Investigation on immunity induced by Schistosoma spindale against S. mekongi in experimental mice
Janecharut, T.; Kitikoon, V.; Usawattanakul, W.; Sornmani, S.
Southeast Asian Journal of Tropical Medicine and Public Health 19(1): 123-129
1988
ISSN/ISBN: 0125-1562 PMID: 3406801 Document Number: 316848
Mice that had been immunized with 100 S. spindale cercariae were challenged between 2 and 16 weeks later with 500 S. spindale cercariae. Lung recovery assays performed 5 days after challenge revealed that mice immunized between 5 and 16 weeks before challenge harboured significantly fewer schistosomula than non-immunized controls; recovery of schistosomula was lowest in mice immunized 8 weeks before challenge. 10 mice that had been immunized with S. spindale 8 weeks previously and 10 non-immunized controls were challenged with 100 S. mekongi cercariae. Significantly fewer schistosomula were recovered from the immunized mice, 5 days after challenge. 12 immunized mice were killed 54 days after challenge with 20 S. mekongi cercariae. The total numbers of worms, and the numbers of mature males and females, and immature worms were all significantly lower in immunized mice than in non-immunized controls. The mean egg output/female worm was significantly lower in immunized mice than in controls, 54 days after challenge with 10 S. mekongi cercariae. The mean number of eggs/female worm recovered from the tissues of these mice was also significantly lower in immunized animals. It is concluded that immunization with S. spindale cercariae confers both homologous and heterologous immunity.