Screening of Capillaria philippinensis infection using Trichuris muris and Trichinella spiralis antigens

Abstract

Background: Intestinal capillariasis is a disease caused by Capillaria philippinensis. Human infections became more prevalent in many countries including Egypt. This nematode is related to Trichinella and Trichuris species, all of them belong to Trichinelloidea superfamily. Diagnosis of intestinal capillariasis may be missed by stool examination.Objective: This study aimed to use enzyme-linked immunosorbent assay (ELISA) and immunoblotting in screening for intestinal capillariasis as a practical and rapid diagnostic test.Subjects and Methods: Trichuris muris and Trichinella spiralis adult worms were isolated from infected mice and crude antigens were prepared. The protein content for both adult worm extracts was determined. Human blood samples were collected from 20 capillariasis patients, 20 control individuals and 10 W bancrofti infected patients. The study evaluated cross-reactivity between T. spiralis and T. muris antigens and sera from cases infected with C. philippinensis using ELISA and immunoblotting.Results: In ELISA, T. muris crude antigen cross reacted with 100% of capillariasis sera with 100% sensitivity and specificity and cross reacted with 10% of sera from bancroftian filariasis. T. spiralis crude antigen cross reacted with 50% of capillariasis sera, and 9% of sera from bancroftian filariasis. Neither T. muris nor T. spiralis crude antigens reacted with sera from control group. Immunoblotting results showed that IgG antibodies from control group didn't recognize specific proteins in T. muris antigen, while in W. bancrofti group, only one band in one sample appeared (100-135 kDa). IgG antibodies from capillariasis cases recognized multiple common protein bands (35-180 kDa). IgG antibodies from capillariasis, control and W. bancrofti sera did not recognize specific proteins in T. spiralis crude antigen.Conclusion: Antigens from T. muris and T. spiralis can be used successfully to detect infection with C. philippinensis using serum samples of cases by ELISA. Crude antigen of T. muris gave better results than that of T. spiralis. Immunoblotting can be used for diagnosis of capillariasis by using crude antigen of T. muris.