A Boulos1, J M Rolain, M N Mallet, D Raoult. 1. Unité des Rickettsies, CNRS UMR 6020, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France.
Abstract
OBJECTIVES AND METHODS: Whipple's disease is a rare multisystem chronic infection, involving the intestinal tract as well as various other organs. Tropheryma whipplei is a slow-growing facultative intracellular bacterium that remains poorly understood. In vitro antibiotic susceptibility testing has previously been assessed in cells using a real-time quantitative PCR assay. In this study, we have evaluated the antibiotic susceptibility of three strains of T. whipplei grown in axenic medium using the same assay. RESULTS: The active compounds in axenic medium were doxycycline, macrolide compounds, penicillin G, streptomycin, rifampicin, chloramphenicol, thiamphenicol, teicoplanin, vancomycin, amoxicillin, gentamicin, aztreonam, levofloxacin and ceftriaxone, with MICs in the range 0.06-1 mg/L. Cefalothin was less active, with MICs in the range 2-4 mg/L. We found that co-trimoxazole was active with MICs in the range 0.5-1 mg/L, and sulfamethoxazole alone was active with MICs in the range 0.5-1 mg/L. MICs of trimethoprim varied from 64-128 mg/L. CONCLUSIONS: Co-trimoxazole was effective in vitro, but this activity was due to sulfamethoxazole alone. These results were in accordance with the fact that T. whipplei does not contain the encoding gene for dihydrofolate reductase, the target for trimethoprim.
OBJECTIVES AND METHODS: Whipple's disease is a rare multisystem chronic infection, involving the intestinal tract as well as various other organs. Tropheryma whipplei is a slow-growing facultative intracellular bacterium that remains poorly understood. In vitro antibiotic susceptibility testing has previously been assessed in cells using a real-time quantitative PCR assay. In this study, we have evaluated the antibiotic susceptibility of three strains of T. whipplei grown in axenic medium using the same assay. RESULTS: The active compounds in axenic medium were doxycycline, macrolide compounds, penicillin G, streptomycin, rifampicin, chloramphenicol, thiamphenicol, teicoplanin, vancomycin, amoxicillin, gentamicin, aztreonam, levofloxacin and ceftriaxone, with MICs in the range 0.06-1 mg/L. Cefalothin was less active, with MICs in the range 2-4 mg/L. We found that co-trimoxazole was active with MICs in the range 0.5-1 mg/L, and sulfamethoxazole alone was active with MICs in the range 0.5-1 mg/L. MICs of trimethoprim varied from 64-128 mg/L. CONCLUSIONS: Co-trimoxazole was effective in vitro, but this activity was due to sulfamethoxazole alone. These results were in accordance with the fact that T. whipplei does not contain the encoding gene for dihydrofolate reductase, the target for trimethoprim.
Authors: Jan Bureš; Marcela Kopáčová; Tomáš Douda; Jolana Bártová; Jan Tomš; Stanislav Rejchrt; Ilja Tachecí Journal: Gastroenterol Res Pract Date: 2013-06-17 Impact factor: 2.260