摘要
Trans-trans farnesol （tt-farnesol） is a bioactive sesquiterpene alcohol commonly found in propolis （a beehive product） and citrus fruits, which disrupts the ability of Streptococcus mutans （S. mutans） to form virulent biofilms. In this study, we investigated whether tt-farnesol affects cell-membrane function, acid production and/or acid tolerance by planktonic cells and biofilms of S. mutans UA159. Furthermore, the influence of the agent on S. mutans gene expression and ability to form biofilms in the presence of other oral bacteria （Streptococcus oralis （S. oralis） 35037 and Actinomyces naeslundii （.4. naeslundil） 12104） was also examined. In general, tt-farnesol （1 mmol-L-1） significantly increased the membrane proton permeability and reduced glycolytie activity of S. mutans in the planktonic state and in biofilms （P〈0.05）. Moreover, topical applications of 1 mmol-L＂l tt-farnesol twice daily （1 min exposure/treatment） reduced biomass accumulation and prevented ecological shifts towards S. mutans dominance within mixed-species biofilms after introduction of 1% sucrose. S. oralis （a non-cariogenie organism） became the major species after treatments with tt-farnesol, whereas vehicle-treated biofilms contained mostly S. mutans （〉90% of total bacterial population）. However, the agent did not affect significantly the expression of S. mutans genes involved in acidogenicity, acid tolerance or polysaccharide synthesis in the treated biofilms. Our data indicate that tt-farnesoi may affect the competi- tiveness of S. mutans in a mixed-species environment by primarily disrupting the membrane function and physiology of this bacterium. This naturally occurring terpenoid could be a potentially useful adjunctive agent to the current anti-biofilm/anti-caries chemotherapeutic strategies.
Trans-trans farnesol （tt-farnesol） is a bioactive sesquiterpene alcohol commonly found in propolis （a beehive product） and citrus fruits, which disrupts the ability of Streptococcus mutans （S. mutans） to form virulent biofilms. In this study, we investigated whether tt-farnesol affects cell-membrane function, acid production and/or acid tolerance by planktonic cells and biofilms of S. mutans UA159. Furthermore, the influence of the agent on S. mutans gene expression and ability to form biofilms in the presence of other oral bacteria （Streptococcus oralis （S. oralis） 35037 and Actinomyces naeslundii （.4. naeslundil） 12104） was also examined. In general, tt-farnesol （1 mmol-L-1） significantly increased the membrane proton permeability and reduced glycolytie activity of S. mutans in the planktonic state and in biofilms （P〈0.05）. Moreover, topical applications of 1 mmol-L＂l tt-farnesol twice daily （1 min exposure/treatment） reduced biomass accumulation and prevented ecological shifts towards S. mutans dominance within mixed-species biofilms after introduction of 1% sucrose. S. oralis （a non-cariogenie organism） became the major species after treatments with tt-farnesol, whereas vehicle-treated biofilms contained mostly S. mutans （〉90% of total bacterial population）. However, the agent did not affect significantly the expression of S. mutans genes involved in acidogenicity, acid tolerance or polysaccharide synthesis in the treated biofilms. Our data indicate that tt-farnesoi may affect the competi- tiveness of S. mutans in a mixed-species environment by primarily disrupting the membrane function and physiology of this bacterium. This naturally occurring terpenoid could be a potentially useful adjunctive agent to the current anti-biofilm/anti-caries chemotherapeutic strategies.
基金
supported by IADR/GSK Innovation in Oral Care Award, USPHS Research grant 1R01DE 018023 from the National Institute of Dental and Craniofacial Research (National Institutes of Health)
Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (2009-0071090)
