| Autor: |
Dewan S. Billal, Muneki Hotomi, Kazuma Yamauchi, Keiji Fujihara, Shinji Tamura, Kiyonori Kuki, Rinya Sugita, Miyoko Endou, Jun Mukaigawa, Noboru Yamanaka |
| Zdroj: |
Journal of Infection & Chemotherapy (Springer Science & Business Media B.V.); Number 2, Vol. 10 Issue 2, p115-120, 6p |
| Abstrakt: |
The growing number of macrolide-resistant strains of Streptococcus pyogenes is an increasing problem worldwide. This study evaluated 300 clinical isolates obtained from the upper respiratory tract. Minimal inhibitory concentrations (MICs) of erythromycin (EM), azithromycin (AZM), and clindamycin (CLDM), serotypes, and macrolide resistance genes of mefA, ermB, and ermTR were determined. The genetic relationship of EM-resistant and susceptible strains were also analyzed by pulsed-field gel electrophoresis (PFGE). Twenty-nine (9.7%) EM-resistant S. pyogenes were identified. Of the 29 strains showing resistance to EM, 22 isolates (7.3%, MIC 3.13–12.5µg/ml) expressed the mefA gene. The predominant serotypes among the mefA-positive isolates were T12, emm9 or T25, emm75-1. The two isolates (0.1%) that possessed the ermB gene were highly resistant to EM (MIC ≫ 100µg/ml). The remaining five strains (1.6%) possessed the ermTR gene (MIC 3.13–100µg/ml). Restriction fragment polymorphism analyzed by pulsed-field gel electrophoresis (PFGE) by SmaI and ApaI digestions showed several clones among the mefA-positive S. pyogenes. Our findings suggest that the mefA gene is the predominant mechanism for macrolide resistance and that this gene is horizontally transmitted among M phenotype strains of S. pyogenes. Consequently, macrolides would not be the first drug of choice for treatment of tonsillitis and other S. pyogenes-related diseases. Physicians and researchers need to take into consideration the macrolide resistance of some strains of S. pyogenes. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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