Pseudomonas species are mainly associated with spoilage of dairy products due to their proteolytic activity . Therefore, the goal of the present study was to isolate pseudomonas spp and then identify their virulence factors that have a bad impact on milk qulity . One hundred milk and milk products samples from ( raw milk ,Karish cheese , youghrt and Ice cream) divided to 25 samples from each one were collected and examined to found that Pseudomonas and then identify their species using PCR technique ps. aeuroginosa was present in 20 ,16 ,8 and 8 %in the examined raw milk , karish cheese ,youghrt and ice cream respectively while ,ps. Fluorescence present in 28, 20,12 and 8% respectively in examined samples in the meanwhile ps. Putida was present in 8 and 4% that not indicated youghrt and ice cream , ps.diminuta and ps. Fragi 12 and 8 % respectively in examined samples of raw milk and karish cheese while not indicated in youghrt and ice cream giving incidence percent of pseudomonus spp in examined samples of raw milk , karish cheese , youghrt and ice cream 56 % , 24% and 20% respectively.
Pseudomonas aeuroginosa isolates were subjected to PCR technique to detect the alkaline protease gene oprl, opsl and txoA its virulence genesThe results reveal proteolytic activity and presence of these virulent genes in milk and their spoilage potential at different temperatures..