Antimicrobial resistance amongst isolates of Streptococcus pyogenes and Staphylococcus aureus in the PROTEKT antimicrobial surveillance programme during 1999-2000

Abstract

Abstract The pattern of susceptibility to a range of antimicrobials was tested for 1485 isolates of Streptococcus pyogenes and 1547 isolates of S taphylococcus aureus included in the international PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) surveillance study (1999–2000). Overall, almost 10% of S. pyogenes isolates were erythromycin A resistant. There was a wide heterogeneity of resistance, with high levels of macrolide resistance in Poland (42%), Hong Kong (28%), Italy (25%), Portugal (24%) and Spain (21%), and no macrolide resistance in Indonesia, Austria, Belgium, the Netherlands or the UK. Using NCCLS tentative breakpoints, 97.6% of isolates were susceptible to telithromycin, with MIC 90 ≤ 0.015 mg/L in most regions. Resistance among S. pyogenes to the β-lactams (MIC 90 ≤ 0.12 mg/L for all except cefaclor) and fluoroquinolones was not detected. Macrolide resistance was present among the S. aureus isolates, and as with S. pyogenes , there was a wide heterogeneity of resistance, with lower rates in Australia, Indonesia, Hungary, Austria, Germany, the Netherlands, Portugal, Sweden and Switzerland. Methicillin-resistant isolates were resistant to the β-lactams and the macrolides. Resistance to telithromycin was detected in methicillin-resistant isolates in Latin and North America, Asia and Europe. Telithromycin resistance was non-existent or low (MIC 90 range 0.06–0.25 mg/L) in Australia, Indonesia, Hungary, Austria, Germany, the Netherlands, Portugal, Sweden and Switzerland. Regardless of methicillin susceptibility, resistance to linezolid, teicoplanin or vancomycin was not apparent globally.