黄芩提取物对脓肿分枝杆菌生长及生物膜形成的影响

Effect of Scutellaria baicalensis extract on the growth and biofilm formation of Mycobacterium abscessus

为了研究黄芩提取物对脓肿分枝杆菌浮游细菌及生物膜的影响,本研究以脓肿分枝杆菌标准菌株ATCC 19977以及临床分离株作为受试菌,采用Alarmar-Blue液体药敏法测定黄芩提取物对脓肿分枝杆菌的最小抑菌浓度(MIC),平板涂布法测定最小杀菌浓度(MBC),结晶紫染色法和扫描电子显微镜分析黄芩提取物对脓肿分枝杆菌生物膜形成量及形态结构的影响,进一步采用了RT-qPCR探究黄芩提取物对分枝菌酸合成相关基因表达的影响.结果表明黄芩提取物对脓肿分枝杆菌标准菌株ATCC 19977以及8株临床分离株的MIC 90为50~100 mg/mL,MBC为50~200 mg/mL;黄芩提取物可显著降低脓肿分枝杆菌生物膜形成量(P<0.05),破坏生物膜的结构,并且显著降低分枝菌酸合成相关基因表达量(P<0.01).本研究表明黄芩提取物能够抑制脓肿分枝杆菌的生长以及生物膜的形成.

To study the effect of Scutellaria baicalensis extract on Mycobacterium abscessus,the standard strain of M.abscessus ATCC 19977 and clinical isolates were used as the test bacteria.The minimum inhibitory concentration(MIC)of S.baicalensis extract against M.abscessus was determined by the Alarmar-Blue method;the minimum bactericidal concentration(MBC)was determined by plate coating method;crystal violet staining method and scanning electron microscope assay were used to analyze the effect of S.baicalensis extract on the biomass formation and morphological structure of M.abscessus;RT-qPCR was further used to investigate the effect of S.baicalensis extract on the gene expression which involves in mycolic acid synthesis.The inhibitory effects of S.baicalensis extract against M.abscessus standard strain ATCC 19977 and 8 clinical isolates were evaluated,the results showed that the MIC 90 was 50~100 mg/mL,and the MBC was 50~200 mg/mL.The biofilm formation of M.abscessus was significantly decreased after adding S.baicalensis extract(P<0.05),and S.baicalensis extract disrupted the biofilm formation.The expression of genes related to mycolic acid synthesis was significantly decreased in the S.baicalensis extract treatment group(P<0.01).S.baicalensis extract inhibits planktonic M.abscessus growth;meanwhile,it reduces the bacterial adhesion and aggregation on M.abscessus biofilm formation.