Macrolide resistance determinants of group A streptococci in Ankara, Turkey.
OBJECTIVE
Macrolide-lincosamide-streptogramin B (MLSB) resistance determinants of group A streptococci (GAS) in Ankara, Turkey, were defined for the first time. ISOLATES AND METHODS: A total of 1355 GAS isolates, collected from three different regions of Ankara, were screened for erythromycin resistance. Resistance phenotypes were determined by a triple-disc test, and the gene determinants responsible were determined by PCR. MICs of erythromycin, clindamycin and spiramycin were measured for the resistant isolates, and susceptibility rates to some further antibiotics were determined.


RESULTS
Thirty-six isolates (2.6%) were resistant to erythromycin. Of these, 17 (47.2%) expressed macrolide-restricted resistance (M phenotype), while the remainder expressed inducible (16 isolates, 44.4%) or constitutive (three isolates, 8.3%) MLSB resistance. All isolates of the M phenotype harboured the mef(A) gene. Of non-M isolates, 14 harboured erm(A) subclass erm(TR) and five had erm(B) genes. There was a significant relationship between tetracycline resistance and the inducible phenotype (P < 0.05). Macrolide resistance was significantly higher in adults (P < 0.05), and increased more than two-fold in 2002 compared with 2001 (P < 0.05).


CONCLUSIONS
The prevalence of macrolide resistance in GAS is low in Ankara; therefore, routine antimicrobial susceptibility testing against these agents seems unwarranted.
Acikgoz
Ziya Cibali
ZC
Microbiology and Clinical Microbiology Department of Fatih University School of Medicine, Ankara, Turkey. zcacikgoz@yahoo.com
Gocer
Safiye
S
Tuncer
Serdar
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004917:Erythromycin / Q000494:pharmacology; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D013290:Streptococcal Infections / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics*; D014421:Turkey
D000900:Anti-Bacterial Agents; D004917:Erythromycin