Biomphalaria alexandrina

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

Schistosomiasis in newly reclaimed areas in Egypt. 1-distribution and population seasonal fluctuation of intermediate host snails.

Abstract: Two newly reclaimed areas located west & east of Suez Canal, namely El Manayef area and El Morra area, were studied for patterns of distribution and population seasonal fluctuation of Biomphalaria alexandrina and Bulinus truncatus, the intermediate host snails of Schistosoma mansoni and S. haematobium, respectively. In this study Geographic Information System (GIS) techniques were utilized for producing maps and analyzing the results. Habitats of the two vector snail species were categorized into suitability levels depending on the frequency with which snails were collected over a 12 months period. Data obtained from the most suitable habitats were only used for studying the seasonal fluctuation of snail population. The results showed that both study areas were almost similar in major physico-chemical parameters. However, oxygen content in canals was higher than in drains and conductivity was higher in drains than in canals. As regards snail distribution and density, most snails of both considered species were clustering in much fewer numbers of sites, more pronouncedly in the case of Biomphalaria than Bulinus. Population density of snails was significantly higher in El-Manayef area than in El-Morra area and in canals than in drains. Both species exhibited 2 population peaks/year, the peaks of Biomphalaria were in March-April & August in both study areas, while for Bulinus these peaks occurred in March-May and August in El-Manayef area and in May and March, respectively, in El-Morra area.

Influence of Capparis spinosa and Acacia arabica on certain biochemical haemolymph parameters of Biomphalaria alexandrina.

Abstract: The work investigated the molluscicidal potency of dried Capparis spinosa and Acacia arabica leaves on selected biochemical parameters of Bionimphalaria alexandrina, in order to render them, physiologically, unsuitable for S. mansoni infection or at least disturb the life-cycle of the parasite within its respective snail host. The effect of the two plants on lactate dehydrogenase (LDH), 5'-nucleotidase, acid phosphatase (AP), aspartate and alanine aminotransferases (AST & ALT), alkaline phosphatase (ALP) and glucose content were studied. This work was extended to evaluate the effect of these two plants on protein profile as well as total protein (TP) content of snail's in haemolymph after 24 hours and one week of snails plants feeding. The study revealed that both plants induced marked alteration in all the measured parameters, where LC50 of C. spinosa after fed one week showed the most potent effect.

Update of fasciolosis-transmitting snails in Egypt (review and comment).

Abstract: Several snail species may contribute in transmission of fasciolosis in Egypt. These molluscs show a variable sensibility to natural infections with Fasciola species. Radix natalensis is considered to be the essential intermediate host for F. gigantica based on field and experimental studies. Cercarial production from R. natalensis experimentally infected with F. gigantica is affected by the species of definitive host from which the eggs are obtained, as well as the different laboratory conditions. Another lymnaeid, Galba truncatula, may play a role in transmitting this parasite in Egypt, as it was found naturally infected with F. gigantica. Latter snail species, originated from France, was susceptible to experimental infections with Egyptian miracidia of F. gigantica and it had a cercarial production close to that of local R. natalensis. Two other snails, Pseudosuccinea columella and Biomphalaria alexandrina, were naturally found harboring larvae of Fasciola sp. At the level of intermediate hosts of F. gigantica, the conditions are thus favorable in Egypt to transmit fasciolosis which could also be caused by another fasciolid, F. hepatica, as the existance of this fluke was confirmed in Egypt.

Laboratory assessment of the molluscicidal activity of Commiphora molmol (Myrrh) on Biomphalaria alexandrina, Bulinus truncatus and Lymnaea cailliaudi.

Abstract: The molluscicidal properties of the oil extract of Commiphora molmol (Myrrh) were tested against Egyptian snail species: Biomphalaria alexandrina, Bulinus truncatus and Limnaea cailliaudi. The impact of the extract on the egg cluches of B. alexandrina and L. cailliaudi was also evaluated. Snails and their eggs were exposed for 24 and 48 hr at 22-26 degrees C to various concentrations of the extract. The results showed different susceptibilities B. alexandrina showed higher LD50 and LD90 (155, 195 ppm) than B. truncatus (50, 95 ppm) and L. cailliaudi (50, 85 ppm) after 24 hr exposure. 100% mortality was obtained for the egg cluches of B. alexandrina and L. cailliaudi at concentrations of 100 ppm and 75 ppm respectively. Lower concentrations were needed to obtain the same results after 48 hr. The present laboratory studies demonstrated that Myrrh has a molluscicidal effect on the snail intermediate hosts, particularly on their eggs. Field studies are recommended.

Polymeric controlled release formulations of niclosamide for control of Biomphalaria alexandrina, the vector snail of schistosomiasis.

Abstract: Schistosomiasis is one of the most important public health problems in many developing countries. The present study was conducted to investigate the effect of the polymeric niclosamide formulations against Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni in Egypt. Three new polymeric formulations were prepared for the molluscicide niclosamide. The formulations were prepared either by the chemical modifications of poly(glycidyl methacrylate) or by physical entrapment of the niclosamide in calcium alginate beads. The release of the niclosamide from the polymeric formulations was investigated. The activity of the prepared formulations against Biomphalaria alexandrina was investigated. The results obtained revealed higher potency for polymerized niclosamide B3 than B1; the lowest potency was revealed for B2. After an exposure period of 24 hours, LC(50) values were 0.073, 0.098 and 1.09 ppm for B3, B1 and B2, respectively. In addition, the molluscicidal potency of the test polymeric niclosamide was age-dependent, where old snails were more tolerant to the test solutions than young and newly hatched snails. The results also indicated that the molluscicidal activity of B3 was extended for 21 days and 17 days for B1, compared with 5 days for free niclosamide. However, the molluscicidal potency of the polymerized niclosamide was increased after boiling for one hour, and was increased with increasing the pH of the medium to pH 9. In addition, their potency was increased with decreasing the water hardness concentrations (CaCO(3)).Molluscicidal activity of free niclosamide and its polymeric formulations vs. exposure time.