الفهرس | Only 14 pages are availabe for public view |
Abstract Listeria monocytogenes was first isolated from animal in 1911, and the first confirmed report of listeric infection in human appeared in 1929. Also the first bacteriological confirmed case of listeric meningitis was reported in 1935. Since 1981, about four confirmed dairy-related listeriosis outbreaks resulted from consumption of milk and dairy products were reported. During the course of this work a survey on the presence of Listeria monocytogenes was carried out in milk and dairy products by using cold and warm enrichment techniques. 33 samples of raw milk, 14 samples of Domiati cheese, 14 samples of Karish cheese, 5 samples of cream and another 5 ones sample of butter being collected from Mansoura, Samanoud and Aga cities were examined. Potassium thiocyanate broth (p.Th.B.) was used as an enrichment 4 or 37’e for 6 and 4 weeks, respectively. Viable bacterial counts were detected and plated with Naladixic Acid Blood Agar (NABA) at 37’ e for 48 h. The number of colonies surrounded with clear zone iP-haemolytic) was enumerated, and calculated as % of total counts on NABA. Samples of raw, pasteurized and UHT-milk were also preenriched for the growth of L. monocytogenes at 4 and 37’e, and samples were aseptically. |