Genetic diversity and relationships of the liver fluke Fasciola hepatica (Trematoda) with native and introduced definitive and intermediate hosts

Fasciolosis is a worldwide spread parasitosis mainly caused by the trematode Fasciola hepatica. This disease is particularly important for public health in tropical regions, but it can also affect the economies of many developed countries due to large infections in domestic animals. Although several studies have tried to understand the transmission by studying the prevalence of different host species, only a few have used population genetic approaches to understand the links between domestic and wildlife infections. Here, we present the results of such genetic approach combined with classical parasitological data (prevalence and intensity) by studying domestic and wild definitive hosts from Camargue (southern France) where fasciolosis is considered as a problem. We found 60% of domestic hosts (cattle) infected with F. hepatica but lower values in wild hosts (nutria, 19%; wild boars, 4.5%). We explored nine variable microsatellite loci for 1,148 adult flukes recovered from four different populations (non-treated cattle, treated cattle, nutria and wild boars). Populations from the four groups differed, though we found a number of migrants particularly non-treated cattle and nutria. Overall, we detected 729 different multilocus genotypes (from 783 completely genotyped individuals) and only 46 genotypes repeated across samples. Finally, we experimentally infected native and introduced intermediate snail hosts to explore their compatibility with F. hepatica and assess the risks of fasciolosis expansion in the region. The introduced species Galba truncatula and Pseudosuccinea columella attained the higher values of overall compatibility in relation to the European species. However, concerning the origin, sympatric combinations of G. truncatula were more compatible (higher prevalence, intensity and survival) than the allopatric tested. According to our results, we should note that the assessment of epidemiological risks cannot be limited to a single host–parasite system, but should focus on understanding the diversity of hosts in the heterogeneous environment through space and time.Fil: Vázquez, Antonio A.. Instituto de Medicina Tropical “Pedro Kourí”; Cuba. Université Montpellier II; Francia. Centre National de la Recherche Scientifique; FranciaFil: Sabourin, Emeline. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Alda, Maria del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Zoología de Invertebrados I; Argentina. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Leroy, Clémentine. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Leray, Carole. Institut de Recherche de la Tour du Valat; FranciaFil: Carron, Eric. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Mulero, Stephen. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; Francia. Université de Perpignan Via Domitia; FranciaFil: Caty, Céline. Institut de Recherche de la Tour du Valat; FranciaFil: Hasfia, Sarah. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Boisseau, Michel. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Saugné, Lucas. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Pineau, Olivier. Institut de Recherche de la Tour du Valat; FranciaFil: Blanchon, Thomas. Institut de Recherche de la Tour du Valat; FranciaFil: Alba, Annia. Instituto de Medicina Tropical “Pedro Kourí”; Cuba. Università di Corsica Pasquale Paoli; FranciaFil: Faugère, Dominique. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; FranciaFil: Vittecoq, Marion. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; Francia. Institut de Recherche de la Tour du Valat; FranciaFil: Hurtrez Boussès, Sylvie. Centre National de la Recherche Scientifique; Francia. Université Montpellier II; Franci

L’histoire économique entre France et Espagne, XIXe-XXe siècles

Ce numéro est un hommage au Professeur Gérard Chastagnaret, fondateur de l’UMR TELEMME et rénovateur de Rives méditerranéennes à la fin des années 1990. Il présente un ensemble de contributions qui entendent rappeler l’importance de l’activité scientifique déployée par ce chercheur dans le champ de l’histoire économique de l’Espagne et de la France, et plus largement de l’espace méditerranéen, pour les XIXe et XXe siècles. Les cinq contributions du dossier prolongent les grands thèmes de recherche qu’il a labourés au cours des quatre dernières décennies, les directions de recherche qu’il a impulsées et les principaux apports conceptuels et méthodologiques qu’il a livrés

Host-dependence of in vitro reassortment dynamics among the Sathuperi and Shamonda Simbuviruses

Orthobunyaviruses are arboviruses (Arthropod Borne Virus) and possess multipartite genomes made up of three negative RNAs corresponding to the small (S), medium (M) and large (L) segments. Reassortment and recombination are evolutionary driving forces of such segmented viruses and lead to the emergence of new strains and species. Retrospective studies based on phylogenetical analysis are able to evaluate these mechanisms at the end of the selection process but fail to address the dynamics of emergence. This issue was addressed using two Orthobunyaviruses infecting ruminants and belonging to the Simbu serogroup: the Sathuperi virus (SATV) and the Shamonda virus (SHAV). Both viruses were associated with abortion, stillbirth and congenital malformations occurring after transplacental transmission and were suspected to spread together in different ruminant and insect populations. This study showed that different viruses related to SHAV and SATV are spreading simultaneously in ruminants and equids of the Sub-Saharan region. Their reassortment and recombination potential was evaluated in mammalian and in insect contexts. A method was set up to determine the genomic background of any clonal progeny viruses isolated after in vitro coinfections assays. All the reassortment combinations were generated in both contexts while no recombinant virus was isolated. Progeny virus populations revealed a high level of reassortment in mammalian cells and a much lower level in insect cells. In vitro selection pressure that mimicked the host switching (insect-mammal) revealed that the best adapted reassortant virus was connected with an advantageous replicative fitness and with the presence of a specific segment

A scaffold-free graft for large critical size bone defect: preclinical evidence to clinical proof of concept

INTRODUCTION: Large critical size bone defect is one of the most challenging pathologies in orthopaedic surgery. This study aims to demonstrate the potential of a scaffold-free osteogenic approach. METHODS: The bioactivity of the scaffold-free graft was in vivo studied in 2 nude rat models: (i) the comparison of fresh/decellularized grafts in term of angiogenesis (up to 1 month) in a fibrotic tissue (in a cauterized muscular pocket,n=20);(ii) the in vivo osteogenicity of the scaffold-free graft (in comparison to HA/bTCP bone substitute) was assessed, at 1/2/3 months postimplantation, in an irreversible femoral critical size bone defect (n=28). The angiogenesis was quantified by histomorphometry while the osteogenesis was studied by micro-CTscan and Q-RTPCR (for osteogenic genes expression) on graft explants. A 5-year-old boy with congenital pseudarthrosis of the tibia was proposed for the autologous scaffold-free graft approach. At 3 months post-AT procurement, the 3D-graft was placed into the defect in view to be followed clinically/radiologically. RESULTS: After intra-muscular transplantation, cellular survival (with major osteogenic genes expression) of human ASCs and the promotion of angiogenesis was found at 1month postimplantation. A complete integration and bone fusion were found (at 4/8 weeks postimplantation in the femoral defect) for the 3D graft in comparison to the bone substitute alone which revealed a lack of tissue remodelling and osteogenesis. Specific genes of the skeletal development were overexpressed in the bone defect treated with the 3D grafts (at 4/8 weeks post-implantation) while no osteoinduction was found for the HA/bTCP alone. A large volume (>15cm3) of the 3D graft was manufactured in GMP and then implanted without any modification of the surgical procedure. The graft was easily handled and implanted. The graft demonstrated a continuous remodelling (with bone formation) up to 14 months post-implantation to obtain a sufficient bone fusion (allowing walk without pain) and no recurrence of the disease. CONCLUSION: The scaffold-free 3D-graft (made of ASCs) play a major role to promote ASCs engraftment and consequence to induce osteogenesis in a fibrotic environment and to recover a bone fusion in a critical-sized bone defect

A scaffold-free graft for large critical size bone defect: preclinical evidence to clinical proof of concept

Background & Aim : Large critical-sized bone defect (CBD) remains a challenging pathology in orthopaedics. The direct application of adipose stem cells (ASCs) remains limited by a low homing efficiency and a low survival rate. This study aims to show the osteogenic role of ASCs in a scaffold-free approach. [...

Genetic diversity and relationships of the liver fluke <i>Fasciola hepatica</i> (Trematoda) with native and introduced definitive and intermediate hosts

International audienceFasciolosis is a worldwide spread parasitosis mainly caused by the trematode Fasciola hepatica. This disease is particularly important for public health in tropical regions, but it can also affect the economies of many developed countries due to large infections in domestic animals. Although several studies have tried to understand the transmission by studying the prevalence of different host species, only a few have used population genetic approaches to understand the links between domestic and wildlife infections. Here, we present the results of such genetic approach combined with classical parasitological data (prevalence and intensity) by studying domestic and wild definitive hosts from Camargue (southern France) where fasciolosis is considered as a problem. We found 60% of domestic hosts (cattle) infected with F. hepatica but lower values in wild hosts (nutria, 19%; wild boars, 4.5%). We explored nine variable microsatellite loci for 1,148 adult flukes recovered from four different populations (non-treated cattle, treated cattle, nutria and wild boars). Populations from the four groups differed, though we found a number of migrants particularly non-treated cattle and nutria. Overall, we detected 729 different multilocus genotypes (from 783 completely genotyped individuals) and only 46 genotypes repeated across samples. Finally, we experimentally infected native and introduced intermediate snail hosts to explore their compatibility with F. hepatica and assess the risks of fasciolosis expansion in the region. The introduced species Galba truncatula and Pseudosuccinea columella attained the higher values of overall compatibility in relation to the European species. However, concerning the origin, sympatric combinations of G. truncatula were more compatible (higher prevalence, intensity and survival) than the allopatric tested. According to our results, we should note that the assessment of epidemiological risks cannot be limited to a single host–parasite system, but should focus on understanding the diversity of hosts in the heterogeneous environment through space and time

Host-dependence of in vitro reassortment dynamics among the Sathuperi and Shamonda Simbuviruses

Orthobunyaviruses are arboviruses (Arthropod Borne Virus) and possess multipartite genomes made up of three negative RNAs corresponding to the small (S), medium (M) and large (L) segments. Reassortment and recombination are evolutionary driving forces of such segmented viruses and lead to the emergence of new strains and species. Retrospective studies based on phylogenetical analysis are able to evaluate these mechanisms at the end of the selection process but fail to address the dynamics of emergence. This issue was addressed using two Orthobunyaviruses infecting ruminants and belonging to the Simbu serogroup: the Sathuperi virus (SATV) and the Shamonda virus (SHAV). Both viruses were associated with abortion, stillbirth and congenital malformations occurring after transplacental transmission and were suspected to spread together in different ruminant and insect populations. This study showed that different viruses related to SHAV and SATV are spreading simultaneously in ruminants and equids of the Sub-Saharan region. Their reassortment and recombination potential was evaluated in mammalian and in insect contexts. A method was set up to determine the genomic background of any clonal progeny viruses isolated after in vitro coinfections assays. All the reassortment combinations were generated in both contexts while no recombinant virus was isolated. Progeny virus populations revealed a high level of reassortment in mammalian cells and a much lower level in insect cells. In vitro selection pressure that mimicked the host switching (insect-mammal) revealed that the best adapted reassortant virus was connected with an advantageous replicative fitness and with the presence of a specific segment

Host-dependence of in vitro reassortment dynamics among the Sathuperi and Shamonda Simbuviruses

Orthobunyaviruses are arboviruses (Arthropod Borne Virus) and possess multipartite genomes made up of three negative RNAs corresponding to the small (S), medium (M) and large (L) segments. Reassortment and recombination are evolutionary driving forces of such segmented viruses and lead to the emergence of new strains and species. Retrospective studies based on phylogenetical analysis are able to evaluate these mechanisms at the end of the selection process but fail to address the dynamics of emergence. This issue was addressed using two Orthobunyaviruses infecting ruminants and belonging to the Simbu serogroup: the Sathuperi virus (SATV) and the Shamonda virus (SHAV). Both viruses were associated with abortion, stillbirth and congenital malformations occurring after transplacental transmission and were suspected to spread together in different ruminant and insect populations. This study showed that different viruses related to SHAV and SATV are spreading simultaneously in ruminants and equids of the Sub-Saharan region. Their reassortment and recombination potential was evaluated in mammalian and in insect contexts. A method was set up to determine the genomic background of any clonal progeny viruses isolated after in vitro coinfections assays. All the reassortment combinations were generated in both contexts while no recombinant virus was isolated. Progeny virus populations revealed a high level of reassortment in mammalian cells and a much lower level in insect cells. In vitro selection pressure that mimicked the host switching (insect-mammal) revealed that the best adapted reassortant virus was connected with an advantageous replicative fitness and with the presence of a specific segment

Guidelines for the use and interpretation of assays for monitoring autophagy

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field