Weak phospholipase-positive Listeria monocytogenes: a challenge for the diagnostic laboratory.

Abstract

Listeria monocytogenes isolates from environmental samples of a food producing company harboured a C424G mutation in the prfA gene that results in a G141A substitution in PrfA. This mutation results in strongly decreased phospholipase activity and is therefore challenging for culture-based detection of L. monocytogenes and may even lead to misidentification.