JAC Advance Access originally published online on January 24, 2008
Journal of Antimicrobial Chemotherapy 2008 61(3):603-611; doi:10.1093/jac/dkm525
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Original research |
Increasing telithromycin resistance among Streptococcus pyogenes in Europe
1 Department of Pathology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242-1009, USA 2 Instituto Valenciano Microbio, Masia El Romeral, Betera, Valencia 46117, Spain 3 Laboratory of Microbiology, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
Received 17 August 2007; returned 1 December 2007; revised 22 October 2007; accepted 11 December 2007
* Corresponding author. Tel: +1-319-356-2990; Fax: +1-319-356-4916; E-mail: sandra-richter{at}uiowa.edu
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 2002–03 (n = 2165) and 2004–05 (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 2004–05 (11.6%) was similar to 2002–03 (10.4%). The proportion of macrolide-resistant isolates with the constitutive MLSB phenotype increased from 29.3% (2002–03) to 45.7% (2004–05). Telithromycin resistance increased from 1.8% in 2002–03 to 5.2% in 2004–05. 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 2002–03 to 2004–05 in Europe. Macrolide use appears to be a factor in the emergence of ketolide resistance among S. pyogenes in Western Europe.
Keywords: group A streptococci , ketolides , macrolides