Impact of Schistosoma mansoni and Echinococcus granulosus experimental coinfection on interleukin 10 and interferon gamma cytokines profile

Echinococcus granulosus hydatid cyst location is modified by Fasciola hepatica infection in cattle

BACKGROUND

Natural parasite infection occurs in wild and domestics animals with more than one parasite species at the same time, generating an infection called polyparasitism. Cystic echinococcosis reports are usually based only on infection with Echinoccocus granulosus leaving aside other internal parasitoses that could modulate both the immune response and pathogenesis of the natural infection. Fasciola hepatica is another cosmopolitan parasite in ruminants with a similar distribution to E. granulosus in different parts of the world, but no information of the effect of co-infection with E. granulosus has been described. The aims of this report were to establish E. granulosus prevalence and explore the association of F. hepatica co-infection and natural E. granulosus infections in cattle.

RESULTS

From 1725 animals, the prevalence of E. granulosus and F. hepatica was 21.16 and 51.3%, respectively. Considering both infections, older cattle (> 4 years) presented higher prevalence compared to younger animals. In E. granulosus-infected cattle, 5.21% had fertile cysts, 71.78% infertile cysts, and in 23.01% cysts were smaller than 1 cm in diameter. Considering cyst location, 39.72% had lungs cysts, 24.72% had liver cysts and 36.94% had cysts in both organs. Cyst location significantly differed between age groups: 44.68% of younger animals had cysts only in the lungs, while older animals presented hydatid cyst in the lungs and liver simultaneously (44.15%). With E. granulosus infection alone, 30.26% of cysts were found in the lungs, 31.79% in the liver and 37.95% in both organs. Regarding the co-infection of E. granulosus with F. hepatica, the proportion was significantly different (P < 0.05) with most animals having cysts only in the lungs (49.41%) and a lower level of liver infection (15.88%). Analyzing organ cyst distribution and F. hepatica absence/presence ratio within each cyst type, small cysts showed the highest difference in ratio.

CONCLUSIONS

To the best of our knowledge, this is the first report indicating that F. hepatica co-infection in cattle could be affecting the instate of hydatid cysts in the liver, displacing toward lung localization, suggesting an antagonistic relationship.

Parasite-Parasite Interactions in the Wild: How To Detect Them?

Inter-specific interactions between parasites impact on parasite intra-host dynamics, host health, and disease management. Identifying and understanding interaction mechanisms in the wild is crucial for wildlife disease management. It is however complex because several scales are interlaced. Parasite-parasite interactions are likely to occur via mechanisms at the within-host level, but also at upper levels (host population and community). Furthermore, interactions occurring at one level of organization spread to upper levels through cascade effects. Even if cascade effects are important confounding factors, we argue that we can also benefit from them because upper scales often provide a way to survey a wider range of parasites at lower cost. New protocols and theoretical studies (especially across scales) are necessary to take advantage of this opportunity.

Th9/IL-9 profile in human echinococcosis: their involvement in immune response during infection by Echinococcus granulosus

Th9 cells have been reported to contribute to immune responses; however, the role of Th9 cells in Echinococcus granulosus infection is unknown. This study is to determine whether Th9 cells and IL-9 are involved in human Echinococcus granulosus infection. Compared with healthy controls (HC group), the mRNA levels of PU.1, IL-9, and GATA-3 were significantly increased in patients before therapy (CE group), as revealed by qRT-PCR. Flow cytometry analysis showed that the percentages of Th9 and Th2 cells in CE group were significantly higher. The levels of IL-9, IL-4, IL-10, and TGF-β in CE group were also significantly increased, as detected by CBA assay. The percentages of Th9 and Th2 cells in CE group were positively correlated. After treatments of surgery in combination with albendazole, the PU.1 and GATA-3 mRNA levels were significantly decreased in patients after therapy (PCE group) compared with CE group. The numbers of Th9 and Th2 cells and levels of IL-9, IL-4, IL-10, and TGF-β were also significantly decreased in PCE group. In conclusion, the ratios of Th9 cells and IL-9 levels were significantly decreased after treatment, suggesting that Th9/IL-9 may be involved in immune response induced by Echinococcus granulosus infection.