Methicillin-Resistant Staphylococci Isolated from Companion Animals and Humans: Antibiograms and Genetic Comparison

Abstract

Community-associated methicillin-resistant staphylococci (CA-MRS) are considered an important problem in many countries. CA-MRS can disseminate not only within human communities, but also between companion animals and their owners as they share environments and living conditions. In this study, 592 staphylococci were isolated from February to April 2012 by taking swab samples from companion animals, owners, the general public who did not have contact with companion animals, and the veterinary hospital staff in Seoul, Korea. Prevalence of the isolates, their antimicrobial resistance patterns, and genetic relationships were subsequently investigated. The most prevalent species isolated from companion animals was Staphylococcus intermedius (55.5%). In addition, all 3 human groups—animal owners, the general public, and veterinary hospital staff—carried the common predominant species Staphylococcus epidermidis (51.7%, 43.3%, and 56.1%, respectively). All 4 groups showed the highest resistance rate against the antimicrobial agent ampicillin, and all were susceptible to amikacin. Isolates from companion animal showed higher resistance rates against chloramphenicol, enrofloxacin, and sulfamethoxazole than that shown by the human isolates (P < 0.05). Antimicrobial resistance patterns among the general public group were similar to that of the owner group. These results suggest that antimicrobial resistance patterns in humans may not be influenced by physical contact of humans with companion animals. In addition, the resistance patterns shown by the general public group were different from those shown by the veterinary hospital group. Among 15 antimicrobial agents, 8 (ampicillin, cefoxitin, ciprofloxacin, enrofloxacin, erythromycin, oxacillin, sulfamethoxazole, and tetracycline) were more resistible in the veterinary hospital staff group

individuals in this group are more likely to be exposed to bacteria and antimicrobial agents (P < 0.05). Moreover, several isolates with a genetic similarity of 99%, as measured using Random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR) were detected from companion animals and their owner in the same household, suggesting the possibility of contact transmission of bacteria between the 2 groups. However, results of comparisons of ccr gene sequences associated with methicillin resistance in staphylococci suggested that horizontal transfer of ccr genes between companion animals and owners did not occur. In conclusion, transmission of staphylococci may occur in households between companion animals and owners

however, the possibility of horizontal transfer of methicillin resistance-associated genes between 2 groups can be ruled out in the present study.