ANTIMICROBIAL RESISTANCE IN Staphylococcus intermedius GROUP ISOLATED FROM COMPANION ANIMALS IN A VETERINARY TEACHING HOSPITAL: A ONE YEAR STUDY

Introduction: Staphylococcus intermedius group are important opportunistic pathogens of companion animals, especially dogs. Canine infections caused by these microorganism are mostly dermatitis, wounds, otitis, endometritis, cystitis and others infections. Until recently, S. intermedius group isolates were generally susceptible to penicillinase-stable β-lactam antibiotics, but, since 2006, Methicillin-resistant S. intermedius (MRSP) has emerged as a significant animal health problem in veterinary medicine. MRSP isolates are often not only resistant to b-lactam antibiotics, but also to several other classes of antimicrobial drugs. The treatment of infections with MRSP is a new challenge in veterinary medicine because of the very limited therapeutic options. Several reports on isolates not susceptible to any antimicrobials authorized for use in veterinary medicine have been published. This has resulted in potential pressure for veterinarians to use antimicrobials authorized for human medicineObjective: The aim of this study was to characterize Staphylococcus intermedius group for its antimicrobial resistance isolated from sick dogs in a veterinary teaching hospital in Londrina city between July 2016 to June 2017. Materials and methods: In the present study, we screened CPS strains from dogs in a veterinary teaching hospital to determine the prevalence of methicillin-resistant CPS (MRCPS). Clinically sick adult dogs suffering from infections (n= 175) were selected for the study. The samples were collected in the veterinary hospital and send to a pharmaceutical skills laboratory in University Hospital (HU). The samples were cultivated in Trypitic Soya Broth (TSB), overnight incubation, and then in Chromogenic Agar, Manitol Salt Agar and Blood Agar. The colonies were identified by manual methodology standardized by Jorgensen et al. (2015). The antimicrobial susceptibility was performance by diffusion disk, according CLSI (2017). Results: Staphylococcus spp. were identified in 46/175 (26%) and 33 isolates were identified as S. intermedius group (71.7 % from a total number of isolated staphylococci) of which, only 1 (3%) isolate was identified as Methicillin-resistant S. pseudointermedius. Data on susceptibility to different antimicrobials revealed a high resistance was seen towards penicillin G (70 %), tetracycline (62 %) and trimethoprim-sulfametoxazol (61 %). For fluoroquinolones and gentamicine, resistances were 36% and 23%, respectively. All isolates were susceptible to linezolid. Conclusion: The antimicrobials penicillin, sulfamethoxazole-trimethoprim and tetracyclines presented the highest resistance indexes, however oxacillin resistance was still low among the isolates evaluated. Further studies, with a larger number of samples, are required to determine the true prevalence of S. intermedius group in the city of Londrina.