Varshney Anshul, Puranik Nidhi, Kumar Manoj, Pal Vijai, Padmaja J, Goel A K
Defence Research & Development Establishment, Jhansi Road, Gwalior, 474 002, India.
Department of Microbiology, Andhra Medical College, Visakhapatnam, 530 002, India.
Biologicals. 2019 Jan;57:55-60. doi: 10.1016/j.biologicals.2019.01.001. Epub 2019 Jan 8.
In this study, an ELISA was developed for simultaneous detection of antibodies against both the important toxins of B. anthracis i.e. protective antigen (PA) and lethal factor (LF). A chimera of PA and LF was made by fusion and cloned and expressed in E. coli. The purified recombinant protein was used in plate ELISA for serodiagnosis of anthrax. The chimera could detect antibodies against both the toxins of Bacillus anthracis. The human serum samples (n = 98) collected from anthrax endemic and non-endemic areas were tested employing ELISA. The ELISA gave sensitivity of 100% (95% Confidence Interval [CI], 92.13 to 100) and specificity of 97.78% (95% Confidence Interval [CI], 88.23 to 99.94) with a J index of 0.97. The efficiency of ELISA was found to be 98.9% with the positive predictive value (PPV) and negative predictive value (NPV) of 97.8% and 100%, respectively. The chimera of PA and LF could be a better diagnostic antigen for serodiagnosis as the assay detects antibodies against both the toxins in early as well delayed infection cases of anthrax. Therefore, it can be a very useful tool for the surveillance as well as for confirmation of cutaneous anthrax cases.
在本研究中，开发了一种酶联免疫吸附测定法（ELISA），用于同时检测针对炭疽芽孢杆菌两种重要毒素即保护性抗原（PA）和致死因子（LF）的抗体。通过融合制备了PA和LF的嵌合体，并在大肠杆菌中进行克隆和表达。纯化的重组蛋白用于平板ELISA法进行炭疽的血清学诊断。该嵌合体能够检测针对炭疽芽孢杆菌两种毒素的抗体。采用ELISA法检测了从炭疽流行区和非流行区采集的98份人血清样本。ELISA法的敏感性为100%（95%置信区间[CI]，92.13至100），特异性为97.78%（95%置信区间[CI]，88.23至99.94），J指数为0.97。ELISA法的效率为98.9%，阳性预测值（PPV）和阴性预测值（NPV）分别为97.8%和100%。PA和LF的嵌合体可能是一种更好的血清学诊断抗原，因为该检测方法能够在炭疽早期感染病例以及延迟感染病例中检测到针对两种毒素的抗体。因此，它对于皮肤炭疽病例的监测以及确诊可能是一种非常有用的工具。
