Genetic characterization of Shigatoxigenic and enteropathogenicEscherichia coliO80:H2 from diarrhoeic and septicaemic calves and relatedness to human ShigatoxigenicE. coliO80:H2

Aim The purpose of this work was to identify and genetically characterize enterohemorrhagicEscherichia coli(EHEC) and enteropathogenicE. coli(EPEC) O80:H2 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 O80:H2 serotype and ST301, harboured theeae xi gene, and 23 of the 29 EHEC contained thestx2dgene. Phylogenetically, they were distributed in two major sub-lineages: one comprised a majority of bovine EPEC whereas the second one comprised a majority ofstx2dbovine and human EHEC. Conclusions Not only EPEC but also EHEC O80:H2 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 O80:H2 and to understand the evolution of bovine and human EHEC and EPEC O80:H2.

Automated summary

The study identified EHEC O80:H2 in diarrhoeic and septicaemic calves in Belgium, which are genetically related to human EHEC. The findings support the need to assess cattle as a potential source of contamination of humans by EHEC O80:H2 and to understand the evolution of these bacteria.