Biomphalaria alexandrina

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

Intermediate host (Biomphalaria alexandrina) antigens partly protect against subcutaneous infections with cercariae of Schistosoma mansoni but are ineffective in infections by percutaneous invasion

Abstract: Mice were immunized against hepatopancreas homogenate of Biomphalaria alexandrina, using Al(OH)3 as adjuvant, and challenged by subcutaneous (s.c.) injection of Schistosoma mansoni cercariae, percutaneous invasion of cercariae and intravenous (i.v.) injection of mechanically prepared schistosomula of different ages. Significantly reduced (about 50%) numbers of adult S. mansoni were found 42 days after challenge in immunized animals infected by s.c. injection of cercariae. Protective effects were detectable as early as 4 days after infection when the numbers of schistosomules in the lungs were reduced in immunized animals. However, immunized animals lacked protective immunity against S. mansoni when infected via the percutaneous route with cercariae or by i.v. injection of schistosomules of different ages. Experiments show that immunization of hosts against intermediate host antigens does not protect against S. mansoni infection via the natural route.

Toxicity of commiphora molmol (myrrh) water suspension to some non-target aquatic organisms and its molluscicidal and biological activities on bulinus truncatus and biomphalaria alexandrina (mollusca, gastropoda) -

Abstract: The molluscicidal activity of Commiphora molmol (myrrh) water suspension showed that Bulinus truncatus snails were found to be about 3 times more susceptible than Biomphalaria alexandrina snails. The 24-hour LC50 values recorded were 46.4 and 145.8 ppm, respectively. There was a significant negative correlation between LC values and exposure periods. The present study is yet the first attempt to investigate the toxicity of C. molmol aquous suspension (in vitro) against non-target aquatic organisms coexisting with vector snails in their habitat. The obtained results revealed that the plant water suspension was more toxic at the molluscicidal levels to the crustaceans Daphnia sp, Cypris sp, Cyclops sp. , Cardina nilotica and the fish Gambuzia affinis at a concentration of 50 ppm (in average) after 48 hr of exposure. Culex larvae were more tolerant to the plant suspension than other organisms. Chronic effects of sublethal concentrations of C. molmol water suspension on some biological parameters of B. truncatus snails showed a significant decrease in food consumption and egg production of snails. At the sublethal concentration of LC50, no hatching was observed after 17 days of exposure. After 24 hour of exposure to C. molmol water suspension 70% mortality of newly hatched snails (3-days old) was observed at 50 ppm. In addition, biochemical investigation showed significant differences as compared to the control regarding the total protein content, and the activity of transaminases (AST, ALT) and Lactate dehydrogenase (LD) except a mild decrease in glycogen concentration and alkaline phosphatase activity in digestive gland tissue of snails. Ultrastuctural investigation of exposed snails to C. molmol water suspension showed some alterations in the digestive gland of snails (i.e. marked vaculation, increased lysosomal activity, swollen mitochondria and consumption of stored lipid and glycogen). Based on the toxicity of C. molmol to the aquatic ecosystem at the examined sublethal levels, it is not recommended as a herbal molluscicide.