Prevalence and Mechanisms of Erythromycin Resistance in Group A and Group B Streptococcus: Implications for Reporting Susceptibility Results

摘要: Increased rates of erythromycin resistance among group B Streptococcus (GBS) and A (GAS) have been reported. Cross-resistance to clindamycin may be present, depending on the mechanism resistance. We determined prevalence macrolide-resistant determinants in GBS GAS isolates guide laboratory reporting susceptibility. Susceptibilities were by disk diffusion broth microdilution methods. Inducible constitutive was double-disk method. The presence ermTR, ermB, mefA genes confirmed PCR. Of 338 isolates, 55 (17%) resistant erythromycin, whereas 26 (8%) clindamycin. erm methylase gene identified 48 22 which had inducible remaining seven mefA. 593 49 6 (1%) clindamycin, respectively. Erythromycin due 33 14 erm-mediated (9 5 resistance). In our population, predominantly mediated erm. Regional differences mechanisms need taken into consideration when deciding whether report susceptibility results basis vitro test results. Testing method would an approach that could used address this issue, especially for GAS.