母牛分支杆菌菌苗预防糖尿病并发肺结核的实验研究

目的　探讨母牛分支杆菌 (Mycobacteriumvaccae)菌苗对实验性糖尿病大鼠发生肺结核的预防作用。方法　大鼠腹腔注射链脲佐菌素建立糖尿病模型 1周后 ,随机分为 4组 :糖尿病结核组、母牛分支杆菌菌苗免疫组、卡介苗 (BCG)免疫组、联合免疫组 ,分别给予不同的处理 ,观察母牛分支杆菌菌苗的免疫预防作用。 1个月后自大鼠尾静脉注入标准结核分支杆菌H3 7Rv,H3 7Rv 感染 6周后剖杀大鼠。观察肺脏结核分支杆菌定量培养、结核病变指数、肺泡巨噬细胞吞噬的结核分支杆菌数 ,并作肺组织病理学分析。结果　母牛分支杆菌菌苗免疫组的病变指数、肺脏结核分支杆菌定量培养、肺泡巨噬细胞吞噬的结核分支杆菌计数分别为 2 5± 0 7、(4 1± 0 6 )× 10 4 cfu、2 6± 0 9;未免疫组分别为 3 3± 0 5、(9 9± 1 0 )× 10 4 cfu、7 2± 0 7。P值分别为 <0 0 5、<0 0 1、<0 0 1。组织病理学分析显示母牛分支杆菌菌苗和 (或 )BCG免疫组肺脏结核病变以增殖结节为主 ,无坏死结节 ;未免疫组肺脏则以淋巴细胞结节、坏死结节为主。提示母牛分支杆菌菌苗能减轻糖尿病大鼠的肺结核病变。结论　母牛分支杆菌菌苗对糖尿病大鼠发生肺结核有较好的预防作用

Experimental study on prevention of diabetes complicated wi th tuberculosis by Mycobacterium vaccae

OBJECTIVE: To study if Mycobacterium vaccae has any effect in prevention of rats with diabetes from tuberculosis. METHODS: Wistar rats with diabetes which were produced by injection of streptozotocin one week before were divided into four groups. Mycobacterium vaccae was injected into Wistar rats with diabetes and one month later H(37)R(v) was injected intravenously. The rats were sacrificed six weeks later to observe pathomorphologic changes in lung tissues. Indexes for evaluation included quantitative culture of Mycobacterium tuberculosis of lung tissue, tubercular lesion, count of Mycobacterium tuberculosis in alveolar macrophages and histopathological changes. RESULTS: Pathological change index of tubercular lesion, quantitative culture of Mycobacterium tuberculosis in lung tissue, count of Mycobacterium tuberculosis in alveolar macrophages were 2.5 +/- 0.7, (4.1 +/- 0.6) x 10(4) cfu, 2.6 +/- 0.9 respectively in group injected with Mycobacterium vaccae, while 3.3 +/- 0.5, (9.9 +/- 1.0) x 10(4) cfu, 7.2 +/- 0.7 respectively in the control group. Statistically significant differences were found between the two groups (P < 0.05, < 0.01, < 0.01 respectively). The histopathological changes of lung tissue in group of diabetes complicated with tuberculosis revealed that the lesions were predominant with necrosis, while in group injected with Mycobacterium vaccae, the lesions showed proliferation mainly. This indicated that Mycobacterium vaccae could decrease the damage to the lung tissue of the rat with diabetes by tubercle bacilli. CONCLUSION: Mycobacterium vaccae might play a role in prevention of rat with diabetes from tuberculosis.