Epidemiosurveillance of antimicrobial compound resistance of Staphylococcus intermedium clinical isolates from canine pyodermas.

In a retrospective study, 131 Staphylococcus intermedius strains isolated from apparently healthy dogs, and 187 Staphylococcus intermedius strains isolated from dog pyodermas in the clinical microbiology laboratory at the National Veterinary School in Nantes, during three successive periods: 1986-87, 1992-93 and 1995-96, were investigated and compared for their antimicrobial susceptibility. Results indicated that 60% to 65% of the strains were susceptible to Chloramphenicol and Doxycyclin, 65% to 80% of the strains were susceptible to macrolides (Erythromycin, Lincomycin and Clindamycin) and to Trimethoprim/Sulfonamide association. More than 95% of the strains were susceptible to three betalactamins tested: Oxacillin, Amoxycillin/Clavulanic acid, Cephalexin, to Gentamicin, to Fucidic Acid and to two quinolones: Enrofloxacin and Marbofloxacin. This last group is made up of choice antibacterials for the treatment of dog pyoderma. Many different resistance patterns were observed in each period with no really predominant profile, because of low plasmidic vs chromosomal balance of the genetic basis of antibacterial resistance in Staphylococcus intermedius. However, the proportion of multiresistant (> or = 3 drugs) strains increased from 10.8% in the first period, to 28% in the third period. This increased frequency of resistance suggests strongly that, as in Staphylococcus aureus human infections, the prescription of antibiotic compounds increases the prevalence of resistant strains.