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Adrien Quiles - One of the best experts on this subject based on the ideXlab platform.
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microsporidian infections in the species complex gammarus roeselii amphipoda over its geographical range evidence for both host parasite co diversification and recent host shifts
Parasites & Vectors, 2019Co-Authors: Adrien Quiles, Karolina Bacelaspychalska, Maria Teresa Teixeira, Nicolas Lambin, Michal Grabowski, Thierry Rigaud, Remi WattierAbstract:Microsporidians are obligate endoparasites infecting taxonomically diverse hosts. Both vertical (from mother to eggs) and horizontal (between conspecifics or between species) transmission routes are known. While the former may promote co-speciation and host-specificity, the latter may promote shifts between host species. Among Aquatic Arthropods, freshwater amphipod crustaceans are hosts for many microsporidian species. However, despite numerous studies, no general pattern emerged about host specificity and co-diversification. In south-eastern Europe, the gammarid Gammarus roeselii is composed of 13 cryptic lineages of Miocene to Pleistocene age but few genotypes of one lineage have spread postglacially throughout north-western Europe. Based on nearly 100 sampling sites covering its entire range, we aim to: (i) explore the microsporidian diversity present in G. roeselii and their phylogenetic relationships, especially in relation to the parasites infecting other Gammaridae; (ii) test if the host phylogeographical history might have impacted host–parasite association (e.g. co-diversifications or recent host shifts from local fauna). We used part of the small subunit rRNA gene as source of sequences to identify and determine the phylogenetic position of the microsporidian taxa infecting G. roeselii. Microsporidian diversity was high in G. roeselii with 24 detected haplogroups, clustered into 18 species-level taxa. Ten microsporidian species were rare, infecting a few individual hosts in a few populations, and were mostly phylogenetically related to parasites from other amphipods or various crustaceans. Other microsporidians were represented by widespread genera with high prevalence: Nosema, Cucumispora and Dictyocoela. Two contrasting host association patterns could be observed. First, two vertically transmitted microsporidian species, Nosema granulosis and Dictyocoela roeselum, share the pattern of infecting G. roeselii over most of its range and are specific to this host suggesting the co-diversification scenario. This pattern contrasted with that of Dictyocoela muelleri, the three species of Cucumispora, and the rare parasites, present only in the recently colonised region by the host. These patterns suggest recent acquisitions from local host species, after the recent spread of G. roeselii. Microsporidians infecting G. roeselii revealed two scenarios of host–parasite associations: (i) ancient associations with vertically transmitted parasites that probably co-diversified with their hosts, and (ii) host shifts from local host species, after the postglacial spread of G. roeselii.
Jean-francois Guégan - One of the best experts on this subject based on the ideXlab platform.
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Chitin promotes Mycobacterium ulcerans growth
FEMS Microbiology Ecology, 2016Co-Authors: Daniel Sanhueza, Christine Chevillon, Rita Colwell, Jérémie Babonneau, Estelle Marion, Laurent Marsollier, Jean-francois GuéganAbstract:† Equally contributed as co-supervisors of this work One sentence summary: Chitin increased Mycobacterium Ulcerans (MU) growth significantly providing a nutrient source or environmental support for the bacillus, thereby, providing a focus on the association between MU and Aquatic Arthropods. ABSTRACT Mycobacterium ulcerans (MU) is the causative agent of Buruli ulcer, an emerging human infectious disease. However, both the ecology and life cycle of MU are poorly understood. The occurrence of MU has been linked to the Aquatic environment, notably water bodies affected by human activities. It has been hypothesized that one or a combination of environmental factor(s) connected to human activities could favour growth of MU in Aquatic systems. Here, we tested in vitro the growth effect of two ubiquitous polysaccharides and five chemical components on MU at concentration ranges shown to occur in endemic regions. Real-time PCR showed that chitin increased MU growth significantly providing a nutrient source or environmental support for the bacillus, thereby, providing a focus on the association between MU and Aquatic Arthropods. Aquatic environments with elevated population of Arthropods provide increased chitin availability and, thereby, enhanced multiplication of MU. If calcium very slightly enhanced MU growth, iron, zinc, sulphate and phosphate did not stimulate MU growth, and at the concentration ranges of this study would limit MU population in natural ecosystems. 20 25
Remi Wattier - One of the best experts on this subject based on the ideXlab platform.
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microsporidian infections in the species complex gammarus roeselii amphipoda over its geographical range evidence for both host parasite co diversification and recent host shifts
Parasites & Vectors, 2019Co-Authors: Adrien Quiles, Karolina Bacelaspychalska, Maria Teresa Teixeira, Nicolas Lambin, Michal Grabowski, Thierry Rigaud, Remi WattierAbstract:Microsporidians are obligate endoparasites infecting taxonomically diverse hosts. Both vertical (from mother to eggs) and horizontal (between conspecifics or between species) transmission routes are known. While the former may promote co-speciation and host-specificity, the latter may promote shifts between host species. Among Aquatic Arthropods, freshwater amphipod crustaceans are hosts for many microsporidian species. However, despite numerous studies, no general pattern emerged about host specificity and co-diversification. In south-eastern Europe, the gammarid Gammarus roeselii is composed of 13 cryptic lineages of Miocene to Pleistocene age but few genotypes of one lineage have spread postglacially throughout north-western Europe. Based on nearly 100 sampling sites covering its entire range, we aim to: (i) explore the microsporidian diversity present in G. roeselii and their phylogenetic relationships, especially in relation to the parasites infecting other Gammaridae; (ii) test if the host phylogeographical history might have impacted host–parasite association (e.g. co-diversifications or recent host shifts from local fauna). We used part of the small subunit rRNA gene as source of sequences to identify and determine the phylogenetic position of the microsporidian taxa infecting G. roeselii. Microsporidian diversity was high in G. roeselii with 24 detected haplogroups, clustered into 18 species-level taxa. Ten microsporidian species were rare, infecting a few individual hosts in a few populations, and were mostly phylogenetically related to parasites from other amphipods or various crustaceans. Other microsporidians were represented by widespread genera with high prevalence: Nosema, Cucumispora and Dictyocoela. Two contrasting host association patterns could be observed. First, two vertically transmitted microsporidian species, Nosema granulosis and Dictyocoela roeselum, share the pattern of infecting G. roeselii over most of its range and are specific to this host suggesting the co-diversification scenario. This pattern contrasted with that of Dictyocoela muelleri, the three species of Cucumispora, and the rare parasites, present only in the recently colonised region by the host. These patterns suggest recent acquisitions from local host species, after the recent spread of G. roeselii. Microsporidians infecting G. roeselii revealed two scenarios of host–parasite associations: (i) ancient associations with vertically transmitted parasites that probably co-diversified with their hosts, and (ii) host shifts from local host species, after the postglacial spread of G. roeselii.
Daniel Sanhueza - One of the best experts on this subject based on the ideXlab platform.
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Chitin promotes Mycobacterium ulcerans growth
FEMS Microbiology Ecology, 2016Co-Authors: Daniel Sanhueza, Christine Chevillon, Rita Colwell, Jérémie Babonneau, Estelle Marion, Laurent Marsollier, Jean-francois GuéganAbstract:† Equally contributed as co-supervisors of this work One sentence summary: Chitin increased Mycobacterium Ulcerans (MU) growth significantly providing a nutrient source or environmental support for the bacillus, thereby, providing a focus on the association between MU and Aquatic Arthropods. ABSTRACT Mycobacterium ulcerans (MU) is the causative agent of Buruli ulcer, an emerging human infectious disease. However, both the ecology and life cycle of MU are poorly understood. The occurrence of MU has been linked to the Aquatic environment, notably water bodies affected by human activities. It has been hypothesized that one or a combination of environmental factor(s) connected to human activities could favour growth of MU in Aquatic systems. Here, we tested in vitro the growth effect of two ubiquitous polysaccharides and five chemical components on MU at concentration ranges shown to occur in endemic regions. Real-time PCR showed that chitin increased MU growth significantly providing a nutrient source or environmental support for the bacillus, thereby, providing a focus on the association between MU and Aquatic Arthropods. Aquatic environments with elevated population of Arthropods provide increased chitin availability and, thereby, enhanced multiplication of MU. If calcium very slightly enhanced MU growth, iron, zinc, sulphate and phosphate did not stimulate MU growth, and at the concentration ranges of this study would limit MU population in natural ecosystems. 20 25
Romain Thomas - One of the best experts on this subject based on the ideXlab platform.
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upper cretaceous amber from vendee north western france age dating and geological chemical and palaeontological characteristics
Cretaceous Research, 2017Co-Authors: Didier Neraudeau, Vincent Perrichot, David J Batten, Anais Boura, Vincent Girard, Laurent Jeanneau, Youssef Nohra, Simona Saintmartin, Jeanpaul Saintmartin, Romain ThomasAbstract:The Upper Cretaceous lignite deposits of La Garnache, Vendee (western France), consist of two lignitic clay series, Garnache 1 and Garnache 2, separated by a fault. The first series cropped out to the south of the fault during road works until 2002 but is now covered by an embankment. It has provided numerous pieces of amber containing arthropod and microorganism inclusions. The second lignitic series, exposed to the north of the fault, is rich in fossil wood but devoid of amber. Palynological analysis of Garnache 1 revealed several Normapolles species belonging to the genera Atlantopollis, Complexiopollis, Osculapollis, Plicapollis and Trudopollis, but larger forms typical of Senonian deposits are absent. By contrast, Garnache 2 proved to be dominated taxonomically and numerically by spores (Appendicisporites, Camarozonosporites, Gleicheniidites, Patellasporites, Stereisporites), associated with a few gymnosperm (Cerebropollenites, Phyllocladidites, Classopollis) and angiosperm (Liliacidites, Retitricolpites and a single specimen of the Normapolles Complexiopollis) taxa. Garnache 1 is, therefore, younger than Garnache 2, the latter being clearly Cenomanian in age whereas Garnache 1 is more likely to be Turonian. Lignitic clay of Garnache 1 contains numerous translucent, orange to red, pieces of amber. Vendean amber is rich in Aquatic Arthropods, such as tanaids and epicarideans (Crustacea), as well as marine or brackish siliceous microorganisms such as diatoms and sponge spicules. These Aquatic inclusions indicate that resin-producing trees grew along and close to the seashore. The amber-bearing clay was deposited in a calm, estuarine or lagoonal, muddy environment.