Stability assessment of whole cell ELISA for Burkholderia pseudomallei antibodies detection

Melioidosis is a life-threatening infectious disease prevalent in tropical and subtropical environments. Large-scale serological screening is crucial in detecting evidence of exposure to B. pseudomallei. Serological assays are usually easy to execute, cost-effective and substantially reduce the time required for laboratory diagnosis. In the present study, the stability of whole-cell ELISA (WC-ELISA) was assessed using polyclonal antibodies generated in BALB/c mice. B. pseudomallei cells at a concentration of 10⁸ CFU/mL were immobilized on immuno-modules and stored at 4℃ for subsequent evaluation. The WC-ELISA assay remained consistent for up to 2 months, showing coefficients of variation of 2.21%, 1.65%, 4.10%, and 5.12% on days 15, 30, 45, and 68, respectively, compared to day 0. The decline in WC-ELISA performance was noticed from day 68 onwards, with a coefficient of variation of 20.64% between days 0 and 90. The findings of the present study suggest that the WC-coated immuno-modules remain stable for > 2 months when stored at 4℃. These pre-coated immuno-modules offer the potential for the economical large-scale screening of serological samples and require less time than conventional ELISA methods.