Microbiology Exam Ii

MICROBIOLOGY EXAM II

CODE 4

SIMPLE COMPLETIONS: Each of the questions or incomplete statements in this group is followedby four or five suggested answers or completions. Select the one which is best in each case and markthe corresponding letter on the answer sheet.

1. Which of the following is NOT TRUE regarding Nocardia?

It is weakly acid-fast.
It is Gram negative.
It grows well in compost.
It may cause disseminated infection.
It grows well on most laboratory media.

2. Which of the following is true of the non tuberculosis mycobacteria?

A. Positive skin tests are rare.

B. Person-to-person spread occurs commonly.

C. Clinical illness is more common in the immunocompromised host.

D. They do not grow in soil.

E. They never produce pigment.

3. INH (isoniazid) is beneficial in preventing the recrudescence or reactivation of asymptomatic

tuberculosis infection. However, the most common side effect that the clinician must monitoris:

A. rash.

B. diarrhea.

C. headache.

D. hepatitis.

E. arthritis.

4. The reservoir of Salmonella typhi is:

A. dogs

B. cats

C. turtles

D. pigs

E. humans

5. Hemolytic uremic syndrome (HUS) is a sequela associated with this verotoxin-producing

pathogen.

A. EHEC (Enterohemorrhagic E. coli)

B. EIEC (Enteroinvasive E. coil)

C. ETEC (Enterotoxigenic E. coli)

D. EAggEC (Enteroaggregative E. coil)

E. EPEC (Enteropathogenic E. coil)

6. The most common cause of urinary tract infection is:

A. Salmonella typhimurium

B. Escherichia coli

C. Enterobacter

D. Shigella flexneri

E. Klebsiella pneumoniae

7. The most common cause of community-acquired pneumonia is:

A. Salmonella typhimurium

B. Escherichia coli

C. Enterobacter

D. Shigella flexneri

E. Klebsiella pneumoniae

8. Which of the following statements is true about Chlamydia?

A. Chlamydia can produce colonies on artificial media

B. Chlamydia synthesize their own ATP

C. Chlamydia contain cytochromes

D. Chlamydia have a unique developmental cycle

9. The metabolically active stage in the chiamydial life cycle is the:

A. reticulate body

B. exocytic particle

C. elementary body

D. cytoadsorption body

10. Which of the following is the most likely causative agent of neonatal inclusion conjunctivitis?

A. C. trachomatis

B. C. psittaci

C. C. pneumoniae

D. None of the above

11. Syphilis:

A. has an annual incidence of less than 10,000 reported cases in the U.S.

B. can not be transmitted transplacentally.

C. is characterized by a primary lesion called a gumma.

D. is never asymptomatic.

E. can cause neurologic symptoms.

12. Relapsing Fever and Lyme disease:

A. are caused by members of the genus Leptospira.

B. are transmitted by arthropods.

C. are most commonly acquired in urban areas.

D. do not stimulate host antibody responses.

E. are not found in the United States.

13. Similarities between Syphilis and Lyme disease include all of the following EXCEPT:

A. Mode of transmission.

B. Progress from local to systemic disease.

C. Occurrence of persistent infection.

D. Spirochetal etiology

E. Occurrence of cardiovascular manifestations.

14. Control of Brucellosis has been achieved primarily by:

A. Cooking meat

B. Controlling this disease in livestock

C. Hyperchlorination of the water supply

D. Eradication of insect reservoirs

15. Clinical manifestations of Francisella tularensis include:

A. typhoidal disease

B. toxic shock

C. tetanus

D. arthritis

16. Legionella infection can be diagnosed using the following laboratory tests:

A. Isolation from a transtracheal aspirate on standard bacteriologic media

B. Specific detection with fluorescein-labeled antibodies

C. Detection of a soluble L. pneumophila serogroup 5 antigen in spinal fluid

D. Appearance as Gram-negative diplococci upon staining of sputum r

17. To test a stool specimen for Campylobacter, all of the following measures would be used

except:

A. Passing the samples through 0.45 micron filters

B. Plating on agar containing glucose or sucrose

C. Plating on Campy blood agar containing 5 antibiotics

D. Incubating the plates in an atmosphere of 5% O2, 10% CO2

E. Incubating the plates at 42°C

18. Which of the following statements is true about the toxin produced by Vibrio cholera?

A. It has its own adenylate cyclase activity.

B. The Al subunit indirectly stimulates the host adenylate cyclase.

C. The B subunit directly stimulates the host adenylate cyclase.

D. The toxin blocks the host adenylate cyclase.

19. A patient has been diagnosed with a gastric ulcer. A test of the patient's serum showsreactivity withHelicobacter pylori antigens. Which of the following is true?

A. The Helicobacter pylori infection most likely has nothing to do with the patient's

condition.

B. The patient will be treated with amoxicillin to eradicate H. pylori colonization and

eliminate its recurrence.

C. The patient's gastrin-hydrochloric homeostasis has been maintained.

D. Damage to the patient's gastric mucosa has been primarily caused by the patient's own

immune response.

20. A urine specimen kept at room temperature for 2 hours after collection is sent to the

microbiology laboratory for culture. This specimen will be:

A. diluted

B. rejected

C. processed

D. inoculated

E. disinfected

21. In the diagnosis of a urinary tract infection, which of the following specimens IS NOT

acceptable for culture:

A. the tip of a Foley's catheter

B. a clean-catch urine specimen

C. urine from a neonatal bag

D. urine obtained by needle aspiration

22. The following microorganism is assumed to be an etiological agent of disease when isolated

from a stool culture:

A. Klebsiella

B. Enterobacter

C. Proteus .

D. Salmonella

E. Morganella

23. The identification of Enterobacteriaceae in the laboratory is based on their:

A. Gram stain morphology

B. tolerance to antibiotics

C. ability to ferment specific carbohydrates

D. acid-fast property

24. Haemophilus influenzae strains found in cases of acute bacterial meningitis are usually:

A. not encapsulated

B. encapsulated

C. isolated from newborns

D. isolated from young adults

25. In the diagnosis of Whooping cough, Bordetella pertussis is most likely isolated from:

A. a blood culture

B. a throat swab

C. a nasopharyngeal swab

D. an abscess site swab

E. cerebrospinal fluid

26. Meningitis due to H. influenzae type B occurs more frequently in:

A. Neonates (newborns)

B. Children under 6 years of age

C. Adolescents (12-19 yearsof age)

D. Adults (20-59 years of age)

E. Adults over 60

27. A 44 yr-old poultry farmer has a well-defined wine-colored lesion on his right arm which ispainful and itching. A swab is taken from the lesion. The resulting culture revealsGram-positive rods with production of H2S. Which of the following is most likely causativeorganism?

A. Bacillus anthraces

B. Listeria monocytogenes

C. Erysipelothrix rhusiopathiae

D. Bacillus cereus

E. Corynebacterium diphtheriae

28. The vaccine against infection by Corynebacterium diphtheriae:

A. should be administered with anti-toxin.

B. is not currently available in the U.S.

C. provides short-term immunity (less than one year).

D. is a toxoid.

E. is a live attenuated strain of C. diphtheriae.

29. Which of the following is the least accurate statement regarding Gardnerella vaginalis

infection?

A. Treatment should include penicillin.'

B. Vaginal pH is increased.

C. Wet smears yield epithelial cells covered with tiny rods.

D. vaginalis is the only medically relevant species of this genus.

E. G. vaginalis is Gram-variable and nonmotile

30. Listeria monocytogenes may be mistaken for a hemolytic streptococcus (because it can appearcoccoid in direct smears) or corynebacteria (because it grows well on potassium tellurite agar).Which of the following tests distinguishes L. monocytogenes from these other bacteria?

A. Gram positive cell wall

B. Sensitivity to ampicillin

C. Catalase production

D. 13-hemolysis on blood agar

E. Growth at 4°C

31. The etiologic agent of Cat Scratch disease is thought to be:

A. Bartonella (Rochalimaea) henselae

B. Rickettsia akari

C. Ureaplasma urealyticum

D. Mycoplasma pneumoniae

32. Rickettsia:

A. can only be successfully cultured in anaerobic conditions

B. exhibit rapid growth (24-48 hours) on routine blood agar plates

C. can be cultured in fertile eggs and in some tissue cultures

D. can not be cultured in vitro

33. Mycoplasma pneumoniae:

A. lacks both cell wall and a cell membrane

B. is a strict aerobe

C. has a cell wall but lacks a cell membrane

D. requires an arthropod vector for transmission

34. Synergy in anaerobic infection pathogenesis is best demonstrated by which of the following:

A. Earlier tissue death in anaerobic conditions

B. Production of virulence factors

C. Increased virulence when anaerobes and aerobes infect together

D. Bacterial growth with less energy consumption

E. Infection occurs at low tissue redox potential

35. Which of the following is not a virulence factor for Bacteroides fragilis?

A. Superoxide dismutase

B. Hemolysin

C. Heparinase

D. Endotoxin

E. Collagenase

36. Which one of the following specimens does not usually contain anaerobes?

A. Aspiration from an infected maxillary sinus

B. Expectorated sputum from a patient with community-acquired pneumonia

C. Throat swab from a patient with a sore throat

D. Cerebral spinal fluid from a patient with meningitis -

E. Vaginal secretions from a woman with suspected candidal vaginitis

37. Of the following known causes of diarrhea, which one is most likely to be associated with

diarrhea occurring in a patient receiving antibiotics?

A. Clostridium perfringens

B. Clostridium difficile

C. Shigella sonnei

D. Campylobacter jejuni

E. Enterotoxigenic E. coli

38. Which one is a risk factor for tuberculosis?

A. Middle aged adult.

B. Scandinavian.

C. asymptomatic HIV infection.

D. attorney.

E. female.

MATCHING:

Choose the best answer. Answers may be used once, more than once, or not at all.

39. _____ Cerebrospinal fluid A. This clinical specimen can be refrigerated for a fewhours after collection, before being processed forbacterial cultures.

40. _____ Sputum

41. _____ Urine B. This clinical specimen must be submitted to the

microbiology laboratory immediately after

collection.

42._____ Stool

43. _____ Biopsy

TRUE OR FALSE

Choose the best possible answer. A = True; B = False

44. _____ Anthrax toxin is secreted by Bacillus anthraces as a single polypeptide.

45. _____ Diphtheria toxin is secreted by Corynebacterium diphtheriae as a single

polypeptide.

46. _____ The presence of squamous cells in sputum indicates a good specimen.

47. _____ Acid-fast bacteria do not stain well by the Gram stain procedure.

48. _____ Mycobacterium tuberculosis can be positively identified on acid-fast smears.

49. _____ Serological identification of Enterobacteriaceae is used in epidemiological

investigations.

ANSWERS:

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