Antimicrobial activities of trimethoprim/sulfamethoxazole; 5-iodo-2′-deoxyuridine and rifampicin against

Johannes Zander (1) , Silke Besier (1) , Sebastian Faetke (1) , Stephan H. Saum , Volker Müller , Thomas A. Wichelhaus (1)

1 Goethe-Universität Frankfurt am Main

Trimethoprim/sulfamethoxazole (SXT), alone and in combination with rifampicin (RIF), is a therapeutic option against , including strains expressing meticillin resistance. However, the antimicrobial activity of SXT is antagonised by thymidine, which can be present in infected and/or inflamed tissues such as the airways of cystic fibrosis (CF) patients. In this study, thymidine concentrations in CF sputa were determined and the antimicrobial activities of SXT, 5-iodo-2′-deoxyuridine (IdUrd) and RIF alone and in combination against were analysed. Thymidine concentrations in the sputa of ten different CF patients varied from <100μg/L to 38 845μg/L. The abolished antimicrobial activity of SXT against 22 strains in the presence of thymidine was restored by combination with IdUrd. In contrast, SXT combined with RIF in the presence of thymidine did not show a synergistic effect and, furthermore, allowed the emergence of RIF-resistant bacteria. Adding RIF to the combination of SXT and IdUrd did not improve antimicrobial activity against . In conclusion, the combination of SXT and RIF as a therapeutic option against infections in chronic inflamed tissues should be judged critically.

Mots clés: Rifampicin; Trimethoprim/sulfamethoxazole; 5-Iodo-2′-deoxyuridine; Antimicrobial activity; Thymidine

Johannes Zander, Silke Besier, Sebastian Faetke, Stephan H. Saum, Volker Müller, et al.. Antimicrobial activities of trimethoprim/sulfamethoxazole; 5-iodo-2′-deoxyuridine and rifampicin against. International Journal of Antimicrobial Agents, 2010, 36 (6), pp.562. ⟨10.1016/j.ijantimicag.2010.08.007⟩. ⟨hal-00640442⟩