Monitoring of Yersinia enterocolitica in murine and bovine feces on the basis of the chromosomally integrated luxAB marker gene.

We previously integrated the luxAB gene into the Yersinia enterocolitica chromosome. In this article, we assessed, by luminometry, the survival of the engineered strain KNG1024 in the digestive tracts of mice and cows. In situ detection and a count of the released strain were performed on feces from orally inoculated BALB/c mice for 24 days. This method is a rapid and reliable system for long-term monitoring of genetically engineered bacteria. In cow feces, the count of Y. enterocolitica ranged from 210 to 6,000 CFU/g of feces. This very low count was not detectable by direct luminometry.