[Investigation of erythromycin resistance and resistance phenotypes in group A beta hemolytic streptococci].

Although penicillin resistance has not been determined in group A beta haemolytic streptococci (GABHS) yet, resistance to erythromycin and other macrolids is being reported frequently in the last years. In this study we investigated erythromycin resistance by using agar dilution method in 282 GABHS strains which were isolated from throat cultures that had been evaluated in the Ministry of Health, Ankara Training and Research Hospital's, Microbiology Laboratory. We also determined resistance phenotypes of resistant strains by double disc synergy method using erythromycin and clindamycin discs. Twelve of 282 strains (4.3%) were found resistant to erythromycin; five (41.7%) of which were M phenotype, four (33.3%) of which were constitutive type MLSB phenotype and three (25%) of which were inducible type MLSB phenotype. Investigation of resistance to macrolides that are alternatives to penicillin therapy in GABHS, is very important for the determination of the therapy and also to provide epidemiological data.