Targeting the Enterococcal Fibronectin Binding Protein- A of Enterococcus faecalis with Bioactive Compounds from Aegle Marmelos: An In-vitro and In-silico Pilot Study

Introduction: Enterococcus faecalis (E. faecalis) is a significant endodontic pathogen, and its virulence has been shown to be significantly influenced by Enterococcal fibronectin binding protein-A (EfbA). Targeting this virulent protein using alternative strategies would be a novel idea to combat the complications of E. faecalis in dental healthcare settings. Thus, the rationale of this investigation is to identify potent bioactive compounds from Aegle marmelos for their antimicrobial properties against EfbA of E. faecalis. Aim: To assess the frequency of EfbA among clinical isolates of E. faecalis and evaluate the antibacterial activity of essential bioactive compounds from Aegle marmelos. Materials and Methods: An in-vitro and in-silico pilot study was conducted from April 2022 to June 2022 in the Department of Microbiology, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India to detect the frequency of EfbA in E. faecalis. Patients with typical root caries were included. Microbiological processing of 20 root caries samples was performed to characterise E. faecalis and detect the EfbA gene using Polymerase Chain Reaction (PCR) amplification. Crude methanol extract was obtained from A. marmelos and assessed for its antimicrobial effect against the isolated strains of E. faecalis. Furthermore, several biomolecules from A. marmelos were evaluated for their inhibitory properties through in-silico docking analysis. Results: E. faecalis was identified in 12 (60%) out of 20 root caries samples, and three isolates (25%) were identified as Multidrug-Resistant (MDR) strains based on the antibiogram susceptibility profile, showing resistance to more than three different tested antibiotic groups. EfbA was detected in two of the three MDR strains (66.7%). The crude extract of A. marmelos exhibited promising antibacterial activity. In-silico analysis of the essential oil compounds from A. marmelos revealed that Aegeline had a high interaction with low docking energy and a high number of hydrogen bonds. Conclusion: The current study highlights the potential of aegeline from A. marmelos as an antibacterial agent against resistant strains of E. faecalis. However, additional in-vivo research must be conducted to experimentally validate these findings.