Blood fluke and snail relationship counseling

Hyperdiverse Gene Cluster in Snail Host Conveys Resistance to Human Schistosome Parasites

Freshwater snails are the intermediate hosts of schistosomes. . of schistosomiasis is a confluence of the schistosome relationship with its. Elucidating the genetic basis of snail-schistosome interaction is a key to this strategy. . bcorrelation coefficient (r) with grc1 among 94 snails We are grateful to Christopher Bayne for support and advice during this project. The relationship between genetic variability and the susceptibility of as well as reference control Biomphalaria alexandrina snails from the Schistosome.

Schistosomiasis - Wikipedia

These bands were found in all snail groups and were considered to be characteristic bands for B. The number of amplified and polymorphic bands generated by each primer is shown in Table IV. The highest total number of bands 37 bands was obtained using primer OPA, while the lowest number 16 bands was obtained with the OPA-9 primer. Regarding the total number of bands amplified using all primers in each snail group, Ismailia snails showed the highest number of bands 24while the lowest number 16 bands was recorded for the SBSC and the Kafr El-Sheikh groups.

The specific detected fragments obtained from each snail group showed that primer OPA-1 amplified the highest number of specific fragments 26 fragmentsproducing six fragments with molecular weights ranging from bp in SBSC snails, another six fragments with molecular weights of bp for Giza snails and four bands for the Fayoum bp and Ismailia bp groups.

Three fragments with different molecular weights were recorded for Kafr El-Sheikh and Damietta snails. The OPA-9 primer amplified only five specific fragments, one of bp for the SBSC snail group, two for the Giza group bp and bpone fragment of molecular weight bp for the Ismailia group and one bp for the Damietta snail group.

The number of amplified bands per primer varied from eight bands with primer OPA-9 to 29 bands with primer OPA-1with a mean of Genetic relationships among different B. The highest value 0. The dendrogram showed three major groups. The second major group was split into two subgroups, with the first including only the Fayoum group and the second containing two snail groups Ismailia and Kafr El-Sheikh. The third major group included only the Damietta snail group. Impact of geographic distances on infection rates and similarity coefficients between B.

A negative correlation was observed between the infection rates of the different snail groups with the distance between their corresponding governorates and the source of the parasite Fig.

The infection rates of the different snail groups and their similarity coefficients with B. There was no evidence of the presence of B. These findings have significant implications regarding the understanding of the relationship between genetic diversity and susceptibility to parasitism, both in the context of B.

Nasal schistoma or nasal granulama in cow

Species identification of Biomphalaria - B. Specifically, Kristensen et al. However, in the present study, species-specific PCR assays were performed to identify Biomphalaria snails collected from the field. According to the results of these assays, all of the Biomphalaria snails collected from the field were B.

This finding agrees with results reported by Lotfy et al. These results, in combination with the findings presented here, suggest that B. In the same context, Abou-El-Naga et al. Their morphological analyses included both external shell morphology and the internal anatomy of the renal ridge and their molecular analysis used a species-specific PCR technique.

The results of these authors demonstrated that there was an absence of B. Population-level susceptibility to S. Snail progenies usually reflect the same pattern of susceptibility as the parent snails El-Khayat et al. The present results show clear differences in the degree of susceptibility to infection with the S.

The infection rates of snails from these populations were These variations in susceptibility agree with the findings of Frandsenwho reported that B.

Infection Landscapes: Schistosomiasis

In the same context, Bakry reported that B. The higher infection rates exhibited by the SBSC This agrees with the theory of local adaptation of the parasite to its local snail host sympatric compatibility Maning et al.

In a few instances, however, this generalisation does not apply and less compatibility exists between a snail population and its local parasite strain CridlandMohamed This may be attributed to the geographic location of the Fayoum, which is considered to be an area isolated from the Nile Delta.

This is in agreement with Sapp and Lokerwho suggested that the geographic isolation of the parasite and snail strains is the cause of the inability of Schistosoma douthitti to develop in Lymnaea stagnalis.

Additionally, Coelho and Bezerra noted that some lineages or geographic isolates of the same species of Biomphalaria present great variation in their susceptibility to the parasite. For example, a geographic lineage of B. RAPD-PCR methods for determining population genetic diversity - The present study demonstrates that a short primer of bp nucleotides can be used to reproducibly amplify segments of DNA from different B.

The greatest total number of bands 37 bands was obtained using primer OPA, while the lowest number was obtained with the OPA-9 primer 16 bands.

Ismailia snails exhibited the greatest number of bands 24while the lowest number 16 bands was recorded for the SBSC and Kafr El-Sheikh snail groups. The identification of polymorphic bands was based on a comparison of banding patterns on the same gel for each of the six snail groups investigated Larson et al.


Employing an equivalent sequence of oligonucleotides, Vidigal et al. However, the results obtained here using primer OPA, which produced numerous polymorphic bands in the B. The greatest number of specific fragments obtained using all of the tested primers was recorded in snails of the Giza and Damietta groups 12 fragmentswhile the lowest 5 fragments was reported for the Kafr El-Sheikh snails.

This primer may be useful in differentiating between different B. The estimated similarity coefficients among B. The dendrogram constructed including all DNA fragments produced by the four primers among the six B. The second split into two subgroups: The third major group contained only snails obtained from Damietta.

Nevertheless, these data are not sufficient to indicate that the close populations in the dendrogram may have a common origin, whereas the most distant populations might be introduced from other locations.

Relationship between geographic distance and susceptibility - In the present study, the impact of geographic distances on the infection rates and similarity coefficients between different B.

Furthermore, the infection rates of snails from different governorates were found to be positively correlated with their similarity coefficients with reference to control B. This phylogeographical pattern may be partly related to the geographical distribution of these populations and allows these correlations between genetic variability and geographic distance to be established.

This finding confirms that not all Biomphalaria populations are equally susceptible to S. However, Cridland stated that although the distance from Nawa to Qualuob Egypt is short, snail colonies from Nawa exhibit a low-to-moderate susceptibility to S.

The variation observed in the infection rate, which ranged from Variation in the susceptibility of the snail hosts of schistosomes to infection with allopatric parasite strains is a well-documented phenomenon, which was first noted by Vogel and subsequently verified by numerous investigators. Michelson and DuBois suggested that this phenomenon cannot be restricted to distantly geographically separated snail strains.

Additionally, Wiehn et al. Moreover, Mulvey and Vrijenhoek concluded that these variations could have implications in experiments where genetic uniformity of the studied organisms is necessary. Moreover, Abdel-Hamid et al. In addition, Ittiprasert et al. Although Mendelian genetics governs adult resistance to infection, juvenile resistance and susceptibility are complex traits. Genetic variation between susceptible and non-susceptible snails to Schistosoma mansoni infection using random amplified polymorphic DNA analysis RAPDs.

Identification of a genetic marker associated with the resistance to Schistosoma mansoni infection using random amplified polymorphic DNA analysis. Mem Inst Oswaldo Cruz Biomphalaria species in Alexandria water channels. Biological studies on different forms of Biomphalaria snails Pulmonata: Genetic variation between Biomphalaria alexandrina and Biomphalaria glabrata snails and their Infection with Egyptian strain of Schistosoma mansoni.

J App Sci Res 5: Susceptibility of snail intermediate hosts of Schistosoma from northeastern Brazil to the infection with Schistosoma mansoni. Arbitrarily primed DNA fingerprinting for phylogenetic reconstruction in vertebrates: Mol Biol Evol Molecular epidemiology of Brazilian Biomphalaria: Behavioural responses of miracidia of Schistosoma mansoni and other trematodes to substances emitted by snails.

The influence of host-parasite dispersion upon the capacity of Schistosoma mansoni miracidia to infection Australorbis glabratus. Amer J Trop Med Hyg Prospects for estimating nucleotide divergence with RAPDs. Compatibility of Biomphalaria tenagophila with Schistosoma mansoni: Results of exposure of batches from highly susceptible and less susceptible strains of Biomphalaria alexandrina from Egypt to strains of Schistosoma mansoni from Cairo and Alexandria.

Bull Wld Hlth Org Evolutionary relationships and biogeography of Biomphalaria Gasteropoda: Planorbidae with implications regarding its role as host of the human blood fluke, Schistosoma mansoni. Study of the susceptibility of Biomphalaria alexandrina collected from five different localities in Egypt to infection with local strain of Schistosoma mansoni.

Studies on the relationship between Schistosoma and their intermediate hosts. Host-parasite interactions for virulence and resistance in a malaria model system. J Evol Biol The effects of host genotype and spatial distribution on trematode parasitism in a bivalve population. Identification of immediate response genes dominantly expressed in juvenile resistant and susceptible Biomphalaria glabrata snails upon exposure to Schistosoma mansoni. Mol Biochem Parasitol The identification of markers segregating with resistance to Schistosoma mansoni infection in the snail Biomphalaria glabrata.

Molecular studies of Biomphala-ria glabrata, an intermediate hosts of Schistosoma mansoni. Inter J Parasitol Molecular characterization of Biomphalaria species in Egypt.

J Moll Stud Parasite susceptibility phenotypes of F 1 Biomphalaria glabrata progeny derived from interbreeding Schistosoma mansoni resistant and -susceptible snails. Migration, virulence and the geographic mosaic of adaptation by parasites.

A molecular survey of Biomphalaria in Egypt: Specific identification of Egyptian Biomphalaria species and possible hybrids using the polymerase chain reaction based on nuclear and mitochondrial loci. Mol Cell Probes Geographic compatibility of the freshwater snail Bulinus globosus and schistosomes from the Zimbabwe highveld. Int J Parasitol Susceptibility of Bahian population of Biomphalaria glabrata to an allopatric strain of Schistosoma mansoni.

An epidemiological study of Schistosoma haematobium and S. Trop Geogr Med Genetic variation among laboratory strains of the planorbid snail Biomphalaria glabrata. Genetic differentiation between populations of Biomphalaria glabrata Mollusca: If the eggs do not get excreted, they can become engrained in the body tissues and cause a variety of problems such as immune reactions and organ damage.

Humans encounter larvae of the Schistosoma parasite when they enter contaminated water while bathing, playing, swimming, washing, fishing, or walking through the water. The diagnosis is improved through the use of the Kato techniquea semiquantitative stool examination technique. Other methods that can be used are enzyme-linked immunosorbent assaycircumoval precipitation test, and alkaline phosphatase immunoassay.

Stool examination should be performed when infection with S. Eggs can be present in the stool in infections with all Schistosoma species. Because eggs may be passed intermittently or in small numbers, their detection is enhanced by repeated examinations or concentration procedures, or both. Eggs can be found in the urine in infections with S. Quantification is possible by using filtration through a nucleopore filter membrane of a standard volume of urine followed by egg counts on the membrane.

Tissue biopsy rectal biopsy for all species and biopsy of the bladder for S. Test sensitivity and specificity vary widely among the many tests reported for the serologic diagnosis of schistosomiasis and are dependent on both the type of antigen preparations used crude, purified, adult worm, egg, cercarial and the test procedure.

Centers for Disease Control and Preventiona combination of tests with purified adult worm antigens is used for antibody detection. Immunoblots with adult worm microsomal antigens are species-specific, so a positive reaction indicates the infecting species. The presence of antibody is indicative only of schistosome infection at some time and cannot be correlated with clinical status, worm burden, egg production, or prognosis.

People and livestock are strictly prohibited from entering the water! The World Health Organization is promoting these efforts. In some cases, urbanization, pollution, and the consequent destruction of snail habitat have reduced exposure, with a subsequent decrease in new infections. The drug praziquantel is used for prevention in high-risk populations living in areas where the disease is common.