3%), emm75T25 (14.6%), emm28T28 (13.2%), emm6T6 (9.8%), emm12T12 (6.8%) and emm11T11 (4.1%) which represented 87.8% of the erythromycin-resistant isolates. High macrolide resistance rates were associated with the above emm/T types: emm75T25 (93.5%), emm4T4 (84.7%), emm11T11 (50%), emm28T28 (50%), emm6T6 (43.3%)

and emm12T12 (29.4%). In the present tetracycline-resistant see more population (61), 20 different emm/T types were identified (Table 3). emm77T28 (37.3%) was the main emm/T type associated with tetracycline resistance; all emm77T28 find more isolates detected over the 13 years of the study were resistant to this antibiotic. In the erythromycin- and tetracycline-resistant population population (19), 7 emm/T types were observed, the majority being emm11T11 (57.8%) (Table 3); indeed, 45.8% of all emm11T11 recovered from the initial GAS population (898) were co-resistant. The correlation between the different emm/T types and macrolide resistance genotypes is shown in Table 2. The mef(A)/msr(D) gene complex was the most common in almost all emm/T types, either alone or in combination with other genes. The mef(A)/msr(D) genotype was the most common in the emm1T1 (6/10), GSK3235025 nmr emm4T4 (62/116), emm6T6 (26/29)

and emm12T12 (10/20) types. The msr(D)/mef(A)/erm(A)(36/116) was the most common genotype among the emm4T4 (36/116) and emm75T25 (17/43) types. PFGE typing In the erythromycin-resistant population (295 isolates), 79 (26.8%) SmaI-restricted and 216 (73.2%) SmaI-non-restricted isolates were identified. SmaI-restricted isolates generated 30 pulsotypes with a similarity range of 38.8% to 94.7% (Figure 1). Their distribution by phenotype was: M (11 isolates),

cMLSB (58) and iMLSB (6). Figure 1 Sma I-pulsotypes, emm/ T PtdIns(3,4)P2 and phenotypes of erythromycin- and/or tetracycline-resistant S. pyogenes. The 216 SmaI-non-restricted isolates (Table 4) were typed with SfiI, generating 22 pulsotypes with a similarity range of 12.2% to 88.9% (Figure 2). The M phenotype (212 isolates) predominated over the cMLSB (2) and iMLSB (2) phenotypes. In addition, 11 different emm/T types were detected (Table 4) among 216 SmaI-non-restricted isolates, the most common being emm4T4 and emm75T25. All emm4T4 and all emm75T25 erythromycin-resistant isolates but one were SmaI non-restricted and had the M phenotype; together these accounted for 53.9% of the macrolide-resistant isolates in our study. Table 4 Distribution of emm /T types, phenotypes and genotypes of erythromycin-resistant Sma I-non-restricted isolates emm T Phenotype No. of isolates Genotypes (no.