应用免疫磁珠分离-改良罗氏培养技术检测痰结核分枝杆菌的研究

Using immunomagnetic bead separation and solid Roche culture to detect Mycobacterium tuberculosis in sputum

目的通过免疫磁珠分离技术(immunomagnetic beads separation techniques,IMBS)富集痰液中的结核分枝杆菌,提高痰液培养的阳性率,以期用于结核病的快速诊断。方法制备兔抗结核杆菌IgG抗体,并将其结合于免疫磁珠表面。采集71例确诊结核病患者的痰液标本,通过免疫磁珠分离技术捕获、富集吸附结核分枝杆菌后用改良罗氏培养基培养,并与传统改良罗氏(L-J)培养法和痰涂片抗酸染色法作比较。结果 71例结核病患者痰涂片抗酸染色检查阳性26例,阳性率36.6%;传统改良L-J培养阳性34例,阳性率47.9%;免疫磁珠分离技术捕获、富集结核分枝杆菌后进行改良L-J培养阳性48例,阳性率67.6%。三者阳性率差异有统计学意义(P<0.05),改良L-J培养和痰涂片检查阳性率差异无统计学意义(P>0.05)。结论采用免疫磁珠分离技术捕获、富集痰液中的结核分枝杆菌后进行培养,可显著提高痰培养的阳性率,该方法可用于结核病的快速诊断。

Objectives To isolate Mycobacterium tuberculosis from sputum using immunomagnetic bead separation（IMBS）and to increase the rate at which M.tuberculosis in a sputum culture is isolated using a solid Roche culture（L-J culture）in order to rapidly diagnose tuberculosis（TB）. Methods Rabbit anti-M.tuberculosis H37 Rv IgG was prepared and then immobilized on the surface of active magnetic beads.M.tuberculosis in sputum samples from 71 patients with TB was isolated using IMBS and then cultured on solid L-J medium.The conventional L-J culture and sputum smear acidfast staining test were used as controls. Results Of 71 sputum samples from patients with TB,26（36.6%）were positive for TB according to smears,34（47.9%）were positive for TB according to L-J culturing,and 48（67.6%）were positive for TB according to L-J culturing after isolation with IMBS.The rate at which TB was isolated differed significantly among these three methods（P〈0.05）.The rate at which TB was isolated did not differ significantly for conventional LJ culturing and sputum smears（P〉0.05）. Conclusion 〗Isolating M.tuberculosisin sputum cultures with IMBS clearly improved the rate at which TB was isolated,providing an experimental basis for the diagnosis of tuberculosis.