The genetic basis for phenicol resistance was examined in 38 phenicol-resistant clinical Escherichia coli isolates from poultry. Out of 62 isolates, 38 showed resistance for chloramphenicol and nine for florfenicol, respectively. Each strain also demonstrated resistance to a variety of other antibiotics. Molecular detection revealed that the incidence rates of the cat1, cat2, flo, flo-R, cmlA, and cmlB were 32, 29, 18, 13, 0, and 0%, respectively. Nineteen strains were tolerant to organic solvents. PCR amplification of the complete acrR (regulator/repressor) gene of five isolates revealed the amino acid changes in four isolates. DNA sequencing showed the non-synonymous mutations which change the amino acid, silent mutation, and nucleotide deletion in four isolates. MY09C10 showed neither deletion nor mutation in nucleotide. The AcrA protein of the AcrAB multidrug efflux pump was overexpressed in these strains. Complementation with a plasmid-borne wild-type acrR gene reduced the expression level of AcrA protein in the mutants and partially restored antibiotic susceptibility one- to fourfold. This study shows that mutations in acrR are an additional genetic basis for phenicol resistance.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální geny genetika   MeSH
• DNA bakterií genetika   MeSH
• Escherichia coli účinky léků   genetika   izolace a purifikace   MeSH
• genotyp MeSH
• kur domácí MeSH
• membránové transportní proteiny genetika   MeSH
• mikrobiální testy citlivosti veterinární   MeSH
• mnohočetná bakteriální léková rezistence účinky léků   genetika   MeSH
• mutace MeSH
• nemoci drůbeže mikrobiologie   MeSH
• proteiny z Escherichia coli genetika   MeSH
• regulace genové exprese u bakterií MeSH
• represorové proteiny genetika   MeSH
• rezistence na chloramfenikol účinky léků   genetika   MeSH
• testy genetické komplementace veterinární   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH