Final Finalsss Flashcards
A physician inquiry about repeated sputum specimens, negative on routine bacterial culture, that are reported to contain only normal oropharyngeal flora on routine bacterial culture. The patient is a 67-year- old man who smokes 15 to 20 cigarettes a day and persistent cough, malaise, and a fever of 102-105°F. Empiric antimicrobial therapy and the cough and fever persist. The most recent direct Gram’s stain of sputum shows 3+ PMNs, mucus present, and rare epithelial cells. A likely etiologic agent is?
a. Haemophilus influenzae
b. Legionella pneumophila
c. Pseudomonas aeruginosa
d. Streptococcus pneumoniae
Legionella pneumophila
Anaerobic gram-positive bacilli with subterminal spores were recovered from several blood
cultures obtained from a patient diagnosed with a malignancy of the colon. The following
results were recorded: Indole = Neg Urease = Neg Lipase = Neg Catalase = Neg Lecithinase
= Neg Growth on blood agar = Swarming colonies What is the correct identification?
a. Clostridium sordellii
b. Clostridium septicum
c. Clostridium perfringens
d. Propionibacterium acnes
Clostridium septicum
Which of the following is NOT true about Chlamydia pneumoniae?
I. Common agent of lower respiratory tract infection
II. Humans become infected from animal reservoirs.
III. High risk for patients with nerve ending damages
IV. Hep 2 cell culture and Macro-immunofluorescence
a. II, IV
b. I, III
c. II, III
d. I, IV
I, III
Gram negative coccobacilli was isolated from ear discharge after 48 hours of incubation
on Horse Blood agar plate. The isolates were positive on ornithine and Urea tests. What
most likely is the organism?
a. H. Parainfluenzae Biotype II
b. H. Haemolyticus Biotype I
c. H. influenzae Biotype I
d. H. parahaemolyticus Biotype IV
e. H. ducreyi Biotype III
H. influenzae Biotype I
Anaerobic gram-positive, spore-forming bacilli were recovered from the feces of a
chemotherapy patient with severe diarrhea. The patient had undergone antibiotic therapy 1
week prior. The fecal culture produced growth only on the CCFA plate. No aerobic growth
of normal flora was seen after 48 hours.
The following results were noted:
Kanamycin = Sensitive Vancomycin = Sensitive Colistin = Resistant
Lecithinase = negative Lipase = negative Nitrate = negative
Indole = colorless ring Urease = orange Catalase = Neg
Spores = positive
Colonial morphology
CCFA agar = Growth of yellow, “ground-glass” colonies that fluoresce chartreuse (yellow-green)
A. Clostridium sordellii
B. Clostridium tetani
C. Clostridium difficile
D. Clostridium perfringens
Clostridium perfringens
Egg yolk agar is used to detect which enzyme produced by Clostridium species?
a. β-Lactamase
b. Lecithinase
c. Catalase
d. Oxidase
Lecithinase
Which of the following products is responsible for satellite growth of Haemophilus spp.
around colonies of Staphylococcus and Neisseria spp. on sheep blood agar?
a. Oxidase
b. Hemin
c. Indole
d. NAD
NAD
Which mechanism is responsible for botulism in infants caused by Clostridium botulinum?
a. Virulence of the organism
b. Ingestion of preformed toxin in food
c. Lipase activity of the organism
d. Ingestion of spores in food or liquid
Ingestion of spores in food or liquid
Francisella tularensis is the bacterium that causes tularemia, a disease not uncommonly
seen in hunters. Which of the following statements best characterizes this bacterium?
A. It produces at least one protein toxin consisting of two subunits. A and R, that causes severe spasmodic
cough usually in children.
B. It secretes erythrogenic toxin that causes the characteristic signs of scarlet fever. Strep. pyogenes
C. It secretes exotoxin that has been called “verotoxin” and ‘Shiga-like toxin”; Infection is mediated by a specific attachment to mucosal Membranes.
D. It requires cysteine for growth
E. It produces toxin that blocks protein synthesis in an infected cell and carries a lytic bacteriophage that
produces the genetic information for toxin production.
It requires cysteine for growth
Anaerobic gram-positive diphtheroids , non-spore formers were cultured from two separate
blood culture bottles (at 5 days) obtained from a 25-year-old patient admitted to the
hospital with dehydration, diarrhea, and other flulike symptoms. Four other blood culture
bottles did not grow any organisms at 7 days and were discarded. The following results
were obtained from the recovered anaerobe: positive in Indole, Nitrate, and Catalase test.
Susceptible in Susceptible in kanamycin and vancomycin while resistant in Colistin. What
is the correct identification?
a. Eubacterium lentum
b. Actinomyces spp.
c. Propionibacterium acnes
d. Peptostreptococcus spp.
Propionibacterium acnes
All of the following genera are anaerobic cocci that stain gram positive except:
a. Peptostreptococcus spp.
b. Streptococcus spp.
c. Peptococcus spp.
d. Veillonella spp.
Veillonella spp.
Identify the Haemophilus species:
Requirement for X factor: positive
Requirement for V factor. positive
Hemolysis: negative
ALA: negative
Fermentation of glucose: positive
Fermentation of sucrose: negative
Fermentation of lactose: negative
Fermentation of fructose: negative
A. H. influenzae
B. H. parahaemolyticus
C. H. ducreyi
D. H. Parainfluenzae
E. H. Haemolyticus
H. influenzae
Detection of antibody against cardiolipin is useful for the diagnosis of which of the
following disease?
A. Relapsing fever
B. Lyme disease
C. Leptospirosis
D. Syphilis
Syphilis
Haemophilus influenzae causes ocular infections and requires X and V factors in the
primary medium for growth. The subspecies Haemophilus influenza biogroup aegyptius
can further be identified and differentiated by which two tests?
a. Indole and xylose
b. Oxidase and catalase
c. ALA test and oxidase
d. Glucose and urease
Indole and xylose
The causative agent of endemic or murine typhus is
A. Rickettsia conorii
B. Rickettsia typhi
C. Rickettsia akari
D. Rickettsia prowazekii
Rickettsia typhi
Rocky Mountain Spotted fever is transmitted by the bite of a tick infected with.
a. Rickettsia prowazekii
b. Rickettsia conorii
c. Rickettsia rickettsii
d. Rickettsia akari
Rickettsia rickettsii
Which gram-negative bacilli produce black pigment and brick red fluorescence when
exposed to an ultraviolet light source?
a. Bacteroides spp. and Fusobacterium spp.
b. Porphyromonas spp. and Prevotella spp.
c. Fusobacterium spp. and Actinomyces spp.
d. All of these options
Porphyromonas spp. and Prevotella spp.
A gram-negative coccobacillus was isolated from upper respiratory tract sections with
these biochemical reactions: Hemin factor: no growth; NAD factor with growth, with red
end-colored in fermentation of mannose and mannitol, and colorless at ONPG
a. H. Parainfluenzae
b. H. influenzae
c. H. ducreyi
d. H. parahaemolyticus
e. H. Haemolyticus
H. parahaemolyticus
The diagnosis of Lyme disease can be made by:
A. silver impregnation techniques to demonstrate spirochete in tissue
B. serological demonstration of antibody in patient’s serum using enzyme immunoassay
C. growth on blood and chocolate agar
D. both A and B
E. all of the above
all of the above
rationale: in stages I and II of Lyme disease, EIA testing is performed on serum for antibodies. PCR testing and culture of Borrelia spp. are performed on a skin biopsy. In stage III, synovial fluid, skin biopsy, and CSF are tested for Borrelia spp. by PCR
The mild type of typhus fever that is caused by recrudescence of an initial attack of
epidemic typhus is known as:
a. Brill-Zinsser disease
b. Q fever
c. Tsutsugamushi disease
d. Relapsing fever
Brill-Zinsser disease
Identify the following bacterium and specimen pairing that is mismatched (specimen not
appropriate for isolation).
a. Chlamydia trachomatis: first voided urine
b. Chlamydia psittaci: fecal swab
c. Chlamydia trachomatis: endocervical swab
d. Chlamydia pneumonia: throat swab or sputum
Chlamydia psittaci: fecal swab
The following characteristics of an obligate anaerobic gram-negative bacilli best describe
which of the listed genera? Gram stain: long, slender rods with pointed ends colonial
appearance: dry bread crumbs or “fried-egg” appearance Penicillin 2-unit disk test:
Susceptible
a. Bacteroides spp.
b. Fusobacterium spp.
c. Porphyromonas spp.
d. Prevotella spp
Fusobacterium spp.
An elderly woman who cared for several domestic cats was hospitalized with suspected
cat-scratch disease. Blood cultures appeared negative, but a small, slightly curved
pleomorphic gram-negative bacillus grew on BHI agar. What is the most likely
identification?
a. Haemophilus spp.
b. Bartonella spp.
c. Kingella spp.
d. Brucella spp.
Bartonella spp.
Obligate anaerobic gram-negative bacilli that do not form spores grow well in 20% bile and
are resistant to penicillin 2-unit disks are most likely:
a. Prevotella spp.
b. Bacteroides spp.
c. Fusobacterium spp.
d. Porphyromonas spp.
Bacteroides spp.
The δ-ALA test is a confirmatory procedure for which test used for identification of
Haemophilus species?
a. V factor requirement
b. Urease production
c. Indole production
d. X factor requirement
X factor requirement
A Porphyromonas spp.
a. Bacteroides spp.
b. Prevotella spp.
c. Fusobacterium spp
Fusobacterium spp
The majority of Haemophilus influenzae infections are caused by which of the following
capsular serotypes?
a. b
b. a
c. c
d. d
b capsular serotypes
Borrelia burgdorferi, a spirochete transmitted by Ixodes dammini and the etiologic agent
of?
a. Q fever
b. Lyme disease
c. Relapsing fever
d. Rat-like fever
Lyme disease
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 of this isolate?
a. Clostridium difficile
b. Bacteroides urealyticus
c. Bacteroides fragilis
d. Clostridium perfringens
Clostridium perfringens
During the first week of leptospirosis, the most reliable way to detect the presence of the
causative agent is by the direct
I. culturing blood
II. culturing urine
III. Examination of blood
IV. Examination of CSF
A. I, III
B. IV only
C. II
D. I only
I only