M162-3

Wound: Bacillus thuringiensis – Shipped August 15, 2016

HISTORY

A simulated wound sample collected from a 48 year old farmer with arm injury was sent to category A and B laboratories.

Participants were expected to isolate, identify and report Bacillus thuringiensis / Bacillus species, not anthracis.

MAIN EDUCATIONAL POINTS from M162-3

1. Any isolate of the B. cereus group should be evaluated to exclude B. anthracis, particularly in a patient with potential for occupational exposure as described in this challenge.
2. β-hemolytic colonies essentially rule out B. anthracis, but B. cereus is a  well-recognized opportunistic pathogen and should not be dismissed a normal flora.
3. Any manipulations performed to rule out B. anthracis should be performed in a biological safety cabinet by staff wearing gloves.

Full critique (PDF)