Genetic characterization of Shigatoxigenic and enteropathogenic Escherichia coli O80:H2 from diarrhoeic and septicaemic calves and relatedness to human Shigatoxigenic E. coli O80:H2.

ABSTRACT

AIM: The purpose of this work was to identify and genetically characterize enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) O80H2 from diarrhoeic and septicaemic calves in Belgium and to comparing them with human EHEC after whole genome sequencing. METHODS AND RESULTS: Ten EHEC and 21 EPEC O80 identified by PCR between 2009 and 2018 from faeces, intestinal content and a kidney of diarrhoeic or septicaemic calves were genome sequenced and compared to 19 human EHEC identified between 2008 and 2019. They all belonged to the O80H2 serotype and ST301, harboured the eaeξ gene, and 23 of the 29 EHEC contained the stx2d gene. Phylogenetically, they were distributed in two major sub-lineages one comprised a majority of bovine EPEC whereas the second one comprised a majority of stx2d bovine and human EHEC. CONCLUSIONS: Not only EPEC but also EHEC O80H2 are present in diarrhoeic and septicaemic calves in Belgium and are genetically related to human EHEC. SIGNIFICANCE AND IMPACT OF THE STUDY These findings support the need to assess cattle as potential source of contamination of humans by EHEC O80H2 and to understand the evolution of bovine and human EHEC and EPEC O80H2.