M123-4

Abscess fluid: Actinomyces israelii – Shipped November 2012

HISTORY

A simulated abscess fluid sample was sent to category A laboratories. It was collected from a 29 year old male with an dental abscess following a wisdom tooth extraction 6 weeks prior.

Participants were expected to isolate a grampositive anaerobic bacillus and refer for identification or report the presence of Actinomyces israelii. No susceptibilities were required.

MAIN EDUCATIONAL POINTS from M123-4

  1. Anaerobic cultures should be done on deep tissue abscesses, particularly those located adjacent to an oral-mucosal surface.
  2. Extended incubation of anaerobic plates is required in order to recover slow-growing organisms including Actinomyces species.

Full critique (PDF)

Posted in Clinical Bacteriology Results, critiques