Study the ability of Enterotoxigenic E.coli antigens to induce cellular immune response by erythrocyte-rosette formation and leukocyte migration inhibition factor in rabbits

Abstract EN

Objectives :This study was aimed to investigate the ability of Enterotoxigenic E.coli and their enterotoxins to induce cellular immune response by means of erythrocyte-rosette formation and leukocyte migration inhibition factor tests.

Methods: Total of 30 stool sample was collected from patient with severe diarrhea whom attended to Al-Sadder teaching hospital in Al-Najaf city in period extended from April to June 2013.

All bacterial isolates was identified according to morphological and biochemical testes and by API 20 E system, which further conformational tested for heat stable enterotoxin production by Suckling Mice Assay (SMA).

three antigens (heat killed bacterial cell, crude enterotoxin and purified heat stable enterotoxin ETECST) was prepared and injected in experimental animals(rabbit) and tested in the level of systemic and mucosa (appendix and duodenum).

Statistical analysis was done by least significant difference (LSD).

Results: The results showed that 20% (6 isolates) was Enterotoxigenic E.coli and the immune experiments showed significant increase level of E-rosette formation in rabbit injected with heat killed antigen (50.1%, 49.7% and 53.0%) compared with control (23.1%, 31.8% and 29.6%) in blood appendix and duodenum consecutively, while high level appeared in crude enterotoxin and ETECST in appendix (41.3%) and (47.4%) consecutively.

The assessment of ETECST LIF in migration percent to sensitizer was showing high significant LIF (54.5%, 47.6% and 43.3%) compared with control (82.0%, 79.5% and 79.5%) in blood appendix and duodenum consecutively.

Conclusions: crud and partially purified enterotoxins have ability to induce cellular immune response in blood and mucosa.

Recommendation: prepare a carrier molecule model for partially purified enterotoxins to make a vaccine against Enterotoxigenic E.coli .