title: Prevalence of decreased susceptibility to triclosan in Salmonella enterica isolates from animals and humans and association with multiple drug resistance.
abstract: Previous laboratory studies have implicated triclosan as a possible selective force driving resistance to multiple antibiotics and have identified a number of triclosan resistance mechanisms in Salmonella enterica. The aim of this work was to determine the prevalence of decreased susceptibility to triclosan in a panel of human and animal isolates of S. enterica and to identify the mechanisms of triclosan resistance in these strains. Over 400 animal and human isolates of non-typhoidal Salmonella were screened for decreased susceptibility to triclosan and a panel of antibiotics. The prevalence of decreased susceptibility to triclosan was ca. 4%. Of the isolates with decreased triclosan susceptibility, 56% were multidrug-resistant (MDR) compared with 12% of triclosan-sensitive isolates. MDR and triclosan-resistant strains showed increased efflux activity compared with strains with reduced susceptibility to triclosan alone. No high-level triclosan resistance was seen in this panel of isolates. A reservoir of strains with low-level decreased triclosan susceptibility is present in animals and humans. These isolates are MDR as a result of generic mechanisms of antimicrobial resistance and do not carry specific mutations within fabI.
authors.affiliation: Antimicrobial Agents Research Group, School of Immunity and Infection, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: Justin L
authors.initials: JL
authors.lastname: Copitch
authors.forename: Rebekah N
authors.initials: RN
authors.lastname: Whitehead
authors.forename: Mark A
authors.initials: MA
authors.lastname: Webber
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D012480:Salmonella Infections / Q000382:microbiology*; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D019779:Salmonella enterica / Q000187:drug effects* / Q000302:isolation & purification; D014260:Triclosan / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D014260:Triclosan