Screening for Bongkrekic Acid in Food Using a Monoclonal Antibody-Based Indirect Competitive Enzyme-Linked Immunosorbent Assay (icELISA)
Huiling Wu, Jing Chen, Fei Pan, Qisheng Xia, Shiwei Zhang, Xuejian Chen, Ronghu Feng, Guihong Zhang, Lei Liu, Xintian Lai, Pan Tan
Abstract
Pseudomonas cocovenenans subsp. farinofermentans is a pathogenic bacterium that causes the poisoning of fermented rice products. Its isomeric products, bongkrekic acid (BA) and isobongkrekic acid (IBA), have become popular research topics. In this study, we developed a heterologous-coating strategy for high-sensitivity indirect competitive enzyme-linked immunoassay (icELISA) for BA and IBA using monoclonal antibodies (mAbs). The optimized procedure exhibited an IC50 of 5.49 ng/mL, a limit of detection of 0.99 ng/mL, and a linear range from 2.12 to 14.21 ng/mL. Notably, this method exhibited negligible cross-reactivity to other small toxins, and the recoveries of the samples, including rice noodles, Auricularia auricula, and flat rice noodles, ranged from 92.0%–111.9%, 105.6%–115.0%, and 83.2%–109.0%, respectively, with coefficients of variation below 12%. A comparison of the recoveries of high-performance liquid chromatography-mass spectrometry (HPLC-MS) and icELISA demonstrated that the developed approach provides good accuracy and reliability. Overall, the simple preparation of IBA combined with the suitability of icELISA for high-throughput analysis is efficient and cost-effective, making it suitable for routine screening of food.