The Development and Evaluation of a Selective Enrichment for the Detection of Escherichia albertii in Food

Abstract

Escherichia albertii is an emerging pathogen causing foodborne infections with diarrhea, abdominal pain, and fever. E. albertii has been isolated from various food sources, such as chicken and pork. Although many foodborne outbreaks of E. albertii have been reported, the causative food has not been identified. It is necessary to develop effective detection methods for E. albertii. Because enrichment procedure as the first step of food test is important for growing pathogens, this study aimed to develop a novel effective enrichment for E. albertii detection in food. In this study, we investigated the optimal concentration and combination of cefixime and tellurite for supplementing modified EC broth (mEC) to effectively isolate E. albertii from chicken meat. The results showed that mEC supplemented with 50 μg/L cefixime and 2.5 mg/L tellurite (CT-mEC) inhibited the growth of competitive bacteria in chicken meat but not that of E. albertii. Therefore, it was indicated that CT-mEC had strong potential to selectively grow E. albertii. In an E. albertii foodborne outbreak, CT-mEC was evaluated. E. albertii was successfully isolated from a food sample, a kind of salad, by enrichment with CT-mEC but not buffered peptone water and mEC. In this study, CT-mEC as a selective enrichment broth has been developed to detect E. albertii in chicken meat. It was demonstrated that the selective enrichment broth was effective for the efficient detection of E. albertii in food.