A rapid increase in macrolide resistance in Streptococcus pyogenes isolated in Poland during 1996-2002.
OBJECTIVE
The aim of this study was to investigate Polish clinical isolates of Streptococcus pyogenes collected during a 7 year period using phenotypic and genotypic techniques.


METHODS
A total of 816 isolates of S. pyogenes recovered from 33 medical centres in Poland were tested for their susceptibility to various antimicrobial agents. Erythromycin-resistant isolates were analysed by PFGE, multilocus sequence typing and emm typing methods.


RESULTS
The tetracycline resistance rate was high (43%) among all S. pyogenes strains. Ninety-eight (12%) isolates were resistant to erythromycin. A low prevalence of the M phenotype (5.1%) associated with the presence of the mef(A) gene was found. All the isolates of the iMLSB phenotype harboured the erm(TR) gene. Out of the cMLSB isolates, 71.4% and 28.6% carried erm(TR) and erm(B), respectively. All isolates with erm(B) were resistant to telithromycin. PFGE analysis discerned 13 different patterns, A-N, with two predominant PFGE profiles--A (41 isolates) and B (25 isolates)--that in multilocus sequence typing corresponded, respectively, to a novel sequence type (ST) 367 and ST63. Overall, the representatives of these clones accounted for >90% of isolates of the iMLSB phenotype.


CONCLUSIONS
A significant increase in erythromycin resistance was observed among clinical S. pyogenes collected in Poland over a 7 year period driven by the spread of two epidemic clones.
Department of Epidemiology and Clinical Microbiology, National Institute of Public Health, Chelmska str 30/34, 00-725 Warsaw, Poland. kazbunda@cls.edu.pl
Katarzyna
K
Szczypa
Ewa
E
Sadowy
Radosław
R
Izdebski
Waleria
W
Hryniewicz
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial / Q000235:genetics; D005838:Genotype; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D011044:Poland / Q000453:epidemiology; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D018942:Macrolides