MODIFIED DOT ELISA FOR DIAGNOSIS OF ZOONOTIC TOXOPLASMOSIS IN MAN AND SHEEP WITH CLINICAL SUGGESTIVE MANIFESTATIONS

Document Type : Original Article

Authors

1 Departments of Parasitology, Faculty of Veterinary Medicine, Cairo University, Egypt.

2 Department of Parasitology, Faculty of Medicine, Al-Azhar University, Nasr City, Egypt.

3 Departments of Parasitology, Faculties of Veterinary Medicine, Cairo University.+

4 Beni-Sweif University, Egypt.

5 Department of Biology, Animal Reproduction Research Institute, Giza, Egypt.

Abstract

Fractionation of Toxoplasma gondii RH strain tachyzoites (TTAg) using SDS-PAGE and identification of its specific bands versus control sera using EITB revealed five group of specific fractions corresponding to molecular weight (MW) level of 32-34 kda, 46kda, 53 kda, 78 kda and 100 kda. Fractions of 32-34 kda were the most sensitive and specific one able to capturing very low level of anti-Toxoplasma Ab in the sera and did not cross react with anti-parasites antibodies (Ab) as hydatedosis, S. mansoni, HCV, F. gigantica and Cysticercus ovies as well as control noninfected sera. Thick transverse gel strip containing the fraction of 32-34kda were cut out, its contents were eluted and concentrated, Dotting of 2μl from this fraction on 4mm diameter nitrocellulose (NC) discs for development a modified dot-ELISA technique were evaluated in diagnosis of toxoplasmosis in group of suspected women and sheep. This technique succeeded in diagnosis of the specific anti-toxoplasma Ab in sera of seven suspected sheep, all of them aborted after this. Investigation of some haematological and serum chemical parameters demonstrated significant (p≤0.05) deviations in the values of WBCs, AST, Urea and Cholesterol, which considered to be important in supporting early diagnoses of infection in suspected cases. Adaptation of modified Dot-ELISA technique described in this work perform an easily field applied mass screening technique depends on using a minute amount of serum without special equipment. Dot-ELISA by this way gathering the benefits of accuracy of EITB and overcome the cross reaction phenomenon characteristic to ELISA. This improved capability of early diagnosis
and control strategy of toxoplasmosis in man and animals.

Keywords