M121-3

Wound: Pseudomonas aeruginosa – Shipped May 2012

HISTORY

The challenge was sent to category A and B laboratories. The sample was a simulated thigh wound obtained from a 30 year old burn patient.

Participants were expected to isolate and identify Pseudomonas aeruginosa. Laboratories were asked to report susceptibilities to the following antibiotics: piperacillin/piperacillintazobactam, ceftazidime, and gentamicin/tobramycin. Correlation with results obtained for the companion Gram challenge (G121) was also expected.

MAIN EDUCATIONAL POINTS from M121-3

  1. In addition to β-lactamases, other resistance mechanisms such as efflux and impermeability may play a role in an organism’s resistance to various β-lactam agents. Different resistance mechanisms may demonstrate specific resistance patterns to various antimicrobials.

Full critique (PDF)

Posted in Clinical Bacteriology Results, critiques