Biomphalaria alexandrina

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

The influence of temperature, darkness, and starvation on growth and survival of Helisoma duryi, Biomphalaria alexandrina and Bulinus truncatus.

Abstract: The influence of 10 degrees, 18 degrees, 26 degrees, 28 degrees and 33 degrees C, different periods of complete darkness and starvation on growth and survival of H. duryi, B. alexandrina and B. truncatus were studied. The optimum temperature for the growth and survival was about 26 degrees C. Survivorship and growth rates decreased proportionately according to starvation period. However, darkness had no significant effect on the growth of B. truncatus and H. duryi. Under the chosen experimental conditions H. duryi revealed higher tolerance limits and survival rates than B. alexandrina and B. truncatus. The potential of H. duryi as biological control agent of Schistosome vector snails is discussed.

Infected freshwater snails, biomphalaria alexandrina, the intermediate host of schistosoma mansoni

Abstract: The objective was to study the chromosomes of Biomphalaria alexandrina snails (class Gastropoda) in control and infected state which could be helpful in understanding how host-parasite relationships in feasible and effective control measures. The chromosomal changes were studied using the air-drying method. The results showed that B. alexandrina had a diploid chromosome number, 2n = 36. Also, the meiotic stages were detected as early- leptotene and late leptotene, zygotene, diplotene, metaphase I. The result also revealed the presence of a primitive sperm, with a conical head and a very long, uni-flagellate tail. A comparative meiotic chromosome analysis between the control and infected ones showed some significant differences, as pachytene and diplotene were more condensed.

Histopathological and Ultrastructural Studies on Biomphalaria alexandrina Snails Infected with Schistosoma mansoni miracidia and Treated with Plant Extracts

Abstract: Background: Biomphalaria alexandrina snails are the intermediate host of Schistosoma mansoni in Egypt. Aim of the work: this study aimed to evaluate the molluscicidal activity of the methanol extract of the plants Anagallis arvensis and Viburnum tinus against B. alexandrina (Normal and S. mansoni infected). Results: the present results proved high activity for both plant extracts (LC50 & LC90 which reached 45& 60 ppm and 38&59 ppm for A. arvensis and V. tinus, respectively). The effect of sub-lethal concentration, ½ LC5, of the two plant extracts (26 and 11 ppm, respectively) affected B. alexandrina survival rate to be in the following order, control > V. tinus treated > A. arvensis treated > infected > infected-A. arvensis treated > infected- V. tinus treated. On the other hand, exposure to those sub-lethal doses caused considerable reduction in the infection percentages. In addition, the histopathological effects of the examined sub-lethal concentrations on hepatopancreatic tubules of the treated snails showed cells vacuolation, presence of hyaline substances filled the lumens of the tubules and necrotic focal areas in case of A. arvnsis and vacuolar degeneration with the necrotic changes in case of V. tinus. While, alterations in the hermaphrodite glands of the treated snails included: degeneration and necrotic changes in the acini. The severity of lesions was progressed with infection as a result of invading of snail tissue by developmental stages of the S. mansoni cercariae. The ultrastructural micrographs were used to explain and confirm the recorded histopathological alterations in the hermaphrodite glands of the infected-treated snails. In comparison with the control and infected snail groups, infected-treated snails showed degeneration with severe deformation and destruction in their reproductive units, degeneration in developmental stages tissues of S. mansoni cercariae and accumulation of the toxic agents.Conclusion: the two examined plants, A. arvensis and V. tinus plant extracts showed high activity against B. alexandrina and provide a considerable scope in exploiting local indigenous resources for snail’s molluscicidal agents. The sub-letal concentrations, ½ LC5, of the two plant extracts caused a considerable reduction in survival rate and infection rate among S. mansoni infected snails. Histopathological changes in the digestive glands showed cells vacuolation, hyaline substance filled lumens of the tubules and necrotic focal areas in the digestive glands. Histopathological effects explained and confirmed by TEM images showed degeneration with severe deformation and destruction in the reproductive units.

Biochemical studies on the genetic material of fresh water snails, intermediate hosts of schistosomiasis--II. Effect of a chemical mutagen, cyclophosphamide, on the chemical nature of deoxyribonucleic acid.

Abstract: L'ADN a ete isole de limacons d'eau douce Biomphalaria alexandrina. Apres traitement par un mutagene chimique, l'endoxan, la determination de la composition des bases de l'ADN isole a ete faite par chromatographie sur papier

Evaluation of the Pesticide Emamectin and Methanol Extract of Wheat Bran against Biomphalaria Alexandrina Snails, Their Hemocytes and Their Infection with SchistosomaMansoni

Abstract: The present study was carried out to evaluate the molluscicidal activity of the pesticide Emamectin (5% aqueous solution) and the methanol extract from the wheat bran (MEWB) against B alexandrina and their infection with Schistosoma mansoni was studied. The LC90 and LC50 values for Emamectin were 50.4 and 22.3 ppm, respectively. Infection of snails with S. mansoni under the effect of the tested agents was evaluated via four experimental groups, each of 50 snails For three consecutive days, one group of snails was exposed to 9.08 ppm aqueous Emamectin solution, another group received 100 ppm methanol extract of wheat bran (MEWB), a third group was administered by a combination of 9.08 ppm Emamectin and 100ppm MEWB, The fourth group was control maintained under similar experimental conditions. After three days, all the experimental groups were infected with S. mansonimiracidia and observed till shedding of cercariae. The physiological and histological changes were assessed before and after the infection.The changes in hemocytes of infected snails after administration with LC25 of Emamectin or wheat bran was significantly (20% and 30%, respectively) suppressed compared to 75% for the control snails. However, the snails treated with joint of Emamectin and MEWB were the least infected snails (10%). On the other hand, the biochemical test results showed a remarkable reduction of GOT (p<0.01) GPT (p<0.05) and total protein (0.05) in the heamolyph extracted from the snails treated with an aqueous Emamectin solution. Yet, the levels of GOT were significantly increased in the groups administered with the MEWB alone (p<0.01) or in combination with the Emamectin (p<0.001). As for the total protein levels, there were slightly declining (p<0.05) in the group exposed to the aqueous Emamectin and to the contrary, theses levels were significantly increased (P<0.05) in the snails of the two other experimental groups when compared to the controls. Moreover, the haemocytes cells showed a differentiation which varied in number when detected under the microscope. Administration of the aqueous Emamectin solution resulted in a significant increase (p<0.05) of the amaebocytes and a considerable decrease (p<0.05) in the number of granulocytes and hyalinocytes compared to the control snails. On the contrary, a remarkable surge (P<0.05) of granulocytes and decrease of the amaebocytes was detected in the haemolyph of snails treated with MEWB.