faecalis in the Title Loaded From File course of logarithmic development. faecalis together with the slightly elevated MICs of licochalcone A two instances larger than the initial MIC of licochalcone A after at least 90 days or 140 days of arduous induction. Having said that, as the handle, the identical E. faecalis isolate using the sharply enhanced MICs of linezolid 64 instances greater than the initial MIC of linezolid just after a similar time of induction as that to licochalcone A. These outcomes suggested that E. faecalis was tough to develop drug resistance beneath the stress of licochalcone A, and thus indicates that licochalcone A features a higher drug resistance barrier, which is also the prospective advantage of its clinical application in future. Ultimately, this study detected the gene mutations inside the licochalcone A nonsensitive E. faecalis isolates by wholegenome sequencing. Our outcomes demonstrated that there have been mutations in multiple transcriptional genes MarR household transcriptional regulator, TetR family members transcriptional regulator, and MerR family members transcriptional regulator. At present, MarR loved ones transcriptional regulator and TetR family transcriptional regulator had been discovered that closely associated to bacterial oxidative pressure, biofilm formation, and drug resistance by regulating the efflux pump and signal transduction Colclough et al., 2019 Fritsch et al., 2019 Nag and Mehra, 2021 Van Loi et al., 2021. Licochalcone A might have numerous target genes in E. faecalis, as an example, the MarR family members transcriptional regul.Acid.in the main factors for antimicrobials therapy failure and relapsing infections Harms et al., 2016. Thus, lowering the production of bacterial persister cells is expected to minimize chronic or relapsing infections, to improve the effect of antiinfection therapy Fisher et al., 2017. Licochalcone A isolated in the root of Glycyrrhiza species was reported, that had low cytotoxicity against host cells Si et al., 2018. This implies that at high concentrations, licochalcone A may well bring about significantly less damage to human cells than other chemically synthesized antimicrobials. Nevertheless, the damaging effect of a high concentration of licochalcone A on host cells nevertheless must be additional studied. The present study has investigated that licochalcone A substantially inhibited the biofilm formation of E. faecalis at subinhibitory concentrations. Previous studies also identified that licochalcone A inhibited the biofilm formation of candida albicans, S. suis, and S. aureus Hao et al., 2013 Shen et al., 2015 Seleem et al., 2016. This study also found that licochalcone A considerably inhibited the transcription of agg, esp, and srtA in E. faecalis in the course of logarithmic growth. The esp, agg, and srtA are involved in the attachment and earlystage biofilm formation of E. faecalis Tendolkar et al., 2004 Guiton et al., 2009 Kaviar et al., 2022. As a result, licochalcone A may perhaps cut down the biofilm formation of E. faecalis by inhibiting its early adhesion andaggregation. Though licochalcone A can substantially lower the biofilm formation of E. faecalis, licochalcone A alone or combined with other antimicrobials has no eradicating effect around the established biofilms of E. faecalis. This really is related to other studies which state that when bacterial biofilms are established, it is challenging for antimicrobials to remove them Shen et al., 2015 Suresh et al., 2019. To discover the feasible target genes of licochalcone A in E.