母牛分支杆菌预防尘肺并发结核的实验研究

目的探讨母牛分支杆菌预防尘肺并发结核的作用。方法大鼠染尘２周后用母牛分支杆菌免疫，免疫１个月后自大鼠尾静脉注射Ｈ３７Ｒｖ结核分支杆菌感染，３个月后处死动物。评价指标为结核病变指数；肺脏结核分支杆菌定量培养；肺泡巨噬细胞中结核分支杆菌计数和组织病理学分析。结果尘肺结核＋母牛分支杆菌组其病变指数、肺脏结核分支杆菌定量培养和肺泡巨噬细胞中结核分支杆菌计数分别为２．６±０．５、（４．４０±４．００）×１０４ＣＦＵ、７．２±３．２。而对照组分别为３．１±０．３、（１８．９±１８．２）×１０４ＣＦＵ、１２．５±６．３。Ｐ值分别为＜０．０５、＜０．０１、＜０．０５。组织病理学分析显示尘肺结核＋母牛分支杆菌组结核病变以增殖结节、淋巴样结节为主，而对照组以坏死结节为主。结论母牛分支杆菌对大鼠实验性尘肺有较好预防并发结核的作用。

Experimental study on prevention of pneumoconiosis complicating with tuberculosis by Mycobacterium vaccae

OBJECTIVE: To explore the role of Mycobacterium vaccae in prevention of pneumoconiosis complicating with tuberculosis. METHOD: Mycobacterium vaccae was injected into rats which had been exposed to quartz for 2 weeks, and H37Rv was injected into their tail veins 1 month later. All the rats were killed 3 months later. Indexes for evaluation in the study included tuberculous lesion pathological change index, Mycobacterium tuberculosis culture in a fixed amount in lung tissues, count of Mycobacterium tuberculosis and histopathological changes in alveolar macrophages. RESULT: Tuberculous lesion pathological change index, Mycobacterium tuberculosis culture in a fixed amount in lung tissues and count of Mycobacterium tuberculosis in alveolar macrophages were 2.6 +/- 0.5, (4.40 +/- 4.00) x 10(4) CFU and 7.2 +/- 3.2 respectively in pneumoconiosis complicated with tuberculosis and injecting Mycobacterium vaccae group, while 3.1 +/- 0.3, (18.9 +/- 18.2) x 10(4) CFU and 12.5 +/- 6.3 respectively in the control group. And statistically significant differences were found between the two groups (P < 0.05, 0.01, 0.05 respectively). The histopathological analysis revealed that proliferative and lymphoid nodules were predominant in the pneumoconiosis complicated with tuberculosis and injecting Mycobacterium vaccae group, while necrotic nodules in the control group. CONCLUSION: Mycobacterium vaccae might play a role in prevention of pneumoconiosis complicating with tuberculosis.