The present study was undertaken to investigate the influence of some environmental factors including temperature, water vegetation, bed mud and pH on LC 50, LC 90 and LT 50 of bisphenol A (BPA) on the snail host of Schistosoma mansoni, Biomphalaria alexandrina. Effects of exposure to the sublethal concentrations of BPA on some biological aspects of the snails and on the cercarial output form S. mansoni infected snails were studied. Results showed that temperature, water vegetation, bed mud and pH markedly affected the lethality of BPA. The biological parameters of B. alexandrina including survival rate, egg hatchability and egg laying capacity were greatly affected by exposure to BPA and the response was dose dependent. Regarding the possible effect of BPA on transmission of schistosomiasis, results showed that exposure to different concentration of BPA for 7 days before miracidial infection caused the death of all the snails before reaching the patent period while, no cercarial output was recorded from snails exposed to BPA for 24 hrs till their death. In conclusion, our results showed that the environmental characteristics may alter the biological impacts of BPA and the exposure of snail to BPA may affect the transmission of schistosomiasis.organs, enlarged sex glands, oviduct deformities, and increased fecundity), oviduct rupture, and mortality [12]. In the mollusk Mytilus edulis, spawning induction, as well as oocyte and ovarian follicle damage, was observed following BPA exposure for 3 weeks at 50.0 mg L -1 [13]. The effect of BPA appears to vary considerably among related taxa, and it appears that some invertebrates may be hypersensitive to BPA exposure (freshwater molluscs and insect larvae, and marine copepods in particular).The present study was undertaken to investigate the influence of some environmental factors including temperature, water vegetation, bed mud and pH on the effect of bisphenol A on the fresh water snails, B. alexandrina and consequently the transmission of schistosomiasis. The possible effect of BPA on the Schistosoma cercarial output form the snails was also studied.
Materials and MethodsMaintenance and rearing of B. alexandrina snails B. alexandrina snails were collected from fresh water canals in Warrak El-Arab village, Giza Governorate. The collected snails were maintained in glass tank filled with dechlorinated tap water under constant temperature (25 ± 2 ºC) with diurnal alteration and fed on dried lettuce leaves for at least three weeks before being used for the following experiments. Maintenance and rearing of the snails were done according to [14].
Determination of LC 50, LC 90 and LT 50 of bisphenol A against B. alexandrina snailsBisphenol A (4,4´-isopropylidinedi-phenol) was purchased from Sigma Aldrich Company, Germany. Stock solution of BPA (100 mg L -1 ) was prepared according to the method of [15]. A series of
IntroductionStudying the environmental conditions related to the occurrence of snail intermediate host can provide valuable information on its breeding s...
