Clonal spread of group A streptococcus with the new type of erythromycin resistance Finnish Study Group for Antimicrobial Resistance

: Kataja J, Huovinen P, Muotiala A, Vuopio-Varkila J, Efstratiou A, Hallas G, Seppälä H

: 1998

: Journal of Infectious Diseases

: The Journal of infectious diseases

: J Infect Dis

: 177

: 3

: 786

: 9

: 4

: 0022-1899

DOI: https://doi.org/10.1086/517809

In 1990, a new type of erythromycin resistance phenotype, designated NR, was found in group A streptococcus (GAS) in Finland. In the present study, the distribution of GAS isolates with this and other erythromycin-resistance phenotypes was surveyed in Finland, and the clonality of the isolates was explored. Of 4179 GAS isolates collected from all over Finland, 695 (17%) were resistant to erythromycin, and 82% of these had the NR phenotype. Of a group of 96 isolates with the NR phenotype from different areas, 91% was T4 serotype, opacity factor-positive. The majority of these isolates were studied further: All were M4 serotype and 88% were of one clonal origin in genetic analyses. Thus, one single clone predominates among erythromycin-resistant GAS in Finland. This clone is of T4M4 serotype and mediates the new type of erythromycin resistance, characterized by the NR phenotype.