Detection and tracing of Paucilactobacillus wasatchensis from dairy farm to creamery using N-acetyltransferase (NAT) gene-derived primers

Abstract

A specific, reliable, and fast PCR method to detect Paucilactobacillus wasatchensis, a heterofermentative lactic acid spoilage bacterium, in dairy products, food contact surfaces, and environmental samples from the farm to the processing plant was developed. A primer set was designed specifically targeting the GNAT family N-acetyltransferase (NAT) gene of Plb. wasatchensis. The PCR method developed was specific for Plb. wasatchensis with a detection limit of 2 log cfu mL−1 with ten-fold concentrated milk sample. The method was further validated through tracing the potential source of Plb. wasatchensis from the dairy farm to the cheese processing plant, and the final product; Plb. wasatchensis was detected in the silage, raw silo, defective Cheddar cheese products, raw milk, as well as food contact surfaces after enrichment. This method provides a quick, simple, reliable way to detect Plb. wasatchensis in source materials, dairy farm, production lines, and final aged hard cheese products.