الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
 |  | from | 124 |  |  |
| | | from | 124 | | |
Abstract
Food-borne diseases are important group of infections and intoxications that may manifest themselves in a mild form or as serious conditions often leading in death. In recent years, an increase in the incidence of food-borne diseases has been noticeable almost allover the world. Numerous microbiological hazards and risks are associated with preparation of ready-to-eat foods. They are often prepared under unhygienic condition, prepared and kept for several hours at ambient temperatures before consumption and left overs are normally kept over night without refrigeration and served the following day. Moreover, mishandling of the food could contribute risk to the consumers. This study aimed to search for possible organisms causing food-borne diseases such as Salmonellae, Shigellae, E. coli, Staph. aureus together with the total viable bacterial count in different types of ready-to-eat foods in many districts in Alexandria. The study was performed on 200 ready-to-eat food samples (101 meat and meat products, 60 bean and tameia, 22 egg and egg products, 7 poultry and 10 carbohydrate diet) collected from different districts in Alexandria (Masr station, Ramle station,Manchia,El-Ibrahimia,El-Hadra,Miami, Bahari, Sporting, Cleopatra and Bakous). Ten grams of each sample were weighted under aseptic condition, transferred to a stomacher bag with 90 ml buffered peptone water and mixed thoroughly in a stomacher for 4 minutes. Then each food sample was subjected to: (1) Total aerobic plate count on plate count agar after transferring 1 ml from food homogenate to 9 ml of peptone saline diluent to obtain 6 dilutions for each sample. Duplicate plates for each sample were cultured and the plates were incubated, one set at room temperature, the other at 37?C for 24 hours. The plates were counted with the aid of Quebec counter, and the TAPC per gram of the tested sample was calculated. (2) Pre-enrichment in buffered peptone water at 37?C for 24 hours. One loopful of this culture was streaked over the surface of Baird-parker and incubated at 37?C for 48 hours. Suspected colonies of Staph. aureus were identified by coagulase test. (3) Enrichment: one ml of pre-enrichment culture was transferred to 10 ml of tetrathionate both and incubated at 42?C for 24 hours. One loopful was streaked on XLD agar and incubated at 37?C for 48 hours. One ml of pre-enrichment culture was transferred to each 10 ml of GN and 10 ml of LST broth and incubated at 37?C for 24 hours. One loopful from each broth was streaked on XLD and MacConkey agar respectively and incubated at 37?C for 24 hours. All suspected colonies of Salmonellae, Shigellae and E. coli were identified by biochemical tests.