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Home , Diphtheria, Streptococcus sobrinus

DAMB 721 Microbiology Exam 3A 100 points October 25, 2004

Your name:

______

1 I. Multiple Choice: Choose the ONE BEST answer. Mark the correct answer in Part 1 of your answer sheet.

1. A pseudomembrane is a symptom of disease caused by these :

A. perfringens and diphtheria B. Corynebacterium diphtheria and Clostridium difficile C. Clostridium difficile and D. Corynebacterium diphtheria and monocytogenes

2. Diseases caused by this genus of bacteria are never transmitted by inhalation.

A. Clostridium B. Corynebacterium C. Staphylococcus D. E.

3. Diseases caused by this genus of bacteria are never transmitted through contaminated food.

A. Listeria B. Staphylococcus C. Clostridium D. E. Bacillus

4. Which of the following diseases is not a zoonose?

A. B. C. diphtheria D. E.

5. Pulmonary anthrax:

A. is caused by the inhalation of Bacillus anthrasis endospores B. may be spread to humans after an epidemic in animals C. is also called “Woolsorter’s Disease” D. is dependent upon bacterial in vivo expression of the anthrax and a polypeptide capsule E. All of the above.

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6. Of the following, the most life threatening manifestation of diphtheria is:

A. the pseudomembrane B. caused by toxemia C. transient caused by toxemia D. bull neck

7. Which of the following is etiologic in ?

A. B. C. D. Bacillus anthrasis

8. The best stain for studying the cellular morphology of the mycobacteria is:

A. acid fast stain B. Gram stain C. metachromatic granule stain D. spore stain

9. The form of tuberculosis in which patients are coughing up aerosols of mycobacteria and are most contagious is:

A. primary tuberculosis B. latent-dormant tuberculosis C. active tuberculosis D. disseminated tuberculosis

10. Lecithinase (phospholipase C) is a toxic, membrane-destroying . It is an important virulence factor for:

A. Bacillus anthrasis B. Clostridium perfringens C. Mycobacterium tuberculosis D.

11. Endospores are important virulence factors that allow of diseases caused by the genera:

A. Staphylocccus and Actinomyces B. Bacillus and Streptococcus C. Clostridium and Bacillus D. Corynebacterium and Nocardia E. Actinomyces and Nocardia 3

12. What combination of anthrax will cause swelling and death?

A. edema factor (EF) and lethal factor (LF) B. protective factor (PA) and edema factor (EF) C. LF and PA D. PA, LF and EF

13. Which of the following diseases is caused by an agent that produces neither nor endotoxins?

A. Anthrax B. Tetanus C. Botulism D. Gas gangrene E. Tuberculosis

14. Which of the following is an outcome of primary tuberculosis in which granulomatous lesions form in a number of organs. In infants and compromised patients this is a life threatening .

A. primary tuberculosis B. latent-dormant tuberculosis C. active tuberculosis D. .

15. The differences between the AB toxins produced by various bacteria are:

A. the release from the bacterial cell as a single “progenitor” B. the activation of the AB subunits by proteolytic cleavage followed by reduction of bonds C. binding of the high molecular weight, B subunit, to the target cell D. the active (toxic) enzymatic subunit is the A subunit E. the target cell and activity of the B and A subunits

16. Corynebacterium diphtheria, Clostridium botulinum, and Clostridium tetani have the following in common:

A. They have AB toxins as virulence determinants. B. They all cause diseases that result from bacterial colonization of the oropharynx. C. They are all anaerobes. D. All of the above. E. A and B.

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17. Bacterial toxin(s) that have the unique ability to resist the proteolytic activity of trypsin in the small intestine is/are:

A. The Staphylococcus aureus enterotoxin B. The Clostridium botulinum toxin C. The Clostridium tetani toxin (tetanospasmin) D. A and B. E. All of the above.

18. The exfoliative toxin is produced by ______and it causes the symptoms of ______.

A. faecalis; scalded skin syndrome B. ; scarlet C. Staphylococcus aureus; scalded skin syndrome D. E. Staphylococcus aureus; impetigo

19. Mannitol salt agar is selective and differential for ______. The selective component is ______; the differential component is ______.

A. ; 7.5% sodium chloride; mannitol B. Staphylococcus aureus; 7.5% sodium chloride; mannitol C. Corynebacterium diphtheria; tellurite; mannitol D. Staphylococcus aureus; mannitol; 7.5% sodium chloride E. Streptococcus pneumoniae; optochin; α-hemolytic response

20. Protein A is:

A. Useful for serotyping strains of Streptococcus pyogenes.

B. A protein that is a virulence determinant for the Staphylococcus aureus and can activate fibrinogen to cause clott formation around the bacterial cell.

C. A protein that is unique to the cell surface of Staphylococcus aureus and that contributes to the virulence of the bacterium by binding the Fc region of immunoglobulins

D. Toxic for white blood cells.

E. The unusual capsule of B. anthrasis.

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21. The best explanation for the influence of iron on expression of the is:

A. The gene for the diphtheria toxin is encoded by a prophage. B. A repressor protein encoded on the host chromosome regulates expression of the toxin gene. C. Iron is a co-repressor. In conditions of plentiful iron, it binds the repressor protein, DtxR; the iron/DtxR complex then binds the tox gene promoter to prevent transcription. D. Iron is a co-repressor; in high iron concentrations it dissociates from the DtxR repressor resulting in expression of the toxin gene.

22. A method of epidemiologic investigation that is useful for determining the source of nosocomial caused by S. aureus is:

A. serotyping B. pyocin typing C. phage () typing D. cell wall composition

23. The bacteria that cause human caries are:

A. Streptococcus sobrinus and B. Streptococcus sobrinus and Streptococcus maccaccae C. Streptococcus cricetus and Streptococcus rattus D. Streptococcus mutans and Streptococcus rattus E. Streptococcus ferus and Streptococcus rattus

24. A Staphylococcus aureus that cannot produce this enzyme is avirulent.

A. catalase B. lipase C. coagulase D. hyaluronidase E. staphylokinase

25. Bacteria that are aciduric are virulent in this disease:

A. Ludwig’s angina B. strep throat C. subacute bacterial endocarditis D. osteomyelitis E. caries

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26. Protein A is a virulence factor that has the following activity:

A. binds the Fc region of immunoglobulins to disrupt complement activation and opsonization. B. converts fibrin to fibrinolysin. C. chelates calcium. D. converts urea to carbon dioxide and ammonia. E. converts hydrogen peroxide to oxygen and water.

27. Bacteria with the ability to survive, metabolize and reproduce at pH 5.5 and below are:

A. acidogenic B. have glucosyl transferases C. asaccharolytic D. aciduric E. inhibitors of acid diffusion

28. One of the following is a disease whose symptoms are not caused by a toxin that is also a super antigen. Which one?

A. B. staphylococcal food poisoning C. scalded skin syndrome D.

29. The cell component of S. pneumoniae that is a virulence determinant and is used to serotype the .

A. teichoic acid B. alpha hemolysin C. carbohydrate capsule D. M protein E. fimbriae

30. The most frequent cause(s) of meningitis in newborns is(are):

A. Streptococcus pyogenes B. C. Streptococcus pneumoniae and Enterococcus faecalis D. Streptococcus agalactiae and Escherichia coli E. Enterococcus faecalis

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31. An elderly patient develops meningitis 3 days after being admitted to the hospital. Upon culture of the patient’s cerebrospinal fluid, a Gram + diplococcus is isolated that is α- hemolytic on blood agar and sensitive to the bile salt, optochin. This is a presumptive diagnosis for:

A. Staphylococcus aureus B. Escherichia coli C. Streptococcus pyogenes D. Streptococcus pneumoniae E. Streptococcus agalactiae

32. A streptococcus is isolated from a patient with a suppurative . When grown on blood agar, it is beta hemolytic and sensitive to a bacitracin disc. This is a presumptive positive test for:

A. Streptococcus pneumoniae B. C. Streptococcus agalactiae D. Enterococcus faecalis E. Streptococcus pyogenes

33. 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.

34. These streptococci do not have the Lancefield group-specific carbohydrate:

A. Viridans streptococci and Streptococcus pneumoniae B. Most beta hemolytic streptococci C. Enterococcus faecalis and D. S. anginosus and S. milleri E. Streptococcus agalactiae and Streptococcus pyogenes

35. 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. D. rheumatoid arthritis

8 36. Use of this medical device/procedure involves substantial risk of transmission of blood-borne (hepatitis and HIV) both to patients and hospital personnel.

A. urinary catheter B. hemodialysis C. respirator D. vascular catheters

37. Of the following, which conveys the lowest risk of nosocomial infection to a hospitalized patient:

A. the hospital environment (rooms, floors, fomites) B. invasive medical devices (catheters, respirators, etc.) C. hospital personnel, including physicians

38. The bacterium ______is the most frequent cause of nosocomial infections while ______is the second most frequent cause.

A. Staphylococcus aureus; Escherichia coli B. Escherichia coli; Enterococcus faecalis C. Enterococcus faecalis; Staphylococcus aureus D. Escherichia coli; Staphylococcus aureus

39. Bacteria with a pleomorphic cell morphology include all except:

A. Corynebacterium diphtheria B. Actinomyces israelii C. Mycobacterium tuberculosis D. E. Clostridium perfringens

40. These two low virulence pathogens frequently cause opportunistic infections in burn patients.

A. Escherichia coli and Staphylococcus aureus B. Pseudomonas aeruginosa and Enterococcus faecalis C. Escherichia coli and Pseudomonas aeruginosa D. Pseudomonas aeruginosa and Serratia marcescens E. Serratia marcescens and Staphylococcus aureus

41. A bacterium that reduces tellurite in selective media to produce black colonies is:

A. Actinomyces israelii B. Corynebacterium diphtheria C. Staphylococcus aureus D. Clostridium botulinum E.

9 42. Statement A: In tuberculosis, a Type IV hypersensitivity response can both protect and destroy host tissue. Statement B: The macrophage is the most important host cell in the establishment of tuberculosis.

A. Statement A is true. B. Statement B is true. C. Statements A and B are true. D. Neither statement is true.

43. This bacterium is an intracellular parasite and the virulence of the bacterium depends on actin-dependent intracellular motility and intercellular spread

A. Mycobacterium tuberculosis B. Corynebacterium diphtheria C. Listeria monocytogenes D. Clostridium difficile E. Actinomyces viscosus

44. The M protein is:

A. Useful for serotyping strains of Staphylococcus aureus.

B. A protein that is a virulence determinant for Staphylococcus aureus and can activate fibrinogen to cause clott formation around the bacterial cell.

C. A protein that is unique to the cell surface of Staphylococcus aureus and that contributes to the virulence of the bacterium by binding the Fc region of immunoglobulins

D. Is coiled around the pili of Streptococcus pyogenes; acts as an adhesin by binding the bacteria to keratinocytes and epithelial cells; activates fibrinogen to form a fibrin clot that protects the bacterium from opsonization and phagocytosis.

E. The unusual capsule of B. anthrasis.

45. Neonatal diseases caused by Listeria monocytogenes are spread through:

A. respiratory droplets B. transplacental passage C. consumption of contaminated milk D. contact with family pets

10 Part II. Matching: The questions below consist of headings followed by a list of phrases. For each phrase select the ONE heading that best describes that phrase. Mark the answer in Part 2, numbers 1 through 11, of your answer sheet.

1. necrotizing fasciitis 8. casei 2. hyaluronidase 9. osteomyelitis 3. puerperal fever 10. glucan (mutan) 4. cellulitis 11. viridans streptococci 5. coagulase 12. catalase 6. streptokinase 7. human carriers

1. inflammation caused by bacterial invasion of the lymphatics and connective tissues under the skin

2. “spreading factor” produced by members of the streptococci, staphylococci and clostridia

3. etiologic in more than 80% of subacute bacterial endocarditis infections

4. important to the transmission of diphtheria

5. Infection of uterus after delivery

6. secondary invader of carious lesions

7. an infection in a long bone that is a focal infection caused by S. aureus growing in a nearby blood vessel

8. rapid biochemical test that will distinguish streptococci from staphylococci

9. a form of gangrene caused by Streptococcus pyogenes

10. water insoluble component of cariogenic plaque

11. an important virulence factor for the “flesh eating bacteria”

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Part III. Matching: The questions below consist of headings followed by a list of phrases. For each phrase select the ONE heading that best describes that phrase. Mark the answer in Part 2, numbers 12 through 20, of your answer sheet. Any of the headings may be used more than once and not every heading has to be used.

1. 6. Actinomyces viscosus 2. Actinomyces israelii 7. Actinomyces naeslundii 3. Actinomyces bovis 8. Actinomyces naeslundii and A. viscosus 4. Type I fimbriae 9. Type II fimbriae 5. M. tuberculosis 10. Nocardia asteroides

12. cause of pyogenic lung abscesses

13. A disease characterized by granulomatous lesions connected by sinus tracts; the sinus tracts may contain sulfur granules that drain to open lesions on the skin surface.

14. bacterium with both Type I and Type II fimbriae

15. virulence factor allows attachment to protein in dental (salivary) pellicle

16. virulence factor allows attachment to galactose on oral mucosa or other bacteria

17. etiologic agent(s) of human root caries

18. most frequently the etiologic agent of actinomycosis

19. a disease that results from the endogenous contamination of a surgical site or from trauma involving explanted endogenous organisms

20. causes a caseous granulomatous lesion

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