Diagnosis of Fasciola infection by SDS–PAGE eluted excretory secretory (ES) protein fractions using dot-ELISA

Fascioliasis is now recognized as an emerging zoonotic disease in Egypt. Diagnosis in suspected patients still needs some degree of accuracy. In the present study, three Fasciola gigantica execratory secretory (ES) protein bands of molecular weight (MW) ranging from 14 to 20 kDa, 25 to 32 kDa and 45 to 65 kDa were eluted after fractionation of the parasite antigen using SDS–PAGE. The extracted kDa protein bands were concentrated and evaluated in diagnosis of Fasciola infection. Moreover the level of their cross reaction with other parasitic infections in infected and suspected patients of known parasite eggs/gram stool was evaluated using the dot-ELISA technique. Protein bands in the range of 14–20 kDa and that of 25–32 kDa were markedly specific and sensitive in diagnosis of different levels of anti-Fasciola antibodies (Ab) in sera of infected cases. These two groups of bands were able to exclude cross-reaction between anti-Fasciola Ab and other parasites recorded in stool of selected patients suffering from Schistosoma mansoni, Ascaris, and Giardia, either in single or mixed conditions with Fasciola eggs. While that of 45–65 kDa appeared less specific than the other previously mentioned bands. Protein bands in the range of 25–32 kDa appeared more sensitive than the other protein bands in detection of anti-Fasciola Ab at higher serum dilutions. The Dot-ELISA technique was proved to be more economic and easy in application. The dotted very small amount of antigens can be stored in a freezer and used at request in diagnosis of large numbers of samples.