Occurrence and genetic characterization of Shiga toxin-producing Escherichia coli on bovine and pork carcasses and the environment from transport trucks

COLELLO, R.; BAIGORRI, M.; DEL CANTO, F.; GONZALEZ, J.; ROGÉ, A.; VAN DER PLOEG, C.; SANCHEZ CHOPA, F.; SPARO M.; ETCHEVERRÍA, A.I.; PADOLA, N.L.

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

SPRINGER

Año: 2023

0959-3993

Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens causing severe diseases. The ability of STEC toproduce disease is associated with Shiga toxin (Stx) production. We investigated the occurrence of STEC on bovine andpork carcasses and walls of trucks where they were transported, and we characterized virulence genes and serotypes ofSTEC strains. We compared the whole genomic sequencing of a STEC O157:H7 strain isolated from a bovine carcass inthis work and a STEC O157:H7 strain isolated from a child with HUS, both isolated in 2019. We studied the relationshipbetween these isolates and others collected in the database. The results show a 40% of STEC and two different serogroupswere identified (O130 and O157). STEC O157:H7 were isolated from bovine carcasses and harbored stx2, eae, ehxA, katP,espP, stcE, ECSP_0242/1773/2687/2870/2872/3286/3620 and were classified as lineage I/II. In STEC non-O157 isolates,three isolates were isolated from bovine carcasses and harbored the serogroup O130 and one strain isolated from porkcarcasses was O-non-typeable. All STEC non-O157 harbored sxt1 gene. The analysis from the whole genome showed thatboth STEC O157:H7 strains belonged to the hypervirulent clade 8, ST11, phylogroup E, carried the allele tir 255 T > A T,and they were not clonal. The analysis of information allows us to conclude that the STEC strains circulate in pork andbovine carcasses arriving in transport. This situation represents a risk for the consumers and the need to implement anintegrated STEC control in the food chain.