Transmission of Similar Mcr-1 Carrying Plasmids among Different Escherichia coli Lineages Isolated from Livestock and the Farmer
Antibiotics publish this investigation article
March 17th, 2021
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
Vines J., Cusco A., Napp S., Alvarez J., Saez-Llorente JL., Rosas-Rodoreda M., Francino O. and Migura-Garcia L.
 | Servei Veterinari de Genètica Molecular (SVGM). Universitat Autònoma de Barcelona (UAB). |
| Vetgenomics. | |
| Centre de Recerca en Sanitat Animal (CReSA). Universitat Autònoma de Barcelona (UAB). |
 | Instituto de Investigación y Tecnología Agroalimentarias (IRTA). Generalitat de Catalunya. |
 | Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
| Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
 | Subdirección General de Sanidad e Higiene Animal y Trazabilidad. Dirección General de la Producción Agraria. Ministerio de Agricultura, Pesca y Alimentación (MAPA). |
| Departamento de Agricultura, Ganadería, Pesca, Alimentación y Medio Natural. Generalitat de Catalunya. |
