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D. Rondelaud - One of the best experts on this subject based on the ideXlab platform.
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omphiscola glabra gastropoda lymnaeidae changes occurring in natural infections with fasciola hepatica and paramphistomum daubneyi when this snail species is introduced into new areas
Annales De Limnologie-international Journal of Limnology, 2010Co-Authors: G Dreyfuss, P Vignoles, D. RondelaudAbstract:Cross-transplantations of Omphiscola glabra between two French departments (Haute-Vienne and Indre) were carried out to study snail settlement in these new sites during six years and to determine if this snail species was well adapted to its local parasites (Fasciola hepatica and Paramphistomum daubneyi ). Local Snails placed in new sites for each department were used as controls. In Indre furrows, the number of adults per population and the area of each habitat peaked on the third year post-introduction. Similar findings were also noted in the Haute-Vienne furrows occupied by local Snails but peaks were only observed on the fourth year. In contrast, in Haute-Vienne sites populated by introduced Snails, there was a progressive decrease in snail abundance and habitat area from the second year. The local O. glabra transplanted in Haute-Vienne kept their same degree de susceptibility to F. hepatica and P. daubneyi , thus demonstrating a good adaptation of these Snails to their parasites. In other groups of transplanted Snails, the first natural infections were only noted from the second or third year post-introduction and their prevalence progressively increased over time. Local adaptation of these latter Snails to parasites would be more progressive in time and would stretch over several snail generations.
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cercarial production of fascioloides magna in the snail galba truncatula gastropoda lymnaeidae
Parasitology Research, 2006Co-Authors: P Vignoles, D. Rondelaud, Adam Novobilský, V Bellet, P Treuil, Břetislav Koudela, Gilles DreyfussAbstract:Single-miracidium infections of Fascioloides magna in two populations of Galba truncatula were carried out under laboratory conditions to count free rediae and cercariae in snail cadavers just after death. Cercaria-shedding Snails were in low numbers, and their shell height at day 60 p.e. was significantly greater than that of numerous infected Snails that died without cercarial shedding. In Snails that died between days 44 and 60 p.e. (at 20°C), the numbers of second-generation rediae significantly increased with increasing shell heights of infected Snails. First-generation rediae showed insignificant, quantitative variations, while scarce rediae of the third generation were only found in the highest Snails. Cercariae were only produced by the second redial generation. In both groups of Snails, free cercariae appeared from 6 mm of shell height, and their numbers increased in the upper classes up to 32.9 per snail. Metacercariae were only found from 9 mm of shell height and were in low numbers. The global cercarial production ranged from 163.5 to 210.0 in the highest classes of snail size from both groups and was limited, whereas the mean burdens of free rediae fluctuated from 39.5 to 43.9. The death of numerous infected Snails without cercarial shedding might be explained by the presence of a very high number of second-generation rediae simultaneously growing within the body of these Snails.
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paramphistomum daubneyi the development of redial generations in the snail lymnaea truncatula
Parasitology Research, 1996Co-Authors: M Abrous, D. RondelaudAbstract:Rediae of Paramphistomum daubneyi were counted and measured in Lymnaea truncatula to elucidate the variability in the numbers of free rediae and cercariae occurring between naturally infected Snails and experimental single-miracidium infections. Experiments were performed using one miracidium per snail and snail raising was carried out at 20°C. Two redial generations succeeded each other in the snail until day 49. A mean of 8–10 rediae differentiated in the sporocyst at days 7 and 14; the remaining germ balls and redial embryos decreased in number after day 21. First-generation rediae became free in the snail’s body starting at day 14 and their number increased to a mean of 7.5 at day 49, with a maximum of 10 rediae being detected in 1 snail. They produced second-generation rediae, which exited from the body starting at day 28, and then cercariae, which exited from day 42 onward. The count of second-generation rediae was 6–6.2/snail at day 49, with a maximum of 12 being detected in 1 snail; they produced only cercariae.
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the characteristics of redial generations in lymnaea truncatula exposed to fasciola hepatica miracidia after poisoning by sublethal doses of cupric chloride
Veterinary Research, 1995Co-Authors: D. RondelaudAbstract:Adult Lymnaea truncatula were placed in a sublethal dose of copper chloride (0.1 mg/l) for 1 h, and then in normal water before being exposed to a single Fasciola hepatica miracidium on the 2nd or 9th day of the experiment. Infection rates were higher in untreated Snails and in Snails infected 9 d after treatment (73.5 and 71.4%) then in Snails infected 2 d after copper contact (48.1%). Histological examination of surviving snail on the 30th day after miracidial exposure revealed that the total number of rediae was 25 and 31 per snail in snail groups infected 2 and 9 d respectively after copper contact, and 44 in untreated controls. There was a drop in the number of live, free rediae in infected Snails after treatment contact. This decrease was more marked in the first redial generation than in the first cohort of the second generation. These results reveal that the infection rate in Snails and the redial burden of F hepatica were reduced by the copper treatment of Snails before miracidial exposure but placement of survivors in water for 8 d after treatment limited the consequences of chemical toxicity.
Herve Acloque - One of the best experts on this subject based on the ideXlab platform.
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snail2 and zeb2 repress p cadherin to define embryonic territories in the chick embryo
Development, 2017Co-Authors: Herve Acloque, Oscar H Ocana, Diana Abad, Claudio D. Stern, Angela M NietoAbstract:Snail and Zeb transcription factors induce epithelial to mesenchymal transition (EMT) in embryonic and adult tissues by direct repression of E-Cadherin transcription. The repression of E-Cadherin transcription by the EMT inducers Snail1 and Zeb2 plays a fundamental role in defining embryonic territories in the mouse, as E-Cadherin needs to be downregulated in the primitive streak and in the epiblast concomitant with the formation of mesendodermal precursors and the neural plate, respectively. Here we show that in the chick embryo, E-Cadherin is weakly expressed in the epiblast at pre-primitive streak stages where it is substituted by P-Cadherin We also show that Snail2 and Zeb2 repress P-Cadherin transcription in the primitive streak and the neural plate, respectively. This indicates that E- and P-Cadherin expression patterns evolved differently between chick and mouse. As such, the Snail1/E-Cadherin axis described in the early mouse embryo corresponds to Snail2/P-Cadherin in the chick, but both Snail factors and Zeb2 fulfill a similar role in chick and mouse in directly repressing ectodermal Cadherins to promote the delamination of mesendodermal precursors at gastrulation and the proper specification of the neural ectoderm during neural induction.
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Snail2 and Zeb2 repress P-cadherin to define embryonic territories in the chick embryo
Development (Cambridge England), 2017Co-Authors: Herve Acloque, Oscar H Ocana, Diana Abad, Cd Stern, M.a. NietoAbstract:Snail and Zeb transcription factors induce epithelial-to-mesenchymal transition (EMT) in embryonic and adult tissues by direct repression of E-cadherin transcription. The repression of E-cadherin transcription by the EMT inducers Snail1 and Zeb2 plays a fundamental role in defining embryonic territories in the mouse, as E-cadherin needs to be downregulated in the primitive streak and in the epiblast, concomitant with the formation of mesendodermal precursors and the neural plate, respectively. Here, we show that in the chick embryo, E-cadherin is weakly expressed in the epiblast at pre-primitive streak stages where it is substituted for by P-cadherin. We also show that Snail2 and Zeb2 repress P-cadherin transcription in the primitive streak and the neural plate, respectively. This indicates that E- and P-cadherin expression patterns evolved differently between chick and mouse. As such, the Snail1/E-cadherin axis described in the early mouse embryo corresponds to Snail2/Pcadherin in the chick, but both Snail factors and Zeb2 fulfil a similar role in chick and mouse in directly repressing ectodermal cadherin genes to contribute to the delamination of mesendodermal precursors at gastrulation and the proper specification of the neural ectoderm during neural induction.
Jutamas Namsanor - One of the best experts on this subject based on the ideXlab platform.
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culture of fecal indicator bacteria from snail intestinal tubes as a tool for assessing the risk of opisthorchis viverrini infection in bithynia snail habitat
Parasites & Vectors, 2019Co-Authors: Courtney C Nawrocki, Nadda Kiatsopit, Jutamas Namsanor, Elizabeth J CarltonAbstract:BACKGROUND: Like many trematodes of human health significance, the carcinogenic liver fluke, Opisthorchis viverrini, is spread via fecal contamination of snail habitat. Methods for assessing snail exposure to fecal waste can improve our ability to identify snail infection hotspots and potential sources of snail infections. We evaluated the feasibility of culturing fecal indicator bacteria from Bithynia snail intestinal tubes as a method for assessing snail exposure to fecal waste. Snails and water samples were collected from a site with a historically high prevalence of O. viverrini infected Snails ("hotspot" site) and a site with historically no infected Snails ("non-hotspot" site) on two sampling days. Snails were tested for O. viverrini and a stratified random sample of Snails from each site was selected for intestinal tube removal and culture of gut contents for the fecal indicator bacteria, Escherichia coli. Water samples were tested for E. coli and nearby households were surveyed to assess sources of fecal contamination. RESULTS: At the hotspot site, 26 of 2833 Bithynia siamensis goniomphalos Snails were infected with O. viverrini compared to 0 of 1421 Snails at the non-hotspot site. A total of 186 Snails were dissected and cultured. Escherichia coli were detected in the guts of 20% of uninfected Snails, 4% of O. viverrini-positive Snails and 8% of Snails not examined for cercarial infection at the hotspot site. Only one of 75 Snails from the non-hotspot site was positive for E. coli. Accounting for sampling weights, Snails at the hotspot site were more likely to have gut E. coli than Snails from the non-hotspot site. The concentration of fecal indicator bacteria in surface water was higher at the hotspot vs non-hotspot site on only the first sampling day. CONCLUSIONS: Fecal indicator bacteria can be detected in the intestinal tubes of Bithynia Snails. The presence of fecal indicator bacteria in Bithynia snail guts may indicate risk of O. viverrini infection in snail populations. This method has the potential to aid in identifying locations and time windows of peak snail infection risk and may be applicable to other trematodes of human-health significance.
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an ecological study of bithynia Snails the first intermediate host of opisthorchis viverrini in northeast thailand
Acta Tropica, 2015Co-Authors: Yichen Wang, Richard Cheng Yong Ho, Chenchieh Feng, Jutamas NamsanorAbstract:Abstract Infection with the food-borne trematodiasis, liver fluke Opisthorchis viverrini , is a major public health concern in Southeast Asia. While epidemiology and parasitic incidence in humans are well studied, ecological information on the O. viverrini intermediate hosts remains limited. This study aimed to investigate the factors affecting the distribution and abundance of the first intermediate host, Bithynia siamensis goniomphalos Snails. Water quality and Snails were sampled in 31 sites in Muang District, Khon Kaen Province, Thailand from June 2012 to January 2013 to characterize the B.s. goniomphalos snail habitats. Species relative abundance and Shannon's diversity and evenness indices were employed to describe snail compositions and diversities across different habitat types. Statistical analyses were conducted to examine the extent to which the water quality variables and species interactions account for the relative abundance of B.s. goniomphalos Snails. The results showed that the freshwater habitats of ponds, streams and rice paddies possessed significantly different abiotic water qualities, with water temperature and pH showing distinct statistical differences ( P B.s. goniomphalos snail abundance at rice paddy habitats. The differences in snail abundance might be due to the distinct sets of abiotic water qualities associated with each habitat types. The relative abundance of B.s. goniomphalos Snails was found to be negatively correlated with that of Filopaludina martensi martensi Snails ( r = −0.46, P B.s. goniomphalos snail population. Field work observations revealed that rice planting seasons and irrigation could regulate snail population dynamics at rice paddy habitats. This study provides new ecological insights into the factors affecting Bithynia snail distribution and abundance. It bridges the knowledge gap in O. viverrini disease ecology and highlights the potential effect of anthropogenic irrigation practices on B.s. goniomphalos snail ecology.
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an ecological study of bithynia Snails the first intermediate host of opisthorchis viverrini in northeast thailand
Acta Tropica, 2015Co-Authors: Yichen Wang, Chenchieh Feng, Jutamas Namsanor, Paiboon SithithawornAbstract:Infection with the food-borne trematodiasis, liver fluke Opisthorchis viverrini, is a major public health concern in Southeast Asia. While epidemiology and parasitic incidence in humans are well studied, ecological information on the O. viverrini intermediate hosts remains limited. This study aimed to investigate the factors affecting the distribution and abundance of the first intermediate host, Bithynia siamensis goniomphalos Snails. Water quality and Snails were sampled in 31 sites in Muang District, Khon Kaen Province, Thailand from June 2012 to January 2013 to characterize the B.s. goniomphalos snail habitats. Species relative abundance and Shannon's diversity and evenness indices were employed to describe snail compositions and diversities across different habitat types. Statistical analyses were conducted to examine the extent to which the water quality variables and species interactions account for the relative abundance of B.s. goniomphalos Snails. The results showed that the freshwater habitats of ponds, streams and rice paddies possessed significantly different abiotic water qualities, with water temperature and pH showing distinct statistical differences (P<0.05). Different habitats had different snail diversity and species evenness, with high B.s. goniomphalos snail abundance at rice paddy habitats. The differences in snail abundance might be due to the distinct sets of abiotic water qualities associated with each habitat types. The relative abundance of B.s. goniomphalos Snails was found to be negatively correlated with that of Filopaludina martensi martensi Snails (r=-0.46, P<0.05), underscoring the possible influence of species interaction on B.s. goniomphalos snail population. Field work observations revealed that rice planting seasons and irrigation could regulate snail population dynamics at rice paddy habitats. This study provides new ecological insights into the factors affecting Bithynia snail distribution and abundance. It bridges the knowledge gap in O. viverrini disease ecology and highlights the potential effect of anthropogenic irrigation practices on B.s. goniomphalos snail ecology.
Smarn Tesana - One of the best experts on this subject based on the ideXlab platform.
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effects of aestivation on survival of bithynia siamensis goniomphalos Snails and the infection of opisthorchis viverrini in the irrigation area of wet and dry season rice paddy
Acta Tropica, 2019Co-Authors: Monticha Chaiyasaeng, Apiporn Suwannatrai, Phornpitcha Pechdee, Chanisala Sereewong, Thewarach Laha, Smarn TesanaAbstract:Abstract The snail Bithynia siamensis goniomphalos acts as the first intermediate host of the human liver fluke, Opisthorchis viverrini, a major cause of cholangiocarcinoma in Northeast Thailand. In this study, we investigated host-parasite interactions in wet- and dry-season rice paddy plantation. The Snails that aestivated through 4-month-dried period after rice harvest had average mortality rate of 36.45% and monthly increasing from 17.76% to 54.57%. Surprisingly, at depths greater than 5 cm experienced a higher mortality rate than upper level. Average mortality rate at the depth more than 5 cm, was 42.97%. In the initial month of aestivation, mortality rate of 0–5 and 5–10 cm depth was 9.13% and 26.39% then increase to 57.58% and 51.97%, respectively in the last 4th month. The average prevalence O. viverrini infection in Snails during the study period was 0.44%. The highest prevalence of O. viverrini infection was found in the cool dry and wet season. The odds of O. viverrini infection in female Snails and large Snails were higher relative to male Snails and medium-sized Snails. The physicochemical factors involved in increased prevalence of O. viverrini infection in snail hosts were mean daily air temperature and average monthly rainfall. Short aestivation period made lower mortality in irrigation area than the previous report of non-irrigation area, that is, the aestivation is one of snail population control.
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differential protein expression in the hemolymph of bithynia siamensis goniomphalos infected with opisthorchis viverrini
PLOS Neglected Tropical Diseases, 2016Co-Authors: Kulwadee Suwannatrai, Apiporn Suwannatrai, Pairat Tabsripair, Jariya Umka Welbat, Sirikachorn Tangkawattana, Cinzia Cantacessi, Jason Mulvenna, Smarn Tesana, Alex Loukas, Javier SotilloAbstract:Bithynia siamensis goniomphalos is a freshwater snail that serves as the first intermediate host of the human liver fluke Opisthorchis viverrini. This parasite is a major public health problem in different countries throughout the Greater Mekong sub-region (Thailand, southern Vietnam, Lao PDR and Cambodia). Chronic O. viverrini infection also results in a gradual increase of fibrotic tissues in the biliary tract that are associated with hepatobiliary diseases and contribute to cholangiocarcinoma (a fatal type of bile duct cancer). Infectivity of the parasite in the snail host is strongly correlated with destruction of helminths by the snail’s innate immune system, composed of cellular (hemocyte) and humoral (plasma) defense factors. To better understand this important host-parasite interface we applied sequential window acquisition of all theoretical spectra mass spectrometry (SWATH-MS) to identify and quantify the proteins from the hemolymph of B. siamensis goniomphalos experimentally infected with O. viverrini and compare them to non-infected Snails (control group). A total of 362 and 242 proteins were identified in the hemocytes and plasma, respectively. Of these, 145 and 117 proteins exhibited significant differences in expression upon fluke infection in hemocytes and plasma, respectively. Among the proteins with significantly different expression patterns, we found proteins related to immune response (up-regulated in both hemocyte and plasma of infected Snails) and proteins belonging to the structural and motor group (mostly down-regulated in hemocytes but up-regulated in plasma of infected Snails). The proteins identified and quantified in this work will provide important information for the understanding of the factors involved in snail defense against O. viverrini and might facilitate the development of new strategies to control O. viverrini infection in endemic areas.
Christopher J E Haggerty - One of the best experts on this subject based on the ideXlab platform.
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aquatic macrophytes and macroinvertebrate predators affect densities of snail hosts and local production of schistosome cercariae that cause human schistosomiasis
PLOS Neglected Tropical Diseases, 2020Co-Authors: Christopher J E Haggerty, Sidy Bakhoum, David J Civitello, Giulio A De Leo, Nicolas Jouanard, Raphael A Ndione, Justin V Remais, Gilles Riveau, Simon SenghorAbstract:Author(s): Haggerty, Christopher JE; Bakhoum, Sidy; Civitello, David J; De Leo, Giulio A; Jouanard, Nicolas; Ndione, Raphael A; Remais, Justin V; Riveau, Gilles; Senghor, Simon; Sokolow, Susanne H; Sow, Souleymane; Wolfe, Caitlin; Wood, Chelsea L; Jones, Isabel; Chamberlin, Andrew J; Rohr, Jason R | Abstract: BACKGROUND:Schistosomiasis is responsible for the second highest burden of disease among neglected tropical diseases globally, with over 90 percent of cases occurring in African regions where drugs to treat the disease are only sporadically available. Additionally, human re-infection after treatment can be a problem where there are high numbers of infected Snails in the environment. Recent experiments indicate that aquatic factors, including plants, nutrients, or predators, can influence snail abundance and parasite production within infected Snails, both components of human risk. This study investigated how snail host abundance and release of cercariae (the free swimming stage infective to humans) varies at water access sites in an endemic region in Senegal, a setting where human schistosomiasis prevalence is among the highest globally. METHODS/PRINCIPAL FINDINGS:We collected snail intermediate hosts at 15 random points stratified by three habitat types at 36 water access sites, and counted cercarial production by each snail after transfer to the laboratory on the same day. We found that aquatic vegetation was positively associated with per-capita cercarial release by Snails, probably because macrophytes harbor periphyton resources that Snails feed upon, and well-fed Snails tend to produce more parasites. In contrast, the abundance of aquatic macroinvertebrate snail predators was negatively associated with per-capita cercarial release by Snails, probably because of several potential sublethal effects on Snails or snail infection, despite a positive association between snail predators and total snail numbers at a site, possibly due to shared habitat usage or prey tracking by the predators. Thus, complex bottom-up and top-down ecological effects in this region plausibly influence the snail shedding rate and thus, total local density of schistosome cercariae. CONCLUSIONS/SIGNIFICANCE:Our study suggests that aquatic macrophytes and snail predators can influence per-capita cercarial production and total abundance of Snails. Thus, snail control efforts might benefit by targeting specific snail habitats where parasite production is greatest. In conclusion, a better understanding of top-down and bottom-up ecological factors that regulate densities of cercarial release by Snails, rather than solely snail densities or snail infection prevalence, might facilitate improved schistosomiasis control.
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Aquatic macrophytes and macroinvertebrate predators affect densities of snail hosts and local production of schistosome cercariae that cause human schistosomiasis.
eScholarship University of California, 2020Co-Authors: Christopher J E Haggerty, Bakhoum Sidy, Civitello, David J, De Leo, Giulio A, Jouanard Nicolas, Ndione, Raphael A, Remais Justin, Riveau Gilles, Senghor Simon, Sokolow, Susanne HAbstract:BACKGROUND:Schistosomiasis is responsible for the second highest burden of disease among neglected tropical diseases globally, with over 90 percent of cases occurring in African regions where drugs to treat the disease are only sporadically available. Additionally, human re-infection after treatment can be a problem where there are high numbers of infected Snails in the environment. Recent experiments indicate that aquatic factors, including plants, nutrients, or predators, can influence snail abundance and parasite production within infected Snails, both components of human risk. This study investigated how snail host abundance and release of cercariae (the free swimming stage infective to humans) varies at water access sites in an endemic region in Senegal, a setting where human schistosomiasis prevalence is among the highest globally. METHODS/PRINCIPAL FINDINGS:We collected snail intermediate hosts at 15 random points stratified by three habitat types at 36 water access sites, and counted cercarial production by each snail after transfer to the laboratory on the same day. We found that aquatic vegetation was positively associated with per-capita cercarial release by Snails, probably because macrophytes harbor periphyton resources that Snails feed upon, and well-fed Snails tend to produce more parasites. In contrast, the abundance of aquatic macroinvertebrate snail predators was negatively associated with per-capita cercarial release by Snails, probably because of several potential sublethal effects on Snails or snail infection, despite a positive association between snail predators and total snail numbers at a site, possibly due to shared habitat usage or prey tracking by the predators. Thus, complex bottom-up and top-down ecological effects in this region plausibly influence the snail shedding rate and thus, total local density of schistosome cercariae. CONCLUSIONS/SIGNIFICANCE:Our study suggests that aquatic macrophytes and snail predators can influence per-capita cercarial production and total abundance of Snails. Thus, snail control efforts might benefit by targeting specific snail habitats where parasite production is greatest. In conclusion, a better understanding of top-down and bottom-up ecological factors that regulate densities of cercarial release by Snails, rather than solely snail densities or snail infection prevalence, might facilitate improved schistosomiasis control
