穿心莲内酯对金黄色葡萄球菌生物膜的体外抑制作用

目的：研究穿心莲内酯对金黄色葡萄球菌生物膜的体外抑制作用。方法从临床分离30株金黄色葡萄球菌，通过刚果红平板法筛选生物膜阳性菌株和结晶紫染色法半定量检测生物膜；以万古霉素为阳性对照药，微量肉汤二倍稀释法测定抗菌药物的最低抑菌浓度（MIC）和药物对细菌生物膜的最小抑膜浓度（SMIC）；XTT减低法评价穿心莲内酯对不同时间段金黄色葡萄球菌生物膜的早期黏附能力的影响。结果30株金黄色葡萄球菌中，刚果红平板法生物膜阳性菌株有12株，即生物膜形成率为40％，结晶紫染色法半定量生物膜实验阳性有22株（73.3％）；穿心莲内酯对金黄色葡萄球菌生物膜的SMIC50为125 mg／L，SMIC80为500 mg／L；1000、500和250 mg／L的穿心莲内酯对金黄色葡萄球菌生物膜的早期黏附能力均有较强的抑制作用。结论一定浓度的穿心莲内酯对金黄色葡萄球菌生物膜的形成和黏附有抑制作用，但效果不及万古霉素。

Inhibitory effect of andrographolide on staphylococcus aureus biofilms in vitro

Objective To study the inhibitory effect of andrographolide on staphylococcus aureus biofilms in vitro.Methods 30 clinical isolates of staphylococcus aureus were collected and screened for biofilm positive strains by Congo red plate method .Semi-quantitative testing was done to measure the biofilm by using crystal violet staining .The MIC and SMIC of antibiotics were determined by double dilution of the microbroth with vancomycin as the positive control . XTT reduction assay was used to evaluate the influences of andrographolide on initial adhesion capability of staphylococcus aureus biofilm .Results Of 30 strains of staphylococcus aureus , there were 12 biofilm positive strains that accounted for 40%detected by Congo red plate , while 22 strains (73.3%) were positive for semi quantitative biofilm test by crystal vi-olet staining.SMIC50 and SMIC80 of andrographolide against staphylococcus aureus biofilms were 125 and 500 mg/L, re-spectively.Andrographolide significantly inhibited the early adhesion of staphylococcus aureus biofilm at 1000, 500 and 250 mg/L.Conclusion A certain concentration of andrographolide can inhibit staphylococcus aureus biofilm formation and adhesion , but the effect is less than that of vancomycin .