title: Detection of a Novel qnrB19-Carrying Plasmid Variant Mediating Decreased Fluoroquinolone Susceptibility in Salmonella enterica Serovar Hadar.
abstract: Thirty Salmonella enterica subsp. enterica serovar Hadar isolates of avian origin collected between 2007 and 2010 from chicken carcasses in five geographically spread abattoirs in Germany were investigated for plasmid-mediated quinolone resistance determinants. Four isolates were identified by PCR analysis and hybridization experiments to carry qnrB genes. The isolates were indistinguishable by their XbaI macrorestriction patterns and did not exhibit a mutation in the quinolone resistance-determining regions of the DNA gyrase and topoisomerase IV genes. The qnrB genes were found to be located on small plasmids of ∼2.6 kb, which mediated decreased susceptibility only to quinolones. The plasmids were assigned to the same type, pHAD28, and transformation studies into an Escherichia coli recipient strain confirmed their transferability. Sequence analysis of the complete plasmid pHAD28 revealed the presence of a qnrB19 gene. The gene was found on a novel variant of qnrB19-harboring plasmids with high similarity to plasmids pPAB19-3 from E. coli and pPAB19-4 from Salmonella sp. M9397. A presumptive recombination side was detected, suggesting that interplasmid recombination events might have played a role in the development of this plasmid variant.
authors.affiliation: 1 Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover , Foundation, Hannover, Germany .
authors.forename: Ulrike
authors.initials: U
authors.lastname: Fiegen
authors.affiliation: 1 Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover , Foundation, Hannover, Germany .
authors.forename: Günter
authors.initials: G
authors.lastname: Klein
authors.affiliation: 2 Bayer Animal Health GmbH , Leverkusen, Germany .
authors.forename: Anno
authors.initials: A
authors.lastname: de Jong
authors.affiliation: 1 Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover , Foundation, Hannover, Germany .
authors.forename: Corinna
authors.initials: C
authors.lastname: Kehrenberg
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D027081:DNA Gyrase / Q000235:genetics; D027101:DNA Topoisomerase IV / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D024841:Fluoroquinolones / Q000494:pharmacology*; D014644:Genetic Variation / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics*; D015363:Quinolones / Q000494:pharmacology; D012480:Salmonella Infections / Q000188:drug therapy / Q000382:microbiology; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D065288:Serogroup
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D024841:Fluoroquinolones; D015363:Quinolones; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase
keywords: Salmonella Hadar; fluoroquinolone; poultry; qnrB; small plasmids