Prevalence of coagulase-positive staphylococci in the skin of dogs; antibacterial resistance and plasmid profile of the isolates

This study was designed to understand the prevalence of coagulase-positive staphylococci in the skin of dogs and the role of dogs as reservoirs of pathogenic and antimicrobial-resistant staphylococci. Swab samples were taken from the surface of the skin at muzzle sites of 100 clinically normal dogs. Antibiotic susceptibility of coagulase-positive staphylococci isolates was assessed by antibiotic disc diffusion method using filter paper discs and plasmid DNAs were extracted from the isolates. Staphylococci were isolated from 79 of the 100 dogs sampled and of these 51 were coagulase positive. All coagulase-positive staphylococci isolates were resistant to penicillin G, amoxicillin, cefazolin, streptomycin, erythromycin, ampicillin, tetracycline, gentamicin, trimethoprim-sulfamethoxazole, and enrofloxacine at 100%, 100%, 72%, 48%, 44%, 44%, 12%, 4%, 8%, and 4% respectively. Characterization of plasmid DNAs by agarose gel electrophoresis showed that 22 out of the 51 coagulase-positive staphylococci isolates harbored a single plasmid. The results of the present study indicate that pathogenic and resistant staphylococci are located in the skin of the dogs and may transfer to human and other hosts. It is important to establish reliable antibiotic sensitivity data regarding these bacteria to select suitable antibacterial treatment.