Light inactivation of metronidazole sensitivity discs.

Abstract

We found that daylight inactivated metronidazole sensitivity discs. They should therefore be stored in light-proof containers.

Incomplete anaerobiosis as a cause of metronidazole 'resistance'.

“…It was reported recently that metronidazole sensitivity discs can be inactivated by light (Jones and Scott, 1977); we report here another explanation for the apparent failure of these discs. Some months ago, when testing the sensitivity of campylobacters to metronidazole, it was found that when Clostridium welchii was used as a control, this organism grew well in the microaerophilic conditions used but appeared resistant to metronidazole, although the campylobacter was sensitive.…”