Impact of Schistosoma sp., infection on biological, behavioral, physiological, histological, and genotoxicological aspects of Biomphalaria alexandrina and Bulinus truncatus snails

Abstract

Trematodes infection of genus Schistosoma can lead to physiological and behavioral changes in intermediate snail hosts. This is because the parasite consumes essential resources required for the host's survival, but the hosts can adaptively modify their behavior to ensure some level of fitness before parasite-induced mortality. The present study examined the reproductive and biochemical parameters of Biomphalaria alexandrina and Bulinus truncatus during the shedding stage of infection with Schistosoma mansoni and haematobium, respectively. The study found that the infection rate with S. mansoni was 34.7% and 30.4% with S. haematobium. In B.alexandrina infected with S. mansoni, a survival rate of 65.2% was recorded, along with a mean duration of shedding of 32.8 ± 5.5 days, a mean prepatent period of 37.5 ± 1.15 days, and a mean life span of 57.0 ± 1.21 days. Meanwhile, in B. truncatus infected with S. haematobium, a survival rate of 56.4% was recorded, with a mean duration of shedding of 42.6 ± 2.6 days, a mean prepatent period of 46.7 ± 2.3 days, and a mean life span of 65.9 ± 1.6 days. The feeding behavior was increased in the two infected species snail, while the net reproductive rate (Ro) of the infected species snails was reduced. Total antioxidant (TAO) and lipid peroxidation activity were increased in the two infected snails during shedding, while Glutathione-S-transferase was reduced. Lipid peroxidase (LPO) activity and nitrogen oxide (NO) levels decreased significantly in infected B. alexandrina and increased in infected Bulinus. Steroid hormone measurements were increased in the infected Biomphalaria, while they were reduced in infected Bulinus. Comet assay parameters were increased in the two infected genera after infection than control snails, and histopathological damage occurred. These observations demonstrated that infection initiates diverse biochemical, hormonal, genotoxic, and histopathological change to the tissues responsible for fecundity and reproduction in B. alexandrina and B. truncatus.