摘要
目的研究五倍子对耐甲氧西林金黄色葡萄球菌（methicillin-resistant staphylococcus aureus,MRSA）41577菌株生物被膜（bacterial biofilm,BF）的抑制作用及机制。方法采用氯化三苯基四氮唑（TTC）法测定五倍子对MRSA 41577 BF形成和成熟BF的抑制作用;采用刚果红法测定五倍子对MRSA 41577 PIA合成的影响;采用微量紫外分光光度计测定五倍子对MRSA 41577 e DNA释放的影响;采用RT-PCR技术测定五倍子对MRSA 41577 ica A和cid A基因表达量的影响。结果五倍子对MRSA 41577 BF形成和成熟BF有显著的抑制作用,其抑制MRSA 41577 BF形成的最低抑菌浓度（minimum inhibitory concentration,MIC）和最低杀菌浓度（minimal bactericidal concentration,MIC）为0.5 mg/mL和1 mg/mL。抑制MRSA 41577成熟BF的MIC和MBC为4 mg/mL和16 mg/mL。刚果红检测结果显示,五倍子能抑制MRSA 41577 PIA的合成,且呈浓度剂量依赖。微量紫外分光光度计结果显示,五倍子能抑制MRSA 41577 e DNA的分泌释放,其中当五倍子的浓度为1/2MIC时,eDNA分泌释放量为3.61μg/OD_（595）,对照组分泌释放量为11.91μg/OD_（595）,2者相比,e DNA的分泌释放量减少了69.7%（P〈0.01）。RT-PCR结果根据2^（-△△CT）公式计算显示,五倍子能够抑制ica A及cid A的基因表达量,五倍子浓度为1/2MIC时,ica A和cid A基因表达量分别为9.7%和6.67%,对照组icaA和cidA基因表达量均为100%,与对照组比较,ica A和cid A基因表达量分别减少90.3%和93.3%（P〈0.01）。结论五倍子抑制MRSA 41577生物被膜的作用机制,主要是通过抑制ica A及cid A基因的表达量,进而影响PIA的合成以及e DNA的分泌释放实现的。
Objective To investigate the inhibition mechanism of gallnut on biofilm formation by MRSA 41577.Methods TTC assay was used to detect inhibitory effects of biofilms formation and mature biofilms.The of PIA on biofilm formation was studied using Congo red agar method.MicroUltraviolet Spectrophotometer was used to detect inhibitory effects of the release of e DNA.The influence for Baicalein on ica A and cid A gene expression were detected by RT-PCR method.Results The inhibitory concentration（MIC） and minimum bactericidal concentration（MIC） of MRSA 41577 BF were 0.5 mg/mL and 1 mg/mL,respectively.The inhibitory effect of galla on MRSA 41577 BF formation and mature BF was significantly inhibited.Inhibition of MRSA 41577,the MIC and MBC of mature BF were 4 mg/mL and 16 mg/mL.Congo red test results show that Galla can inhibit the synthesis of MRSA 41577 PIA,and the concentration was dose-dependent.The results showed that gallnut could inhibit the release of MRSA 41577 e DNA,and the release amount of e DNA was 3.61 μg/OD595 and 11.91 μg/OD595,respectively,when the concentration of gall was 1/2MIC.The release of e DNA was reduced by 69.7%（P〈0.01）.The expression of ica A and cid A genes in the control group was 9.7% and 6.67%,respectively.The expression of ica A and cid A in the control group was significantly lower than that in the control group（ica A and cid A,and cid A gene expression were 100%,the expression of ica A and cid A genes were reduced by 90.3% and 93.3%,respectively（P〈0.01）.Conclusion The inhibitory effect of gallnut on the biofilm of MRSA 41577 is mainly through inhibiting the expression of ica A and cid A genes,and then affecting the synthesis of PIA and the secretion of e DNA.
出处
《中国生化药物杂志》
CAS
2017年第2期24-27,共4页
Chinese Journal of Biochemical Pharmaceutics
基金
辽宁省自然科学基金(201602462)
辽宁省教育厅科学研究一般项目(L201683675)
关键词
五倍子
生物被膜
耐甲氧西林金黄色葡萄球菌
Gallnut
biofilm
methicillin-resistant staphylococcus aureus MRSA 41577
