pasty and moist colonies were seen. Wet mount using lactophenol cotton blue of the culture showed the presence of very fine hyphae and tear-dropshaped conidia. A. The probable organism will form yeast cells when grown in brain heart infusion blood agar at 37 C B. The culture above showed the tissue form of the fungus C. The infection was most likely acquired from diving in deep stagnant water D. The causative fungus easily disseminates to other tissues Answer: A

19. Calcium dipicalinate is found in: A. Aspergillus C. Escherichia B. Bacillus D. Mycobacteria Answer: B 20. Antimicrobial which exert its action through inhibition of cell wall synthesis. A. Aminoglycoside C. Penicillin B. Tetracycline D. Rifampicin Answer: C 21. The diagnosis of a primary infection requires that a 4-fold increase in titer of this antibody be demonstrated A. IgG C. IgD B. IgM D. IgA Answer: A

27. The presence of multiple budding cells in chain in a biopsy specimen obtained from subcutaneous nodules in the legs is suggestive of A. Paracoccidioidomycosis C.lobomycosis

22. The presence of granules in discharge from draining sinus tracts is indicative of 2

B. Blastomycosis sporotrichosis Answer: C

D.

33. Which of the following is true about Rickettsiae A. All are transmitted by arthropods B. All infections are characterized by skin rashes C. All are obligate intracellular parasites D. All survive the environment by producing endospores Answer: C

28. The tissue form of Histoplasma capsulatum is seen as A. Intracellular yeast in macrophages C. multiple budding cells B. Spherules D. encapsulated yeast Answer: A 29. The infection caused by this fungus is initiated by inhalation of arthroconidia, which are found in semi-arid regions A. C. neoformans C. B. dermatitidis B. C. immitis D. H. capsulatum Answer: B

34. A 16-year old salesgirl present to the physician with the chief complaints of headache, vomiting, neck stiffness, highgrade fever, photophobia and petechial rashes. P.E. reveals an ill-appearing child unable to flex his neck without eliciting pain and diffuse petechial rashes in his extremities. Kernig and Brudzinski signs are positive. CSF analysis reveals increased neutrophils, increased protein and low glucose. What is the most probable causative agent A. Listeria monocytogenes C. Neisseria meningitidis B. Escherichia coli D. Reovirus Answer: C

30. In histoplasmosis, the causative organism identified based on the presence of A. tuberculate macroconidia in culture at room temperature B. encapsulated yeast by India ink preparation C. mucoid colonies on Sabouraud’s agar D. single budding yeast cells in infected tissue Answer: A

35. Which is the best method of diagnosis of typhoid fever? A. Widal test C. blood culture B. Typhi dot D. stool culture Answer: C

31. Which of the following is true about the members of the family Enterobacteriaceae? A. Salmonella serotype typhi is transmitted by human carriers as well as by animals B. Shigella dysenteriae toxin kills cells by activating adenyl cylcase C. Escherichia coli usually produces intestinal disease only when it carries a plasmid or a phage that code for virulence factors D. Proteus mirabilis is an important cause of gastroenteritis Answer: C

36. Which is the most common cause of nongonococcal urethritis? A. C. trachomatis C. U. urealyticum B. M. pneumoniae D. S. aureus Answer: A 37. Resistance to tuberculosis is mediated by A. Cell-mediated immunity C. interferon B. Humoral immunity D. NK cells Answer: A

32. True about opportunistic members of the family Enterobacteriaceae A. They are nonpathogenic in the intestinal tract B. Infections are produced in and out of the intestines C. They are the most abundant flora of the colon D. They are not known to cause septicemia Answer: A

38. Which of the following is LEAST likely about Escherichia coli? A. Pathogenicity in the GIT is associated with the presence of a plasmid B. Strains producing K1 antigen are associated with neonatal meningitis 3

C. Enterotoxigenic strains produce diarrhea by invasion of the intestinal mucosa D. Serotype O157:H7 is associated with hemolytic uremic syndrome Answer: C

43. A 20-year-old woman presents with sudden onset of fever of 40 C, severe headache and generalized petechial rash. Physical examination reveals nuchal rigidity. Meningococcemia is suspected and is confirmed by a culture CSF. She has a history of several serious infections with the causative organism. Which one of the following is the MOST likely predisposing factor? A. She is HIV antibody-positive B. She is deficient in CD8-positive cells C. She is deficient in one of the lateacting complement components D. She is deficient in antigen-presenting cells Answer: C

39. Which of the following characterize Salmonella typhi? A. Infects man and animals B. Non-invasive C. The organism is a non-lactose fermenting, nonmotile bacillus D. Chronic carriers harbor the organism in the gallbladder Answer: D 40. One of the following produces a toxin that inhibits protein synthesis by ADPribosylation of EF-2 A. S. dysenteriae C. C. diphtheriae B. S. pyogenes D. M. tuberculosis Answer: C

44. This test will differentiate staphylococcus from streptococcus A. coagulase C. oxidase B. catalase D. sugar fermentation Answer: B

41. Which of the following produces a mononucleosis-like disease A. Orientia tsutsugamushi C. Ehrlichia chafeensis B. Rickettsia prowazeki D. Coxiella burnetii Answer: C

45. Laboratory procedure of choice for primary syphilis. A. darkfield microscopy C. MHA TP B. RPR D. VDRL Answer: A 46. Infective particle of chlamydia A. Elementary body endospore B. Reticulate body fission body Answer: A

42. A 63-year old man has been hospitalized for the previous 21 days for the management of newly diagnosed leukemia. During the period of hospitalization, the patient developed a urinary tract infection with Escherichia coli and was treated for 14 days with broad-spectrum antibiotics. On the 21st hospital day, the patient developed fever and shaking chills. Within 24 hours, the patient became hypotensive, and ecthymic skin lesions appeared. Despite aggressive therapy with antibiotics, the patient expired. Multiple blood cultures were positive for gram negative bacilli that showed negative results in most biochemical tests and failed to ferment sugars. Which of the following is the MOST likely causative agent? A. E. coli B. K. pneumoniae C. L. pneumophila aeruginosa Answer: D

D.

C. D.

47. The toxin of V. cholerae is antigenically similar to A. shiga toxin C. ST of E. coli B. LT of E. coli D. enterotoxin of shigella Answer: B 48.

P.

Responsible for the virulence of M. tuberculosis A. exotoxin C. mycolic acid B. trehalose 6,6 dimyculate D. endotoxin Answer: B

49. A 5-year-old girl was brought by her mother in the E.R. due to high grade fever. The patient also complained of dysphagia and sore throat. On physical exam, the throat was erythematous 4

throat with white, leathery membrane on both tonsillar pillars. Culture and sensitivity was done to the patient. Corynebacterium dipthteriae was isolated.

is the most sensitive technique that you will request in the laboratory? A. complement fixation B. ELISA C. countercurrent immunoelectrophoresis D. indirect immunoflorescence Answer: B

This organism produces dipthteria toxin. This toxin A. is a neurotoxin B. inhibits protein synthesis C. induce cAMP production D. heat stable Answer: B

55. The biologic properties of Ig is a function of A. Fc fragment C. Hinge region B. Fab fragment D. Disulfide bonds Answer: A

50. Purpose/s of giving Penicillin in cases of tetanus infection is/are: A. inhibit the growth of C. tetani B. neutralize unbound toxin C. relax the muscle D. to sterilize the necrotic tissue Answer: A

56. High levels in fetus with intrauterine infection: A. IgG B. IgM C. IgE D. IgD Answer: B

51. A high titer of this in the serum indicates acute or recent infection A. IgG B. IgM C. IgD D. IgA Answer: B

57. Predominant antibody in tears A. IgG B. IgM C. IgA D. IgE Answer: C

52. A patient had a viral infection that started to manifest 7 days ago. Laboratory test showed that the patient’s antibodies against this virus have a high ratio of IgM to IgG. What is your conclusion? A. It’s likely that the patient has been exposed to the virus for the first time B. It’s likely that the patient has an autoimmune disease C. The patient is predisposed to type 1 hypersensitivity reactions D. The patient developed an anamnestic response to the virus Answer: A

58.

Predominant antibody in immune response A. IgG B. IgM C. IgA D. IgE Answer: A

secondary

59. The coating of bacteria by antibody leading to engulfment by phagocytes is known as A. ADCC C. anamnestic response B. opsonization D. hybridization Answer: B

53. A patient is suspected of having diphtheria. The bacterium was isolated but you want to test if it produces an exotoxin. An agar plate, in which a filter paper containing specific amtitoxin is embedded, was streaked with the bacterial isolate perpendicular to the filter paper. A precipitin line was formed between the antitoxin and the isolate. Which technique was used? A. double immunodiffusion B. single radial immunodiffusion C. immunoelectrophoresis D. immunoblot Answer: A

60. This function of the T cells plays a central role in both humoral and CMI. A. effector function C. regulatory function B. anaphylaxis D. atopy Answer: C 61. Which is true about the complement? A. All of the complement components are produced by the liver B. Always in an active state under normal conditions. C. Activated via a cascade mechanism. D. Alternative pathway is part of the Adaptive Immunity Answer: C

54. You want to determine whether your patient is infected with a deadly virus, HIV. Which 5

62. Dengue hemorrahgic fever is an example of: A. Anaphylactic C. Immune complex B. Cytotoxic D. Delayed Answer: C

70. A patient who partially recover from paralytic Poliomyelitis experiences a new onset of muscular weakness, pain and muscular atrophy, 25-35 years after the acute illness. Which is condition is described? A. Aseptic Poliomyelitis C. Paralytic Polio B. Post-poliomyelitis Syndrome D. Nonparalytic Polio Answer: B

63. What method will you use to detect antigen directly in tissue? A. ELISA C. Immunoflourescence B. ImmunoelectrophoresisD. Hemagglutination Answer: C 64.

71. The most antigenically unstable influenza type A. type A C. type C B. type B D. all Answer: A

Protective antibody in viral infections localized in the respiratory tract A. IgG B. IgM C. IgA D. IgE Answer: C

72.

65. Which is the most potent anaphylatoxin: A. C5a B. C5b C. C4a D. C3a Answer: A

Which denotes infectivity and HBV replication A. Hbe Ag B. HBs Ah C. Anti HBe Answer: A

66. The Fc region of an immunoglobulin is involved in A. binding with antigen B. binding with complement C. interaction with class I MHC of T cells D. all of the above Answer: B

73.

67. A 3-year-old boy is having recurrent infections particularly by encapsulated bacteria. You suspect that he is immunodeficient particularly a low level of IgA. The most appropriate test to determine this is A. single radial immunodiffusion B. ELISA C. Immunoflourescnce D. complement fixation test Answer: A

D. Anti HBs

Which is NOT a member of family Herpesviridae a. herpes simplex virus C. chickenpox virus b. cytomegalovirus D. variola virus Answer: D

74. Which is true about Hepadnaviridae? A. has RNA genome B. carries reverse transcriptase C. has infectious genome D. dependent on delta hapatitis virus for replication Answer: D 75. A neutralization test was done in a patient who is suspected to be suffering from a viral infection characterized by fever, malaise and respiratory symptoms. Using anti-echovirus antibody, no CPE was observed. Which statement is true regarding this infection? A. The patient is infected with enterovirus B. The patient is infected with echovirus C. The patient is unlikely to produce antibodies against enterovirus D. The result is inconclusive, other tests must be done Answer: B

68. The most common cause of bronchiolitis and pneumonitis in infants A. adenovirus C. RSV B. parainfluenza virus D. measles virus Answer: C 69. Which is pathognomonic of Rabies? A. viral culture C. flourescent antibody test B. negri bodies D. none Answer: B 6

76. Viruses are cultivated in the following EXCEPT A. cell culture C. animals B. chick embryo D. enriched agar medium Answer: D

C. the human population is protected because of previous infection with human strain D. antigenic drift Answer: B 82.

77. Which of the following identifies a virus using a labeled specific antibody? A. Immunoflourescence C. electron microscopy B. PCR D. virus isolation Answer: A

83. Which is true about poliovirus infection? A. CNS involvement is NOT common B. Most infections have translent viremia C. The virus multiplies in the muscles D. There is no effective preventive measure Answer: B

78. Hemagglutination inhibition test is NOT applicable in which virus A. influenza virus C. RSV B. mumps virus D. parainfluenza virus Answer: C 79. A 2-month pregnant mother suspected of having acquired rubella because of exposure to a friend who has the illness, was tested for antibodies using HAI test. The result showed that the mother was positive for IgG but not IgM. Which is the best statement that describes this case? A. The mother has been infected with the virus in the past before pregnancy B. The mother is incubating snd would manifest the infection later C. The fetus will most likely be infected transplacentally D. The mother has no immunity Answer: A

84. Herpangina, which is characterized by the formation of vesicular lesions in the pharynx is most commonly associated with A. poliovirus C. coxsackie A virus B. hepatitis A virus D. coxsackie B virus Answer: C 85. An astray dog bit your neighbor. The wound was bleeding and was cleaned with soap and water. Your advise will be A. kill the dog and submit the head for examination for Negri bodies B. give rabies immunoglobulin and vaccine C. observe the dog D. observe the patient Answer: B

80. A hemagglutination inhibition test was done on the serum of a 6-month old boy, who is suffering from severe respiratory distress. The results showed that hemagglutination occurred when parainfluenza virus type 1 Ag was reacted with the serum; no hemagglutination with parainfluenza virus type 2; hemagglutination with RSV. Which is the infecting agent? A. Parainfluenza type 1 C. RSV B. Parainfluenza type 2 D. the result is inconclusive Answer: B 81.

Which is associated with congenital abnormalities? A. mumps C. rubeola B. german measles D. all of the above Answer: B

86. Latency occurs in the trigeminal ganglion A. HSV 1 C. HSV 6 B. HSV 2 D. HSV 8 Answer: A 87. Latency occurs in the mononuclear cells and kidneys. A. HSV 1 C. CMV B. HSV 3 D. Variola Answer: C

Genetic reassortment occurs when segmented genomes of duck strains of influenza A virus are enclosed together with those of human strains in a capsid. Which of the followng is the most likely to occur? A. point mutation B. new strain of virus will appear

88. The difference between Dengue fever and Dengue Hemorrhagic fever is that A. presence of bleeding in DHF B. hematocrit is elevated in DHF 7

C. PPT is prolonged in DHF D. absence of AbV in the former formation Answer: B

96.

Which is associated with extrahepatic manifestations A. HAV B. HCV C. HBV D. HEV Answer: C

89. A 4-year-old girl is brought to the physician’s office because she developed red cheeks that appear as if someone has slapped her, and a lacy ash on her upper extremities and trunks. What is the MOST probable causative agent? A. Adenovirus C. Marburg virus B. Parvovirus D. Rotavirus Answer: B

97.

A woman appears in a hospital ER with vesicular lesions on her vulva. These lesions clinically resemble those caused by herpes simplex virus. From which of the following clinical specimens would the virus most likely to be isolated? A. urine C. Throat secretions B. Blood D. Vesicular fluid Answer: D

98.

90. Defective virus that cause infection only in presence of HBV A. HAV B. HBV C. HCV D. HDV Answer: D

99. A 30-year-old school teacher presents with cough of 1 mont duration, fever, night sweats and weight loss. PE is normal. How many sputum smears are recommended by the council on Tuberculosis to establish a diagnosis of TB? A. Four C. Two B. Three D. One Answer: B

91. Very important serologic marker for HBV during the window phase A. Anti HBs C. Anti HBc B. HBs Ag D. HBe Ag Answer: C

100.

A woman develops fever, rash and polyarthralgia during menstruation. Gram stain of the synovial fluid of her right knee reveals gram-negative diplococci. Which of the following organisms is MOST likely to be responsible? A. Haemophilus influenzae C. Neisseria gonorrhoeae B. Staphylococcus epidermidis D. Pseudomonas aeruginosa Answer: C

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92. A modified cellular protein that is capable of auto-catalytically make several copies of itself A. viroid C. prion B. virusoid D. satelitte RNA Answer: C 93. Responsible for attachment of influenza virus on specific host cell receptor A. H glycoprotein C. matrix protein B. N glycoprotein D. capsid protein Answer: A 94. Measles is most infectious during tha appearance of A. Koplik spots B. Fever, cough and coryza and conjunctivitis C. Macupapular rash D. Photophobia Answer: B 95.

A 5-year old child presents fever for 8 days, lympadenopathy, splenomegaly and numerous reactive or atypical lymphocytes on peripheral blood smear. The monospot test is negative. A likely cause of the clinical picture is infection with A. respiratory syncytial virus C. Adenovirus B. Cytomegalovirus D. herpes virus Answer: B

Oseltamivir is an antiviral drug-used against A. parainfluenza C. measles B. influenza D. RSV Answer: B 8