The emergence and dissemination of carbapenem-resistant Enterobacteriaceae (CRE) comprise a serious threat to public health (1). To date, 20 New Delhi metallo-ßlactamase (NDM) variants have been identified in CRE (2). Among them, NDM-5 possesses enhanced carbapenemase activity compared with NDM-1 (3). In China, blaNDM-5 has been described in various Enterobacteriaceae isolates from humans, pigs, and dairy cows (4–7) and samples from chickens, dogs, flies, and wild birds at commercial farms (8).

In this study, 60 meropenem-resistant Escherichia coli isolates were obtained from fecal swab samples from seven swine farms in Henan Province, China, in 2018. Among them, 51 isolates harbored blaNDM-5, and the remaining 9 isolates carried blaNDM-1, according to PCR assay (9, 10). MLST results assigned the 60 blaNDM-positive E. coli isolates to 11 sequence types, including ST218, ST7111, ST167, ST746, ST813, ST165, ST1178, ST10, ST48, ST206, and ST761, with ST218 predominating (n 25). Antimicrobial susceptibility testing was determined using broth microdilution (11). MIC results indicated that these blaNDM-positive ST218 E. coli isolates were resistant to ß-lactams, including meropenem, ceftazidime, cefoxitin, and cefazolin but not aztreonam (see Table S1 in the supplemental material).