Liu Xiaoju, Xiong Yanpeng, Shi Yiyi, Deng Xiangbin, Deng Qiwen, Liu Yansong, Yu Zhijian, Li Duoyun, Zheng Jinxin, Li Peiyu
Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infection, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China.
Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.
Front Microbiol. 2022 Oct 21;13:970901. doi: 10.3389/fmicb.2022.970901. eCollection 2022.
This study aims to evaluate the antibacterial and anti-biofilm activities of licochalcone A on and to investigate the possible target genes of licochalcone A in . This study found that licochalcone A had antibacterial activities against , with the MIC and MIC were 25 μM. Licochalcone A (at 4 × MIC) indicated a rapid bactericidal effect on planktonic cells, and killed more planktonic cells (at least 3-log cfu/ml) than vancomycin, linezolid, or ampicillin at the 2, 4, and 6 h of the time-killing test. Licochalcone A (at 10 × MIC) significantly reduced the production of persister cells (at least 2-log cfu/ml) than vancomycin, linezolid, or ampicillin at the 24, 48, 72, and 96 h of the time-killing test. Licochalcone A (at 1/4 × MIC) significantly inhibited the biofilm formation of . The RNA levels of biofilm formation-related genes, , and , markedly decreased when the isolates were treated with licochalcone A at 1/4 × MIC for 6 h. To explore the possible target genes of licochalcone A in , the licochalcone A non-sensitive clones were selected by induction of wildtype strains for about 140 days under the pressure of licochalcone A, and mutations in the possible target genes were detected by whole-genome sequencing. This study found that there were 11 nucleotide mutations leading to nonsynonymous mutations of 8 amino acids, and among these amino acid mutations, there were 3 mutations located in transcriptional regulator genes (MarR family transcriptional regulator, TetR family transcriptional regulator, and MerR family transcriptional regulator). In conclusion, this study found that licochalcone A had an antibacterial effect on , and significantly inhibited the biofilm formation of at subinhibitory concentrations.
本研究旨在评估甘草查尔酮A的抗菌和抗生物膜活性，并探究甘草查尔酮A在[具体对象]中的可能靶基因。本研究发现甘草查尔酮A对[具体对象]具有抗菌活性，其MIC和MIC为25μM。甘草查尔酮A（4×MIC）对[具体对象]的浮游细胞显示出快速杀菌作用，在杀菌试验的2、4和6小时时，杀死的[具体对象]浮游细胞（至少3-log cfu/ml）比万古霉素、利奈唑胺或氨苄西林更多。在杀菌试验的24、48、72和96小时时，甘草查尔酮A（10×MIC）比万古霉素、利奈唑胺或氨苄西林显著减少了[具体对象]持留菌细胞的产生（至少2-log cfu/ml）。甘草查尔酮A（1/4×MIC）显著抑制了[具体对象]的生物膜形成。当[具体对象]分离株用1/4×MIC的甘草查尔酮A处理6小时时，生物膜形成相关基因[具体基因]、[具体基因]和[具体基因]的RNA水平显著降低。为了探究甘草查尔酮A在[具体对象]中的可能靶基因，通过在甘草查尔酮A压力下对野生型菌株诱导约140天来选择甘草查尔酮A不敏感的[具体对象]克隆，并通过全基因组测序检测可能靶基因中的突变。本研究发现有11个核苷酸突变导致8个氨基酸的非同义突变，在这些氨基酸突变中，有3个突变位于转录调节基因（MarR家族转录调节因子、TetR家族转录调节因子和MerR家族转录调节因子）中。总之，本研究发现甘草查尔酮A对[具体对象]有抗菌作用，并在亚抑菌浓度下显著抑制[具体对象]的生物膜形成。
