Rapid on-site detection of viable Vibrio parahaemolyticus in seafood using cis-diamminedichloroplatinum and colorimetric loop-mediated isothermal amplification (CDDP-LAMP).

Abstract

Vibrio parahaemolyticus in seafood and marine environments poses significant health risks, causing gastroenteritis worldwide. Current detection methods fail to differentiate live from dead cells, leading to inaccuracies in food safety assessments. This study introduces a novel method combining cis-diamminedichloroplatinum (CDDP) with direct colorimetric loop-mediated isothermal amplification (LAMP) for rapid and accurate detection of viable V. parahaemolyticus cells in seafood samples. CDDP treatment at 37 °C for 30 min selectively inhibits DNA from dead cells, enhancing the specificity of the assay by ensuring only live cell DNA is amplified. The optimized CDDP-LAMP procedure detects alive V. parahaemolyticus within 1 h, with results observable through a color change. The CDDP-LAMP assay demonstrates excellent specificity, identifying live V. parahaemolyticus cells while excluding dead cells and other bacteria. It shows a detection limit of 2.348 CFU per reaction and successfully detects V. parahaemolyticus in seafood samples across different food matrices. This study is the first to combine CDDP with colorimetric LAMP for direct detecting viable bacteria in food, enhancing specificity by eliminating signals from dead cells. The CDDP-LAMP assay provides a rapid, accurate process for detecting viable V. parahaemolyticus cells, especially in resource-limited settings. It also gives a model for screening different bacterial pathogens, speeding up and improving foodborne illness risk assessments.