Common findings of bla CTX-M-55 -encoding 104-139 kbp plasmids harbored by extended-spectrum β-lactamase-producing Escherichia coli in pork meat, wholesale market workers, and patients with urinary tract infection in Vietnam.

Extended-spectrum, β-lactamase-producing Escherichia coli (ESBL-E) harboring the blaCTX-M-55 -encoding plasmid (ESBL-E55) has been reported to be associated with urinary tract infection (UTI). The aims of this study were to clarify the prevalence of ESBL-E55 in pork meats and workers from the same wholesale market, as well as patients with UTI from a nearby hospital in Vietnam; we also investigated the plasmids encoding blaCTX-M-55 . Sequencing analysis showed that 66.6% of the ESBL-E isolated from pork meats contained blaCTX-M-55 , whereas the gene was present in 25.0% of workers and 12.5% of patients with UTI. Plasmid analysis showed that several sizes of plasmid encoded blaCTX-M-55 in ESBL-E55 isolated from pork meats, whereas ESBL-E55 isolated from workers and patients with UTI contained only 104-139 kbp of blaCTX-M-55 -encoding plasmids. This indicates that the 104-139 kbp sizes of blaCTX-M-55 -encoding plasmids were commonly disseminated in pork meats, wholesale market workers, and patients with UTI.