Mima polymorpha bacteremia. False-positive cultures due to contaminated penicillinase

Abstract

Over a ten-month period 56 blood cultures from 27 patients grew Mima polymorpha. Only three patients in this group had clinical evidence of bacteremia. Most of the 48 positive blood cultures in the 24 patients without clinical evidence of bacteremia were caused by addition to the blood cultures of penicillinase, which was contaminated with M polymorpha. Several patients were treated because of the false-positive blood culture results.