PART 2.2 Flashcards
Routine laboratory testing for Treponema pallidum involves:
A. Culturing
B. Serological analysis
C. Acid-fast staining
D. Gram staining
B. Serological analysis
Which of the following organisms is the cause of Lyme disease?
A. Treponema pallidum
B. Neisseria meningitidis
C. Babesia microti
D. Borrelia burgdorferi
D. Borrelia burgdorferi
Primary atypical pneumonia is caused by: A. Streptococcus pneumoniae B. Mycoplasma pneumoniae C. Klebsiella pneumoniae D. Mycobacterium tuberculosis
B. Mycoplasma pneumoniae
Which organism typically produces “fried-egg” colonies on agar within 1-5 days of culture from a genital specimen?
A. Mycoplasma hominis
B. Borrelia burgdorferi
C. Leptospira interrogans
D. Treponema pallidum
A. Mycoplasma hominis
A direct smear from a nasopharyngeal swab stained with Loeffler’s methylene blue stain showed various letter shapes and metachromatic granules. The most likely identification is:
A. Corynebacterium spp.
B. Nocardia spp.
C. Listeria spp.
D. Gradnerella spp.
A. Corynebacterium spp.
Which of the following is the best rapid, noncultural test to perform when Gradnerella vaginalis is suspected in a patient with vaginosis?
A. 10% KOH
B. 3% H2O2
C. 30% H2O2
D. All of these
A. 10% KOH
A gram-positive spore-forming bacillus growing on blood agar anaerobically produces a double zone of beta-hemolysis and is positive for lecithinase. What is the presumptive identification?
A. Bacteroides ureolyticus
B. Bacteroides fragilis
C. Clostridium perfringens
D. Clostridium difficile
C. Clostridium perfringens
Which spore type and location is found on C. tetani?
A. Round, terminal spores
B. Round, subterminal
C. Ovoid, subterminal spores
D. Oval, terminal spores
A. Round, terminal spores
Which Clostridium spp. is most often recovered from a wound infection with gas gangrene?
A. C. sporogenes
B. C. sordellii
C. C. novyi
D. C. perfringens
D. C. perfringens
A Gram stain smear taken from the periodontal pockets of a 30-year-old male with poor dental hygiene showed sulfur granules containing gram-positive rods (short diphtheroids and some unbranched filaments). Colonies on blood agar resembled “molar teeth” in formation. The most likely organism is: A. Actinomyces israelii B. Propionibacterium acnes C. Streptococcus intermedius D. Peptostreptococcus anaerobius
A. Actinomyces israelii
Mycobacteria stained with Ziehl-neelsen or Kinyuon methods using a methylene blue counterstain, are seen microscopically as:
A. Bright red rods against a blue background
B. Bright yellow rods against a yellow background
C. Orange-red rods against a black background
D. Bright blue rods against a pink background
A. Bright red rods against a blue background
Acid-fast staining of a smear prepared from a digested sputum showed slender, slightly curved, beaded red mycobacterial rods. Growth on Middlebrook 7H10 slants produced buff-colored microcolonies with a serpentine pattern after 14 days at 37 oC. Niacin and nitrate reduction tests were positive. What is the most probable presumptive identification?
A. Mycobacterium tuberculosis
B. Mycobacterium ulcerans
C. Mycobacterium kansasii
D. Mycobacterium avium complex
A. Mycobacterium tuberculosis
Which of the following mycobacteria produces pigmented colonies in the dark (is a scotochromogen)?
A. M. szulgai
B. M. kansasii
C. M. tuberculosis
D. All of these
A. M. szulgai
All of the following Mycobacterium spp. produce the enzyme required to convert niacin to niacin ribonucleotide except:
A. M. kansasii
B. M. tuberculosis
C. M. avium
D. All of these
B. M. tuberculosis
Which nonpathogenic Mycobacterium sp. is isolated most often from clinical specimens and is called the “tapwater bacillus”?
A. M. kansasii
B. M. avium
C. M. leprae
D. M. gordonae
D. M. gordonae
Which of the following Mycobacterium spp. would be most likely to grow on MacConkey agar plate?
A. M.chelonei-fortuitum complex
B. M. ulcerans
C. M. marinum
D. M. avium-intracellulare comples
A. M.chelonei-fortuitum complex
For which clinical specimens is the potassium hydroxide direct mount technique for examination of fungal elements used?
A. Skin
B. CSF
C. Blood
D. Bone marrow
A. Skin
The India ink stain is used as a presumptive test for the presence of which organism?
A. Aspergillus niger in blood
B. Crytococcus neoformans in CSF
C. Histoplasma capsulatum in CSF
D. Candida albicans in blood/body fluids
B. Crytococcus neoformans in CSF
Which of the following yeast enzymes is detected using birdseed (niger seed) agar?
A. Phenol oxidase
B. Catalase
C. Urease
D. Nitrate reductase
A. Phenol oxidase
Which of the following yeasts is characteristically positive for germ tube production?
A. Candida tropicalis
B. Candida pseudotropicalis
C. Crytococcus neoformans
D. Candida albicans
D. Candida albicans
Dimorphic molds are found in the infected tissue in which form?
A. Mold phase
B. Yeast phase
C. Encapsulated
D. Latent
B. Yeast phase
The mycelial form of which dimorphic mold produces thick-walled, rectangular, or barrel-shaped alternate arthroconidia?
A. Coccidioides immitis
B. Sporothrix schenckii
C. Histoplasma capsulatum
D. Blastomyces dermatitidis
A. Coccidioides immitis
The yeast form of which dimorphic fungus appears as oval or elongated cigar shaped, some with multiple buds?
A. Coccidioides immitis
B. Sporothrix schenckii
C. Histoplasma capsulatum
D. Blastomyces dermatitidis
B. Sporothrix schenckii
The yeast form of which dimorphic mold shows a large parent yeast cell surrounded by smaller budding yeast cells?
A. Paracoccidioides brasiliensis
B. Sporothrix schenckii
C. Coccidioides immitis
D. Histoplasma capsulatum
A. Paracoccidioides brasiliensis
Tinea versicolor is a skin infection caused by:
A. Malassezia furfur
B. Trichophyton rubrum
C. Trichophyton schoenleinii
D. Microsporum gypseum
A. Malassezia furfur
Which Trichophyton sp. causes the favus type of tinea capitis seen in Scandinavian countries and in the Appalachian region of the United States?
A. T. verrucosum
B. T. violaceum
C. T. tonsurans
D. T. schoenleinii
D. T. schoenleinii
The hair baiting test is used to differentiate which two species of Trichophyton that produce red colonies on Sabouraud’s agar plates?
A. T. mentagrophytes and T. rubrum
B. T. tonsurans and T. schoenleinii
C. T. tonsurans and T. violaceum
D. T. verrucosum and T. rubrum
A. T. mentagrophytes and T. rubrum
Which virus is the most common etiological agent of viral respiratory diseases in infants and children?
A. Respiratory syncytial virus
B. Measles virus
C. Coxsackie A virus
D. Coxsackie B virus
A. Respiratory syncytial virus
Which virus belonging to the Reoviridae group causes gastroeneteritis in infants and young children but asymtomatic infection in adults?
A. Coxsackie B virus
B. Rotavirus
C. Respiratory syncytial virus
D. Rhabdovirus
B. Rotavirus
A very small, single-stranded DNA virus that causes a febrile illness with a rash and is called the fifth childhood disease after rubeola, rubella, varicella and roseola is:
A. Rotavirus
B. Adenovirus type 40
C. Coxsackie A virus
D. Parvovirus B19
D. Parvovirus B19
