HARR EE2 7.7 Flashcards
Obligate anaerobes, facultative anaerobes, and
microaerophiles are terms referring to bacteria
that require:
A. Increased nitrogen
B. Decreased CO2
C. Increased O2
D. Decreased O2
D. Decreased O2
Which of the following most affects the
oxidation–reduction potential (Eh or redox
potential) of media for anaerobic bacteria?
A. O2
B. Nitrogen
C. pH
D. Glucose
C. pH
Which of the following is the medium of choice
for the selective recovery of gram-negative
anaerobes?
A. Kanamycin–vancomycin (KV) agar
B. Phenylethyl alcohol (PEA) agar
C. Cycloserine–cefoxitin–fructose agar (CCFA)
D. THIO broth
A. Kanamycin–vancomycin (KV) agar
Anaerobic bacteria are routinely isolated from
all of the following types of infections except:
A. Lung abscesses
B. Brain abscesses
C. Dental infections
D. Urinary tract infections
D. Urinary tract infections
Methods other than packaged microsystems used to identify anaerobes include: A. Antimicrobial susceptibility testing B. Gas–liquid chromatography (GLC) C. Special staining D. Enzyme immunoassay
B. Gas–liquid chromatography (GLC)
Which broth is used for the cultivation of
anaerobic bacteria in order to detect volatile fatty
acids as an aid to identification?
A. Prereduced peptone–yeast extract–glucose (PYG)
B. THIO broth
C. Gram-negative (GN) broth
D. Selenite (SEL) broth
A. Prereduced peptone–yeast extract–glucose (PYG)
A gram-positive spore-forming bacillus growing on
sheep-blood agar anaerobically produces a double
zone of β-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
Egg yolk agar is used to detect which enzyme produced by Clostridium species? A. Lecithinase B. β-Lactamase C. Catalase D. Oxidase
A. Lecithinase
Which of the following organisms will display lipase activity on egg yolk agar? A. Clostridium botulinum B. Clostridium sporogenes C. Clostridium novyi (A) D. All of these options
D. All of these options
Which spore type and location is found on Clostridium tetani? A. Round, terminal spores B. Round, subterminal spores C. Ovoid, subterminal spores D. Ovoid, terminal spores
A. Round, terminal spores
Gram-positive bacilli recovered from two blood cultures from a 60-year-old diabetic patient gave the following results
- Spores seen = Neg
- Hemolysis = + (double zone)
- Motility = Neg
- Lecithinase = +
- Volatile acids by GLC (PYG) = acetic acid (A) and butyric
acid (B)
What is the most likely identification?
A. Clostridium tetani
B. Clostridium perfringens
C. Clostridium novyi (B)
D. Clostridium sporogenes
B. Clostridium perfringens
Which mechanism is responsible for botulism in infants caused by Clostridium botulinum? A. Ingestion of spores in food or liquid B. Ingestion of preformed toxin in food C. Virulence of the organism D. Lipase activity of the organism
A. Ingestion of spores in food or liquid
The classic form of foodborne botulism is characterized by the ingestion of: A. Spores in food B. Preformed toxin in food C. Toxin H D. All of these options
B. Preformed toxin in food
Which test is performed in order to confirm an infection with Clostridium botulinum? A. Toxin neutralization B. Spore-forming test C. Lipase test D. Gelatin hydrolysis test
A. Toxin neutralization
Which Clostridium spp. causes pseudomembranous
colitis or antibiotic-associated colitis?
A. C. ramosum
B. C. difficile
C. C. perfringens
D. C. sporogenes
B. C. difficile
