MICROBIOLOGY EXAM 4 NEWEST ACTUAL EXAM
COMPLETE 220 QUESTIONS AND CORRECT DETAILED
ANSWERS
What are some general characteristic of the nonfermenters? - ANSWER: Found in
most environments, prefer aerobic environments, resistant to many antibiotics,
rarely a part of host microbiota
What are the general biochemical reactions of the nonfermenters? - ANSWER:
Oxidase +, fail to acidify OF media when overlaid with mineral oil, cannot acidify TSI
agar butts
Some organisms are oxidizers, some are asaccharolytic
What are the 3 common tests used to look for nonfermenters? - ANSWER: Growth
on MAC agar, oxidase, glucose OF test
What are the most common nonfermenters seen in the clinical laboratory? -
ANSWER: Pseudomonas aeruginosa, Acinetobacter spp., Burkholderia spp.,
Stenotrophomonas maltophilia
What are some general characteristics of the Pseudomonas genus? - ANSWER: Gram
- bacilli, strict aerobes, motile, oxidase and catalase +, oxidizes carbohydrates,
usually grows on MAC
Where is P. aeruginosa typically found? - ANSWER: Moist environments (pools, hot
tubs, catheters, humidifiers)
What pigment does P. aeruginosa produce that fluoresces under UV light? -
ANSWER: Pyoverdin
What illnesses can be caused by P. aeruginosa? - ANSWER: Nosocomial respiratory
tract infections, LRT infections in patients with cystic fibrosis, wound infections,
nosocomial UTIs
What patients can quickly become colonized by P. aeruginosa? - ANSWER: Patients
who are mechanically ventilated
What is the colony morphology of P. aeruginosa? - ANSWER: Flat, spreading colonies
with a characteristic metallic sheen. Fruity, grapelike odor
What are some biochemical characteristics that can be used to identify P.
aeruginosa? - ANSWER: Oxidase +, catalase +, B-hemolysis, ADH +, citrate +
What agar is selective and differential for P. aeruginosa? - ANSWER: Cetrimide agar
, What can be used to treat P. aeruginosa? - ANSWER: Aminoglycosides, semisynthetic
penicillins, third and fourth generation cephalosporins
What characteristics can be used to differentiate P. fluorescens and P. putida from P.
aeruginosa? - ANSWER: Does not produce pyocyanin, cannot reduce nitrate
What are the nonfluorescent Pseudomonas species? - ANSWER: P. stutzeri, P.
mendocina, P. pseudoalcaligenes, P. alcaligenes
What hospital equipment is Acinetobacter associated with? - ANSWER: Ventilators,
humidifiers, catheters
What infections caused by A. baumannii have a high mortality rate? - ANSWER: VAP
and sepsis
What are some infections that can be caused by S. maltophilia (Stenotrophomonas)?
- ANSWER: Pneumonia, endocarditis, wound infections, bacteremia
What are some infections that can be caused by B. cepacia (Burkholderia)? -
ANSWER: Pneumonia in CF and CGD patients, endocarditis, UTIs, osteomyelitis,
dermatitis, wound infections
What is the selective agar used to identify B. cepacia? - ANSWER: BCSA
What are some other Burkholderia species besides B. cepacia? - ANSWER: B. mallei,
B. pseudomallei, B. gladioli
What has Psychrobacter been isolated from? - ANSWER: Fish, processed meat,
poultry
What are some general characteristics of the Alcaligenes and Achromobacter
species? - ANSWER: Grow well on most media, nonpigmented, flagella
What are some general biochemical reactions of Chromobacterium violaceum? -
ANSWER: Fermentative, gram - bacilli, oxidase variable, motile, violet pigment,
catalase +, indole -
What are some general biochemical reactions of Flavobacteriaceae? - ANSWER:
Lavender-green discoloration of media, DNAse +, oxidase +, weakly indole +
What are some factors that can predispose a patient to an infection by an anaerobe?
- ANSWER: Trauma, vascular stasis, entry to a reduced environment
What are some general characteristics of the Clostridium spp.? - ANSWER: Gram +
bacilli, anaerobe, spore-forming, mostly exogenous infections
What species of Clostridium causes endogenous infections? - ANSWER: C. difficile
COMPLETE 220 QUESTIONS AND CORRECT DETAILED
ANSWERS
What are some general characteristic of the nonfermenters? - ANSWER: Found in
most environments, prefer aerobic environments, resistant to many antibiotics,
rarely a part of host microbiota
What are the general biochemical reactions of the nonfermenters? - ANSWER:
Oxidase +, fail to acidify OF media when overlaid with mineral oil, cannot acidify TSI
agar butts
Some organisms are oxidizers, some are asaccharolytic
What are the 3 common tests used to look for nonfermenters? - ANSWER: Growth
on MAC agar, oxidase, glucose OF test
What are the most common nonfermenters seen in the clinical laboratory? -
ANSWER: Pseudomonas aeruginosa, Acinetobacter spp., Burkholderia spp.,
Stenotrophomonas maltophilia
What are some general characteristics of the Pseudomonas genus? - ANSWER: Gram
- bacilli, strict aerobes, motile, oxidase and catalase +, oxidizes carbohydrates,
usually grows on MAC
Where is P. aeruginosa typically found? - ANSWER: Moist environments (pools, hot
tubs, catheters, humidifiers)
What pigment does P. aeruginosa produce that fluoresces under UV light? -
ANSWER: Pyoverdin
What illnesses can be caused by P. aeruginosa? - ANSWER: Nosocomial respiratory
tract infections, LRT infections in patients with cystic fibrosis, wound infections,
nosocomial UTIs
What patients can quickly become colonized by P. aeruginosa? - ANSWER: Patients
who are mechanically ventilated
What is the colony morphology of P. aeruginosa? - ANSWER: Flat, spreading colonies
with a characteristic metallic sheen. Fruity, grapelike odor
What are some biochemical characteristics that can be used to identify P.
aeruginosa? - ANSWER: Oxidase +, catalase +, B-hemolysis, ADH +, citrate +
What agar is selective and differential for P. aeruginosa? - ANSWER: Cetrimide agar
, What can be used to treat P. aeruginosa? - ANSWER: Aminoglycosides, semisynthetic
penicillins, third and fourth generation cephalosporins
What characteristics can be used to differentiate P. fluorescens and P. putida from P.
aeruginosa? - ANSWER: Does not produce pyocyanin, cannot reduce nitrate
What are the nonfluorescent Pseudomonas species? - ANSWER: P. stutzeri, P.
mendocina, P. pseudoalcaligenes, P. alcaligenes
What hospital equipment is Acinetobacter associated with? - ANSWER: Ventilators,
humidifiers, catheters
What infections caused by A. baumannii have a high mortality rate? - ANSWER: VAP
and sepsis
What are some infections that can be caused by S. maltophilia (Stenotrophomonas)?
- ANSWER: Pneumonia, endocarditis, wound infections, bacteremia
What are some infections that can be caused by B. cepacia (Burkholderia)? -
ANSWER: Pneumonia in CF and CGD patients, endocarditis, UTIs, osteomyelitis,
dermatitis, wound infections
What is the selective agar used to identify B. cepacia? - ANSWER: BCSA
What are some other Burkholderia species besides B. cepacia? - ANSWER: B. mallei,
B. pseudomallei, B. gladioli
What has Psychrobacter been isolated from? - ANSWER: Fish, processed meat,
poultry
What are some general characteristics of the Alcaligenes and Achromobacter
species? - ANSWER: Grow well on most media, nonpigmented, flagella
What are some general biochemical reactions of Chromobacterium violaceum? -
ANSWER: Fermentative, gram - bacilli, oxidase variable, motile, violet pigment,
catalase +, indole -
What are some general biochemical reactions of Flavobacteriaceae? - ANSWER:
Lavender-green discoloration of media, DNAse +, oxidase +, weakly indole +
What are some factors that can predispose a patient to an infection by an anaerobe?
- ANSWER: Trauma, vascular stasis, entry to a reduced environment
What are some general characteristics of the Clostridium spp.? - ANSWER: Gram +
bacilli, anaerobe, spore-forming, mostly exogenous infections
What species of Clostridium causes endogenous infections? - ANSWER: C. difficile
