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At least 19 recordsLinked to original sources
PubMed1992

[Biology of Biomphalaria occidentalis Paraense, 1981 and Biomphalaria tenagophila (d'Orbigny, 1835), in laboratory conditions].

Specimens of Biomphalaria occidentialis and Biomphalaria tenagophila were reared in S. Paulo, Brazil under laboratory conditions, with a view to know their biological characteristics. Oviposition and eggs/oviposition ratio were recorded over twelve months so as to obtain information on the number of egg-masses per animal and the number of eggs per egg-mass, as also the number of hatched eggs per egg-mass for each period of 30 days, i.e., the hatching-rate per period. The incubation period was about the same for both species, but the oviposition and egg oviposition ratio were greater in B. tenagophila.

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PubMedDate not supplied

Differentiation of the sibling species Biomphalaria occidentalis and Biomphalaria tenagophila by the electrophoretic patterns of their hemoglobin.

A simple and rapid method for differentiating the sibling species Biomphalaria tenagophila and Biomphalaria occidentalis by agarose gel electrophoresis (AGE) is described. Snail hemolymph is used as the test sample and the red coloration of the hemoglobin fraction permits visualization of the migration patterns without resorting to specific stains. Moreover, hemolymph samples may be obtained without killing the snail, thus permitting its use for other studies or for breeding.

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PubMed1978

Immunodiffusion studies on Schistosoma mansoni and its host stage specific antigens. 2. Immunoelectrophoresis cross-reactions between hepato-pancreas of Biomphalaria glabrata and Biomphalaria alexandrina.

IMMUNOELECTROPHORESIS was used for studies on immunological cross-reactions between both Schistosoma mansoni (S. m.) intermediate host snails Biomphalaria glabrata and Biomphalaria alexandrina. The preparation of antigens and their corresponding antisera from hepato-pancreas of S. m. infected and non infected snails was described as the homologous reactions of both snails either infected or non infected were rather similar, close immunological relationship between B. glabrata and B. alexandrina could be deduced.

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PubMed1989

Identification of snails infected with schistosomes by ELISA employing monoclonal antibodies: Schistosoma mansoni in laboratory snails (Biomphalaria glabrata) and in field snails (Biomphalaria pfeifferi) from Kenya.

An enzyme-linked immunosorbent assay (ELISA) employing monoclonal antibodies was used for detecting Schistosoma mansoni antigens in hemolymph of laboratory snails (Biomphalaria glabrata) in Kenya. Infected laboratory snails shedding cercariae were differentially identified by ELISA from uninfected snails with 100% sensitivity and specificity. Prepatent infections were detected by ELISA from 2 weeks after exposure to miracidia. Thus, ELISA revealed infection 3 weeks before maximal patency was reached (5-6 weeks post-exposure). Infected field snails (B. pfeifferi) shedding cercariae were differentially identified by ELISA, with 100% sensitivity and specificity, from uninfected field snails and from snails naturally infected with other trematodes (echinostomes and strigeids). Prepatent infections with S. mansoni were readily identified by ELISA in field snails. A case is demonstrated where infection rate, as determined by shedding test alone, was 9.8%, whereas the combined figure of prepatent and patent infection rates was 22.9%

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PubMed1989

[Competitive behavior of Biomphalaria glabrata and Biomphalaria tenagophila--laboratory studies].

Observation about cohabitation among B. glabrata and B. tenagophila revealed a greater vulnerability of B. tenagophila population during the process of competition when its density was severely decreased in 12 trials, moderate in 2 trials. It was higher than B. glabrata in only one trial. Some snail water chemical parameters analysed such as pH, alkalinity, conductivity and oxygen dissolved, and the viability rate of batch of eggs didn't give subsidy to explain the competition mechanism. The newly-born survival, in the situation of cohabitation, was low for both species. This reveals the existence of intra and interspecific competitive interaction. The fertility rate reduction of B. tenagophila during the cohabitation was considered as a cause of its exclusion. One of the factors that seems to have influenced the fertility rate was a possible wrong crossing.

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PubMedDate not supplied

Immunoelectrophoretic study on common antigens of São Lourenço da Mata and Belo Horizonte strains of Schistosoma mansoni adult worms and Biomphalaria snails.

Immunoelectrophoretic studies on common antigens were carried out by using rabbits sera immunized against São Lourenço da Mata and Belo Horizonte strains of Schistosoma mansoni adult worms and antigens of Biomphalaria glabrata pigmented (Jaboatão--PE); B. glabrata albino (Belo Horizonte--MG) and B. straminea (São Lourenço da Mata, PE). Furthermore, the reverse approach was proceeded, namely, sera anti Biomphalaria snails produced in rabbits were tested against both strains of Schistosoma adult worm antigens. The analysis of the common antigens between the SLM strains of S. mansoni adult worm and B. glabrata pigmented showed 8 to 9 precipitin bands, 3 bands with B. glabrata albino and only 1 band with B. straminea crude extracts. On the other hand, the BH strain of S. mansoni adult worm antisera produced 6 to 7 bands with B. glabrata pigmented, 5 bands with B. glabrata albino and 1 band with B. straminea antigenic extract. Biomphalaria snails crude extracts were fractionated by Sephadex G-100 column and three fractions were collected from each snail strain. The fractions were tested with anti SLM and BH strains of S. mansoni adult worm sera by immunoelectrophoresis. The common antigens fractionated from Biomphalaria snails crude extracts and those found for both strains of S. mansoni adult worm mostly existed in the first fraction and they were estimated to have molecular weight over 158,000 daltons. In our laboratory, it was found a relationship between the antigenic similarities and experimental infection rates of S. mansoni towards Biomphalaria snails so that more bands were seen with increasing infection rates of S. mansoni.

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PubMed1992

Studies on common antigenicities between the Belo Horizonte strain, Brazil of Schistosoma mansoni eggs and Biomphalaria snails by immunoelectrophoresis.

Immunoelectrophoretic studies of common antigenicities were carried out by using rabbit sera immunized against the Belo Horizonte strain of Schistosoma mansoni eggs and crude antigens of Biomphalaria snails and vice versa. With regard to common antigenicities between S. mansoni eggs and Biomphalaria snails, S. mansoni eggs produced 4 to 5 bands with Biomphalaria glabrata pigmentado, 3 to 4 bands with B. glabrata albino and only 1 band with B. straminea. In our laboratory, the infection rate of S. mansoni miracidia to B. glabrata pigmentado was 64.3% and 55.0% for B. glabrata albino, but B. straminea was not found to be susceptible to S. mansoni miracidia. It was observe that more bands were seen between S. mansoni egg and suitable hosts. Biomphalaria snail crude antigens were fractionated by Sephadex G-100 column, and each fraction antigen was tested with anti-S. mansoni egg sera by immunoelectrophoresis. As results, three fractions were collected form each snail strains. The common antigenicities between fractionated antigens from Biomphalaria snails crude antigens and anti-S. mansoni egg sera mostly existed in the first fraction and they were estimated to have molecular weights over 45,000.

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PubMed1979

Studies of the relationship between Schistosoma and their intermediate hosts. III. The genus Biomphalaria and Schistosoma mansoni from Egypt, Kenya, Sudan, Uganda, West Indies (St. Lucia) and Zaire (two different strains: Katanga and Kinshasa).

The compatibility between strains of Schistosoma mansoni from Egypt, Kenya, Sudan, Uganda, the West Indies, and Zaire (two strains which came from Katanga and from Kinshasa), and various species and strains of Biomphalaria, i.e. Biomphalaria pfeifferi, B. alexandrina, B. glabrata and B. camerunensis was investigated. Data as mortality, rate of infection of the surviving snails, duration of infection, cercarial production per day per positive snail, etc., were observed. The main emphasis was placed on determining the total cercarial production per 100 exposed snails for each snail population. It was possible to infect all the tested populations of B pfeifferi with the various strains of S. mansoni, but the observation as e.g. TCP/100 exposed snails varied greatly according to the population of snail and the strain of S. mansoni. The results for the remaining species of Biomphalaria varied greatly, depending on the combination, e.g. B. alexandrina was only susceptible to the local S. mansoni from Egypt. The highest TCP/100 exposed snails was more than 1 million for the strains of S. mansoni from Egypt, Kenya and the West Indies in B. alexandrina, B. pfeifferi and B. glabrata, respectively. The next group, with a TCP/100 exposed snails on 7--800 000 consists of S. mansoni from Sudan, Uganda and Zaire (Katanga) all in B. pfeifferi. The last tested strain of S. mansoni, Zaire (Kinshasa) yielded a cercarial production on 500 000 per 100 exposed snails in B. pfeifferi and B. camerunensis. The shortest prepatent period, 19 days, was observed for S. mansoni from Kinshasa, Zaire, in B. camerunensis, and the longest prepatent period, 25 days, was found for strains from Egypt and from the West Indies in B. alexandrina and B. glabrata, respectively. In general, a very long duration of infection, lasting up to 200 days, was observed.

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PubMed1992

Predation of Biomphalaria and non-target molluscs by the crayfish Procambarus clarkii: implications for the biological control of schistosomiasis.

The North American crayfish Procambarus clarkii was examined under laboratory conditions for its ability to prey on Biomphalaria pfeifferi and B. glabrata, molluscan intermediate hosts of human schistosomiasis, and other, non-target gastropod species. Both male and female adult crayfish significantly reduced survival of neonate snails, even though alternative animal and plant foods were both available. In subsequent experiments, no differences in snail consumption were detected, for either adult or juvenile crayfish, in the presence or absence of a plant food alternative. Both adult and juvenile crayfish were able to consume small (2.5 mm) and large (17.5 mm) B. glabrata, suggesting that no size refuge from predation exists. Both adult and juvenile crayfish consumed Biomphalaria egg masses, although this consumption was significantly greater for juveniles. Procambarus clarkii adults were unable to consume substantial numbers of the relatively thick-shelled prosobranch snails Pila ovata and Lanistes carinatus. Crayfish did consume a third prosobranch, Melanoides tuberculata, and the pulmonate snail Physa acuta, but at a lower rate relative to consumption of Biomphalaria. Physa acuta, itself of North American origin, responded to the presence of crayfish by rapidly leaving the water and thereby avoided predation. Implications of these results for the biological control of schistosome-transmitting snails in East Africa are discussed.

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PubMedDate not supplied

[The characterization of Biomphalaria orbignyi Paraense, 1974, a mollusk of medico-epidemiological importance recently reported for Cuba].

The conchological, anatomical and radular characteristics of Biomphalaria orbignyi are described, as well as the morphometric ratio between maximal height and maximal diameter, in which the regression coefficient value is 0.9. The life tables of Biomphalaria orbignyi shows a life range (L phi = 10.37) much higher than in the rest of the species available in Cuba; the value of k = 0.17 is similar to that of Biomphalaria havanensis. It has 2 reproductive peaks at middle age. Differently from other species of the genus, it has lower mortality at early ages and the highest peak is seen when it reaches the adult stage, which means it is a strong species. The zymograms that have been obtained confirm this species is different from B. havanensis. Since there are no marked differences on an individual basis, its correct identification requires to take into consideration every biological and ecological evidence available.

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PubMed1987

Experimental infection of Physa heterostropha, Helisoma trivolvis, and Biomphalaria glabrata (Gastropoda) with Echinostoma revolutum (Trematoda) Cercariae.

Gross and histologic studies were done on laboratory-raised Physa heterostropha, Helisoma trivolvis, and Biomphalaria glabrata snails exposed individually to 100 cercariae of Echinostoma revolutum. Cercariae showed a predisposition for the kidneys of snails. They entered the nephridiopore, migrated up the tubular kidney, and encysted in the saccular kidney within 2 hr. Considerably more cysts were in the kidney of B. glabrata at 24 hr than in H. trivolvis or P. heterostropha kidneys. Encysted metacercariae were not infective to domestic chicks at 2 hr, but were infective by 4 hr. Biomphalaria glabrata exposed to about 1,000 cercariae/snail and necropsied either 10 or 16 wk postexposure contained 300-500 cysts/kidney; about one-half the cysts were viable and infective to chicks. Biomphalaria glabrata is an excellent second intermediate host for the laboratory propagation of E. revolutum.

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PubMed1991

The galactan-degrading enzymes in the snail Biomphalaria glabrata.

1. Embryonic snails incorporate from the perivitelline fluid in which they are embedded a polysaccharide, called galactan, which is composed entirely of D-, or D- and L-galactose. In this investigation the p-nitrophenyl-beta-D-galactoside degrading enzyme of Biomphalaria glabrata which was assumed to be involved in the degradation of the galactans was purified almost to homogeneity and its specificity was studied. 2. It has a mol. wt of 135,000 and is composed of two identical subunits. 3. It could be shown that p-nitrophenyl-beta-D-fucoside was hydrolysed eight times faster, but native galactan was neither decomposed nor was it inhibitory for the hydrolysis of p-nitrophenyl-glycosides. 4. Thus, it is most likely that this galactosidase is not involved in the galactan metabolism. 5. However, a membrane-bound enzyme complex was revealed which was able to metabolize the native galactan of Biomphalaria glabrata completely and which showed graded reactivity towards galactans of other species. 6. Since no intermediate degradation products were found it must be assumed that they were metabolized further in the mitochondria.

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PubMedDate not supplied

Linkage relationships of seven enzyme and two pigmentation loci in the snail Biomphalaria glabrata.

Crossing experiments with inbred stocks of the snail (Biomphalaria glabrata) demonstrated that variants at two loci determining pigmentation and seven enzyme-determining loci exhibited normal Mendelian segregation ratios in F2 progeny. Among 39 pairwise comparisons for joint segregation, there was evidence of genetic linkage between a locus controlling mantle pigmentation (S) and 6-phosphogluconate dehydrogenase (Pgd) and confirmation of a previously described linkage between esterase-2 (Est-2) and catalase (Cat). Recombination fractions were estimated to be 17 +/- 4 for S-Pgd and 33 +/- 5 for Est-2-Cat. The remaining five loci--Acon-1, Pgm-1, Lap-1, Lap-2, and Pgd--assorted independently. This brings to 17 the number of loci examined for segregation and assortment in this medically important species. As Biomphalaria has a chromosome number n = 18, markers should soon be available for most or all of the linkage groups.

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PubMed2025

The structural features and immunological role of biomphalysins in the snail Biomphalaria glabrata.

Biomphalysins are β-Pore Forming Toxins (β-PFT) identified in the planorbid Biomphalaria glabrata that belong to the aerolysin-like protein family. Despite potentially diverse biochemical activities, very few eukaryotic aerolysin-related proteins have been extensively studied. Most of the data refers to their discovery in genomes or to transcriptional activity. The involvement of biomphalysins in the immune response of Biomphalaria glabrata has been studied previously, especially regarding biomphalysin 1, which can bind and kill Schistosoma mansoni mother sporocysts. However, the repartition of biomphalysin 1 protein in B. glabrata has yet to be defined. The transcriptional behavior of the 22 other biomphalysin genes following immune challenge also remains uncharacterized. Therefore, herein, we investigate for the first time the tissular distribution of biomphalysin 1 (and 2) in B. glabrata by histological and cytological analyses through immunofluorescence approaches, notably unveiling unexpected tissue location that are involved in biomphalysin 1 synthesis. Structural predictions of the 23 members of the family have been updated using predictions based on aminoacyl spatial pair representation (AlphaFold2), highlighting unique features of the small lobe. In addition, mass spectrometry-based proteomic data more precisely predicted the regions of post-translational cleavage of biomphalysin 1. Transcriptional activity of the biomphalysin genes was explored, after which the plasmatic presence of the biomphalysin proteins was investigated in naive and S. mansoni-infected snails. The ability of native biomphalysin 1 (and 2) to bind several cell types was also investigated and correlated with the lytic ability of plasma toward the exposed cells, highlighting the central role occupied by biomphalysin 1 (and 2) in the humoral immunity of B. glabrata.

Biomphalaria↗
PubMedDate not supplied

[Resistance of Biomphalaria schrammi of Arcos, Minas Gerais, Brazil, to infection with 2 strains of Schistosoma mansoni].

The descendants of planorbid snail Biomphalaria schrammi Crosse, 1864, collected in the region of Arcos, State of Minas Gerais, Brazil, were exposed to miracidia of two strains of Schistosoma mansoni: the "LE" strain from Belo Horizonte, Minas Gerais State and the "SJ" strain from São José dos Campos, State of São Paulo. Of the 172 snails exposed to miracidia of both strains, none were infected. On the other hand, 100 Biomphalaria glabrata snails of the control group showed infection rates of 88% ("LE" strain) and 40% ("SJ" strain). The mortality rates of B. schrammi and B. glabrata were 40% and 10%, respectively.

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PubMedDate not supplied

[Resistance of Biomphalaria peregrina of Santa Rita do Sapucaí, Minas Gerais, Brazil to infection with 3 strains of Schistosoma mansoni].

The descendants of the planorbid snail Biomphalaria peregrina, collected in the region of Santa Rita do Sapucaí, Minas Gerais, Brazil, were exposed to miracidia of three strains of Schistosoma mansoni: "LE" strain from Belo Horizonte, State of Minas Gerais; "SJ", strain from São José dos Campos, State of São Paulo and "AL" strain from State of Alagoas. Of 300 snails exposed to miracidia of the three strains, none was infected. On the other hand, 300 Biomphalaria glabrata of the control groups showed infection rates of 61.1 to 95.3% with the three strains. The mortality rates of B. peregrina and B. glabrata were 20% and 28%, respectively.

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