M. bovis as a potentially more virulent MDR pathogen

描述(由申请人提供)：毒力可被定义为微生物在宿主防御系统中生存并导致疾病的能力。没有理由相信结核分枝杆菌的多药耐药(MDR)菌株比药物敏感(DS)菌株的毒力更强。另一方面，有证据表明，牛分枝杆菌的毒力比结核分枝杆菌强得多。因此，如果牛分枝杆菌被改造成MDR，它可能会对公共卫生构成比MDRM更严重的威胁。肺结核。这项拟议的研究将利用牛分枝杆菌Ravenel株对小鼠的毒力优于结核杆菌H37Rv，以确定优势毒力是否与诱导肺内更高水平的Th1免疫表达的能力有关，这种优势毒力表现为能够诱导更快的肺部病理发展和更早的死亡。这将通过测量肺中Th1细胞因子、促炎细胞因子和趋化因子基因的表达水平来进行研究。ELISPOT和流式细胞术将用于计数肺部产生的、病原体特异性的CD4和CD8T细胞的总数。牛分枝杆菌更强的毒力也与更高水平的细菌基因表达有关的可能性将被调查，记住牛分枝杆菌和拉弗内尔分枝杆菌导致相同水平的静止肺部感染。实时逆转录聚合酶链式反应将被用来测量病原体基因的表达水平，以每肺和每CFU的mRNA拷贝数为单位。结核分枝杆菌和牛分枝杆菌染色体Rd1区域内的基因，包括esat6和CFP-10，将受到关注。将比较一些牛分枝杆菌和结核分枝杆菌菌株的毒力。

DESCRIPTION (PROVIDED BY APPLICANT): Virulence may be defined as the ability of a microorganism to survive host defenses and cause disease. There is no reason to believe that multi-drug resistant (MDR) strains of Mycobacterium tuberculosis are more virulent than drug sensitive (DS) strains There is evidence, on the other hand, that M. bovis is much more virulent than M. tuberculosis as a species. Therefore, if M. bovis were engineered to be MDR, it could pose a more serious threat to public health than MDRM. tuberculosis. The proposed research will use the superior virulence for mice of the Ravenel strain of M. bovis over M tuberculosis H37Rv to determine whether superior virulence, as manifest by ability to induce faster development of lung pathology and cause earlier death, is associated with the ability to induce a higher level of expression of Th1 immunity in the lung. This will be investigated by measuring levels of expression of genes for Th1 cytokines, proinflammatory cytokines and chemokines in the lungs. Elispot and flow cytometry will be used to enumerate total numbers of IFN-?, producing, pathogen-specific CD4 and CD8 T cells in the lungs. The possibility that superior virulence of M. bovis is also associated with higher levels of bacterial gene expression will be investigated, keeping in mind that M. bovis Ravenel and M. tuberculosis cause the same level of stationary lung infection. Real-time RT-PCR will be used to measure levels of pathogen gene expression in terms of mRNA copy number per lung and per CFU. Genes within the RD1 region of the M. tuberculosis and M. bovis chromosome, including esat6 and cfp-10, will receive attention. The virulence of a number of M. bovis and M. tuberculosis strains will be compared.