B DAMB 721 Microbiology Final Exam B 100 points December 11, 2006
Your name (Print Clearly):
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I. Matching: The questions below consist of headings followed by a list of phrases. For each phrase select the heading that best describes that phrase. The headings may be used once, more than once or not at all. Mark the answer in Part 2 of your answer sheet.
1. capsid 7. CD4 2. Chlamydia pneumoniae 8. Enterococcus faecalis 3. oncogenic 9. hyaluronidase 4. pyruvate 10. interferon 5. Koplik’s spot 11. hydrophilic viruses 6. congenital Treponema pallidum 12. Streptococcus pyogenes
1. “spreading factor” produced by members of the staphylococci, streptococci and clostridia
2. viral protein coat
3. central intermediate in bacterial fermentation
4. persistant endodontic infections
5. a cause of atypical pneumonia
6. nonspecific defense against viral infection
7. has a rudimentary life cycle
8. HIV receptor
9. Hutchinson’s Triad
10. measles
11. resistant to disinfection
12. β-hemolytic, bacitracin sensitive, cause of suppurative pharyngitis
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Matching (Continued): The questions below consist of diseases followed by a list of etiologic agents. Match each disease with the etiologic agent. Continue using Part 2 of your answer sheet.
1. dysentery 6. Legionnaire’s 2. botulism 7. gas gangrene 3. cholera 8. tuberculosis 4. diphtheria 9. necrotizing fascitis 5. enteric fever 10. pneumoniae/meningitis
13. Clostridium botulinum
14. Vibrio cholera
15. Mycobacterium bovis
16. Shigella species
18. Clostridium perfringens
19. Salmonella typhi
20. Streptococcus pyogenes
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II. Multiple Choice: Choose the ONE BEST answer. Mark the correct answer on Part 1 of the answer sheet. Use a #2 pencil.
1. The effector cell in an immediate hypersensitivity reaction is a/an:
A. macrophage B. Langerhans cell C. IgE opsonized mast cell D. lymphocyte E. IgE opsonized erythrocyte
2. Characteristics of the Staphylococcus aureus enterotoxin that make it a dangerous cause of food poisoning:
A. It resists heat. B. Staphylococcus aureus grows in high salt environments. C. It resists proteases such as trypsin. D. A and C. E. A, B and C.
3. Which of the following is an untrue statement about ornithosis?
A. close association with parrots can be a risk factor B. it is also called psittacosis C. it is transmitted to humans via inhalation of Chlamydia psittaci D. it is transmitted to humans via inhalation of Coxiella burnettii E. B and C are untrue statements.
4. Which of the following is a skin test that: takes 24 to 72 hours to develop; is characterized by a lesion that is red, swollen and indurated; is mediated by activated macrophages?
A. tuberculin B. coccidioidin C. histoplasmin D. A, B and C E. A and C
5. Complication of influenzae that occurs in children in conjunction with aspirin therapy:
A. viral pneumonia B. bacterial pneumonia C. Reye’s syndrome D. croup
6. Dental equipment that penetrates intact skin:
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A. Is critical and should be disinfected with a high level disinfectant. B. Is semi-critical and should be disinfected with a low level disinfectant. C. Is critical and should be sterilized. D. Is non-critical and can be disinfected with a low level disinfectant. E. Is semi-critical and can be sterilized or disinfected with a high level disinfectant.
7. One of the bacteria listed below is a common cause of nongonococcal urethritis and eye diseases. In addition, it often causes coinfections with Neisseria gonorrhoea. Which one?
A. Mycoplasma pneumoniae B. Coxiella burnetii C. Chlamydia pneumoniae D. Chlamydia trachomatis
8. Which of the following complement factors will opsonize antigen?
A. C3a, C4a and C5a B. C5a C. C3b, C4b D. C5b through 9
9. Bacteria that grow in low oxygen levels of 5 to 10% are:
A. facultative anaerobes B. microaerophilic C. aerobes D. facultative aerobes E. capneic
10. The streptococci that cause human caries are:
A. Streptococcus cricetus and S. ferus B. S. gordonii and S. mutans C. S. mutans and S. sobrinus D. S. salivarius and S. sobrinus
11. The most important polymer that comprises the extracellular matrix of a persistent cariogenic biofilm will be the:
A. alpha-1,3-branched levan B. alpha-1,3-branched mutan C. alpha-1,6-banched glucan D. alpha-1,6-branched mutan
12. A child that suffers from a pyogenic cellulitis is predisposed to this sequelae of S. pyogenes infections.
A. toxic shock syndrome B. acute glomerulonephritis C. rheumatic fever D. rheumatoid arthritis
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13. The antigen used to subdivide S. pyogenes into serotypes is:
A. the Lancefield carbohydrate B. the β hemolysin C. the M protein D. the teichoic acid E. A, C, and D.
14. A coagulase negative species of staphylococcus that cannot produce coagulase but is a cause of urinary tract infections, mostly in hospitalized patients.
A. Staphylococcus aureus B. Staphylococcus saprophyticus C. Staphylococcus epidermidis D. A and B E. B and C
15. Members of the genus Mycoplasma are unique among bacteria because they:
A. have a rudimentary life cycle. B. have a primary arthropod host that is both a vector and a reservoir C. lack a cell wall and instead have a trilaminar membrane D. have human intermediate host
16. Hepatitis D cannot cause disease except in a coinfection with:
A. HAV B. HBV C. HCV D. HSV1 E. HHV7
17. Compared to the periodontal pathogens more of the bacteria that cause endodontic infections are:
A. mesophiles B. Gram positive C. Gram negative D. aerobic
18. A Staphylococcus aureus that cannot produce this enzyme is avirulent.
A. catalase B. lipase C. coagulase D. hyaluronidase E. staphylokinase
19. One of the following viruses is not oncogenic, which one?
A. HAV
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B. HCV C. HBV D. Papilloma virus E. Epstein Barr virus
20. This rickettsial pathogen is transmitted in aerosols of dried animal waste.
A. Campylobacter fetus B. Rickettsia typhi C. Coxiella burnettii D. Rickettsia rickettsii E. Ehrlichia chaffeensis
21. Reagins are antibodies that:
A. can be used to screen for previous infection with Treponema pallidum. B. are cross reactive with cardiolipin. C. can be used to measure the effectiveness of a treatment for syphilis D. A, B and C. E. A and B.
22. The following is a virulence factor for Vibrio cholera, Pseudomonas aeruginosa and Neisseria gonorrhoea:
A. n-methylphenylalanine pilus B. a polysaccharide capsule C. an alginate capsule D. filamentous hemagglutinin E. AB toxin
23. One of the following is not a common cause of meningitis in newborns. Which one?
A. Streptococcus pneumoniae B. Escherichia coli C. Listeria monocytogenes D. Streptococcus agalactiae
24. Activation of the Hageman Factor (XII) can result in initiation of all of these inflammatory cascades, but one is indirect and secondary to the activation of a cell. Which one?
A. fibrin B. arachidonic acid cascade C. plasmin D. complement E. bradykinin
25. Neonatal diseases caused by Listeria monocytogenes are spread through:
A. respiratory droplets B. transplacental passage
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C. consumption of contaminated milk D. contact with family pets E. B and C
26. Which of the following is the best description of the symptoms of diseases caused by the Rickettsiales?
A. intense headache, fever and rash B. a soft gummy tumor that may form in any organ in the body C. patchy infiltrates in the lungs D. consolidation of the lungs
27. If the portal of exit and portal of entry of a disease is on the same person:
A. this is an endogenous infection. B. this is evidence that the disease is spread by a fomite. C. this is evidence of spread by a biological vector. D. the individual must be immunocompromised.
28. Form of bacterial gene transfer in which either a fragment of DNA or a plasmid from the donor bacterium is transferred across the cell membrane of the recipient bacterium This nuclear material is not contained in a viral coat, and it is not passed through a pilus.
A. conjugation B. transduction C. transformation D. locomotion
29. A vaccine for anthrax is:
A. EF and LF. B. PA and EF. C. LF and PA. D. PA.
30. A mild form of C. perfringens infection that does not have any associated pathology is:
A. enterotoxic. B. cellulitis. C. histotoxic. D. pseudomembranous.colitis E. myonecrosis.
31. The infectious form of tuberculosis is:
A. Disseminated (miliary) tuberculosis B. Secondary (active) tuberculosis C. The tubercle D. Latent tuberculosis
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32. Mutations in the influenzae virus that result in a new strain of virus are:
A. antigenic drift
B. the result of mixed infection with two or more strains of influenzae virus one of which is an avian strain
C. antigenic shift
D. possible because the segmented ssRNA genome allows reassortment of the genes that encode the hemagglutinin and neuraminidase
E. All except A
33. This bacterium is never transmitted from human to human; instead it is transmitted from water sources where it may be parasitic on amoebae.
A. Pseudomonas aeruginosa B. Mycoplasma pneumoniae C. Legionella pneumophilia D. Rickettsia typhii
34. Meningitis may occur following a respiratory infection with this microorganism. Transmission of one form of meningitis is thought to result from inhalation of dried avian feces. What is the pathogen?
A. Chalmydia psittaci B. Cryptococcus neoformans C. Echovirus D. Listeria monocytogenes E. Streptococcus pneumoniae
35. A non-infectious syphilis lesion is:
A. gumma B. chancre C. maculopapule D. furuncle
36. Latency is an outcome particularly characteristic of which one of the following virus groups?
A. Polioviruses B. Herpesviruses C. Rhinoviruses D. Influenza viruses
37. An opportunistic cancer that is associated with human herpes virus 8:
A. Kaposi’s sarcoma B. Nasopharyngeal carcinoma C. B cell lymphoma D. Burkitt’s lymphoma
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38. When a Venereal Disease Research Laboratories (VDRL) test is done on a patient’s serum using cardiolipin-coated latex beads as an antigen, the latex beads agglutinate. How should this result be interpreted?
A. The patient’s serum did not have reaginic antibody. Thus, the patient had not been infected with syphilis.
B. The patient’s serum did have reaginic antibody. This is a positive diagnosis for syphilis.
C. This constitutes a direct test for Treponema pallidum and confirms a diagnosis of syphilis.
D. This is a preliminary diagnosis for syphilis. Since other pathogens may stimulate reagins, the patient diagnosis must be confirmed with an assay that employs a specific, T. pallidum antigen.
39. A patient with shingles is most likely to have had a previous infection with:
A. Varicella B. Zoster C. HTLV D. herpes simplex virus 1 E. herpes simplex virus 2
40. A common opportunistic pathogen that causes infection of the nasal cavity, paranasal sinuses, orbit and CNS in diabetic patients is:
A. Candida albicans B. Mucor species C. Cryptococcus neoformans D. Blastomyces dermatiditis E. Coccidioides immitis
41. Hemolytic uremic syndrome and thrombocytopenia are severe symptoms caused by:
A. EHEC. B. ETEC. C. EPEC. D. Salmonella typhi. E. Vibrio cholera.
42. A patient suffers intermittent episodes of chronic arthritis that appear 1 year after a disease with symptoms of panophthalmitis and musculoskeletal pain. Six months prior to the panophthalmitis she had a strange skin lesion that resembled a bullseye. This patient has been infected with:
A. Treponema pallidum B. Borrelia recurrentis C. Vibrio vulnificus D. Borrelia burghdorferi E. Helicobacter pylori
43. The Epstein-Barr virus is implicated in all of the following diseases EXCEPT:
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A. Burkitt’s lymphoma B. cervical cancer C. nasopharyngeal carcinoma D. chronic fatigue syndrome E. oral hairy leukoplakia
44. Detection of this marker in serum in the absence of other HBV markers indicates vaccination against hepatitis B.
A. HBcAg B. HBeAg C. HBsAg D. anti-HBsAg
45. One of the following is not a common etiologic agent of atypical pneumonia. Which one?
A. Mycoplasma pneumoniae B. Legionella pneumophilia C. Chlamydia pneumoniae D. Ureaplasma urealyticum E. certain viruses
46. A 56-year-old male presented with a large lesion on his right chest wall. The patient was an alcoholic with a history of severe periodontal disease. He was taken to surgery for drainage of his chest lesion. At surgery, 1 L of pus was drained from the chest lesion and the lung. Examination of the pus revealed yellow granules. The granules were crushed, Gram stained, and examined under a microscope. What would be the most likely observation?
A. Gram negative rods. B. Gram positive, spore forming rods. C. Gram positive, pleomorphic rods. D. Gram negative, curved rods.
47. Infectious hepatitis:
A. is blood borne. B. is HAV. C. is spread through fecal/oral contamination. D. has a short incubation time. E. All except A are true.
48. The bacterium that is etiologic in actinomycosis is:
A. Actinomyces israelii. B. Actinomyces bovis. C. Actinomyces viscosus. D. Nocardia asteroides.
49. White patches that appear on the tongue and oral mucosa of AIDS patients:
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A. may be a Candida albicans infection B. may be an infection caused by the Epstein-Barr virus C. A and B are true.
50. A hospitalized patient develops diarrhea and fever. The patient had been treated with clindamycin for an abscessed third molar. Culturing the patient’s stool did not yield any significant pathogens. Which of the following is the most likely etiologic agent?
A. Shigella dysenteriae B. Campylobacter jejuni C. Clostridium difficile D. Yersinia enterocolitica
51. An oral infection caused by Candida albicans that results when contact between the maxillary mucosa and saliva is blocked:
A. denture induced stomatitis B. oral thrush C. angular chelitis D. midline glossitis
52. A dimorphic fungus that produces a lung lesion that resembles a tubercle is:
A. Histoplasma capsulatum B. Blastomyces dermatitidis C. Cryptococcus neoformans D. Candida albicans
53. The Actinobacillus actinomycetemcomitans leukotoxin is a virulence factor that allows the bacterium to evade the host immune system by:
A. killing PMN’s B. killing lymphocytes C. killing old world monkeys
54. The bacterium that is the cause of 90% of aggressive periodontitis in adolescents:
A. Porphyromonas gingivalis B. Prevotella intermedia C. Actinobacillus actinomycetemcomitans D. Campylobacter rectus
55. This virulence factor, which is elaborated by most of the periodontal and endodontic pathogens, can induce tissue destruction and bone resorption by activating the host’s macrophages to release cytokines.
A. leukotoxin B. hemagglutinin C. LPS D. capsule
56. The most common means through which bacteria gain access to the dentinal tubules and subsequently produce inflammation and infection in the dental pulp is:
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A. treatment for periodontal disease B. mechanical exposure due to operative procedures C. trauma D. caries
57. Under what conditions might an infected pulp be a source of periapical infection or inflammation?
A. Periodontal treatment may denude dentin to expose dentinal tubules.
B. Plaque involved in periodontal disease may cover the entire length of the root and reach the apical foramina.
C. Bacteria and bacterial toxins in the infected pulp may move out through the lateral canals, dentinal tubules or the apical foramina.
D. Anaerobic bacteria at the base of carious lesions may invade the dentinal tubules.
58. Which Porphyromonas gingivalis virulence factor enzymatically digests connective tissue in the periodontium and pulp?
A. hemagglutinin B. fimbriae C. collagenase D. IgA protease
59. The bacterium that is most frequently isolated from infected root canals is: A. Porphyromonas endodontalis B. Eubacterium spp. C. Prevotella nigrescens D. Peptostreptococcus spp.
60. The BPB that is/are most often isolated from infected pulp with acute apical abscess.
A. Porphyromonas endodontalis B. Porphyromonas gingivalis C. Prevotella intermedia D. A and B
61. The BPB that is/are most often associated with pregnancy gingivitis:
A. Porphyromonas endodontalis B. Porphyromonas gingivalis C. Prevotella intermedia D. A and B
62. Which of the following microorganisms is most likely to be cultured from chronic, encrusted, ulcerations at the corners of the mouth?
A. Candida albicans B. Aspergillus fumigatis
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C. Histoplasma capsulatum D. Coccidioides immitis
63. Which of the following microorganisms produces aflatoxin?
A. Candida albicans B. Aspergillus fumigatis C. Histoplasma capsulatum D. Coccidioides immitis
64. Which of the following microorganisms is the cause of interstitial plasma cell pneumonia?
A. Pneumocystis carinii B. Aspergillus fumigatis C. Histoplasma capsulatum D. Cryptococcus neoformans
65. Which of the following microorganisms causes severe congenital birth defects?
A. Pneumocystis carinii B. Rubella virus C. Histoplasma capsulatum D. Morbillivirus
66. One of the following is least likely to be contaminating raw chicken. Which one?
A. Shigella sonnei B. Salmonella typhimurium C. Campylobacter jejuni D. Yersinia enterocolitica
Many bacteria are intracellular parasites with specialized mechanisms for survival inside cells. In questions 67 through 73 below, use the following choices to identify the mechanism the bacterium uses for intracellular survival.
A. Escapes the endosome. B. Prevents fusion of the phagosome and lysosome. C. Activates transcription of an acid tolerance response gene.
67. Listeria monocytogenes 68. Salmonella typhi 69. Shigella sonnei 70. Mycobacterium tuberculosis 71. Rickettsia species 72. Ehrlichia chaffeensis 73. Legionella pneumophilia
74. Campylobacter jejuni is:
A. a Gram positive, spiral shaped rod. B. oxidase, urease and catalase positive C. Gram negative, does not produce endospores, cells may take on
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a gull-wing appearance. D. A and B. E. B and C.
75. The infectious agent of a dimorphic fungus is:
A. a hyphae B. a yeast C. a conidiospore D. a mycelium
76. Which of the following is an untrue statement about ornithosis?
A. close association with parrots can be a risk factor B. it is also called psittacosis C. it is transmitted to humans via inhalation of Chlamydia psittaci D. it is transmitted to humans via inhalation of Coxiella burnettii E. B and C are untrue statements.
77. What is the main pathogenic mechanism of Ehrlichia chaffeensis?
A. They disrupt endothelium. B. Hyaluronidase. C. Release of cytokines with an adjuvant effect. D. They grow in white blood cells. E. Damage to respiratory epithelium.
78. A specimen is taken from a purulent urethral discharge. Microscopic evaluation of the purulent specimen shows Gram negative diplococci inside PMNs. When plated on Thayer- Martin medium containing the antibiotics colistin, vancomycin and amphoteracin B, an oxidase positive, Gram negative, diplococcus is isolated. This is a presumptive positive test for:
A. Mycoplasma hominus B. Neisseria gonorrhoeae C. nontypeable Haemophilus influenzae D. Chlamydia trachomatis E. Treponema pallidum
Questions 79 through 82 refer to the sequence of plaque formation. In the space corresponding to the numbered statement, answer:
A. If it describes formation of the dental pellicle on the tooth surface. B. If it describes the initial bacterial colonization of the dental pellicle. C. If it describes secondary plaque buildup and maturation. D. If it does not describe plaque formation.
79. Crevicular fluid components such as albumin and inorganic phosphates adhere to the enamel surface of the tooth.
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80. Calcium and phosphate ions attach salivary mucins to the enamel surface of the tooth.
81. Coaggregating pairs of anaerobic Gram-negative rods form a biofilm on the tooth surface.
82. Actinomyces viscosus attaches to the tooth surface via type 1 fimbriae and to Streptococcus sanguis via type 2 fimbriae
83. To be considered etiologic in periodontal disease a bacterium must satisfy Socransky's Postulates. Which of the following statements is not one of Socransky's Postulates?
A. Treatment eliminating the bacterium from the periodontal lesion should result in clinical improvement.
B. The bacterium should stimulate high antibody titers in the patient.
C. The bacterium should be isolated in pure culture from the periodontal lesion.
D. The bacterium should be present in high numbers in periodontal lesions and either absent or in low numbers in healthy sites.
84. Which of the following microflora would most likely be found in a periodontal lesion?
A. Gram negative, facultatively anaerobic, nonmotile rods B. Gram positive, facultatively anaerobic, cocci C. Gram negative and gram positive facultative rods D. Gram negative, anaerobic, motile rods and spirochetes
85. Pelvic inflammatory disease could be caused by all of the following except:
A. Neisseria gonorrhoeae B. Mycoplasma hominus C. Ureaplasma urealyticum D. Chlamydia trachomatus E. Treponema pallidum
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Bonus Questions:
Partial credit will not be given for individual questions.
1. (2 points) In ancient times people did not bathe or change clothes often and most were infested with lice. In fact, men in the 17th century often shaved their heads and wore wigs to rid themselves of what they referred to as vermin. The symptoms of a common “plague” of the time included fever, headache, muscle pain, nausea, vomiting, rash and delirium. In those pre- antibiotic times, patients usually died within a few days of the onset of symptoms.
A. What disease does this describe?
B. What is the etiology of the disease?
2. (1 point) Rocky Mountain spotted fever is a disease similar to the one described above. What is the etiology of Rocky Mountain spotted fever?
3. (4 points) For each stain listed below, list one genus of bacteria that the stain could be used to identify.
A. Methylene Blue for metachromatic granules______.
B. Spore stain ______
C. Acid fast stain ______
D. Gram stain ______
4. (3 points) Name three antimicrobial factors in saliva.
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