TY - JOUR AU - Perez-Trallero, Emilio AU - Marimón, José María AU - Montes, Milagrosa AU - Orden, Beatriz AU - de Pablos, Manuela T1 - Clonal Differences among Erythromycin-Resistant Streptococcus pyogenes in Spain T2 - Emerging Infectious Disease journal PY - 1999 VL - 5 IS - 2 SP - 235 SN - 1080-6059 AB - The aim of this study was to determine whether the high levels of erythromycin resistance in Streptococcus pyogenes found in Spain are due to the introduction and spread of one or more clones. Phenotypic and genotypic techniques were used to characterize all erythromycin-resistant S. pyogenes (ErR) isolated in Gipuzkoa, Spain, in the last 10 years and 128 ErR isolated in Vitoria and Madrid during 1996. Of 437 ErR, 97% had the M phenotype; all 283 of the strains studied had the mefA determinant of resistance. After biotyping, T serotyping, emm typing, and genotyping, four major clones were detected. Clones B (biotype I, type T4, emm4, pulsed-field gel electrophoresis [PFGE] II) and D (biotype V, type T8.25, emm75, PFGE IV) comprised 78.8% of all ErR. The resistance of S. pyogenes to erythromycin was mainly due to an efflux mechanism of resistance (M phenotype); few clones were responsible for it. KW - Spain DO - 10.3201/eid0502.990207 UR - https://wwwnc.cdc.gov/eid/article/5/2/99-0207_article ER - End of Reference