Biomphalaria alexandrina

About: Biomphalaria alexandrina is a research topic. Over the lifetime, 413 publications have been published within this topic receiving 3781 citations.

Effect of topas (fungicide) on egg laying capacity and hermaphrodite gland of biomphalaria alexandrina snails

Abstract: Sublethal concentration (0.3 ppm) of Topas (fungicide) with active ingredient Penconazole (10%) was tested in combination with Schistosoma mansoni infection on the hermaphrodite gland of adult Biomphalaria alexandrina snails and its egg laying capacity. The obtained results indicated that, the mean number of eggs/snail/week of infected and treated-infected snails was significantly lower than that of control group. The reproductive rate was also greatly reduced by a percentage of 41.3%, 78.9% and 95.9% in treated, infected and treated-infected groups, respectively. Some of egg masses laid by treated snails showed morphological abnormalities with percentage of 15.7% during the experimental period. Topas treatment elicited various histopathological changes on hermaphrodite gland of infected and non-infected B. alexandrina snails. The gland acini became deformed, separated by loose connective tissue and degeneration of male and female gametogenic cells was also observed.

Study of the saponin content of atriplex stylosa viv. and its molluscicidal effect

Abstract: From the aerial parts of Atriplex stylosa Viv, four triterpenoidal saponins have been isolated. Their structures were established as 3-O-a-L-rhamnopyranosyl-(1®3)-b-D-glucuronopyranosyl hederagenin; 3-O-b-D-glucopyranosyl-(1®3)-b-D-glucuronopyranosyl hederagenin; 3-O-a-L-rhamnopyranosyl-(1®3)-b-D-glucuronopyranosyl hederagenin; 28-O-b-D-glucopyranoside and 3-O-a-L-rhamnopyranosyl-(1®)-[b-D-glucopyranosyl-(1®2)]-b-D-glucuronopyranosly oleanolec acid by spectroscopic methods (IR, 1H-NMR, 13C-NMR and FAB-MS) as well as on basis of acidic and alkaline hydrolysis. The three monodesmosidic saponins exhibited various molluscicidal activities against the two aquatic snails; Biomphalaria alexandrina and Lymnaea cailliaudi, the intermediate hosts of Schistosoma mansoni and Fasciola gigantica respectively in Egypt whereas the bidesmosidic saponin was inactive against the two snail species.

Effect of some algal species on the snail intermediate hosts of schistosomiasis in egypt ii. growth, infection and mortality rates

Abstract: This investigation was carried out using isolates of four algal species. Three cyanobacteria (Lyngbya perelegans, Oscillatoria accuminata and Phormidium valderianum) and one green alga (Spirogyra sp.) collected from Kafr Hakem (+ snails) and Sadek canals (- snails) in Giza Governorate, in addition to Nostoc muscorum obtained from Theodor Bilharz Research Institute (TBRI). Snails were fed separately on fresh algal species, on a combination of two species and on a mixture of the five algal species, during twenty weeks (5 months) and lettuce was used as control. Growth rate of snails (shell diameter and height), infection rate and mortality percentage were recorded weekly during the experimental time. Biomphalaria alexandrina and Bulinus truncatus snails fed on separate algal species, sublethal concentration of Phormidium valderianum (LC0) and lettuce demonstrated the highest growth rates, while the lowest rate was recorded in Spirogyra sp. Using mixed food of two algal species, the maximum rate of snail growth was observed in snails fed on the LC0 of Phormidium valderianum + Spirogyra sp, followed by those fed on Oscillatoria accuminata + Spirogyra sp. Snails fed on a mixture of all algal species exhibited the maximum growth rate. The highest rate of infection and lowest percentage of mortality were recorded in both snail species fed on lettuce (59% & 19% for B. alexandrina and 77.3% & 10.7% for B. truncatus, respectively). The minimum rate of infection and maximum percentage of mortality were observed in snails fed on Spirogyra sp. The nutritional value of the algal species and lettuce, using Carbon to Nitrogen ratio (C/N ratio), were analyzed and discussed on the light of the obtained results.

Effect of methyl gallate on immune response of Biomphalaria alexandrina (Ehrenberg, 1831) snails to infection with Schistosoma mansoni (Sambon, 1907)

Abstract: Schistosomiasis still affects a lot of people in many developing countries. Reducing the disease dissemination has been the target of various studies. As methyl gallate has antioxidant properties, it is assumed that it can be a good candidate for stimulating the immune response of snails. So, the aim of this work is to investigate the potential of using methyl gallate as an immunostimulant to Biomphalaria alexandrina snails in order to prevent the development of invading miracidia into infective cercariae. The infected snails were exposed to three concentrations of methyl gallate for two periods: 24 and 72 h. The results indicated that the most effective concentration was the lowest one: 125 mg/L of methyl gallate for 72 h, as it reduced both infection rate and mean number of shed cercariae. Also, it increased the total number of snails’ hemocytes in hemolymph, which were observed in head-foot region and digestive gland of treated snails surrounding degenerated sporocysts and cercariae. In addition, hydrogen peroxide showed its highest content in tissues of snails exposed to 125 mg/L of methyl gallate for 72 h. In conclusion, methyl gallate can be considered as one of the most promising immunostimulants of B. alexandrina snails against infection with Schistosoma mansoni.