A total of 56 E.coli isolates and 8 salmonella isolates were identified biochemically by lactose fermentation , indole, citrate methyl red ,V P,TSI and sugar fermentation tests these isolateswere studied for antimicrobial susceptibility patterns by diskdiffusion method and micro dillution method. Chromosomal DNA and plasmide of 8 E.coli isolates included in this study were subject to PCR with primers specific to blaTEM, bla SHY ,blaOXAgenes.Antimicrobial susceptibility patterns Of 56 E.coli isolatesexamined by disk diffusion test out of 56 E.coli isolates 12isolates were resistant to cefotaxime (21.4%), 55 isolates were resistant to oxacillin (98.2%) withAbsence of complete susceptibility to oxacillin, 20 isolates were resistant to Gentamicin (35.7%) ,19 isolates were resistant to enrofloxacin (33.9%), 54Among all serological tests that had been developed , cELISAcould overcome the problem of cross reaction that occurred from otherbacteria sharing identical epitope , beside being rapid and highlysensitive.IThis assay performed by using mono clonal antibody against Aand M epitopes from lipopolysaccharides of S 19 and Rev 1respectively , as serological responses following infection orvaccination directed predominantly against the lipopolysaccahrides.. The prepared lipopolysaccharides have been characterized by