title: Increasing telithromycin resistance among Streptococcus pyogenes in Europe.
abstract: OBJECTIVE
  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 > or = 2) and erythromycin (MIC > or = 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 MLS(B) 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.
authors.affiliation: Department of Pathology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242-1009, USA. sandra-richter@uiowa.edu
authors.forename: Sandra S
authors.initials: SS
authors.lastname: Richter
authors.forename: Kristopher P
authors.initials: KP
authors.lastname: Heilmann
authors.forename: Cassie L
authors.initials: CL
authors.lastname: Dohrn
authors.forename: Susan E
authors.initials: SE
authors.lastname: Beekmann
authors.forename: Fathollah
authors.initials: F
authors.lastname: Riahi
authors.forename: Juan
authors.initials: J
authors.lastname: Garcia-de-Lomas
authors.forename: Matus
authors.initials: M
authors.lastname: Ferech
authors.forename: Herman
authors.initials: H
authors.lastname: Goossens
authors.forename: Gary V
authors.initials: GV
authors.lastname: Doern
mesh_terms: D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000502:physiology; D005060:Europe / Q000453:epidemiology; D006801:Humans; D048628:Ketolides / Q000378:metabolism / Q000494:pharmacology*; D011500:Protein Synthesis Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D012338:RNA, Ribosomal, 23S / Q000378:metabolism; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D048628:Ketolides; D011500:Protein Synthesis Inhibitors; D012338:RNA, Ribosomal, 23S; C106791:telithromycin