Multicenter Study on Spreading of the tet(M) Gene in Tetracycline-Resistant Streptococcus Group G and C Isolates in Argentina

A prospective multicenter study on invasive infections caused by beta-hemolytic streptococci was performed over 6 months and involved 42 centers from 16 cities in Argentina. Among 33 isolates recovered, 9 group G Streptococcus isolates (39.1%) and 2 group C Streptococcus isolates (20%) exhibited resistance to tetracycline and harbored the tet(M) gene. Genealogical analysis revealed that tetracycline resistance has a polyclonal origin in Argentina.