RESUMO

A collection of 126 pigs was screened for carriage of colistin-resistant Enterobacteriaceae in a farm in Minas Gerais, Brazil. Out of this collection, eight colistin-resistant Escherichia coli isolates were recovered, including one from Minas Gerais State producing a new MCR-3 variant (MCR-3.12). Analysis of the lipopolysaccharide revealed that MCR-3.12 had a function similar to that of MCR-1 and MCR-2 as a result of the addition of a phosphoethanolamine group to the lipid A moiety. Genetic analysis showed that the mcr-3.12 gene was carried by an IncA/C2 plasmid and was embedded in an original genetic environment. This study reports the occurrence of the MCR-3-like determinant in South America and is the first to demonstrate the functionality of this group of enzymes as a phosphoethanolamine transferase.

Assuntos

Antibacterianos/farmacologia , Colistina/farmacologia , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Animais , Brasil , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Variação Genética/genética , Genoma Bacteriano/genética , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Suínos