Streptococcus pyogenes susceptibility to macrolides among inpatients of the Clinical Hospital Mostar

Since February 2000 till September 2001 a survey of antimicrobial resistance of Streptococcus pyogenes was performed. Six hundred and thirteen (613) strains of S. pyogenes were tested against penicillin and macrolides erythromycin, clarithromycin and azithromycin. The strains were isolated from throat swabs 552 (90%), nose swabs 50 (8.2%), ear swabs 4 (0.7%), vagina swabs 2 (0.3%), wound swabs 4 (0.7%) and broncho-aspirat 1 (0.1%). Disk-diffusion tests were used for susceptibility testing.In Clinical Hospital Mostar, the resistance of S.pyogenes to erythromycin was 8%, to azithromycin was 8.5%, and to clarithromycin was 8.7%. All strains were susceptible to penicillin. We had also intermediate strains to erythromycin (5.2%), azithromycin (5.5%) and to clarithromycin (11.3%). The average resistance rates of S.pyogenes to erythromycin, azithromacin and clarithromycin in strains isolated in Clinical Hospital Mostar were not higher than 9%. This percentage of macrolide resistance is similar to other neighbour countries. We did not detect any significant differences of resistance to tested macrolides. We detected only difference at intermediate strains ; to clarithromycin significant higher than to erythromycin and azithromycin. Our results confirm the importance of global resistance data, but also regional resistance data in order to create an antibiotic policy.