Abstract
BackgroundSchistosomiasis japonica is a severe zoonosis. Domestic animals are the primary source of infection and play an important role in disease transmission. Surveillance and diagnosis play key roles in schistosomiasis control; however, current techniques for the surveillance and diagnosis of the disease have limitations. In this study, we developed a novel fluorescence immunochromatographic assay (FICA) strip to detect anti-Schistosoma japonicum antibodies in host serum.MethodsA FICA strip was developed for the diagnosis of Schistosoma japonicum in domestic animals. Streptococcus protein G (SPG) and soluble egg antigen (SEA) were transferred onto a nitrocellulose (NC) membrane to form the control line (C) and the test line (T), respectively. With fluorescence activity as well as binding activity to multispecies IgG, the recombinant protein rSPG-RFP was expressed and employed as an antibody indicator in the FICA strips.ResultsThe dual gene fusion plasmid was verified by PCR and restriction enzyme digestion. The expressed recombinant protein was 39.72 kDa in size, which was consistent with the predicted molecular weight. The western blot results showed binding activity between rSPG-RFP and IgGs from different hosts. Fluorescence microscopy also showed the fluorescence activity of the protein present. The affinity constant (Ka) values of rSPG-RFP with rabbit, donkey, mouse and goat IgG were 1.9 × 105, 4.1 × 105, 1.7 × 105 and 5.4 × 105, respectively. Moreover, based on the recombinant protein, the test strip for detecting S. japonicum in buffaloes could distinguish positive from negative serum. The lower limit of detection of the FICA strip was 1:10,000. Compared with ELISA, the FICA strips exhibited similar results in the diagnosis of infection in clinical bovine serum samples, with a kappa value of 0.9660 and P < 0.01. The cross-reactivities of the FICA strips with Haemonchus contortus and Schistosoma turkestanicum (30.15% and 91.66%, respectively) were higher than those of ELISA (26.98% and 87.5%, respectively).ConclusionsBased on the rSPG-RFP protein that we developed, strip detection can be completed within 15 min. Heightened sensitivity allows the strip to accurately identify schistosome antibodies in serum. In conclusion, this method is convenient, feasible, rapid and effective for detecting S. japonicum.Graphical
Highlights
In addition to the chronic morbidities associated with impaired child growth and development, chronic inflammation, anemia and other nutritional deficiencies, some new disease burden assessments estimate that schistosomiasis accounts for up to 70 million disability-adjusted life years (DALYs) lost annually
Research has shown a close relationship between schistosome infection in domestic animals and humans, which indicates that when there is a significant increase in the Schistosoma japonicum prevalence rate in domestic animals, an increase in the human infection rate occurs [3]
The soluble fraction was purified with Ni-NTA His Bind Resin (Merck-Millipore, USA), and a specific band appeared at 39.72 kDa, which was consistent with the theoretical molecular weight of the recombinant protein rSPG-red fluorescent protein (RFP) (Fig. 3)
Summary
Schistosomiasis is one of the most serious zoonoses caused by schistosomes, and it remains a major public health problem worldwide Schistosomes can infect both humans and animals, affecting the health of people and livestock and causing enormous economic losses. In addition to the chronic morbidities associated with impaired child growth and development, chronic inflammation, anemia and other nutritional deficiencies, some new disease burden assessments estimate that schistosomiasis accounts for up to 70 million disability-adjusted life years (DALYs) lost annually. This global burden estimate exceeds those for malaria and tuberculosis and is almost equivalent to the DALYs lost due to HIV/AIDS [1, 2]. The detection of S. japonicum in infected domestic animals is critical for the control of this disease [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
