Evaluation of a PCR-ELISA for food testing: Detection of selectedSalmonella serovars in confectionery products

摘要

A specific PCR-ELISA detection system was established for the testing of food products for Salmonella contamination. Initially a shortened microbial enrichment comprising two steps, a non-selective and selective incubation each of 8 hours at 37 degrees C, is carried out. DNA is then isolated from 1 ml of the final selective enrichment culture and purified. In vitro amplification of the recovered DNA is performed in a competitive PCR in the presence of internal standard DNA to exclude the possibility of false negative results arising from food-borne inhibitory factors. Salmonella specific amplicons were identified through specific probe hybridization and colorimetric endpoint detection in a microtiter plate, a format which allows a high throughput due to its high potential for automation.