Monorchis parvus and Gymnophallus choledochus: two trematode species infecting cockles as first and second intermediate host

Parasitology ◽  
2020 ◽  
Vol 147 (6) ◽  
pp. 643-658
Author(s):  
Luísa Magalhães ◽  
Guillemine Daffe ◽  
Rosa Freitas ◽  
Xavier de Montaudouin
Keyword(s):  
Intermediate Host ◽  
Severe Disease ◽  
Relevant Literature ◽  
Trematode Species ◽  
New Information ◽  
Second Intermediate Host ◽  
Infection Processes ◽  
Low Prevalence ◽  
Host Parasite

AbstractThe most deleterious stage of a trematode life cycle occurs in the first intermediate host where the parasite penetrates as a miracidium and asexually multiplicates in sporocysts or rediae. When infection advances, other organs can be occupied with severe effects on host individual health and population dynamics. Existing studies focused on these host/parasite systems are still scarce due to the usual low prevalence in ecosystems. Using cockles (Cerastoderma spp.) and two trematode species (Monorchis parvus and Gymnophallus choledochus) infecting these bivalves as first and second intermediate host, the present work aimed to (1) summarize the most relevant literature and (2) provide new information regarding this host/parasite system, taking advantage of a 21-year monthly database from Banc d'Arguin (France). This long-term monitoring showed that different trematode species display varying host size range preference (6–38 and 31–36 mm for M. parvus and G. choledochus, respectively). The occurrence of coinfection was lower than expected, raising some questions related to parasite interspecific competition. This review improved our understanding of the processes shaping the prevalence and distribution of parasitism. This study highlighted that beyond constant trematode assemblage monitoring, there is a need to identify the main predictors of rediae/sporocysts infection, such as the definitive host dynamics and miracidium infection processes, for future better management of host severe disease and mortality episodes.

Guide to the trematodes (Platyhelminthes) that infect the California horn snail (Cerithideopsis californica: Potamididae: Gastropoda) as first intermediate host

Zootaxa ◽  
2019 ◽  
Vol 4711 (3) ◽  
pp. 459-494 ◽  
Author(s):  
RYAN F. HECHINGER
Keyword(s):  
Intermediate Host ◽  
Relevant Literature ◽  
Diagnostic Information ◽  
Background Information ◽  
Trematode Species ◽  
Host Use ◽  
Ecological Research ◽  
Second Intermediate Host ◽  
First Intermediate Host ◽  
Identification Tool

The California horn snail, Cerithideopsis californica, lives in estuarine habitats from California (USA) in North America to Piura (Peru) in South America. Throughout this range, the snail serves as first intermediate host for a diverse guild of digenean trematodes. These parasites are used in teaching laboratories, and have been subject to a large amount of taxonomic, biological, evolutionary, and ecological research. Despite the abundance of research on these trematodes, we lack a satisfactory guide to these parasites. This manuscript treats the 19 trematode species that we are currently able to distinguish morphologically. I provide taxonomic affinities, information on second intermediate host use, an identification key focused on cercaria traits, information and a key for regressed infections lacking cercariae, information on early infections, and species accounts. The species accounts present photographs, additional diagnostic information, taxonomic notes, information concerning cryptic species, and connections to relevant literature. The primary aim of this manuscript is to facilitate research on this trematode guild by serving as an identification tool, and by providing background information, including highlighting gaps in our knowledge. 

Patterns of digenean parasitism of bivalves from the Great Barrier Reef and associated waters

2005 ◽  
Vol 56 (4) ◽  
pp. 387 ◽  
Author(s):  
Nathan J. Bott ◽  
John M. Healy ◽  
Thomas H. Cribb
Keyword(s):  
Great Barrier Reef ◽  
Trematode Species ◽  
Barrier Reef ◽  
Bivalve Species ◽  
Marine Waters ◽  
New Host ◽  
Lizard Island ◽  
Marine Bivalves ◽  
Low Prevalence ◽  
Host Parasite

Digenean parasites of marine bivalves are relatively poorly known, particularly in Australia. We surveyed 2256 bivalve individuals (47 species, 17 families) from Queensland marine waters incorporating south-east Queensland, Heron Island (southern Great Barrier Reef) and Lizard Island (northern Great Barrier Reef). Infections of trematode species from three families, Bucephalidae, Gorgoderidae and Monorchiidae, were found. Overall prevalence of infection was 2.3%. The Bucephalidae was the most commonly found family; 11 species were found in Tellinidae, Ostreidae, Isognomonidae and Spondylidae – the latter two previously unknown as hosts for bucephalids. A single gorgoderid infection was found in a venerid, Lioconcha castrensis. Five species of monorchiids were found from Tellinidae and Lucinidae. All infections are new host/parasite records. No infections were found in 35 of the 47 bivalve species sampled. The generally low prevalence of infection by digeneans of bivalves suggests that it is unlikely that any of the species reported here are seriously damaging to bivalve populations in these waters. We deduce that, at best, we have some life-cycle information but no actual identifications for 10% of the species of trematodes that infect bivalves of Queensland marine waters.

One snail – three Digenea species, different strategies in host-parasite interaction

2011 ◽  
Vol 61 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Elżbieta Żbikowska
Keyword(s):  
Intermediate Host ◽  
Parasite Species ◽  
Lymnaea Stagnalis ◽  
Behavioral Changes ◽  
Diplostomum Pseudospathaceum ◽  
Second Intermediate Host ◽  
Host Parasite ◽  
The Impact ◽  
Plagiorchis Elegans ◽  
First Intermediate Host

AbstractThe mostly lab-based studies on snail-trematode interactions should be complemented by research on naturally invaded hosts. In this mini-review, three different ways of snail exploitation by Digenea larvae are presented. Morphological, physiological and behavioral changes caused by three parasites in the same naturally infected host – Lymnaea stagnalis – differ in species-dependent fashion. The impact of a snail-trematode interaction depends on parasite virulence (i.e. parasite induced lost of fitness of the host). The pathogenicity varies with the survival strategy of the invader. Sporocyst-born Plagiorchis elegans, which uses the same Lymnaea stagnalis individual as a first but also as a second intermediate host, does not disturb host processes as strongly as redia-born Echinoparyphium aconiatum. The third parasite species – Diplostomum pseudospathaceum, also sporocyst-born – is more virulent than P. elegans, but it can modify and relax host exploitation to overwinter in the snail. The data presented demonstrate that successful use of first intermediate host can be arranged in different ways.

Metazoan parasites in an intermediate host population near its southern border: the common cockle (Cerastoderma edule) and its trematodes in a Moroccan coastal lagoon (Merja Zerga)

2008 ◽  
Vol 88 (2) ◽  
pp. 357-364 ◽  
Author(s):  
Mériame Gam ◽  
Hocein Bazaïri ◽  
K. Thomas Jensen ◽  
Xavier de Montaudouin
Keyword(s):  
Species Composition ◽  
Intermediate Host ◽  
Coastal Lagoon ◽  
Life Cycles ◽  
Geographical Range ◽  
Trematode Species ◽  
Intermediate Hosts ◽  
Metazoan Parasites ◽  
Cerastoderma Edule ◽  
Second Intermediate Host

The metazoan parasite community of Cerastoderma edule was studied in the southern geographical range of the host (the coastal lagoon Merja Zerga, Morocco). A total of 11 metazoan species was found in cockles. Nine of these were trematodes using cockles as either first intermediate host (three species) or second intermediate host (six species). In addition, two other endo-metazoan species (Pinnotheres pisum and Paravortex cardii) were recorded from cockles in the studied lagoon. All the observed metazoans in cockles from Merja Zerga have previously been recorded at sites north of Africa.Up to 10% of the cockles in the studied size-groups were first intermediate hosts to castrating parasites (Gymnophallus choledochus, Labratrema minimus and Monorchis parvus). Among trematodes having metacercariae in cockles (second intermediate host) Meiogymnophallus minutus was the most widespread as it was observed in all cockles from all the examined habitats in the lagoon and it occurred in record high intensities. Different sub-communities of the trematode fauna using cockles as second intermediate host could be identified (subtidal vs intertidal associations).The richness and species composition of the macroparasite community in cockles from Morocco are discussed in relation to patterns seen in cockles from other sites along their geographical range. Migratory fish and waterbirds (final hosts) are generally responsible for the large scale spread (latitudinal spread) of trematodes. However, the distributional patterns of involved intermediate hosts in the life-cycles of the different trematode species in cockles are determining the richness and species composition patterns seen in cockles at shallow water sites along the east Atlantic shoreline.

scholarly journals Parasites of Small Mammals in Grand Teton National Park: Babesia and Hepatozoon

1996 ◽  
Vol 20 ◽  
pp. 95-99
Author(s):  
Raychel Watkins ◽  
Suzanne Moshier ◽  
Aelita Pinter
Keyword(s):  
Intermediate Host ◽  
Small Mammals ◽  
National Park ◽  
Protozoan Parasite ◽  
Babesia Microti ◽  
Grand Teton National Park ◽  
Microtus Montanus ◽  
Study Sites ◽  
Host Parasite

Babesia microti, a parasitic protozoan, is endemic in the Microtus montanus of Grand Teton National Park. It is transmitted by the tick Ixodes eastoni and reproduces in the erythrocytes of its vole host. A second protozoan parasite, Hepatozoon sp., which is widespread in small mammals in Europe, is also found in reptiles throughout the world. The record of Hepatozoon in North American small mammals is not extensive. Hepatozoon, unlike Babesia, may be a two-host or a three-host parasite. Also unlike Babesia, for which the intermediate host is always a tick, the intermediate host of Hepatozoon may be a tick, a mite, a flea, or a mosquito. The method of transmission by the vector also differs in the two parasites. Babesia is transmitted in the tick's saliva when it bites, whereas Hepatozoon infection requires the vertebrate host to ingest a vector. In our 1996 studies, we sought more data on these two parasites. The objectives for 1996 focused on Hepatozoon: to sample specific populations of M. montanus, in which we have previously documented Hepatozoon infections; to determine whether differences exist in the infection rates at different study sites in the park; and to search for any additional vectors of Hepatozoon sp. infections in M. montanus by examining ectoparasites. These studies contributed to our long-term objectives of documenting the effects and cost of parasitism on M. montanus populations.

scholarly journals Cockle as Second Intermediate Host of Trematode Parasites: Consequences for Sediment Bioturbation and Nutrient Fluxes across the Benthic Interface

2021 ◽  
Vol 9 (7) ◽  
pp. 749
Author(s):  
Anaïs Richard ◽  
Xavier de Montaudouin ◽  
Auriane Rubiello ◽  
Olivier Maire
Keyword(s):  
Intermediate Host ◽  
Parasite Species ◽  
Nutrient Fluxes ◽  
Sediment Reworking ◽  
Biogeochemical Fluxes ◽  
Time Period ◽  
Second Intermediate Host ◽  
Host Parasite ◽  
High Parasite ◽  
Trematode Parasites

Trematode parasites are distributed worldwide and can severely impact host populations. However, their influence on ecosystem functioning through the alteration of host engineering behaviours remains largely unexplored. This study focuses on a common host parasite system in marine coastal environments, i.e., the trematode Himasthla elongata, infecting the edible cockle Cerastoderma edule as second intermediate host. A laboratory experiment was conducted to investigate the indirect effects of metacercarial infection on sediment bioturbation and biogeochemical fluxes at the sediment water interface. Our results revealed that, despite high parasite intensity, the sediment reworking and bioirrigation rates, as well as nutrient fluxes, were not impacted. This finding was unexpected since previous studies showed that metacercarial infection impairs the physiological condition of cockles and induces a mechanical obstruction of their feet, thus altering their burrowing capacity. There are several explanations for such contrasting results. Firstly, the alteration of cockle behavior could arise over a longer time period following parasite infection. Secondly, the modulation of cockle bioturbation by parasites could be more pronounced in older specimens burying deeper. Thirdly, the intensity of the deleterious impacts of metacercariae could strongly vary across parasite species. Lastly, metacercarial infection alters cockle fitness through an interaction with other biotic and abiotic environmental stressors.

Sharing of Worldwide Spread Knowledge Using Hypermedia Facilities & Fast Communication Protocols (Mosaic and World Wide Web): The Example of ExPASy

1995 ◽  
Vol 34 (01/02) ◽  
pp. 75-78 ◽  
Author(s):  
R. D. Appel ◽  
O. Golaz ◽  
Ch. Pasquali ◽  
J.-C. Sanchez ◽  
A. Bairoch ◽  
...  
Keyword(s):  
World Wide Web ◽  
World Wide ◽  
Relevant Literature ◽  
Communication Protocols ◽  
Laboratory Data ◽  
Central Element ◽  
University Hospital ◽  
New Information ◽  
The University ◽  
Link Information

Abstract:The sharing of knowledge worldwide using hypermedia facilities and fast communication protocols (i.e., Mosaic and World Wide Web) provides a growth capacity with tremendous versatility and efficacy. The example of ExPASy, a molecular biology server developed at the University Hospital of Geneva, is striking. ExPASy provides hypermedia facilities to browse through several up-to-date biological and medical databases around the world and to link information from protein maps to genome information and diseases. Its extensive access is open through World Wide Web. Its concept could be extended to patient data including texts, laboratory data, relevant literature findings, sounds, images and movies. A new hypermedia culture is spreading very rapidly where the international fast transmission of documents is the central element. It is part of the emerging new “information society”.

Enhancing community welfare through improved water quality: a case for applying staggered pollution charges in the river Musi sub-basin of Andhra Pradesh, India

Water Policy ◽  
2005 ◽  
Vol 7 (5) ◽  
pp. 469-483
Author(s):  
Tishya Chatterjee
Keyword(s):  
Andhra Pradesh ◽  
Relevant Literature ◽  
Pollution Prevention ◽  
Economic Benefits ◽  
Environmental Damage ◽  
Marginal Costs ◽  
Community Acceptance ◽  
Level Data ◽  
Over Time

In conditions of severe water-pollution and dormant community acceptance of accumulating environmental damage, the regulator's role goes beyond pollution prevention and more towards remediation and solutions based on the community's long-term expectations of economic benefits from clean water. This paper suggests a method to enable these benefits to become perceptible progressively, through participatory clean-up operations, supported by staggered pollution charges. It analyses the relevant literature on pollution prevention and applies a cost-based “willingness to pay” model, using primary basin-level data of total marginal costs. It develops a replicable demand-side approach imposing charge-standard targets over time in urban-industrial basins of developing countries.

Corticosteroids in Inflammatory Bowel Disease patients: a practical guide for physicians.

2020 ◽  
Vol 15 ◽  
Author(s):  
Maria Carla Di Paolo ◽  
Cristiano Pagnini ◽  
Maria Giovanna Graziani
Keyword(s):  
Severe Disease ◽  
Unknown Etiology ◽  
History Of Disease ◽  
Bowel Diseases ◽  
Literature Evidence ◽  
History Of ◽  
Inflammatory Bowel ◽  
Favorable Safety ◽  
Pass Metabolism

: Inflammatory bowel diseases (IBDs) are chronic conditions characterized by unknown etiology and pathogenesis with deregulation of mucosal immunity. Among possible treatments, corticosteroids, already available from the 50’, are still the mainstay of treatment for moderate-severe disease. Nonetheless, the use of steroids is still largely empirical and solid evidence about therapeutic schemes are lacking. Moreover, due to the important side-effects and for the unsatisfactory impact on long-term natural history of disease, the steroid sparing has become an important therapeutic goal in IBD management. Besides conventional steroids, the so called “low bioavailability” steroids, which are steroids with high affinity for peripheral receptors and elevated hepatic first-pass metabolism, have demonstrated efficacy and more favorable safety profile. In the present review of the literature evidence of efficacy and safety of conventional and low bioavailability steroids in IBD patients are evaluated, and practical suggestions for a correct use in clinical practice are presented according to the current clinical guidelines.

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