A method of enhancing verocytotoxin production by<i>Escherichia coli</i>

Abstract

The number of verocytotoxin producing Escherichia coli (VTEC) present in the faeces during an infection may be very low, making their detection difficult. We report a method for enhancing toxin production by VTEC using mitomycin C as an inducing agent with the aim of improving the detection of VTEC. In pure culture, mitomycin C enhanced toxin production up to 100-fold. When applied to mixed faecal culture, toxin could be detected in mitomycin C treated samples when standard cultures were negative and when substantially fewer verocytotoxin-producing bacteria were present. Use of this method may aid in the detection of VTEC and is appropriate for use in the routine diagnostic laboratory.