Search results for "SNAIL"

A new baseline for fascioliasis in Venezuela: lymnaeid vectors ascertained by DNA sequencing and analysis of their relationships with human and anima…

2011

Abstract Background Human and animal fascioliasis poses serious public health problems in South America. In Venezuela, livestock infection represents an important veterinary problem whereas there appear to be few human cases reported, most of which are passively detected in health centres. However, results of recent surveys suggest that the situation may be underestimated in particular areas. To obtain a baseline for future fascioliasis assessment, studies were undertaken by means of rDNA ITS-2 and ITS-1 and mtDNA cox 1 sequencing to clarify the specific status of Venezuelan lymnaeids, their geographical distribution and fascioliasis transmission capacity, by comparison with other American …

2014

Extreme weather events such as summer heat waves become more frequent owing to global climate change and are predicted to alter disease dynamics. This is because high temperatures can reduce host immune function. Predicting the impact of climate change on host-parasite interactions is, however, difficult as temperature may also affect parasite infective stages and other host characteristics determining the outcome of interaction. Two experiments were conducted to investigate these phenomena in a Lymnaea stagnalis–Echinoparyphium aconiatum (Trematoda) interaction. In the first experiment, the effects of exposure of snails to experimental heat waves [maintenance at 25°C vs. 15°C (control)] wi…

Lymnaea schirazensis, an Overlooked Snail Distorting Fascioliasis Data: Genotype, Phenotype, Ecology, Worldwide Spread, Susceptibility, Applicability

2011

BackgroundLymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity.Methodology/principal findingsA ten-year study in Iran, Egypt, Spain, t…

Climate change effects on trematodiases, with emphasis on zoonotic fascioliasis and schistosomiasis.

2009

The capacity of climatic conditions to modulate the extent and intensity of parasitism is well known since long ago. Concerning helminths, among the numerous environmental modifications giving rise to changes in infections, climate variables appear as those showing a greater influence, so that climate change may be expected to have an important impact on the diseases they cause. However, the confirmation of the impact of climate change on helminthiases has been reached very recently. Only shortly before, helminthiases were still noted as infectious diseases scarcely affected by climate change, when compared to diseases caused by microorganisms in general (viruses, bacteriae, protozoans). Th…

Fascioliasis and other plant-borne trematode zoonoses

2005

Fascioliasis and other food-borne trematodiases are included in the list of important helminthiases with a great impact on human development. Six plant-borne trematode species have been found to affect humans: Fasciola hepatica, Fasciola gigantica and Fasciolopsis buski (Fasciolidae), Gastrodiscoides hominis (Gastrodiscidae), Watsonius watsoni and Fischoederius elongatus (Paramphistomidae). Whereas F. hepatica and F. gigantica are hepatic, the other four species are intestinal parasites. The fasciolids and the gastrodiscid cause important zoonoses distributed throughout many countries, while W. watsoni and F. elongatus have been only accidentally detected in humans. Present climate and glob…

A new metallothionein gene from the giant keyhole limpet Megathura crenulata.

2003

Abstract Metallothioneins (MTs) are small soluble proteins ubiquitously expressed in animals and plants. Different isoforms are present in deuterostomes and protostomes. They do not differ greatly in primary structure, but are clearly distinguishable. Here, I present the gene and the complete cDNA of a novel MT from the mollusk Megathura crenulata . This protein is closely related to the Cu-inducible MTs of the vineyard snail Helix pomatia , but has also some minor sequence features typical of Cd-inducible isoforms of H . pomatia and other molluscs. Overall, the deduced primary structure is similar to the known molluscan MTs, but in addition possesses an insertion of 5 amino acids not found…

Land Snail Fauna of “Porţile de Fier” (“Iron Gates”) Nature Park (Banat, Romania)

2014

Abstract The paper presents an analysis of terrestrial mollusc fauna of the “Iron Gates” Nature Park. Various types of habitats (e.g. forests, rocks, riparian areas) and substrates (e.g. limestone, conglomerate, crystalline schist) were analyzed. A total of 45 species of terrestrial gastropods were identified in 17 sampling points, four of which are mentioned for the first time in the area. Six other species cited in the literature were not found. Limestone substrate allows the development of large populations of terrestrial gastropods, but the specific diversity is larger when it is associated with a forest habitat. The current legal and illegal exploitation of limestone threatens the moll…

Land Snails as a Valuable Source of Fatty Acids: A Multivariate Statistical Approach

2019

The fatty acid (FA) profile of wild Theba pisana, Cornu aspersum, and Eobania vermiculata land snail samples, collected in Sicily (Southern Italy), before and after heat treatment at +100 °C were examined by gas chromatography with a flame ionization detector (GC-FID). The results show a higher content of polyunsaturated fatty acids (PUFAs) in all of the examined raw snails samples, representing up to 48.10% of the total fatty acids contents, followed by monounsaturated fatty acids (MUFAs). The thermal processing of the snail samples examined determined an overall reduction of PUFA levels (8.13%, 7.75%, and 4.62% for T. pisana, C. aspersum and E. vermiculata samples, respectively) and a spe…

Metallothionein in the freshwater gastropod Melanopsis dufouri chronically exposed to cadmium: A methodological approach

2010

Previous studies have demonstrated that the use of differential pulse polarography (DPP) for metallothionein (MT) determination in marine gastropod tissues, particularly the digestive gland, requires taking into account the presence of heat-stable high molecular weight compounds that exhibit polarographic signal. In the present paper, similar compounds were identified in tissues from the freshwater snail Melanopsis dufouri which also interfere with MT determination by DPP and, due to their silver binding capacity, also interfere in the silver assay for MT quantification. Ultrafiltration seems to be effective in removing these high molecular weight compounds from heat-denatured homogenate su…

THE EFFECTS OF MATING SYSTEM AND GENETIC VARIABILITY ON SUSCEPTIBILITY TO TREMATODE PARASITES IN A FRESHWATER SNAIL, LYMNAEA STAGNALIS

2004

The amount and distribution of genetic variability in host populations can have significant effects on the outcome of host-parasite interactions. We studied the effect of mating system and genetic variability on susceptibility of Lymnaea stagnalis snails to trematode parasites. Mating system of snails from eight populations differing in the amount of genetic variability was manipulated, and self- and cross-fertilized offspring were exposed to naturally occurring trematode parasites in a controlled lake experiment. Susceptibility of snails varied between populations, but mating-system treatment did not have a significant effect. Heterozygosity of snails was negatively correlated with the pro…