Modulation of Immune system by Oral Administration Pathogenic Escherichia coli Isolated from Cow Mastitis

The immune system has an effective role in the defense mechanism against different microbial agents. This study aimed to identify the effect of experimentally oral administration of pathogenic Escherichia coli isolated from cow mastitis on modulation of immune system in rats. 15 Wister albino rats divided in to three groups,5 each , control group, G1 orally infected group by 105cfu/ml E.coli and G2 orally infected group by 106cfu/ml E.coli, after 15 days of infection ,blood samples collected and serum separated for identification the level of CD4, CD8 and TNF-alpha, by using ELISA test. Our result revealed that there was no significant difference in CD4 and CD8 between control group and oral group G1, while there was a significant increase in CD4 and CD8 concentration between control group and oral group G2, and a significance increase in TNF-α level in G1 and G2 groups when compared with control group. Conclusion: Oral administration of pathogenic Escherichia coli had a great modulatory effect on the immune system and the dose 106 cfu/ml E.coli was more potent than105 cfu/ml E.coli dose in stimulation and modulation of immune response.