A microbiologist observes culture plates that have larger nonpigmented gray colonies at 24 hours that are indole negative,nonmotile,catalase positive,and resistant to polymyxin B discs.The Gram stain shows this is a gram-negative coccobacilli.What is the most probable organism?
A) Francisella tularensis
B) Brucella mallei
C) Yersinia pestis
D) Burkholderia cepacia

Question

Quizplus · Accepted Answer

Gram-negative coccobacilli or small gram-negative bacilli with poor growth at 24 hours,forming larger nonpigmented gray colonies at 48 hours that are indole negative,nonmotile,catalase positive,and resistant to polymyxin B discs or colistin discs are presumptively identified as B.mallei and must be submitted to the state public health laboratory or a Laboratory Response Network (LRN)reference laboratory.

A Microbiologist Observes Culture Plates That Have Larger Nonpigmented Gray