الفهرس | Only 14 pages are availabe for public view |
Abstract This study was conducted to determine the presence of E.coli spp. in raw milk samples collected from North Sinai Governorate. E.coli isolated from farm milk with a percentage of 10%, from market milk; 11.7% (as from dairy shops and groceries; 12% and from the vendors 11%), with total isolation percentage 8.9%. Sero grouping of E.coli isolates(n:10) revealed the detection of serogroups:O1(2strains),O6(2strains),O55(1strain),O86(1strain),O12 8(2strains) and O158(2strains); distributed as O1 and O55 from farm milk,O6,O86,O128 and O158 from market milk and O1,O128 and O158 from the vendor’s milk. 40% of E.coli strains showed positivity for Congo red dye binding activity test. The antibiogram of E.coli strains performed by using the VITEK 2 apparatus. E.coli strains revealed 100% resistance towards Ampicillin, 80% for Tetracycline, 50% for piperacillin, 40% for Cephalexin, Chloramphenicol and Trimethoprime-Sulfamethaxol. The PCR used for detection of ” phA ”gene in E.coli strains, the results revealed that all E.coli harbored the sequence of that gene(100%).Also the occurrence of virulence genes (stx1,stx2) were analyzed .the results showed that all E.coli strains were devoid of stx1 and only one E.coli strain(O158) carried the stx2 gene. The antibiotic resistance genes were determined in E.coli strains As the ”tetA”gene was detected in 80% of E.coli strains and the ”blaTEM” gene was detected in 100% of E.coli strains. |