Plasmid-mediated florfenicol and ceftriaxone resistance encoded by the floR and bla(CMY-2) genes in Salmonella enterica serovars Typhimurium and Newport isolated in the United States.
Multidrug resistance plasmids carrying the bla(CMY-2) gene have been identified in Salmonella enterica serovars Typhimurium and Newport from the United States. This gene confers decreased susceptibility to ceftriaxone, and is most often found in strains with concomitant resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline. The bla(CMY-2)-carrying plasmids studied here were shown to also carry the florfenicol resistance gene, floR, on a genetic structure previously identified in Escherichia coli plasmids in Europe. These data indicate that the use of different antimicrobial agents, including phenicols, may serve to maintain multidrug resistance plasmids on which extended-spectrum cephalosporin resistance determinants co-exist with other resistance genes in Salmonella.
Doublet
Benoît
B
Unité BioAgresseurs, Santé, Environnement, Institut National de la Recherche Agronomique, 37380 Nouzilly, France.
Carattoli
Alessandra
A
Whichard
Jean M
JM
White
David G
DG
Baucheron
Sylvie
S
Chaslus-Dancla
Elisabeth
E
Cloeckaert
Axel
A
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002443:Ceftriaxone / Q000494:pharmacology*; D018550:Cephalosporin Resistance / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics; D010957:Plasmids; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics*; D013839:Thiamphenicol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D014481:United States; D001618:beta-Lactamases / Q000235:genetics*
D000900:Anti-Bacterial Agents; D002443:Ceftriaxone; C035534:florfenicol; C103022:beta-lactamase CMY-2; D001618:beta-Lactamases; D013839:Thiamphenicol