Emergence of erythromycin- and clindamycin-resistant Streptococcus pyogenes emm 90 strains in Hawaii.

We identified 12 erythromycin- and clindamycin-resistant emm 90 group A streptococcus (GAS) isolates during a retrospective invasive disease survey in Hawaii. A comparison with 20 type-matched isolates showed all resistant isolates to be emm 90.4b with the constitutive or inducible macrolide-lincosamide-streptogramin B resistance phenotype (cMLS(B) or iMLS(B)). All isolates had the same pulsed-field gel electrophoresis (PFGE) pattern, suggesting clonal spread.