High occurrence of multi-antimicrobial resistance in Staphylococcus intermedius isolates from healthy and diseased dogs and domesticated pigeons

Staphylococcus intermedius isolates (n=106), including 44 dog isolates and 62 pigeon isolates, were examined for their susceptibility to ampicillin, cephalexin, erythromycin, gentamicin, kanamycin, lincomycin, norfloxacin, oxacillin, tetracycline, and vancomycin by standard disk-diffusion test. The frequencies of resistance to ampicillin, kanamycin, and tetracycline were significantly higher in dog isolates than pigeon isolates (95.5% vs. 0%, 31.8% vs. 0%, and 45.5% vs. 9.7%, respectively; P<0.01). Antimicrobial resistance patterns of dog isolates and pigeon isolates were categorized respectively into nine and five distinct profiles. Significantly higher occurrence of resistance to two or more antimicrobials was observed in dog isolates than pigeon isolates (54.5% vs. 12.9%; P<0.01) and also in domesticated pigeon isolates than non-domesticated pigeon isolates (53.3% vs. 0%; P<0.01).