Biosurfactant Production

Abstract

Background Schistosomulum stage is believed to be the target of protective immunity. Over the past two decades, several investigators have demonstrated the antigenic communion between Schistosoma mansoni and Biomphalaria alexandrina. Objective The present study aimed to evaluate the effect of combining S. mansoni schistosomal lung antigen preparations and B. alexandrina antigen preparations for use as antischistosomal vaccination in murine models, and to compare their efficacy with and without the use of complete Freund's adjuvant (CFA). Materials and methods Seventy laboratory-bred Swiss albino male mice were used in this study. They were classified into seven groups (10 mice each). Each mouse was sensitized with an initial subcutaneous injection of the extracted antigens. After 2 weeks, a second subcutaneous injection of the same antigen dose was given. Two weeks after the last dose of vaccination, all mice groups were infected with 100 S. mansoni cercariae subcutaneously. Mice were sacrificed by rapid decapitation 7 weeks post-infection for assessment of the inoculated antigens by parasitological (stool egg count, worm burden, tissue egg load, and oogram pattern) and histopathological (hepatic sections stained with hematoxylin and eosin for detection of granuloma number and diameter) studies. Results The data showed that vaccination with combined antigens (S. mansoni schistosomal lung antigen prepations + B. alexandrina antigen preparations with CFA) had the best protective effect. Conclusion The single antigen vaccination did not protect against infection by antigenically complexed S. mansoni. The cocktail vaccine apparently induced an agreeable immune response against many of the antigenic components. This new cocktail represents a promising approach toward the future development of vaccine strategy.