| Title | Propionate, together with triple antibiotics, inhibits the growth of Enterococci |
|---|---|
| Author | Soyoung Jeong1, Yunjae Lee1,2, Cheol-Heui Yun3,4, Ok-Jin Park*1, and Seung Hyun Han1 |
| Address | 1Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul08826, Republic of Korea, 2College of Liberal Studies, Seoul National University, Seoul 08826, Republic of Korea, 3Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea, 4Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea |
| Bibliography | Journal of Microbiology, 57(11),1019–1024, 2019, |
| DOI | 10.1007/s12275-019-9434-7 |
| Key Words | Enterococci, Enterococcus faecalis, propionate, short-chain fatty acids |
| Abstract | Enterococci are Gram-positive facultative anaerobic bacteria that colonize the oral cavity and gastrointestinal tract. Enterococcal infections, mainly caused by Enterococcus faecalis and Enterococcus faecium, include apical periodontitis, endocarditis, and bloodstream infections. Recently, vancomycinresistant Enterococci are considered major pathogens that are common but difficult to treat, especially in nosocomial settings. Moreover, E. faecalis is closely associated with recurrent endodontic infections and failed endodontic treatment. In this study, we investigated the effects of short-chain fatty acids (SCFAs), acetate, propionate, and butyrate, which are metabolites fermented by gut microbiota, on the growth of Enterococci. Enterococci were cultured in the presence or absence of acetate, propionate, or butyrate, and the optical density at 600 nm was measured to determine bacterial growth. The minimum inhibitory concentration/minimum bactericidal concentration test was conducted. Bacteria were treated with a SCFA, together with clinically used endodontic treatment methods such as triple antibiotics (metronidazole, minocycline, and ciprofloxacin) and chlorhexidine gluconate (CHX) to determine the effects of combination treatment. Of the SCFAs, propionate had a bacteriostatic effect, inhibiting the growth of E. faecalis in a dose-dependent manner and also that of clinical strains of E. faecalis isolated from dental plaques. Meanwhile, acetate and butyrate had minimal effects on E. faecalis growth. Moreover, propionate inhibited the growth of other Enterococci including E. faecium. In addition, combination treatment of propionate and triple antibiotics led to further growth inhibition, whereas no cooperative effect was observed at propionate plus CHX. These results indicate that propionate attenuates the growth of Enterococci, suggesting propionate as a potential agent to control Enterococcal infections, especially when combined with triple antibiotics. |