Goc Anna, Sumera Waldemar, Rath Matthias, Niedzwiecki Aleksandra
Dr. Rath Research Institute, 5941 Optical Ct., San Jose, CA 95138, USA.
Microorganisms. 2024 Aug 7;12(8):1613. doi: 10.3390/microorganisms12081613.
is a major pathogenic habitant of oral caries. Owing to its physiological and biochemical features, it prevails in the form of plaque biofilm together with another important mutans streptococci species, . Both species are considered as initiators of cavity lesions, and biofilm is essential to the dental caries process. Compared with the planktonic populations, the biofilm form has higher resistance to environmental conditions and antibiotics. Dental plaques also secure the long-term survival of microorganisms and protection from any stress conditions. To address the need for new antibiofilm agents, we have focused on L-carnitine-fumarate, a fumarate-conjugated quaternary ammonium compound. Using the macro-broth susceptibility testing method, we established its MIC value as 6.0 mg/mL. The MBC value, determined from the broth dilution minimum inhibitory concentration test by sub-culturing it to BHI agar plates, was established as 7.0 mg/mL. Antibiofilm efficacy was tested in 96-well plates coated with saliva using BHI broth supplemented with 1% sucrose as a standard approach. The obtained results allowed us to assess the MIBC as 7.5 mg/mL and the MBBC value as 10.0 mg/mL. The latter concentration also caused approximately 20% eradication of pre-existing biofilm. EPS-rich matrix, forming the core of the biofilm and enabling a confined acidic microenvironment, was also examined and confirmed the effectiveness of 10.0 mg/mL L-carnitine-fumarate concentration in inhibiting EPS formation. Furthermore, the anti-adherent and anti-aciduric impacts of L-carnitine-fumarate were investigated and revealed significant inhibitory effects at sub-MIC concentrations. The influence of L-carnitine-fumarate on the phosphotransferase system was investigated as well. Our results provide a new insight into the antibacterial potential of L-carnitine-fumarate as a valuable compound to be considered for alternative or adjunct anti-caries and antibiofilm preventive approaches.
是口腔龋齿的主要致病微生物。由于其生理生化特性，它与另一种重要的变形链球菌物种一起以菌斑生物膜的形式存在。这两种物种都被认为是龋损病变的起始因素，生物膜对龋齿过程至关重要。与浮游菌群体相比，生物膜形式对环境条件和抗生素具有更高的抗性。牙菌斑还确保了微生物的长期存活并使其免受任何应激条件的影响。为了满足对新型抗生物膜药物的需求，我们专注于L-肉碱富马酸盐，一种富马酸盐共轭季铵化合物。使用宏观肉汤药敏试验方法，我们确定其MIC值为6.0 mg/mL。通过将其接种到BHI琼脂平板上进行肉汤稀释最低抑菌浓度试验确定的MBC值为7.0 mg/mL。使用补充有1%蔗糖的BHI肉汤在涂有唾液的96孔板中测试抗生物膜功效，这是一种标准方法。获得的结果使我们能够评估MIBC为7.5 mg/mL，MBBC值为10.0 mg/mL。后一种浓度还导致约20%的现有生物膜被清除。富含胞外多糖（EPS）的基质形成生物膜的核心并形成一个受限的酸性微环境，也进行了检查，并证实了10.0 mg/mL L-肉碱富马酸盐浓度在抑制EPS形成方面的有效性。此外，还研究了L-肉碱富马酸盐的抗粘附和抗酸作用，并揭示了在亚MIC浓度下的显著抑制作用。还研究了L-肉碱富马酸盐对磷酸转移酶系统的影响。我们的结果为L-肉碱富马酸盐作为一种有价值的化合物的抗菌潜力提供了新的见解，可考虑将其用于替代或辅助抗龋齿和抗生物膜预防方法。
