For determination of the prevalence of molecular character of Enteropathogenic E. coli and Staph. aureus in raw yogurt, pasteurized yogurt and Rayeb milk by using PCR. A total of 40 samples of raw yogurt and 40 samples of pasteurized yogurt from the two trade companies, addition to 40 samples of rayeb milk (divided into, twenty pasteurized milk rayeb and twenty raw milk rayeb).
Bacteriological examination revealed that the percentage of E. coli isolates were 41 recorded (34.2%) while Staph. aureus was 7 (5.8 %), while could not detected Staph. aureus in both pasteurized yogurt and pasteurized rayeb samples.
E. coli and Staph. aureus isolates were subjected to PCR for detection of eaeA, STa , Stx1 and stx2 gene from E. coli, and Sed, See, coa and mecA gene from Staph. aureus . Only stx2 gene was detected in E. coli strain isolated from raw yogurt sample and mecA gene detected in Staph. aureus strain isolated from raw milk rayeb.
Generally, application and implementation of (HACCP) system as a hazards control system should be done in dairy processing plan prevention and to ensure a maximum safety to consumers.
Statistical analytical results of Coliform count of the examined Raw yogurt (small scale) and Pasteurized yogurt (large scale) samples were ranged from 4.50 x 102 to 5.45 x 1102 with a mean value 5.02 x 102 ± 0.57 x 102 for Raw yoghurt samples. And were ranged from 1.55 x 102 to 2.33 x 102 with a mean value 2.08 x 102 ± 0.09 x 102 for Pasteurized yogurt samples While Statistical analytical results of Coliform count of the examined raw milk rayeb (small scale) and Pasteurized milk rayeb (large scale) samples were ranged from 2.65 x 102 to 2.85 x 102 with a mean value 2.34 x 102 ± 0.36 x 102 a for raw milk rayeb samples. And were ranged from 1.04 x 102 to 1.42 x 102 with a mean value 1.17 x 102± 0.09 x 102 For Pasteurized milk rayeb samples. 102
The mean values of total Staphylococcus aureus of Raw yogurt and raw milk rayeb were 1.37 x 102 ± 0.05 x 102 b and 1.86 x 102 ± 0.17 x 102b, respectively. While could not detected Staphylococcus aureus in both, Pasteurized yogurt and pasteurized rayeb.
Key words: Key words: E.coli, Staphylococcus aureus, Raw milk yogurt and Pasteurized Yogurt and Rayeb milk , PCR.
|
