2026-06-27T23:16:13Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/71222023-12-01T11:49:35Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Viñes, Joaquim author Cuscó, Anna author Napp, Sebastian author Alvarez, Julio author Sáez Llorente, José Luis author Rosàs Rodoreda, Montserrat author Francino, Olga author Migura García, Lourdes author Álvarez Sánchez, Julio author 2021-03-17 Colistin use has mostly been stopped in human medicine, due to its toxicity. However, nowadays, it still is used as a last-resort antibiotic to treat hospital infections caused by multi-drug resistant Enterobacteriaceae. On the contrary, colistin has been used in veterinary medicine until recently. In this study, 210 fecal samples from pigs (n = 57), calves (n = 152), and the farmer (n = 1) were collected from a farm where E. coli harboring mcr-1–mcr-3 was previously detected. Samples were plated, and mcr-genes presence was confirmed by multiplex-PCR. Hybrid sequencing which determined the presence and location of mcr-1, other antibiotic resistance genes, and virulence factors. Eighteen colistin resistant isolates (13 from calves, four from pigs, and one from the farmer) contained mcr-1 associated with plasmids (IncX4, IncI2, and IncHI2), except for two that yielded mcr-1 in the chromosome. Similar plasmids were distributed in different E. coli lineages. Transmission of mcr-1 to the farmer most likely occurred by horizontal gene transfer from E. coli of calf origin, since plasmids were highly similar (99% coverage, 99.97% identity). Moreover, 33 virulence factors, including stx2 for Shiga toxin E. coli (STEC) were detected, highlighting the role of livestock as a reservoir of pathotypes with zoonotic potential. 2079-6382 10.3390/antibiotics10030313 https://hdl.handle.net/20.500.14352/7122 https://doi.org/10.3390/antibiotics10030313 https://www.mdpi.com/2079-6382/10/3/313/htm Transmission of Similar Mcr-1 Carrying Plasmids among Different Escherichia coli Lineages Isolated from Livestock and the Farmer