Prevalence of Shiga toxin-producing Escherichia coli (STEC) in Tasmania, Australia

Abstract

(1) To determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) and the incidence of STEC associated enteritis within Tasmania and thereby evaluate the need for routine testing for this organism, and (2) compare detection method(s) for this purpose. 282 selected faecal samples were tested for STEC using selective culture media and multiplex tandem PCR (MT-PCR). The PCR used detected the virulence markers stx1, stx2 and eaeA. STEC were isolated in six of 282 faecal samples. This represents a STEC notification rate for Tasmania of 2.3 cases per 100 000 population. CT-SMAC medium detected one, CHROMagar STEC medium detected three and MT-PCR detected six STEC isolates. CHROMagar STEC medium displayed 50% sensitivity and 93% specificity compared to MT-PCR. The incidence of STEC associated enteritis in Tasmania was almost six times greater than the previously reported Australian average. STEC Screening Easy-Plex MT-PCR was more sensitive than both CHROMagar STEC and CT-SMAC media for the detection of STEC from pre-enriched faecal samples.