Isolation, characterization and population-genetic analysis of microsatellite loci in the freshwater snail <i>Galba cubensis</i> (Lymnaeidae)

The freshwater snail Galba cubensis (Pfeiffer, 1839) has a large distribution in the Americas. Despite being an intermediate host of Fasciola hepatica - the trematode causing fasciolosis in livestock and humans - its population genetics have never been studied. We isolated and characterized 15 microsatellite loci in G. cubensis to evaluate its genetic diversity, population-genetic structure and mating system. We tested the microsatellite loci in 359 individuals from 13 populations of G. cubensis from Cuba, Guadeloupe, Martinique, Puerto Rico, Venezuela, Colombia and Ecuador. We also tested cross-amplification in three closely related species: G. truncatula, G. viator and G. neotropica. We found that G. cubensis has a similar population structure to other selfing lymnaeids that live in temporary habitats: low genetic diversity, large departure from Hardy-Weinberg equilibrium, marked population structure and high selfing rate. We found that seven and six loci amplified in G. truncatula and G. viator, respectively, and that all 15 loci amplified in G. neotropica. This last finding suggests a close relatedness between G. cubensis and G. neotropica, probably being conspecific and synonymous. This new set of microsatellite markers will be a useful tool to study the genetic diversity of this snail species across a large geographical range and, consequently, to understand the emergence and re-emergence of fasciolosis in the Americas.Centro de Estudios Parasitológicos y de VectoresFacultad de Ciencias Naturales y Muse

Isolation, characterization and population-genetic analysis of microsatellite loci in the freshwater snail <i>Galba cubensis</i> (Lymnaeidae)

The freshwater snail Galba cubensis (Pfeiffer, 1839) has a large distribution in the Americas. Despite being an intermediate host of Fasciola hepatica - the trematode causing fasciolosis in livestock and humans - its population genetics have never been studied. We isolated and characterized 15 microsatellite loci in G. cubensis to evaluate its genetic diversity, population-genetic structure and mating system. We tested the microsatellite loci in 359 individuals from 13 populations of G. cubensis from Cuba, Guadeloupe, Martinique, Puerto Rico, Venezuela, Colombia and Ecuador. We also tested cross-amplification in three closely related species: G. truncatula, G. viator and G. neotropica. We found that G. cubensis has a similar population structure to other selfing lymnaeids that live in temporary habitats: low genetic diversity, large departure from Hardy-Weinberg equilibrium, marked population structure and high selfing rate. We found that seven and six loci amplified in G. truncatula and G. viator, respectively, and that all 15 loci amplified in G. neotropica. This last finding suggests a close relatedness between G. cubensis and G. neotropica, probably being conspecific and synonymous. This new set of microsatellite markers will be a useful tool to study the genetic diversity of this snail species across a large geographical range and, consequently, to understand the emergence and re-emergence of fasciolosis in the Americas.Centro de Estudios Parasitológicos y de VectoresFacultad de Ciencias Naturales y Muse

First report of Galba cubensis (Gasteropoda: Lymnaeidae) in Ecuador, host of Fasciola hepatica potential in rice fields of the ecuadorian coast

Las especies invasoras representan una amenaza para la salud humana y los alimentos, especialmente cuando estas especies son introducidas a nuevos hábitats y transmiten parásitos a los seres humanos o a los animales domésticos. El molusco Galba cubensis es el principal hospedador intermediario de Fasciola hepatica – agente causal de la fascioliasis – y está distribuido desde Norte América hasta Sur América. Sin embargo, en Ecuador G. cubensis no se había reportado hasta la presente publicación. En un inventario completo de caracoles pulmonados de agua dulce llevadas a cabo en 1965, las dos únicas especies de la familia Lymnaeidae reportadas fueron el caracol invasor Pseudosuccinea columella y el caracol nativo Galba cousini. Se realizó una búsqueda malacológica en arrozales de la provincia del Guayas, Ecuador, entre 2013 y 2015 y encontramos por primera vez G. cubensis en el país. A continuación, se estudió la morfología de estos caracoles para identifcar la especie. Llegando a la conclusión de que G. cubensis es una especie invasora que se ha introducido al Ecuador en los últimos 50 años. También anticipamos que esta especie podría estar transmitiendo fascioliasis en la región litoral del Ecuador.Biological invasions represent a threat to human and food health when the species introduced transmit parasites to humans or domestic animals. Galba cubensis is the main snail host of Fasciola hepatica—the agent of fasciolosis—and has a current range from North to South America. Nonetheless, in Ecuador G. cubensis has not been reported until now. In a complete inventory of freshwater pulmonate snails carried out in 1965, the only two lymnaeid species reported were the invasive snail Pseudosuccinea columella and the native snail Galba cousini. We carried out a malacological survey in rice felds of the Guayas Province, Ecuador, between 2013 and 2015 and we found for the frst time G. cubensis in this country. We conclude that G. cubensis is an invasive species that has been introduced to Ecuador in the past 50 years. We also anticipate that this species could be spreading fasciolosis from the higher and Andean region to the lower and tropical region of Ecuador.Centro de Estudios Parasitológicos y de Vectore

First report of Galba cubensis (Gasteropoda: Lymnaeidae) in Ecuador, host of Fasciola hepatica potential in rice fields of the ecuadorian coast

Las especies invasoras representan una amenaza para la salud humana y los alimentos, especialmente cuando estas especies son introducidas a nuevos hábitats y transmiten parásitos a los seres humanos o a los animales domésticos. El molusco Galba cubensis es el principal hospedador intermediario de Fasciola hepatica – agente causal de la fascioliasis – y está distribuido desde Norte América hasta Sur América. Sin embargo, en Ecuador G. cubensis no se había reportado hasta la presente publicación. En un inventario completo de caracoles pulmonados de agua dulce llevadas a cabo en 1965, las dos únicas especies de la familia Lymnaeidae reportadas fueron el caracol invasor Pseudosuccinea columella y el caracol nativo Galba cousini. Se realizó una búsqueda malacológica en arrozales de la provincia del Guayas, Ecuador, entre 2013 y 2015 y encontramos por primera vez G. cubensis en el país. A continuación, se estudió la morfología de estos caracoles para identifcar la especie. Llegando a la conclusión de que G. cubensis es una especie invasora que se ha introducido al Ecuador en los últimos 50 años. También anticipamos que esta especie podría estar transmitiendo fascioliasis en la región litoral del Ecuador.Biological invasions represent a threat to human and food health when the species introduced transmit parasites to humans or domestic animals. Galba cubensis is the main snail host of Fasciola hepatica—the agent of fasciolosis—and has a current range from North to South America. Nonetheless, in Ecuador G. cubensis has not been reported until now. In a complete inventory of freshwater pulmonate snails carried out in 1965, the only two lymnaeid species reported were the invasive snail Pseudosuccinea columella and the native snail Galba cousini. We carried out a malacological survey in rice felds of the Guayas Province, Ecuador, between 2013 and 2015 and we found for the frst time G. cubensis in this country. We conclude that G. cubensis is an invasive species that has been introduced to Ecuador in the past 50 years. We also anticipate that this species could be spreading fasciolosis from the higher and Andean region to the lower and tropical region of Ecuador.Centro de Estudios Parasitológicos y de Vectore

Diversity and biological invasions in the liver fluke - Lymnaeidae system : factors of fasciolosis expansion ?

La mondialisation et les changements globaux actuels ont un impact considérable sur la distribution des espèces et la composition des communautés. Lorsque ces espèces sont impliquées dans une interaction hôte-parasite les changements dans leur répartition peuvent entraîner la (ré)émergence de maladies infectieuses. La fasciolose, maladie causée par les grandes douves du foie (Fasciola hepatica et Fasciola gigantica) est réémergente dans de nombreux points du globe. Il est difficile de mettre en place des programmes de contrôle parce que (1) les hôtes intermédiaires, des mollusques d’eau douce de la famille des Lymnaeidae, sont composés d’un groupe d’espèces cryptiques difficilement identifiables et (2) plusieurs espèces impliquées dans cette maladie sont invasives. L’objectif de cette thèse était d’étudier les facteurs écologiques et évolutifs à large échelle de l’interaction entre la grande douve du foie et ses hôtes intermédiaires susceptibles de favoriser une (ré)émergence de la fasciolose. J’ai, dans un premier temps, développé des approches moléculaires pour reconnaître les espèces cryptiques tant du côté de la grande douve du foie que du côté des Lymnaeidae. L’utilisation d’une des techniques développées sur Galba schirazensis, Galba cubensis et Galba truncatula, trois espèces de limnées, m’a permis d’identifier leur distribution respective et de modéliser leur niches bioclimatiques grâce à l’utilisation de modèles de niches écologiques. Cette approche de modélisation de niches permet d’inférer la distribution potentielle des trois espèces et nous amène à discuter des avantages potentiels de ces modèles dans la gestion de la fasciolose. Dans un second temps, je me suis intéressée à la structuration de la diversité génétique chez des espèces invasives du système grande douve du foie-limnée, par des approches de génétique des populations et de phylogénie. J’ai pu retracer l’histoire de colonisation, les dynamiques démographiques et le système de reproduction chez P. columella, G. schirazensis et G. cubensis. J’ai montré que ces trois espèces font préférentiellement de l’autofécondation entrainant des pertes drastiques de diversité génétiques sur le front d’invasion. G. cubensis présente cependant une coexistence de plusieurs génotypes dans les aires anciennement colonisées. Les différences génétiques entre ces trois espèces sont discutées à la lumière de ce qu’on sait de leur écologie. Enfin ces résultats m’ont permis de discuter de l’avantage d'être autofécondant en cas d’invasion biologique. Pour conclure l’invasion par ces populations d’hôtes intermédiaires dépourvus de diversité génétique pourrait représenter un risque épidémiologique. En effet un parasite a plus de probabilité de circuler dans une population hôte clonale que dans une population polymorphe. Cette thèse fait le lien entre écologie, interactions hôtes-parasites et génétique de l’invasion afin de mieux comprendre les facteurs d’expansion de la fasciolose à échelle globale.Globalization and the current global change have significant impacts on species distribution and community composition. When these species are involved in a host-parasite interaction, changes in species range distribution can result in the (re)emergence of infectious diseases. Fasciolosis, a disease caused by the liver flukes (Fasciola hepatica and Fasciola gigantica) is reemerging in many parts of the world. It is difficult to implement control programs because (1) the intermediate hosts, freshwater molluscs of the Lymnaeidae family, are composed by a group of cryptic species (2) several species involved in this system are invasive. The objective of this thesis was to study the ecological and evolutionary factors at a large scale in the interaction between the liver fluke and its intermediate hosts that might drive to fasciolosis (re)emergence. First, I developed molecular approaches to quickly identify cryptic species on the two liver flukes and on three Lymnaeidae species. Using one of these techniques, I identify the respective distribution of Galba schirazensis, Galba cubensis and Galba truncatula and infer their respective climatic envelope by ecological niche modelling. We then modelled and projected the potential species distribution ranges. We discussed the contribution of models to predict the species distribution in space and time giving a considerable advantage to control fasciolosis. I then study the genetic diversity structuration in invasive snails involved in the transmission of F. hepatica, using population genetics and phylogeny. I could infer colonization history, population dynamics and reproductive system of Pseudosuccinea columella, G. schirazensis and G. cubensis. I showed that these three species preferentially make inbreeding causing drastic losses of genetic diversity in the invasion front. However G. cubensis presents a coexistence of several genotypes in formerly colonized areas. Genetic differences between these three species are discussed in the light of what we know about their ecology. Overall, these results illustrate how dramatic the reduction in genetic diversity can be for hermaphrodite animals. Finally, we discuss the epidemiological risk related to the invasion by intermediate hosts depleted in genetic diversity. Indeed, a parasite might circulate easily in a clonal host population than in a polymorphic population. In my thesis I linked ecology, host-parasite interactions with genetics of the invasion to better understand the expansion of fasciolosis at a global scale

Phage-bacteria networks isolated in soil

<p>Collection of 5 networks of bipartite interactions between bacteria (fluorescent Pseudomonads) and lytics phage isolated in soil in Montpellier, France. For details on the methods, see</p> <p>Poisot, Lounnas & Hochberg (2013) The structure of natural microbial enemy-victim networks. Ecological Processes</p> <p>Each network gives the interaction strength between 24 phages and 19 bacteria.</p

Patterns of distribution, population genetics and ecological requirements of field-occurring resistant and susceptible Pseudosuccinea columella snails to Fasciola hepatica in Cuba

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Lymnaeid snails hosts of Fasciola hepatica and Fasciola gigantica (Trematoda: Digenea): A worldwide review

Fasciolosis is a snail-borne disease, causing serious public and veterinary health problems worldwide. This disease is produced by infection with Fasciola hepatica or Fasciola gigantica through the consumption of vegetables or water contaminated with the parasite’s metacercarial cysts. Both species of liver flukes are transmitted worldwide by small freshwater snails of the family Lymnaeidae. A global account on the species that are actually or may act as potential hosts of Fasciola spp., compiling particular research on their geographical distribution and susceptibility, is needed as a helpful tool in the understanding of fasciolosis transmission, and therefore in the control and prevention programmes of the disease. We have gathered here a comprehensive review of those lymnaeid species that are known to transmit the parasites in the field or that have been experimentally tested. We aim to bring forward the main intermediate hosts by regions in order to facilitate the understanding of worldwide transmission.Fil: Vázquez, Antonio A.. University of Montpellier; Francia. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Alda, Maria del Pilar. University of Montpellier; Francia. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lounnas, Manon. University of Montpellier; FranciaFil: Sabourin, Emeline. University of Montpellier; Francia. Institut de recherche de la Tour du Valat; FranciaFil: Alba, Annia. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Pointier, Jean Pierre. Université de Perpignan; FranciaFil: Hurtrez-Boussès, Sylvie. University of Montpellier; Franci

Isolation, characterization and population-genetic analysis of microsatellite loci in the freshwater snail Galba cubensis (Lymnaeidae)

The freshwater snail Galba cubensis (Pfeiffer, 1839) has a large distribution in the Americas. Despite being an intermediate host of Fasciola hepatica - the trematode causing fasciolosis in livestock and humans - its population genetics have never been studied. We isolated and characterized 15 microsatellite loci in G. cubensis to evaluate its genetic diversity, population-genetic structure and mating system. We tested the microsatellite loci in 359 individuals from 13 populations of G. cubensis from Cuba, Guadeloupe, Martinique, Puerto Rico, Venezuela, Colombia and Ecuador. We also tested cross-amplification in three closely related species: G. truncatula, G. viator and G. neotropica. We found that G. cubensis has a similar population structure to other selfing lymnaeids that live in temporary habitats: low genetic diversity, large departure from Hardy-Weinberg equilibrium, marked population structure and high selfing rate. We found that seven and six loci amplified in G. truncatula and G. viator, respectively, and that all 15 loci amplified in G. neotropica. This last finding suggests a close relatedness between G. cubensis and G. neotropica, probably being conspecific and synonymous. This new set of microsatellite markers will be a useful tool to study the genetic diversity of this snail species across a large geographical range and, consequently, to understand the emergence and re-emergence of fasciolosis in the Americas.Fil: Lounnas, Manon. Université de Montpellier; FranciaFil: Vázquez, Antonio A.. Université de Montpellier; Francia. Instituto de Medicina Tropical Pedro Kourí; FranciaFil: Alda, Maria del Pilar. Université de Montpellier; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Sartori, Kevin. Université de Montpellier; FranciaFil: Pointier, Jean Pierre. Université de Perpignan; FranciaFil: David, Patrice. Centre d'Ecologie Fonctionnelle et Evolutive; FranciaFil: Hurtrez Boussès, Sylvie. Université de Montpellier; Franci

Mycobacterium chimaera Pulmonary Disease in Cystic Fibrosis Patients, France, 2010–2017

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