Abstract
BackgroundYellow cattle and water buffalo are two of the most important natural hosts for Schistosoma japonicum in China. Previous observation has revealed that yellow cattle are more suited to the development of S. japonicum than water buffalo. Understanding more about the molecular mechanisms involved in worm development, as well as the pathological and immunological differences between yellow cattle and water buffalo post infection with S japonicum will provide useful information for the vaccine design and its delivery procedure.ResultsThe worm length (p < 0.01), worm recovery rate (p < 0.01) and the percentage of paired worms (p < 0.01) were significantly greater in yellow cattle than those in water buffalo. There were many white egg granulomas in the livers of yellow cattle, but fewer were observed in water buffalo at 7 weeks post infection. The livers of infected yellow cattle contained significantly increased accumulation of inflammatory cells, and the schistosome eggs were surrounded with large amounts of eosinophil infiltration. In contrast, no hepatocyte swelling or lymphocyte infiltration, and fewer white blood cells, was observed in water buffalo. The percentage of CD4+ T cells was higher in yellow cattle, while the percentage of CD8+ T cells was higher in water buffalo from pre-infection to 7 w post infection. The CD4/CD8 ratios were decreased in both species after challenge with schistosomes. Comparing with water buffalo, the IFN-γ level was higher and decreased significantly, while the IL-4 level was lower and increased gradually in yellow cattle from pre-infection to 7 w post infection.ConclusionsIn this study, we confirmed that yellow cattle were more suited to the development of S. japonicum than water buffalo, and more serious pathological damage was observed in infected yellow cattle. Immunological analysis suggested that CD4+ T cells might be an integral component of the immune response and might associate with worm development in yellow cattle. A shift from Th1 to Th2 type polarized immunity was only shown clearly in schistosome-infected yellow cattle, but no shift in water buffalo. The results provide valuable information for increased understanding of host-schistosome interactions, and for control of schistosomiasis.
Highlights
Yellow cattle and water buffalo are two of the most important natural hosts for Schistosoma japonicum in China
The results revealed that the livers from yellow cattle were dark red with many white egg nodules, composed of many egggranulomas, while the livers from water buffalo were red with few or no egg nodules (Figure 1)
Water buffalo reared in endemic areas have more chances and longer time to contact with the contaminated water, that is, there are more chances for water buffalo to get infection and reinfection than yellow cattle and other animals, so water buffalo are less suitable for the development of S. japonicum, they still retained a higher infection rate for this parasite
Summary
Yellow cattle and water buffalo are two of the most important natural hosts for Schistosoma japonicum in China. About 46 species of mammal are known to carry natural infection with S. japonicum, such as rats, rabbits, dogs, cats, horses, cattle, sheep, donkeys, In China, the areas endemic for uncontrolled schistosomiasis are mostly in the marshland/lake and mountainous regions [4,5,6]. Two kinds of bovine reared commonly in these endemic regions are yellow cattle (Bos taurus) and water buffalo (Bubalus bubalis). These animals are naturally infected with schistosomes and spread more eggs into the environment than human and other animal hosts, and are considered to be the main sources of transmission of schistosomiasis in most lake and marshland endemic areas [9,10]
Sign-in/Register to view highlights & summary 
Published Version (
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