Erythromycin-resistant Streptococcus pyogenes
Abstract number: 902_p1092
Streptococcus pyogenes is the most prevalent cause of tonsylopharyngitis in children. The drug of choice for infections caused by this organism is penicillin. The problem with treating such infections arises when erythromycin-resistant strains occur.
The aim of the study was to determine the incidence of S. pyogenes resistant to penicillin. The organism was recovered from the pharynx of children hospitalised or ambulatory treated at the University Children's Hospital in Belgrade.
S. pyogenes was identified on blood agar, using bacitracin disc, and confirmed by latex agglutination test (Slidex Bio Merieux). Disc diffusion test was carried out to estimate the penicillin sensitivity. Erythromycin disc was used as a screening method to detect erythromycin-resistant S. pyogenes. MIC for erythromycin was performed by broth dilution method.
In the study period from January 2001 to December 2003 all 1100 isolates of S. pyogenes showed usual level of penicillin sensitivity. In 2001 only 0.45% of isolates were erythromycin-resistant. In 2002 erythromycin resistance was 0.63%, while in 2003 it was 1.09%. MIC for erythromycin was from 1 to 128mg/L. Three strains expressed constitutive and one strain expressed inducible resistance to clindamycin.
According to the results we can conclude that, despite sensitivity to penicillin, resistance to macrolides is the emerging phenomenon. The reasonable use of macrolide antibiotics is necessary to maintain the resistance at the low level."
|Session name:||XXIst ISTH Congress|
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