الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Food borne diseases are the most wide spread health problem in the world and they have the implication both on health and development. Detection of Salmonella is the most important challenge to the food industry today. Outbreaks have been linked to a wide range of food including meat, poultry and eggs. The present study aimed to evaluate some rapid methods versus the conventional method for the detection of Salmonella in minced meat and eggs, to determine the prevalence of Salmonella in meat and eggs from different localities in Alexandria, to highlight the relation between the presence of indicator organism ( E.coli) and Salmonella in food and to determine the resistant strains of Salmonella to different antibiotic . Therefore the study was carried out on a total of 450 samples, (300) minced meat (150) egg samples collected from different localities in Alexandria. Each sample was collected in sterile container labeled and transferred to laboratory for complete examination. All the samples were subjected to detection of Salmonella by conventional method and fifty minced samples were subjected to detection of Salmonella by TECRA assay. 1-Detection of Salmonella by conventional method: In this study sampling method and microbiological procedures were performed according to the BAM, USDA and FSIS. In which 25 gm of the meat sample were added to 255 ml buffered peptone water ( pre-enrichment media) homogenized in the stomacher and incubated at 37 0C for 24 hours . One ml ,10 ml of pre-enriched sample was transferred into each of 100 ml of Rappaport – Vasiliadis and selenite cystine broth respectively , the first media was incubated at 420C for 24 hours while the second was incubated at 370C for 48 hours. A loopful from each selective enrichment broth was streaked onto plates of a-chromogenic Salmonella agar. b-xylose lysine decarboxylase ( XLD) agar. c-Bismuth sulfite (BS) agar. The first two plates ( Chrom, XLD)were incubated at 370C for 24 hours while BS was incubated at 370C for 48 hours. Salmonella colonies were completely identified by biochemical tests (Triple sugar iron agar, urease, oxidase, indole, lysine, arginine and ornithine). 2- Rapid Biochemical test (MUCAP): Suspected colonies were inoculated from the three selective plating media on Hektoen enteric agar, incubated at 370 C for 24 hours . One drop of the MUCAP reagent was added to the suspected colonies on Hektoen agar and observed under U.V ( 366nm). 3- TECRA unique Salmonella test: This assay is considered a combination of ELISA and dip-sticks, that begins by adding a small volume of the incubated sample to ELISA tube containing a dipstick coated with highly specific purified Abs on its surface to selectively capture any Salmonella Ag present, the dipstick is transferred to another tube and incubated in enrichment broth to allow the captured Salmonella to replicate to detectable level , it then transferred to another tube containing enzyme linked Abs ( conjugate) specific for Salmonella. This conjugate will bind the Salmonella on the dip-stick. Excess conjugate is removed by washing the dipstick and transferring it to another tube which contains substrate for the enzyme for color development. 3- Detection and enumeration of total coliforms and E.coli by MPN: Presumptive test was performed by aseptically pipetting one ml of the different decimal dilutions of minced meat samples into lauryl sulphate broth fermentation tubes with inverted durham tubes. The tubes were incubated at 370C for 24-48 hours. Confirmed test for E.coli was performed by inoculating two loopfuls from each positive presumptive tube into 5 ml E.C broth and incubated in water bath for 24-48 hours at 44.50C. Each positive E.C tube was recorded and the MPN of E.coli/gm food sample was calculated using Macradey tables. The positive E.C were subcultured on L-EMB agar plates and were incubated at 370C for 24 hours. The suspected E.coli colonies were completely identified by Gram staining and biochemical tests. While confirmed test for total coliforms was performed by inoculating two loopfuls from positive presumptive tubes into 5 ml of brilliant green lactose bile broth (BGLBB) and incubated at 370C for 24-48 hours. Each positive BGLBB tube was recorded and the MPN of TC /gm food sample was calculated from Macradey probability tables. The results of this study can be summarized as follows: 1- Out of the 300 minced meat samples, Salmonella was isolated from 15.3