Throat:  No group A streptococcus isolated – Shipped February 2012


A sample simulating a throat swab collected from a 5 year old male with a sore throat was sent to category A, B, and C laboratories.

Participants were expected to report “no β-hemolytic group A streptococcus isolated.”


  1. The intent of this Clinical Relevancy challenge was for participating laboratories to recognize Moraxella catarrhalis and Streptococcus salivarius as part of the commensal respiratory flora in throat cultures, and to report a pathogen specific (eg. No Group A Streptococcus) negative report to receive full marks. With the exception of two laboratories that did not submit a report, and a single laboratory that reported using the wrong form, all participants submitted pathogen specific negative reports and received full marks for this challenge.

Full critique (PDF)

Posted in Clinical Bacteriology Results, critiques