Serological Immunodetection of Fasciola gigantica Excretory/ Secretory Antigens in Naturally Infected Cattle and Human

Abstract

The traditional diagnostic method of fascioliasis was based on the identification of the eggs in the stool, but this is not a reliable way as it has many restrictions. The present work was evaluated to immunodetect the Excretory/ Secretory antigens of Fasciola gigantica by sandwich Elisa in naturally infected cattle's sera and by dot blot in naturally infected human sera and compare these methods and the traditional methods. In this study, fresh adult Fasciola gigantica worms were collected to extract crude excretory/secretory (E/S) antigens. E/S was used to immunize rabbits and mice to raise polyclonal antibodies. The IgG fraction of rabbit and mouse anti-Fasciola antibodies was purified. The protein content of anti-Fasciola IgG antibody, was 8.8 and 5.2mg/ml, respectively. Sandwich ELISA was performed to detect Fasciola antigens in serum samples collected from 248 cattle. Also, a Dot blot was performed to detect Fasciola antigens in 38 human sera. Results showed that after parasitological stool examination, 26 human samples were positive and 12 human sera were healthy. The redbrown color appeared with all infected samples only. This technique is cheap, and saves time; multiple samples can make at the same time and not require expensive laboratory equipment. In conclusion, the sandwich ELISA and Dot blot assays were more reliable tools for early serodiagnosis of fasciolosis than traditional methods. Significance Statement: Different antigenic fractions of Fasciola have been used for serological diagnosis of human fasciolosis.