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Biomphalaria alexandrina

About: Biomphalaria alexandrina is a(n) research topic. Over the lifetime, 413 publication(s) have been published within this topic receiving 3781 citation(s).


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Journal ArticleDOI
TL;DR: These derivatives revealed potential larvicidal effects on both miracidia and cercariae of Schistosoma mansoni at reduced exposure time and their nontoxic effect at all sublethal, lethal, and higher concentrations suggests that these compounds can play an important role as molluscicides and larvicides with environmental safe properties.
Abstract: A series of 10 3-(hetarylaminomethylene)quinolinediones, 12 3-(substituted aminopropenoyl)-4-hydroxyquinolinones, and 10 3-(substituted aminomethylene-5-oxo-pyrazolinyl)-4-hydroxyquinolinones were synthesized as novel enaminones derived from 3-(un)substituted 4-hydroxyquinolin-2(1 H )-ones in 72–94% yields and assayed for their molluscicidal activities against Biomphalaria alexandrina and Lymnaea natalensis snails. Some of the tested enaminones presented high molluscicidal activities (LC 50 ⩽ 20 ppm). The new compounds showed more potency against hatchability of B. alexandrina egg masses, the infection rate and prepatent period of the snails. In addition, these derivatives revealed potential larvicidal effects (100% mortality) on both miracidia and cercariae of Schistosoma mansoni at reduced exposure time. The selected active derivatives were examined against Daphnia magna and their nontoxic effect at all sublethal, lethal, and higher concentrations suggests that these compounds can play an important role as molluscicides and larvicides with environmental safe properties.

81 citations

Journal Article
TL;DR: Calculation of life-table parameters from field data shows that, under optimum field conditions, both species can double their populations in 14-16 days and search for isolated foci of snail breeding and individual treatment of these will effect large savings of chemical and will be effective in controlling the transmission of the parasites.
Abstract: The respective vectors of the two forms of bilharziasis in Egypt do not have the same ecological distribution. Bulinus truncatus is most abundant in large canals, and decreases in density as the water approaches and flows into drains. Biomphalaria alexandrina is most abundant in drains, and decreases in density upstream from these habitats. Both species are most abundant in the presence of aquatic vegetation, but they differ in their respective associations with the water hyacinth, Eichhornia crassipes. Biomph. alexandrina reaches maximum abundance in the presence of this plant, but Bul. truncatus is as uncommon in the absence of plants as in the presence of E. crassipes.Calculation of life-table parameters from field data shows that, under optimum field conditions, both species can double their populations in 14-16 days. The reproductive rates of both species are greatest in March and the death rates in midsummer. The observed peak densities in May and June give a false impression of optima because of undercollection of young snails, which are most abundant in March and April.Control operations should take advantage of the findings on population parameters. A single area-wide treatment with molluscicide in April is recommended. During the remainder of the year, search for isolated foci of snail breeding and individual treatment of these will effect large savings of chemical and will be effective in controlling the transmission of the parasites.

63 citations

Journal ArticleDOI
TL;DR: A nested polymerase chain reaction (PCR) protocol was developed for detecting the presence of Schistosoma mansoni sporocysts in intermediate host snails of the genus Biomphalaria and has utility in determining if snails in endemic areas bear prepatent or inactive infections and in assessing the degree of compatibility between local snail and schistosome populations.
Abstract: A nested polymerase chain reaction (PCR) protocol was developed for detecting the presence of Schistosoma mansoni sporocysts in intermediate host snails of the genus Biomphalaria. To accomplish this, rDNA genes encoding the 18S rRNA of S. mansoni and Biomphalaria alexandrina from Egypt were sequenced, as were 18S-encoding genes of the 13-16-R1 and Salvador strains of Biomphalaria glabrata. Based on a comparison of host and parasite sequences, a nested set of PCR primers was designed to allow specific amplification of portions of S. mansoni 18S rDNA. These primers allowed detection of as little as 10 fg of S. mansoni DNA diluted in 100 ng of snail DNA and did not allow amplification of snail 18S sequences. Using nested PCR, the presence of a single S. mansoni sporocyst within an adult snail could be detected at 1 day postexposure. In DNA samples extracted from each of 74 snails of the M-line strain of B. glabrata exposed to from 1 to 10 S. mansoni miracidia for intervals ranging from 1 to 44 days, use of the outside primer pair alone detected the parasite's presence in 51% of the snails, whereas the sequential use of outside and nested primer pairs detected parasites in 92% of the snails. This approach has utility in determining if snails in endemic areas bear prepatent or inactive infections and in assessing the degree of compatibility between local snail and schistosome populations. It will also facilitate studies of resistance of snails to infection.

55 citations

Book
08 Oct 2014
TL;DR: This study highlights the potential ecological implications of ZnONP release in aquatic environments and may serve to encourage regulatory agencies in Egypt to more carefully monitor and regulate the industrial use and disposal of ZNONPs.
Abstract: Freshwater snails are used as sensitive biomarkers of aquatic ecosystem pollution. The potential impacts of zinc oxide nanoparticles (ZnONPs) on aquatic ecosystems have attracted special attention due to their unique properties. The present investigation was designed to evaluate the possible mechanisms of ecotoxicological effects of ZnONPs on freshwater snail Biomphalaria alexandrina. ZnONPs showed molluscicidal activity against B. alexandrina snails, and the LC50 was 145 μg/ml. Two tested concentrations of ZnONPs were selected: The first concentration was equivalent to LC10 (7 μg/ml), and the second was equivalent to LC25 (35 μg/ml). Exposure to ZnONPs (7 and 35 μg/ml) for three consecutive weeks significantly induced malondialdehyde and nitric oxide with concomitant decreases in glutathione and glutathione-S-transferase levels in hemolymph and soft tissues of treated snails. Moreover, ZnONPs elicited a significant decrease in total protein and albumin contents coinciding with enhancement of total lipids and cholesterol levels as well as activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in hemolymph and soft tissues of treated snails. This study highlights the potential ecological implications of ZnONP release in aquatic environments and may serve to encourage regulatory agencies in Egypt to more carefully monitor and regulate the industrial use and disposal of ZnONPs.

47 citations

Journal Article
TL;DR: It was concluded that the application of LC25 of methanol extracts of E. splendens, A. stylosa and G. officinalis may be helpful in snail control as it interferes with the snails’ biology and physiology.
Abstract: The present work was carried out to evaluate, the molluscicidal activity of cold water, boiled water, methanol, ethanol, acetone and chloroform extracts of some plant species against Biomphalaria alexandrina snails. Preliminary screening tests on 10 plant species showed that the highest molluscicidal potency was recorded for Euphorbia splendens, Atriplex stylosa and Guayacum officinalis. Exposure of B. alexandrina snails to plant’s methanol extracts led to a significant reduction in their survival and growth rates. In addition, newly hatched snails were susceptible to plant’s methanol extracts than elder ones. LC25 of methanol extract from these plants caused a considerable reduction in the infectivity of Schistosoma mansoni miracidia to the snails. It caused a reduction in number of cercariae per snail during the patent period and in the period of cercarial shedding. The results, also, revealed that the glucose concentration in treated snails was increased in haemolymph, while soft tissue glycogen decreased. The activities of glycogen phosphorylase, succinate dehydrogenase (SDH), glucose-6-phosphatase and acetylcholinesterase (AchE) in homogenate of snail’s tissues were reduced (P < 0.001) in response to treatment with plants methanol extract, while glucose-6-phosphate dehydrogenase (G-6-PD) activity increased (P < 0.001). It was concluded that the application of LC25 of methanol extracts of E. splendens, A. stylosa and G. officinalis may be helpful in snail control as it interferes with the snails’ biology and physiology.

45 citations

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202110
202014
201914
201816
201711
201616