title: In vitro activity of josamycin against Streptococcus pyogenes isolated from patients with upper respiratory tract infections in France.
abstract: OBJECTIVE
  The primary objective of our study was to obtain susceptibility data for josamycin against Streptococcus pyogenes isolated from patients presenting with upper respiratory tract infections in France. The secondary objective was to characterize the molecular mechanism of resistance in macrolide-resistant isolates.
  
  
  METHODS
  MICs of erythromycin, clarithromycin, azithromycin, josamycin, and clindamycin were determined by the broth microdilution method. Resistance genes erm(B), erm(TR), and mef(A) were screened by PCR.
  
  
  RESULTS
  The MIC50 and MIC90 of josamycin against 193 isolates of S. pyogenes were 0.12 and 0.25mg/L, respectively, with a resistance rate estimated at 4.7%. Resistance was due to the erm(B) gene whereas strains harboring erm(TR) or mef(A) remained susceptible.
  
  
  CONCLUSIONS
  Josamycin was active against >95% of S. pyogenes isolated from patients with upper respiratory tract infections, and can be used as an alternative for the treatment of pharyngitis.
authors.affiliation: Service de microbiologie et CNR associé de la résistance aux antibiotiques, CHU de Caen, 14033 Caen, France.
authors.forename: M
authors.initials: M
authors.lastname: Auzou
authors.affiliation: Service de bactériologie-hygiène, CHU de Nantes, 44093 Nantes, France.
authors.forename: J
authors.initials: J
authors.lastname: Caillon
authors.affiliation: Service de bactériologie et CNR des streptocoques, groupe hospitalier Cochin - Port-Royal - Paul-Broca, AP-HP, 75014 Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Poyart
authors.affiliation: Laboratoire BIO-VSM LAB, 77360 Vaires-sur-Marne, France.
authors.forename: P
authors.initials: P
authors.lastname: Weber
authors.affiliation: Service de bactériologie-virologie-hygiène, CHU de Limoges, 87042 Limoges, France.
authors.forename: M-C
authors.initials: MC
authors.lastname: Ploy
authors.affiliation: Service de microbiologie et CNR associé de la résistance aux antibiotiques, CHU de Caen, 14033 Caen, France.
authors.forename: R
authors.initials: R
authors.lastname: Leclercq
authors.affiliation: Service de microbiologie et CNR associé de la résistance aux antibiotiques, CHU de Caen, 14033 Caen, France. Electronic address: cattoir-v@chu-caen.fr.
authors.forename: V
authors.initials: V
authors.lastname: Cattoir
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005602:France; D006801:Humans; D015570:Josamycin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D012141:Respiratory Tract Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D015570:Josamycin
keywords: Group A Streptococcus (GAS); Macrolide resistance; Résistance aux macrolides; S. pyogenes; Streptocoque du groupe A (SGA)