Deck 21: Nonfermenting and Miscellaneous Gram-Negative Bacilli

Question 1

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

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

Answer 1

A
If not harboring Acinetobacter spp.already, hospitalized patients may become easily colonized.As many as 45% of patients with a tracheotomy may be colonized with Acinetobacter spp.

Question 2

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

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

Answer 2

B
Members of the Pseudomonas fluorescent group-which includes P.aeruginosa, P.fluorescens, P.putida, P.veronii, and P.monteilii-produce pyoverdine, a yellow-green or yellow-brown pigment.Many strains of P.aeruginosa will also produce the blue, water-soluble pigment pyocyanin.When pyocyanin combines with pyoverdine, the green color characteristic of P.aeruginosa is produced.Most isolates of P.aeruginosa are β-hemolytic on SBA and will produce flat spreading colonies with a characteristic metallic sheen.

Question 3

What organism causes melioidosis?

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

Answer 3

D
Burkholderia pseudomallei cause melioidosis, an aggressive granulomatous pulmonary disease caused by ingestion, inhalation, or inoculation of the organisms, with further metastatic abscess formation in lungs and other viscera.

Question 4

What is the causative agent of glanders?

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

Question 5

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

A)ampicillin.
B)chloramphenicol.
C)trimethoprim-sulfamethoxazole.
D)fluoroquinolones.

Question 6

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 7

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

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

Question 8

Which plant pathogen may be mistaken for Burkholderia cepacia?

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

Question 9

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 10

What substances do nonfermenters fail to ferment in traditional media?

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

Question 11

What organism causes pulmonary disease among individuals with cystic fibrosis?

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

Question 12

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

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

Question 13

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 14

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

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

Question 15

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)Alcaligenes spp.

Question 16

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

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

Question 17

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 18

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

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

Question 19

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 20

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

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

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

Burkholderia pseudomallei is found in all the following areas except:

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

Question 24

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

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

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

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

A)pneumonia.
B)gastroenteritis.
C)endocarditis.
D)meningitis.

Question 27

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

A)aminoglycosides.
B)ceftazidime.
C)sulfamethoxazole-trimethoprim (SXT).
D)piperacillin.

Question 28

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