Deck 21: Pseudomonas, Burkholderia, and Similar Organisms

Question 1

Which organism exhibits bipolar staining on the Gram stain, which resembles a "safety-pin" appearance?

A) Burkholderia mallei
B) Pseudomonas pseudomallei
C) The Centers for Disease Control and Prevention (CDC) group
D) Brevundimonas diminuta

Answer 1

B
P.pseudomallei exhibits bipolar staining on Gram stain that resembles a safety-pin appearance.

Question 2

Which two organisms should be used to determine the validity of urea agar for quality control purposes?

A) Pseudomonas fluorescens and Burkholderia cepacia complex
B) Ralstonia mannitolilytica and Acidovorax delafieldii
C) Brevundimonas diminuta and Brevundimonas vesicularis
D) Brevundimonas vesicularis and Ralstonia pickettii

Answer 2

D
The only two organisms that are negative and positive, respectively, are B.vesicularis and R.pickettii, and they can be used for quality control purposes.

Question 3

An organism described as oxidase-positive, (K/NC)on TSI media, growth at 42° C, and produces a bright bluish-green pigment on Mueller-Hinton agar is most likely:

A) Pseudomonas aeruginosa.
B) Ralstonia pickettii.
C) Burkholderia mallei.
D) Burkholderia pseudomallei.

Answer 3

A
P.aeruginosa, one of the most common gram-negative species encountered in the clinical setting, can be identified conveniently and reliably by the oxidase test, TSI slant, testing for growth at 42° C, and observation of a bright bluish-green, red, or brown diffusible pigment.

Question 4

Which best describes the source of Burkholderia cepacia infections?

A) Rice paddles
B) Medical devices
C) Oropharynx of animals
D) Rodents

Question 5

A convenient and reliable identification scheme for Pseudomonas aeruginosa involves which of the following conventional tests?

A) Oxidase, triple sugar iron (TSI) slant, growth at 42° C on Mueller-Hinton agar or trypticase soy agar
B) Catalase, lysine iron agar (LIA) slant, growth at 42° C on Mueller-Hinton agar or trypticase soy agar
C) Oxidase, TSI slant, growth at 24° C on Mueller-Hinton agar or trypticase soy agar
D) Catalase, TSI slant, growth at 42° C on sheep blood agar or blood trypticase soy agar

Question 6

Oxidative-fermentative base-polymyxin B-bacitracin-lactose (OFPBL)media is the best media to use to isolate which one of the following organisms from the sputa of patients with cystic fibrosis?

A) Pseudomonas pseudomallei
B) Ralstonia pickettii
C) Burkholderia cepacia
D) Acidovorax delafieldii

Question 7

Not including organisms in the Enterobacteriaceae family, the second most common gram-negative bacilli encountered in clinical specimens are:

A) Pseudomonas.
B) Burkholderia.
C) Ralstonia.
D) Vibrio.

Question 8

The disease referred to as melioidosis is caused by which one of the following?

A) Pseudomonas aeruginosa
B) Ralstonia pickettii
C) Burkholderia mallei
D) Burkholderia pseudomallei

Question 9

Which species of Burkholderia is the one most commonly found in clinical specimens?

A) Burkholderia ralstonia
B) Burkholderia pseudomallei
C) Burkholderia mallei
D) Burkholderia cepacia

Question 10

Production of exotoxin A and several proteolytic enzymes and hemolysins are factors that contribute to the pathogenicity of which organism?

A) Pseudomonas aeruginosa
B) Burkholderia cepacia
C) Ralstonia pickettii
D) Burkholderia mallei