Antibiotic resistant beta-hemolytic streptococci.

OBJECTIVE: An antibiotic-sensitivity study was conducted on 117 strains of group A streptococcus (GAS), 60 strains of group G streptococcus (GGS) and 20 strains of group C streptococcus (GCS) in order to understand current resistance trends. METHODS: All strains were tested by the Kirby Bauer disc diffusion method to 15 antibiotics. Resistant strains were confirmed by testing the minimum inhibitory concentration (MIC) of antibiotics by broth dilution technique. RESULTS: Among GAS, highest resistance was observed to tetracycline (27.4%) and erythromycin (16.2%). The GGS and GCS tested, showed similar resistance patterns. CONCLUSION: All beta-hemolytic streptococci were susceptible to penicillin, amoxycillin, cephalosporins and linezolid. Resistance to erythromycin, tetracycline, clindamycin, chloramphenicol, and quinolones is emerging.