Increasing telithromycin resistance among **Streptococcus pyogenes** in EuropeIncreasing telithromycin resistance among **Streptococcus pyogenes** in Europe
Faculty of Medicine and Health Sciences
Vaccine & Infectious Disease Institute (VAXINFECTIO)
The journal of antimicrobial chemotherapy. - London
61(2008):3, p. 603-611
University of Antwerp
Objectives: To assess changes in macrolide and ketolide resistance among Streptococcus pyogenes in Europe and to examine the relationship of resistance to antimicrobial usage. Methods: Clinical S. pyogenes isolates were collected from Denmark, Finland, France, Germany, Italy, Netherlands, Norway, Spain, Sweden, UK, Croatia, Hungary, Poland, Slovak Republic and Slovenia during 200203 (n = 2165) and 200405 (n = 2333). Resistance to telithromycin (MIC 2) and erythromycin (MIC 0.5) was determined by CLSI broth microdilution. Changes in resistance over time and the relationship of resistance to antimicrobial use (European Surveillance of Antimicrobial Consumption data) were assessed. Telithromycin-resistant isolates were characterized by PFGE to determine genetic relatedness and by PCR to detect mef(A), erm(A) and erm(B). Results: The erythromycin resistance rate during 200405 (11.6%) was similar to 200203 (10.4%). The proportion of macrolide-resistant isolates with the constitutive MLSB phenotype increased from 29.3% (200203) to 45.7% (200405). Telithromycin resistance increased from 1.8% in 200203 to 5.2% in 200405. For Western Europe, associations of telithromycin and erythromycin resistance, respectively, were found with azithromycin use (R2 = 0.52 and 0.60), clarithromycin use (R2 = 0.76 and 0.85) and total macrolide/lincosamide use (R2 = 0.75 and 0.69). For Eastern Europe, associations of antimicrobial use with resistance were not apparent. The 162 telithromycin-resistant isolates comprised 42 PFGE patterns with 68.5% in eight major PFGE groups. The erm(B) gene was detected in 155 of the 162 telithromycin-resistant isolates. Conclusions: Significant increases in telithromycin resistance occurred from 200203 to 200405 in Europe. Macrolide use appears to be a factor in the emergence of ketolide resistance among S. pyogenes in Western Europe.