title: Significant Differences Characterise the Correlation Coefficients between Biocide and Antibiotic Susceptibility Profiles in Staphylococcus aureus.
abstract: There is a growing concern by regulatory authorities for the selection of antibiotic resistance caused by the use of biocidal products. We aimed to complete the detailed information on large surveys by investigating the relationship between biocide and antibiotic susceptibility profiles of a large number of Staphylococcus aureus isolates using four biocides and antibiotics commonly used in clinical practice. The minimal inhibitory concentration (MIC) for most clinically-relevant antibiotics was determined according to the standardized methodology for over 1600 clinical S. aureus isolates and compared to susceptibility profiles of benzalkonium chloride, chlorhexidine, triclosan, and sodium hypochlorite. The relationship between antibiotic and biocide susceptibility profiles was evaluated using non-linear correlations. The main outcome evidenced was an absence of any strong or moderate statistically significant correlation when susceptibilities of either triclosan or sodium hypochlorite were compared for any of the tested antibiotics. On the other hand, correlation coefficients for MICs of benzalkonium chloride and chlorhexidine were calculated above 0.4 for susceptibility to quinolones, beta-lactams, and also macrolides. Our data do not support any selective pressure for association between biocides and antibiotics resistance and furthermore do not allow for a defined risk evaluation for some of the compounds. Importantly, our data clearly indicate that there does not involve any risk of selection for antibiotic resistance for the compounds triclosan and sodium hypochlorite. These data hence infer that biocide selection for antibiotic resistance has had so far a less significant impact than feared.
authors.affiliation: Department of Genetics, University Road, University of Leicester, LE1 7RH, UK. mro5@leicester.ac.uk.
authors.forename: Marco R
authors.initials: MR
authors.lastname: Oggioni
authors.forename: Joana Rosado
authors.initials: JR
authors.lastname: Coelho
authors.forename: Leonardo
authors.initials: L
authors.lastname: Furi
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Knight
authors.forename: Carlo
authors.initials: C
authors.lastname: Viti
authors.forename: Graziella
authors.initials: G
authors.lastname: Orefici
authors.forename: Jose-Luis
authors.initials: JL
authors.lastname: Martinez
authors.forename: Ana Teresa
authors.initials: AT
authors.lastname: Freitas
authors.forename: Teresa M
authors.initials: TM
authors.lastname: Coque
authors.forename: Ian
authors.initials: I
authors.lastname: Morrissey
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000187:drug effects*; D006801:Humans; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004202:Disinfectants