Deck 21: Nonfermenting and Miscellaneous Gram-Negative Bacilli

Question 1

What nonfermenter is the leading cause of nosocomial pneumonia and bacteremia?

A) Pseudomonas aeruginosa
B) P. fluorescens
C) P. putida
D) P. mendocina

Answer 1

A
P.aeruginosa is the most commonly isolated species of the genus in clinical specimens.It is an uncommon part of the normal bacterial flora and is isolated from less than 12% of normal stool specimens.It may,however,account for 5% to 15% of all nosocomial infections,especially pneumonia and bacteremia.

Question 2

What biochemical test will differentiate nonfermenters from Enterobacteriaceae (except Plesiomonas)?

A) Oxidase
B) Indole
C) Citrate
D) Voges-Proskauer (VP)

Answer 2

A
Most nonfermentative gram-negative bacilli are oxidase positive,a feature that differentiates them from the Enterobacteriaceae (except Plesiomonas,which is oxidase positive).

Question 3

What organisms,which are gram-negative coccobacilli,can appear as gram-positive cocci in smears made from blood culture bottles?

A) Pseudomonas putida
B) Acinetobacter spp.
C) Haemophilus
D) Alcalgenes spp.

Answer 3

B
All of the Acinetobacter spp.are coccobacilli,oxidase-negative,catalase-positive,and nonmotile.It should be noted that Acinetobacter spp.can appear as gram-positive cocci in smears made from blood culture bottles.

Question 4

What is the name of the genus of organisms that colonized 45% of all tracheotomy patients?

A) Acinetobacter spp.
B) Pseudomonas aeruginosa
C) P. mendocina
D) P. fluorescens

Question 5

What organism causes pulmonary disease among individuals with cystic fibrosis?

A) Pseudomonas fluorescens
B) P. aeruginosa
C) P. putida
D) P. mendocina

Question 6

What organism causes melioidosis?

A) Burkholderia mallei
B) B. cepacia
C) B. gladioli
D) B. pseudomallei

Question 7

All of the following are poor prognostic factors associated with Pseudomonas aeruginosa bacteremia EXCEPT:

A) Septic shock
B) Granulocytopenia
C) Septic metastatic lesions
D) Anemia

Question 8

Despite all its virulence factors,what type of pathogen is Pseudomonas aeruginosa?

A) Opportunistic
B) Primary
C) Secondary
D) Commensal

Question 9

In what single setting does Stenotrophomonas maltophilia produce all its disease?

A) Community
B) Military barracks
C) Nosocomial
D) College dorms

Question 10

All of the following are characteristics of nonfermenters EXCEPT:

A) Thin gram-negative bacilli or coccobacilli
B) Oxidase positive
C) Indole positive
D) Resistance to a variety of antimicrobials, such as aminoglycosides, third-generation cephalosporins, penicillins, and fluoroquinolones

Question 11

A microbiologist is reading the plates from a sputum culture.On the sheep blood agar (SBA),she sees flat spreading colonies with a metallic sheen.On cetrimide agar,she sees a fluorescent green color in the media with clear colonies.On MacConkey,she sees medium clear colonies that have a fruity or grape-like odor.What is the most likely organism?

A) Pseudomonas fluorescens
B) P. aeruginosa
C) P. putida
D) P. stutzeri

Question 12

What is the causative agent of glanders?

A) Burkholderia cepacia
B) B. gladioli
C) B. mallei
D) Stenotrophomonas maltophilia

Question 13

What two species of Pseudomonas have been linked to transfusion-associated septicemia?

A) Pseudomonas aeruginosa and P. stutzeri
B) P. fluorescens and P. aeruginosa
C) P. putida and P. fluorescens
D) P. putida and P. mendocina

Question 14

Which of the following is a virulence factor of Pseudomonas aeruginosa?

A) Endotoxin
B) Exotoxins
C) Capsule
D) All of the above

Question 15

What substances do nonfermenters fail to ferment?

A) Lipids
B) Carbohydrates
C) Proteins
D) Alkaloids

Question 16

What nonfermenter may produce a weak,slow,positive oxidase reaction?

A) Burkholderia cepacia
B) Pseudomonas putida
C) Stenotrophomonas maltophilia
D) P. stutzeri

Question 17

What organism is associated with pneumonia in patients with cystic fibrosis or chronic granulomatous disease (CGD)?

A) Stenotrophomonas maltophilia
B) Pseudomonas putida
C) Pseudomonas fluorescens
D) Burkholderia cepacia

Question 18

Which plant pathogen may be mistaken for Burkholderia cepacia?

A) Pseudomonas putida
B) Burkholderia gladioli
C) Stenotrophomonas maltophilia
D) P. stutzeri

Question 19

Pseudomonas aeruginosa is resistant to all the following antimicrobial agents EXCEPT:

A) Ampicillin
B) Chloramphenicol
C) Trimethoprim-sulfamethoxazole
D) Fluoroquinolones

Question 20

The three species of nonfermenters that make up the majority of isolates routinely seen in clinical laboratories include all the following EXCEPT:

A) Pseudomonas aeruginosa
B) Acinetobacter spp.
C) Stenotrophomonas maltophilia
D) P. putida

Question 21

What organism is an opportunistic pathogen that strikes the immunocompromised patient with neutrophil deficits and produces a violet pigment on nonselective agar?

A) Psychrobacter immobilis
B) Chromobacterium violaceum
C) Chryseomonas luteola
D) Paracoccus phenylpyruvicus

Question 22

Characteristics of Moraxella include:

A) Oxidase-positive and nonmotile
B) Biochemically inert and aerobic
C) Susceptible to penicillin and opportunistic pathogens
D) All of the above

Question 23

What is unique about the Sphingobacterium spp.?

A) Sphingomyelin in the cell wall
B) Cholesterol in the cell wall
C) Sphingophospholipids in the cell wall
D) Collagen in the cell wall

Question 24

Elizabethkingae (Chryseobacterium)meningosepticum causes all the following diseases EXCEPT:

A) Pneumonia
B) Gastroenteritis
C) Endocarditis
D) Meningitis

Question 25

Which nonfermenter is considered by government agencies to be a potential bioterrorist agent?

A) Moraxella catarrhalis
B) Burkholderia mallei
C) Pseudomonas putida
D) B. gladioli

Question 26

Members of the Alcaligenes are usually susceptible to all the following antibiotics EXCEPT:

A) Aminoglycosides
B) Cefoperazone
C) Sulfamethoxazole-trimethoprim (SXT)
D) Piperacillin

Question 27

Burkholderia pseudomallei is found in all the following areas EXCEPT:

A) New Zealand
B) Northern Australia
C) Mexico
D) Southeast Asia

Question 28

What is the most common member of the genus Moraxella isolated in the clinical laboratory?

A) Moraxella nonliquefaciens
B) M. osloensis
C) M. lacunata
D) M. catarrhalis