Extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) isolated from bean sprouts in the Netherlands

Community-acquired carriage and infections due to extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) are increasing worldwide, resulting in increased morbidity, mortality and healthcare costs. The origins of community-acquired ESBL-E carriage and infections remain unclear. Bean sprouts are a potential source of Enterobacteriaceae for the community, as illustrated by outbreaks of pathogenic Enterobacteriaceae in the past. The current study focuses on contamination of retail bean sprouts with ESBL-E in the Netherlands. Of 131 bean sprout samples purchased between 2013 and 2016, 25 (19%) were contaminated with ESBL-E. The detected isolates were almost exclusively Klebsiella spp. and co-resistance to other antibiotics was observed frequently. Over time there was substantial genetic diversity between isolates. On the other hand, isolates from samples closely matched in time were frequently clonally related, indicative of batch contamination. Remarkably, no Escherichia coli was found. In conclusion, bean sprouts frequently harbor ESBL-E, which is a potential source for consumers.