Accéder au contenu
Merck

Influence of dTMP on the phenotypic appearance and intracellular persistence of Staphylococcus aureus.

Infection and immunity (2007-12-28)
Johannes Zander, Silke Besier, Stephan H Saum, Faramarz Dehghani, Stefan Loitsch, Volker Brade, Thomas A Wichelhaus
RÉSUMÉ

Thymidine-dependent small-colony variants (SCVs) of Staphylococcus aureus are frequently associated with persistent and recurrent infections in cystic fibrosis patients. The phenotypic appearance of S. aureus SCVs or normal-colony variants (NCVs) is postulated to be affected by the intracellular amount of dTMP. This hypothesis was proven by metabolic pathway assays revealing altered intracellular dTMP concentrations, followed by investigation of the associated phenotype. Inhibition of the staphylococcal thymidylate synthase, which generated intracellular dTMP from dUMP, using 5-fluorouracil and co-trimoxazole resulted in an SCV phenotype. Inhibition of a nucleoside transporter, which provided the bacterial cell with extracellular thymidine, caused growth inhibition of SCVs. In turn, reversion of SCVs to NCVs was achieved by supplying extracellular dTMP. High-performance liquid chromatography additionally confirmed the intracellular lack of dTMP in SCVs, in contrast to NCVs. Moreover, the dTMP concentration is postulated to influence the intracellular persistence of S. aureus. Cell culture experiments with cystic fibrosis cells revealed that clinical and co-trimoxazole-induced SCVs with a diminished amount of dTMP showed significantly better intracellular persistence than NCVs. In conclusion, these results show that the dTMP concentration plays a key role in both the phenotypic appearance and the intracellular persistence of S. aureus.

MATÉRIAUX
Référence du produit
Marque
Description du produit

Sigma-Aldrich
Acétonitrile, suitable for HPLC, gradient grade, ≥99.9%
Sigma-Aldrich
Acétonitrile, HPLC Plus, ≥99.9%
Sigma-Aldrich
Amphotéricine B solution, 250 μg/mL in deionized water, 0.1 μm filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Acétonitrile, ACS reagent, ≥99.5%
Sigma-Aldrich
Triethylammonium acetate buffer, volatile buffer, ~1.0 M in H2O
Sigma-Aldrich
Acétonitrile, for HPLC, for UV, ≥99.9% (GC)
Sigma-Aldrich
Acétonitrile, anhydrous, 99.8%
Sigma-Aldrich
Chloramphénicol, ≥98% (HPLC)
Sigma-Aldrich
Acétonitrile, suitable for HPLC, gradient grade, ≥99.9%
Sigma-Aldrich
Fluorure de phénylméthanesulfonyle, ≥98.5% (GC)
Sigma-Aldrich
Amphotéricine B solubilisée, powder, γ-irradiated, BioXtra, suitable for cell culture
Sigma-Aldrich
Lysostaphine from Staphylococcus staphylolyticus, lyophilized powder, Protein 50-70 % by biuret, ≥500 units/mg protein
Sigma-Aldrich
Thymidine, powder, BioReagent, suitable for cell culture
Sigma-Aldrich
5-Fluorouracil, ≥99% (HPLC), powder
Sigma-Aldrich
Thymidine, ≥99%
Sigma-Aldrich
Acétonitrile, suitable for HPLC-GC, ≥99.8% (GC)
Sigma-Aldrich
Erythromycin, BioReagent, suitable for cell culture
Sigma-Aldrich
Lysostaphin from Staphylococcus simulans, recombinant, expressed in E. coli, lyophilized powder
Sigma-Aldrich
Uridine, ≥99%
Sigma-Aldrich
Uridine, powder, BioReagent, suitable for cell culture
Sigma-Aldrich
Fluorure de phénylméthanesulfonyle, ≥99.0% (T)
Sigma-Aldrich
Chloramphénicol, BioReagent, suitable for plant cell culture
Sigma-Aldrich
Chloramphenicol, Ready Made Solution, 100 mg/mL in ethanol: isopropanol (95:5), ≥98% (HPLC)
Sigma-Aldrich
Acétonitrile, biotech. grade, ≥99.93%
Sigma-Aldrich
Acétonitrile, ReagentPlus®, 99%
Sigma-Aldrich
Acétonitrile, electronic grade, 99.999% trace metals basis
Sigma-Aldrich
Acétonitrile, suitable for DNA synthesis, ≥99.9% (GC)
Sigma-Aldrich
Lysostaphine from Staphylococcus staphylolyticus, BioUltra, ≥97% (SDS-PAGE), Protein 40-60 % by biuret, ≥2,000 units/mg protein
Sigma-Aldrich
Thymidine, ≥99.0% (HPLC)
Sigma-Aldrich
Chloramphénicol, meets USP testing specifications