【摘要】 H37Rv是结核分枝杆菌标准有毒株,H37Ra是从H37Rv获得的稳定减毒株,但目前H37Ra毒力减弱原因尚不完全清楚。本研究利用表型芯片系统,高通量分析H37Ra生长表型,并与H37Rv表型比较,筛选两菌株表型差异,分析与H37Ra毒力减弱可能的相关表型及分子机制。结果发现,与H37Rv相比,H37Ra耐酸及耐渗透压能力显著下降,且不能利用丁二酸单甲酯和吐温40作为碳源。结核分枝杆菌耐酸能力直接影响其在吞噬体中的生存和代谢,耐高渗能力影响其必需营养物质的跨膜运输,代谢途径的改变影响其在宿主内的能量摄取,三者改变均可能与H37Ra毒力减弱相关。更多还原

【Abstract】 Tuberculosis,caused by Mycobacterium tuberculosis(M.tuberculosis)H37Rv,is a human disease of major importance worldwide.The avirulent M.tuberculosis H37 Ra which is used commonly in the laboratory was derived from H37 Rv in 1935,but the mechanism of its virulence attenuation remains unclear.In order to explore its possible mechanism of virulence attenuation,screening for different phenotypes is important.To make a rapid and high throughput phenotypic analysis between H37 Ra and H37 Rv,as well as catch the different phenotypes related to virulence attenuation,the Biolog Phenotype MicroArray analysis was conducted.In this research,the phenotypes of H37 Ra were determined and compared with its virulent counterpart H37 Rv.Of 765 substrates surveyed,H37 Ra phenotypes were highly similar to that of H37 Rv,but there were several differences in carbon utilization,osmosis and pH arrays.These arrays suggested that H37 Ra could not utilize mono-methyl succinate and Tween 40 as carbon source in contrast to H37 Rv.More interestingly,the differences between H37 Ra and H37 Rv in the tolerance abilities of hyperosmosis and acid were found,and H37 Ra could not tolerate circumstance of pH 5.5or 3% NaCl,but H37 Rv could.These metabolic differences may have a disparate impact on the survival of M.tuberculosis in the hosts and be closely related to the virulence attenuation of H37 Ra.更多还原