5-Fluorouracil sensitivity varies among oral microorganisms.

This study reports the effect of different concentrations of 5-FU (range 0.1-50 µM) on the growth and viability of bacterial monocultures that are present in the oral cavity and the possible role in the activity of dihydropyrimidine dehydrogenase (DPD), an enzyme involved in 5-FU resistance. Our data showed a differential sensitivity among the tested oral species towards physiological concentrations of 5-FU. Klebsiella oxytoca, Streptococcus salivarius, Streptococcus mitis, Streptococcus oralis, Pseudomonas aeruginosa and Lactobacillus salivarius appeared to be highly resistant to all tested concentrations. In contrast, Lactobacillus oris, Lactobacillus plantarum, Streptococcus pyogenes, Fusobacterium nucleatum and Neisseria mucosa already showed a significant reduction in growth and viability already starting from very low concentrations (0.2 - 3.1 µM). We could also provide evidence that DPD is not involved in the 5-FU resistance of the selected species. The observed variability in response to physiological 5-FU concentrations may explain why certain microbiota lead to a community dysbiosis and/or an overgrowth of certain resistant microorganisms in the oral cavity following cancer treatment. PMID: 27296270 [PubMed - as supplied by publisher]
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research