Fecundity, sex hormones and release of cercariae of Schistosoma mansoni in Biomphalaria alexandrina (Ehrenberg, 1831) treated with copper and magnesium chlorophyllin

Abstract

Schistosomiasis is a public health problem in many developing countries. Control of the snail intermediate hosts of Schistosoma is a promising method for eliminating this disease. Copper (Cu-chl) and magnesium chlorophyllin (Mg-chl) are potent photosensitisers used in diverse biological applications. Their effects on the fecundity of Biomphalaria alexandrina (Ehrenberg): its reproductive rate (R 0 ) and total levels of progesterone, testosterone and estradiol were evaluated. Besides, we determined the production of cercariae of S. mansoni. The concentrations LC 10 and LC 25 of Cu-chl and Mg-chl significantly reduced the fecundity and R 0 of the treated snails which could be partially due to the decrease in the level of steroid sex hormones. The reduction rates of R 0 for the snails treated with LC 10 Cu-chl and Mg-chl were 72.7% and 89.7%, respectively. Moreover, Cu-chl and Mg-chl significantly suppressed the cercarial production which dropped from 9,778 cercariae per snail in the light control group to 3,126 and 107 cercariae per snail in the groups treated with LC 10 Cu-chl and Mg-chl 21 days after exposure to miracidia, respectively. Since Cu-chl and Mg-chl negatively interfere with the parasite transmission, they should be considered in schistosomiasis control programmes.

Impact of carbamide perhydrate on the snail Bulinus truncatus, the intermediate host of Schistosoma haematobium

“…A marked reduction in the survivorship (Lx) of B. truncatus snails after treatment with carbamide perhydrate and 4 weeks of recovery was time and concentration dependent (Table 2). Similar results were noticed for B. alexandrina after exposure to carbamide perhydrate (Gawish et al 2009) and after maintaining with copper and magnesium chlorophyllin (Ragheb et al, 2018 &Ibrahim andBakry, 2019).…”

“…Among them is the chemical molluscicides, but due to their toxicity to the non-target organisms and high costs (WHO, 2014), there is an interest to find out suitable environmentally safe compounds. In this context, the safety of photosensitizers to human beings and aquatic ecosystems is an advantage for evaluating their effect against the snail intermediate hosts of schistosomiasis (Gawish et al, 2009 andRagheb et al, 2018). The use of photosensitizing dyes for inactivation of pathogenic agents has been evaluated in red and platelet blood components (Wagner and Skripchenko, 2003).…”

Spatial variation of life-history traits in Bulinus truncatus, the intermediate host of schistosomes, in the context of field application of niclosamide in Côte d’Ivoire

“…Fecundity at population level was also measured based on the parameter Mx (mean number of eggs / snail / week). Mx was computed according to Ragheb et al and Habib et al [ 63 , 64 ]. Egg hatching was also monitored every 2 days over 2 weeks.…”

Impact of Schistosoma sp., Infection on Biological, Feeding, Physiological, Histological, and Genotoxicological Aspects of Biomphalaria alexandrina and Bulinus truncatus Snails

“…De Jong-Brink [ 83 ] illustrated that Schistosomin, a peptide produced by the nervous system of infected snails following schistosome infection, interferes with the host's neuroendocrine system, inhibiting the action of reproductive hormones. Steroid hormones have been documented in various molluscs, including B. alexandrina [ 84 – 87 ] and B. truncates [ 88 ].…”