Genome Characterization of -Positive Isolated From Pigs With Postweaning Diarrhea in China.

Diarrheagenic is the causative agent of diarrhea in infants and animals worldwide. Many isolated strains recovered from pigs with postweaning diarrhea are multidrug resistance (MDR), and hybrids of are potentially more virulent, as enterotoxigenic (ETEC)/Shiga-toxigenic (STEC) hybrids. Here, we used whole-genome sequencing to analyze clinical isolates of the five colistin-resistant . The CAU15104, CAU15134, and CAU16060 belonged to ETEC/STEC hybrids, displaying the same serotype O3:H45 and sequence type ST4214. The CAU16175 and CAU16177 belonged to atypical enteropathogenic (aEPEC), display O4:H11 and O103:H2, ST29, and ST20, respectively. The CAU16175 carries six plasmids. An IncHI2-type plasmid, pCAU16175_1, harbors an IS-enriched MDR region, which includes 16 antimicrobial-resistant genes. An IncFII-type plasmid, pCAU16175_3, harbors (M), and , whereas is located within a Tn derivative. Our findings indicate that the ETEC/STEC strains of the O3:H45 serotype as well as the aEPEC strains of the O4:H11 and O103:H2 serotypes are associated with postweaning diarrhea in swine and that some of diarrheagenic contains IS-enriched MDR region and the gene located within a Tn derivative on IncFII plasmid.