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 disks.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 disks or colistin disks 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