Toll like receptors and their evolution in the lymnaeid freshwater snail species Radix auricularia and Lymnaea stagnalis, key intermediate hosts for zoonotic trematodes

2021 ◽  
pp. 104297
Author(s):  
Alexandra Juhász ◽  
Scott P. Lawton
Keyword(s):  
Lymnaea Stagnalis ◽  
Freshwater Snail ◽  
Snail Species ◽  
Toll Like Receptors ◽  
Intermediate Hosts ◽  
Radix Auricularia

Effects of land use on intermediate snail host fauna, abundance, distribution and cercariae infection rate in Omo-Gibe river basin, Ethiopia

2020 ◽  
Author(s):  
Ketema Deribew ◽  
Etana Jaleta ◽  
Belayhun Mandefro ◽  
Zeleke Mekonnen ◽  
Delenasaw Yewhalaw ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Fresh Water ◽  
River Basin ◽  
Anthropogenic Activities ◽  
Freshwater Snail ◽  
Snail Host ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Biomphalaria Pfeifferi

Abstract Background: Land use and land cover change significantly affects biodiversity, abundance and distribution of intermediate snail host fauna. In Omo-Gibe river basin the extent of land-use change is high due to anthropogenic activities leading to habitat change of freshwater snail intermediate hosts. Most intermediate snail hosts of human Schistosome parasites belong to two genera, Biomphalaria and Bulinus. In Addition, Lymnea spp. is another important host of Fasciola which causes fasciolasis in domestic animals and human. This study aims to assess the effects of land-use on the distribution and abundance of freshwater snail intermediate hosts and cercariae infection rates of fresh water intermediate snail hosts in Omo-Gibe River basin, Ethiopia.Methods: This study was conducted in Omo-Gibe river basin in 130 sampling sites which include rivers, lakes, dams, stream, wetlands and irrigation ditches. At each site data on land use, anthropogenic activities, freshwater snail abundance and species diversity, and water samples were collected. Snails were collected from each sampling sites using a scoop (20cm x 30cm) with a mesh size of 300µm. Snails were sorted by genus on Enamel pan using forceps and preserved in labeled vials containing 75% ethanol. Live snails collected from the same habitat were sorted carefully and put in clean plastic buckets half filled with water. Afterwards, snails were provided with fresh lettuce leaves and maintained in the laboratory. Snails were then identified morphologically to family, genus and to species level. Each snail was examined for cercaria shedding by placing in a petri dish containing water and exposed to the sun for 2 hours. Cercariae were morphologically identified by microscopy. ArcGIS software of version 10.3.1 was used to map snail distribution and data were analysed using SPSS version-20.Results: The results obtained in this study shows clearly that land use change affect the distribution and abundance of fresh water snails in Omo-Gibe river basin. Fresh water snails were more abundant in farmland and settlement areas. Of the total 2,559 freshwater snails collected from 130 surveyed sites in Omo-Gibe river basin, 1749 (68.34%) belongs to medically important snail species. Biomphalaria spp.914 (35.7%),, Lymnea spp.439 (17.1%),, Physa spp. 343(13.4%) and Bulinus spp 53 (2%)). Sphaeriidae group accounted for 810 (31.6%) of the collected specimens. Biomphalaria pfeifferi was the predominant species of the total snail sampled from lakes, wetlands, rivers and irrigation ditches. Biomphalaria pfeifferi was the most infected snail species by different cercariae. Bulinus globosus and L.natalensis were infected by more than one and same type of cercariae. However, none of B. sudanica and P. acuta specimens was infected by trematode.Conclusions: The results of this study revealed that land use change altered the abundance, distribution and diversity of medically important fresh water snails in the study area. In general medically important freshwater snails which include: Biomphalaria spp, Bulinus spp and Lymnaea spp were collected from lakes, rivers, wetlands, irrigation ditches.. The medically important snail species found infected by cercaria are L. natalensis, B. pfeifferi and B. globosus. Biomphalaria pfefferi was the predominant species and highly infected by cercariae. Higher infection rate was observed in snails collected in Farmland (16.59%) and Grassland (36.6%).

scholarly journals Do self-fertilization and genetic drift promote a very low genetic variability in the allotetraploid Bulinus truncatus (Gastropoda: Planorbidae) populations?

1993 ◽  
Vol 62 (2) ◽  
pp. 89-100 ◽  
Author(s):  
Flobert Njiokou ◽  
Christian Bellec ◽  
Patrick Berrebi ◽  
Bernard Delay ◽  
Philippe Jarne
Keyword(s):  
Genetic Drift ◽  
Freshwater Snail ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Bulinus Truncatus ◽  
Genetic Structure Of Populations ◽  
Self Fertilization ◽  
High Gene ◽  
Almost All

SummaryBulinus truncatus, one of the intermediate hosts of the genus Schistosoma is an hermaphrodite freshwater snail species occupying a variety of environments over almost all Africa. These environments are subjected to large variations in water availability. B. truncatus is allotetraploid and its populations exhibit various frequencies of aphallic individuals (unable to reproduce as male). Both traits probably favour a reproduction by self-fertilization. Here we investigate the genetic structure of populations of B. truncatus of Niger and Ivory Coast using protein electrophoresis to analyse the influence of the environment and of both the last traits. To obtain an estimate of the true heterozygosity in this allotetraploid species, we analyse independently the two diploid loci at each tetraploid locus. Our study indicates (i) an extremely low intrapopulation polymorphism with most alleles fixed and the total absence of heterozygotes and (ii) low differentiation between populations. These results indicate high gene flow between populations. However, the existence of private alleles sometimes at high frequency, the low polymorphism and the lack of heterozygotes point to the role of both genetic drift and self-fertilization, the second amplifying the genetic consequences of the first.

scholarly journals The gastropod parasitic nematode Phasmarhabditis hermaphrodita does not affect non-target freshwater snails Lymnaea stagnalis, Bithynia tentaculata and Planorbarius corneus

Nematology ◽  
2015 ◽  
Vol 17 (6) ◽  
pp. 679-683 ◽  
Author(s):  
Gemma Whitaker ◽  
Robbie Rae
Keyword(s):  
Parasitic Nematode ◽  
Lymnaea Stagnalis ◽  
Biological Control Agent ◽  
Freshwater Snail ◽  
Control Agent ◽  
Snail Species ◽  
Planorbarius Corneus ◽  
Bithynia Tentaculata ◽  
In The Wild ◽  
Phasmarhabditis Hermaphrodita

Phasmarhabditis hermaphrodita is a lethal parasite of several slug and snail species that has been formulated into a biological control agent. However, the complete host range of this nematode is poorly understood, in particular its potential to affect non-target aquatic snail species. Here we exposed three species of juvenile and adult freshwater snail (Lymnaea stagnalis, Planorbarius corneus and Bithynia tentaculata) to 30 and 150 P. hermaphrodita cm−2 and assessed survival, as well as differences in weight for 66 days. We show that P. hermaphrodita has no effect on the survival of L. stagnalis, P. corneus and B. tentaculata after 66 days of exposure. In summary, we found little evidence of P. hermaphrodita causing mortality to three freshwater snail species at two different life stages and believe that P. hermaphrodita would have little effect on non-target snail species in the wild.

scholarly journals Annotated and Updated Checklist of Land and Freshwater Molluscs from Asturias (Northern Spain) with Emphasis on Parasite Transmitters and Exotic Species

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 415
Author(s):  
Omar Sánchez ◽  
Jairo Robla ◽  
Andrés Arias
Keyword(s):  
Exotic Species ◽  
Animal Health ◽  
Freshwater Snail ◽  
Parasitic Infections ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Northern Spain ◽  
Current Increase ◽  
Freshwater Molluscs ◽  
Local Diversity

Land and freshwater molluscs are the most abundant non-arthropod invertebrates from inland habitats worldwide, playing important ecological roles and some being important pests in agriculture. However, despite their ecological, and even economic and sanitary importance, their local diversity in many European regions is not perfectly understood, with a particularly notableknowledge gap in the northern Iberian malacofauna. This work aims at providing a revised checklist of continental gastropods and bivalves from the Asturias (northern Spain), based on the examination of newly collected and deposited material and on the critical analysis of published and gray literature. A total of 165 molluscan species are recognized. Ten species constitute new records from Asturias and seven from northern Iberian Peninsula. Seventeen species are introduced or invasive, evidencing the current increase of the bioinvasion rate in continental molluscs. Furthermore, all these exotic species are parasite transmitters or trematode intermediate hosts, and thus represent a potential bio-sanitary risk for human and other animal health. The provided data strongly suggest that the increase of invasive freshwater snail species can lead to an increase in parasitic infections, and this is a crucial point that transcends the merely scientific to the political-social sphere.

scholarly journals Descriptions of strigea cercariae from the Gauteng and North West Provinces, South Africa

2012 ◽  
Vol 79 (1) ◽  
Author(s):  
Esmey B.E. Moema ◽  
Pieter H. King ◽  
Chantelle Baker
Keyword(s):  
Freshwater Snail ◽  
Freshwater Snails ◽  
Parasitic Diseases ◽  
Snail Species ◽  
Intermediate Hosts ◽  
North West ◽  
The North ◽  
Different Types ◽  
Microscopy Techniques ◽  
Lymnaea Natalensis

Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis, amphistomosis and fasciolosis. Two freshwater snail species, Lymnaea natalensis, Krauss 1848 and Bulinus tropicus, Krauss 1848 were sampled from five localities in Gauteng and one locality in the North West Province from 2007 to 2010. These snails were collected in order to study their cercarial sheddings. They were found to be infected with three different types of strigea cercariae, of which the morphology was studied using standard light and scanning electron microscopy techniques.

scholarly journals Susceptibility of 7 freshwater gastropod species in Zimbabwe to infection with Gastrodiscus aegyptiacus (Cobbold, 1876) Looss, 1896 : short communication

2004 ◽  
Vol 75 (4) ◽  
Author(s):  
S. Mukaratirwa ◽  
I.F. Munjere ◽  
M. Takawira ◽  
G. Chingwena
Keyword(s):  
Intermediate Host ◽  
Post Infection ◽  
Experimental Period ◽  
Freshwater Snail ◽  
Wide Distribution ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Biomphalaria Pfeifferi ◽  
Experimental Conditions ◽  
Bulinus Globosus

Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First generation (F-1) of 5 freshwater pulmonate snail species, Bulinus tropicus, Bulinus globosus, Biomphalaria pfeifferi, Helisoma dyuri and Physa acuta that were bred in the laboratory, and 2 prosobranch snail species, Melanoides tuberculata and Cleopatra sp. that were collected from the field were used in this study. Data pertaining to mortalities and cercariae shedding were recorded throughout the experimental period. The prosobranch snails, M. tuberculata and Cleopatra sp. were susceptible to G. aegyptiacus with a minimum prepatent period of 45 days and 54 days, respectively. Bulinus tropicus, P. acuta and H. duryi were susceptible as evidenced by the presence of different generations of rediae and mature cercariae on dissection at 59 days post-infection although attempts to induce the snails to shed from 28 days post-infection did not produce cercariae. Bulinus globosus and Bio. Pfeifferi were refractory to infection. The results revealed the ability of G. aegyptiacus to infect M. tuberculata, Cleopatara sp., B. tropicus, P. acuta and H. duryi under experimental conditions and this may explain the recorded outbreaks of gastrodiscosis in equine populations in Zimbabwe in the absence of the known intermediate hosts. Bulinus tropicus is considered as the most likely major intermediate host of G. aegyptiacus because of its wide distribution in Zimbabwe and is well adapted to a wide variety of environments.

Current status of fasciolosis in Vietnam: an update and perspectives

2015 ◽  
Vol 90 (5) ◽  
pp. 511-522 ◽  
Author(s):  
T.D. Bui ◽  
P.N. Doanh ◽  
C. Saegerman ◽  
B. Losson
Keyword(s):  
Preventive Measures ◽  
Current Status ◽  
Published Data ◽  
Snail Species ◽  
Intermediate Hosts ◽  
The Past ◽  
Lymnaeid Snail ◽  
Contaminated Drinking Water ◽  
Radix Auricularia ◽  
And Control

AbstractVietnam is recognized to be endemic for fasciolosis. However, most of the available publications have not been published in international journals. This review is based on national and international Vietnamese publications and highlights the current status of fasciolosis in Vietnam. It also provides some information available for neighbouring countries. Updated data on responsible species, distribution, transmission and control aspects are summarized. The central region of Vietnam is reported as being highly endemic for fasciolosis, with a high number of human patients (more than 20,000 in 2011). Fasciola gigantica is reported to be the main species in Vietnam. However, hybrids between F. gigantica and F. hepatica were identified. Both humans and animals are infected by the ingestion of raw vegetables and possibly contaminated drinking water. Three lymnaeid snail species (Austropeplea viridis, Radix auricularia and Radix rubiginosa) may act as intermediate hosts of Fasciola spp. However, due to the likely misidentification of snail species and cercariae during the past decade the critical analysis of published data is difficult. A better understanding of transmission aspects of fasciolosis would allow the implementation of preventive measures of this important neglected zoonotic disease.

The life cycle and transmission dynamics of the larval stages ofHypoderaeum conoideum

2000 ◽  
Vol 74 (2) ◽  
pp. 165-172 ◽  
Author(s):  
C. Muñoz-Antolí ◽  
R. Toledo ◽  
J.G. Esteban
Keyword(s):  
Life Cycle ◽  
Freshwater Snail ◽  
Transmission Dynamics ◽  
Freshwater Snails ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Free Living ◽  
Larval Stages ◽  
Life History Stages ◽  
First Intermediate Host

AbstractThe morphology of the different larval stages and life cycle ofHypoderaeum conoideum(Trematoda: Echinostomatidae) are described. The freshwater snail speciesLymnaea peregra(Gastropoda: Lymnaeidae) serves as the natural first intermediate host and this andL. corvusserve as experimental first intermediate hosts. These and other freshwater snails, such asPhysella acutaandGyraulus chinensis, in turn serve as second intermediate hosts. Adult worms were obtained from chicks and ducks, but not from rats, mice and golden hamsters. The morphology of the larval stages is compared with previous work onH. conoideum. Several aspects of the biology of the life history stages are described with emphasis on the transmission dynamics of the free-living stages. Differential suitability of the snail species that may act as first and/or second intermediate hosts is studied and discussed.

scholarly journals Cercarial fauna of freshwater snails in selected agricultural areas in Laguna, Philippines

2019 ◽  
Vol 56 (1) ◽  
pp. 81-86
Author(s):  
V. G. V. Paller ◽  
J. R. M. Macaraig ◽  
R. T. Verona ◽  
L. A. Estaño
Keyword(s):  
Infected Snail ◽  
Freshwater Snail ◽  
The Philippines ◽  
Pomacea Canaliculata ◽  
Freshwater Snails ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Habitat Types ◽  
Public Health Importance ◽  
Agricultural Areas

SummaryFreshwater snails serve as one of trematodes’ intermediate hosts. Previous studies on trematode larval stages in the Philippines have largely focused on species with public health importance. This study sought to investigate the prevalence of cercarial morphotypes in several freshwater snail species found in different habitat types (rice field, irrigation canals, and residential area) in selected agricultural areas in Los Baños and Bay in Laguna. Cercarial emergence was induced through exposure to artificial light. A total of 2,720 freshwater snails were collected and were represented by seven species, namely, Melanoides tuberculata Muller 1774 (n = 1229), Radix quadrasi von Moellendorf (n = 630), Tarebia granifera Lamarck, 1816 (n = 417), Pomacea canaliculata Lamarck 1819 (n = 257), Vivipara angularis philippinensis Nevill (n = 18), Stenomelania sp. (n = 104), Thiara scabra Muller 1774 (n = 65). A 2.57 % over-all prevalence was recorded; the infected snail species were M. tuberculata (2.21 %), R. quadrasi (0.21 %), T. granifera (0.11 %). Four cercarial morphotypes, namely, Parapleurolophocercous cercaria (1.80 %), Virgulate xiphidiocercaria (0.26 %), Megaluruous cercaria (0.29 %), and Echinostome cercaria (0.22 %) were recovered from the infected snail species. Prevalence of cercarial infection was significantly different (p < 0.05) among habitat types.

scholarly journals Transcriptome profiling of Lymnaea stagnalis (Gastropoda) for ecoimmunological research

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Otto Seppälä ◽  
Jean-Claude Walser ◽  
Teo Cereghetti ◽  
Katri Seppälä ◽  
Tiina Salo ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Individual Variation ◽  
Lymnaea Stagnalis ◽  
De Novo ◽  
Transcriptome Profiling ◽  
Snail Species ◽  
Immune Defence ◽  
Immune Activity ◽  
Self Recognition ◽  
Immune Assays

Abstract Background Host immune function can contribute to numerous ecological/evolutionary processes. Ecoimmunological studies, however, typically use one/few phenotypic immune assays and thus do not consider the complexity of the immune system. Therefore, “omics” resources that allow quantifying immune activity across multiple pathways are needed for ecoimmunological models. We applied short-read based RNAseq (Illumina NextSeq 500, PE-81) to characterise transcriptome profiles of Lymnaea stagnalis (Gastropoda), a multipurpose model snail species. We used a genetically diverse snail stock and exposed individuals to immune elicitors (injury, bacterial/trematode pathogens) and changes in environmental conditions that can alter immune activity (temperature, food availability). Results Immune defence factors identified in the de novo assembly covered elements broadly described in other gastropods. For instance, pathogen-recognition receptors (PRR) and lectins activate Toll-like receptor (TLR) pathway and cytokines that regulate cellular and humoral defences. Surprisingly, only modest diversity of antimicrobial peptides and fibrinogen related proteins were detected when compared with other taxa. Additionally, multiple defence factors that may contribute to the phenotypic immune assays used to quantify antibacterial activity and phenoloxidase (PO)/melanisation-type reaction in this species were found. Experimental treatments revealed factors from non-self recognition (lectins) and signalling (TLR pathway, cytokines) to effectors (e.g., antibacterial proteins, PO enzymes) whose transcription depended on immune stimuli and environmental conditions, as well as components of snail physiology/metabolism that may drive these effects. Interestingly, the transcription of many factors (e.g., PRR, lectins, cytokines, PO enzymes, antibacterial proteins) showed high among-individual variation. Conclusions Our results indicate several uniform aspects of gastropod immunity, but also apparent differences between L. stagnalis and some previously examined taxa. Interestingly, in addition to immune defence factors that responded to immune elicitors and changes in environmental conditions, many factors showed high among-individual variation across experimental snails. We propose that such factors are highly important to be included in future ecoimmunological studies because they may be the key determinants of differences in parasite resistance among individuals both within and between natural snail populations.

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