Rapid and simple detection of coliform bacteria in milk using menadione-catalyzed luminol chemiluminescence assay

Abstract

Menadione-catalyzed luminol chemiluminescence assay was evaluated for rapid detection of coliform bacteria in milk. The assay was evaluated using raw milk (non-pasteurized) samples and pasteurized milk samples spiked with Escherichia coli, Enterobacter aerogenes, Klebsiella oxytoca, Citrobacter freundii. The detection limit in this assay was 105-104CFU/ml using a 96-well plate with BGLB broth. Our study revealed that coliform contamination of 101-100CFU/ml of milk could be detected after 18 h of incubation at 35°C in BGLB medium. Moreover, this assay detected gas production in samples of BGLB after only 18 h of a 48-h incubation. As this assay is convenient, quick and inexpensive compared to the conventional method, it should be useful for the rapid detection of coliform contamination in pasteurized milk.