Antimicrobial sensitivity and adherence study in strains of coagulase-negative Staphylococcus spp

Antimicrobial sensitivity was evaluated from 120 strains of coagulase-negative Staphylococcus (CoNS), isolated from urinary infections. The isolated species were identified by conventional methods and sensitivity to vancomycin, tetracyclin, norfloxacin, cephalothin erythromycin, clindamycin, oxacillin, penicillin, cyprofloxacin, ampicillin and ampicillin/sulbactam was tested by the agar dilution technique and the diffusion in disc technique. The distribution of the species was: Staphylococcus epidermidis 26 (21.6%), S. haemolyticus 48 (40.0%), S. saprophyticus 40 (33.4%) and S. simulans 6 (5%). CoNS strains extracted from urinary infections showed a high percentage of vancomycin and tetracyclin sensitivity, and a low sensitivity to beta-lactamic antibiotics, except ampicillin/sulbactam and cephalotin. Isolation percentage resistance to oxacillin was less than 48%. Strains resistant to oxacillin were considered as resistant to both penicillin and ampicillin. From 42% to 80% of S. haemolyticus, S. saprophyticus, Staphylococcus epidermidis and S. simulans were positive to the adherence test. Results from this work showed that slime producing CoNS strains, isolated in Río Cuarto Hospital, had different percentages of resistance to the studied antimicrobial agents.