Fast and Accurate Identification of <i>M. tuberculosis</i>Complex Using an Immunochromatographic MPT64 Antigen Detection Test

Background: A new rapid Immunochromatographic test (ICT) kit (MPT64 TB Ag Kit) for detection of MPT64 Antigen in M. tuberculosis (MTB) isolates used for rapid identification of MTB isolates developed by SD (Standard Diagnostics) Bio line, South Korea was evaluated. The ICT is a rapid, reliable and cheaper method that can be used instead of conventional biochemical tests for confirming MTB in culture isolates in resource limited laboratories. The study also evaluated the ability of ICT to detect MPT64-Antigen before the micro MGIT could signal positive. Material/Methods: A total of 450 sputum samples of individual patients were used for the study. 152 isolates of Mycobacteria were recovered from solid and liquid media. These strains were tested for the detection of MPT64-antigen. H37Rv strain was served as the positive reference control and also used for early detection of Antigen experiment. Findings: The development of bands on both test and sample region when H37Rv strain was tested were seen (MPT64 antigen positive). When 138 MTB isolates were tested, it showed a similar banding pattern indicating 100% sensitivity. MPT64 band formation was not detected in any of the 14 isolates indicating 100% specificity. Both PPV & NPV were 100%. All the isolates negative for MPT64 Ag were confirmed as MOTT by conventional bio-chemical PNBA. The H37Rv strain showed a faint band from the 2nd day onwards from inoculation till 3rd day in the earlier Antigen detection experiment. Conclusion: Rapid identification of MTB culture isolate is a pressing need for diagnosis and proceeding to perform drug susceptibility testing. MPT64 TB Ag detection ICT kit is a rapid, reliable method, good substitute for molecular identification methods, and conventional biochemical test which is time-consuming and technically demanding. The early detection of Antigen can be used as an effective tool in diagnosis.

应用胶体金免疫层析法快速检测恶性疟原虫中HRPⅡ抗原研究

目的建立一种简易快速、适用于基层的胶体金免疫层析法 (ICT)用于检测恶性疟原虫中HRPⅡ抗原 ,判定是否现症感染。方法采用柠檬酸三钠还原法制备胶体金颗粒、标记HRPⅡ单克隆抗体 ,制成免疫测试条。血中HRPⅡ抗原与测试条上金标记单克隆抗体结合后沿着硝酸醋酸纤维素膜移动 ,与膜上的固相特异性单克隆抗体结合形成肉眼可见的褐红色线。结果 ICT测试条只与HRPⅡ抗原有特异性反应 ,与间日疟无交叉反应。与显微镜检比较特异性为 10 0 %。用该法检测体外培养的恶性疟原虫HRPⅡ抗原 ,其灵敏度在体外培养实验中 ,当红细胞感染虫体为 1%时使用 5 μl血稀释 10 0倍仍能检测出来。该法检测 30份用病原学确诊的恶性疟原虫和 2 0份间日疟标本 ,检出率为 10 0 % ,与间日疟无交叉反应。结论 ICT检测血中恶性疟原虫中HRPⅡ抗原特异性强、灵敏度高、简便快速 ,无需特殊仪器设备 。

华支睾吸虫病金标诊断试剂盒的研制和现场初步实验

目的 研制华支睾吸虫病金标快速免疫诊断试剂盒 ,评价其敏感性、特异性和现场试用效果。 方法 以华支睾吸虫成虫水溶性抗原、分泌排泄抗原和重组抗原磷酸甘油酸激酶 (PGK)作为诊断试剂 ,制备胶体金免疫层析检测 (Im-munochromatography test,ICT)试剂盒 ,检测患者血清和唾液中抗华支睾吸虫 Ig G,并与常规 EL ISA血清学检测方法和粪便虫卵检查法相比较。 结果 实验室检测临床确诊的华支睾吸虫病人血清中特异的 Ig G,3种抗原的敏感性均为10 0 %。天然抗原除与慢性血吸虫病人血清有较强的交叉反应外 ,与囊虫、包虫、弓形虫病人血清没有交叉反应。重组PGK抗原同慢性血吸虫病人血清也没有交叉反应。用分泌排泄抗原制备的 ICT检测试剂盒在流行区现场检测被调查者的血清和唾液 ,总符合率为 92 .31% ;ICT与 EL ISA血清检测的总符合率为 81.5 4 %。现场获取了 9人的粪便样本 ,其中 4人检出华支睾吸虫卵 ,其血清 ICT和 EL ISA检测均呈强阳性 ,另外未检出虫卵的 5人中 ,1人血清 ICT和 EL ISA均呈阳性 ,另 1人仅血清 EL ISA呈弱阳性。 结论 诊断华支睾吸虫感染的 ICT抗体检测技术 ,尤其是无创性唾液检测技术 ,简便、快速、准确、安全 ,优于血清 EL ISA检测和粪便虫卵检测 ,适用于临床检验和现场大规模流行病?