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PubMed2004

[Current Streptococcus pyogenes sensitivity responsible for acute tonsillopharyngitis in France].

OBJECTIVE: 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). RESULTS: 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). CONCLUSION: 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.

Acute Disease↗
PubMed1981

Purification and characterization of erythrogenic toxins. IV. Communication: mitogenic activity of erythrogenic toxin produced by Streptococcus pyogenes strain NY-5.

Some in vitro reactions involved in the mitogenic activity of a purified erythrogenic toxin from the group A streptococcus strain NY-5 (ET NY-5) were studied. The optimal dose in the human blood lymphocyte transformation test was 1 to 10(-1) microgram/ml lymphocyte culture, the maximum of 3H-thymidine incorporation was on day 3 or 4. The mitogenic activity showed the signs of nonspecificity, nevertheless, a specific mitogenic effect could not be ruled out either. When Con A and ET NY-5 were added simultaneously in high or low doses at the beginning of lymphocyte cultivation, antagonism or an additive effect was observed, respectively. Incubation of lymphocytes with ET NY-5 resulted in a decrease of mitogenic activity in the supernatants. Erythrocytes had no similar binding activity. ET NY-5 acts as a T-cell mitogen; 98% of ET NY-5-stimulated lymphoblasts formed E rosettes with sheep red blood cells. Thin-layer isoelectric focusing experiments revealed two mitogenic peaks corresponding to toxin types A and C in the ET preparation.

Bacterial Proteins↗