M131-2

Sputum: Haemophilus influenzae  – Shipped May 2013

HISTORY

A simulated sputum sample obtained from a 60 year old hospitalized patient with an acute chronic obstructive pulmonary disease (COPD) exacerbation was sent to category A and B laboratories.

Participants were expected to isolate, identify, and report Haemophilus influenzae; labs were also expected to test and report antibiotic susceptibilities.

MAIN EDUCATIONAL POINTS from M131-2

  1. Whereas a positive β-lactamase test indicates ampicillin resistance, a negative result for Haemophilus influenzae may not accurately predict ampicillin susceptibility because of the presence of other resistance mechanisms.
  2. CMPT supports the testing of ampicillin if the β-lactamase test is negative to avoid mistreating patients with ampicillin-resistant H. influenzae infections.

Full critique (PDF)

Posted in Clinical Bacteriology Results, critiques