Search

Aspergillus niger is a one-of-a-kind fungus with benefits for both terrestrial and aquatic species, although research on the effects of A. niger on aquatic animal species is limited. The present study investigated the impact of Aspergillus niger, A. flavus, and Alternaria alternate filtrates on Biomphalaria alexandrina snails (the main intermediate host of Schistosoma mansoni in Egypt). Moreover, the effect of A. niger (the most toxic fungus) filtrate was assessed against infected B. alexandrina snails with S. mansoni, in addition to its efficacy against S. mansoni free larval stages. Aspergillus niger had more toxicity (100 % mortality) than A. flavus (40% mortality), while Alternaria alternate did not affect B. alexandrina snails. Chronic exposure to sub-lethal concentrations of A. niger caused histopathological changes in the head-foot, digestive gland, kidney, and hermaphrodite gland of B. alexandrina snails. Furthermore, after exposure to the determined sub-lethal concentrations of A. niger, both uninfected and infected snails with S. mansoni showed low survival rates. In addition, the lethal time for miracidia and cercariae after exposure to LC25 of A. niger was 130 and 200 minutes, respectively. Additionally, exposure to sub-lethal A niger concentrations resulted in a significant decrease in the infection rate and mean total count of cercariae shed per snail, as well as the shed of aberrant cercariae. In conclusion, Aspergillus niger filtrate had a potent molluscicidal activity against B. alexandrina, and a damaging effect on cercariae, hence it can play a role in reducing schistosomiasis. [ABSTRACT FROM AUTHOR]

One of the most significant neglected tropical diseases that have a detrimental effect on economic and public health criteria is Schistosomiasis. Therefore, there is a permanent and urgent need to find alternative means of biological control. Ferula hermonis is a herbaceous plant with various pharmaceutical properties and is known for its endocrine-disrupting effects. The objective of the present study was to investigate the molluscicidal activity of F. hermonis roots methanol extract against Biomphalaria alexandrina snails. The experimental results showed that F. hermonis extract has a molluscicidal activity against adult B. alexandrina snails at LC50 (14.2 mg/l) and LC90 (18.1 mg/l). Exposure of snails to sublethal concentrations LC5 (8.3 mg/l) and LC10 (9.8 mg/l) of the extract considerably lowered snail fertility and egg-laying capacity. In addition, results detected an endocrine-disrupting influence where it caused fluctuations in the levels of the three steroid sex hormones (Testosterone, Estradiol (E2), and Estrogen) following acute and chronic exposure of adult B. alexandrina snails to the sublethal doses of the tested extract. Regarding biochemical alterations, glucose and total lipids levels increased significantly, while protein and albumin contents decreased following exposure to sublethal concentrations, compared to the control snails. The sublethal concentrations (LC5, LC10, and LC50) of F. hermonis roots methanol extract exerted noticeable DNA damage in B. alexandrina snails, whereas LC10 was the most genotoxic concentration with 18.20±0.09% tailed cells and 10.54±0.58 px tail length. F. hermonis roots methanol extract can be considered a promising biocontrol agent against B. alexandrina snails, the intermediate host of Schistosoma mansoni in Egypt, via interference with the reproduction processes, and subsequently reducing the population size of snails in endemic areas. [ABSTRACT FROM AUTHOR]