Sensibilité actuelle en France de Streptococcus pyogenes responsable d’angine aiguë

Abstract

Current guidelines recommend that only tonsillopharyngitis due to group A beta-haemolytic streptococcus (GABHS) diagnosed by rapid diagnostic test should be treated with antibiotics. Empirical antibiotic therapy must be based on epidemiological surveillance of resistance of GABHS to antibiotics. The aim of our study was to assess the activity of antimicrobial agents currently recommended for the treatment of GABHS tonsillopharyngitis. Method The activity of penicillin G, amoxicillin, cefaclor, cefpodoxime, cefuroxime, erythromycin, clarithromycin and clindamycin was determined against 93 consecutive GABHS isolates collected in 2002. MIC50 and MIC90 of antibiotics tested were determined by agar dilution method according to CA-SFM guidelines. Macrolide resistance genes (ermA, ermB, mef) were detected by PCR. Genetic diversity of erythromycin-resistant isolates was analysed by pulsotypic method after digestion by SmaI (Finger-printing II, Biorad). The activity of beta-lactam agents tested was similar and no resistant strain was detected (0%). Nevertheless, this study shows an increasing emergence of erythromycin-resistant GABHS strains reaching 14% in 2002 (vs. 6.2% in a previous study carried out in 1996-1999). The empirical antibiotic therapy of tonsillopharyngitis must consider, on the one hand, the high risk of GABHS eradication failure associated with in vitro resistance to erythromycin and clarithromycin, and on the other hand, the sustained susceptibility of GABHS to beta-lactam agents. These results reinforce the recommendations to use beta-lactam agents as first line treatment of GABHS tonsillopharyngitis.