Erythromycin resistance genes in group A streptococci of different geographical origins

A total of 238 erythromycin-resistant Streptococcus pyogenes isolates were collected in 1986-1997 from eight different countries in Europe and North a nd South America. The antibiotic susceptibility patterns of all isolates an d the resistance genes of 92 isolates of known clonal origin were studied. The mefA gene was detected in all 54 isolates with the M-phenotype and was found in every country. The ermTR and the ermB genes were detected in 27 an d 11, respectively, of the 38 isolates with the macrolide-lincosamide-strep togramin B resistance phenotypes. In addition to the mefA gene, the recentl y sequenced ermTR gene was also widely distributed among isolates of differ ent clonal origin.