In vitro antiseptic susceptibilities for Staphylococcus pseudintermedius isolated from canine superficial pyoderma in Japan

摘要

Background - Topical therapy, particularly with chlorhexidine, is becoming increasingly common as a treatment option for canine pyoderma; however, there are limited studies on the susceptibility of Staphylococcus pseudin-termedlus to chlorhexidine compounds.Objectives - To determine the in vitro susceptibility of both meticillin-resistant and meticillin-susceptible S. pseudintermedius isolates to chlorhexidine and other antiseptic agents and the presence of multidrug efflux pump genes.Samples - One hundred S. pseudintermedius isolates from 23 initial and 77 recurrent cases of canine pyoderma.Methods - After bacterial identification and mecA testing, minimal inhibitory concentrations (MICs) of antiseptic agents were determined. Multidrug efflux pump genes, including qacA, qacBand smr, were identified.Results - Of the 100 isolates, 57 were identified as meticillin-resistant S. pseudintermedius. The MIC_(90) of chlorhexidine acetate, chlorhexidine gluconate, acriflavine, ethidium bromide and benzalkonium chloride were 1, 1,2, 0.5 and 2 mug/mL, respectively. Multidrug efflux pump genes QacA qacB and smrwere not detected in any of the isolates.Conclusions and clinical importance - The MICs for chlorhexidine and other antiseptics remain low, and multidrug efflux pump genes were not found in the tested isolates.