الفهرس | Only 14 pages are availabe for public view |
Abstract Listeria is widely distributed organism in nature and has been isolated from a variety of sources including soil, vegetation, fecal material and water. Animals can carry the bacterium without appearing ill and can contaminate food of animal origin such as meat and dairy products. The bacterium has been found in a variety of raw foods, and in processed foods that become contaminated after processing such as soft cheese. Unpasteurized raw milk or foods made from unpasteurized milk may contain the bacterium. Listeria is a foodborne pathogen which is now very well known by individuals concerned with food safety. This organism is ubiquitous in nature and is widely spread in the environment, where it may survive for long periods .It has been associated with serious disease listeriosis in man. The typical symptoms of listeriosis are septicemia, meningitis or abortion in pregnant women. Listeriosis is an opportunistic disease, Individual with normal health may develop no symptoms or show very mild enteric form of the disease, however it is highly fatal in newborn ,infants, and elderly, pregnant women, and immunocompromized people ,such as those with renal disease, heart disease, and AIDS , Listeria can cause high mortality rates.. Listeria spp. are capable of growth at refrigerator temperature and it also can survive at adverse environmental conditions. In the current study, one hundred random samples of raw milk and soft cheese (50 each)free from preservatives and not heat treated were collected from street vendors, different local supermarkets, and dairy shops in Kaleyobeia Governate, Egypt. Two methods were used for isolation of listeria , Oxford method and Palcam method .The composition and the results of both were compared. The obtained results revealed that listeria rnonocytogenes was not found in any sample of both raw milk and soft cheese. Listeria grayi could be isolated from two samples (4%) of the examined raw milk samples, they have been isolated by both Palcam and Oxford methods. And one sample (2%) of the examined soft cheese samples was found to be positive for Listeria grayi, which has been isolated using Oxford method only. These results, the public health importance of listeria spp. in milk and dairy products and also the control measure were discussed. |