Antimicrobial resistance in staphylococci from canine pyoderma: a prospective study of first-time and recurrent cases in Sweden.

In a prospective study involving eight veterinary clinics during 1995 and 1996, samples from first-time and recurrent cases of canine pyoderma were collected by a needle technique. Three hundred and ninety-four staphylococci were isolated and their susceptibility to various antimicrobial drugs was assessed by a microdilution technique. Resistance to macrolides, lincosamides, fusidic add, tetracycline and streptomycin was significantly more common in isolates from the recurrent cases than from the first-time cases; 20 per cent of the isolates from the first-time cases were resistant to three or more of the antimicrobials tested, compared with 45 per cent of those from the recurrent cases. Coresistance between macrolide-lincosamides, tetracyclines and streptomycin was common. No resistance to penicillinase-stable beta-lactams was observed. A comparison with earlier studies indicated that there had been a marked increase in resistance during the previous five years.