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[anses-04372908] Exploring the relationship between Faecalibacterium duncaniae and Escherichia coli in inflammatory bowel disease (IBD): Insights and implications
Inflammatory bowel disease (IBD) is a group of disorders characterized by an inflammation of the gastrointestinal tract (GIT) and represents a major social and economic burden. Despite ongoing research into the etiology and pathophysiology of this multifactorial disease, treatment options remain limited. From this perspective, the gut microbiota has emerged as a potential player in the pathogenesis of IBD, and animal and human studies support this hypothesis. Indeed, the human gut is one of the most complex ecological communities (composed of 1013-1014 microorganisms) that plays a critical role in human health by influencing normal physiology and disease susceptibility through its collective metabolic activities and host interactions. In addition, live probiotic bacteria present in some food products (which transit through the GIT) have been shown to interact with the host immune system and confer several health benefits. The aim of this review is to provide an overview of the link between Faecalibacterium duncaniae and Escherichia coli and IBD, highlighting the main areas of research in this field. An ecological perspective on the gut microbiota may offer new insights for the development of clinical therapies targeting this bacterial community to improve human health.
ano.nymous@ccsd.cnrs.fr.invalid (Alejandro Cabezas-Cruz) 08 Feb 2024
https://anses.hal.science/anses-04372908v1
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[hal-04693283] Broad range molecular detection methods identify only Borrelia spp. in erythema migrans biopsies and blood of tick-bitten patients
In this multicenter study conducted in France, we challenged the hypothesis of the transmission of pathogens other than Borrelia spp. in 22 patients developing erythema migrans following a tick bite. Using a combination of high-throughput microfluidic PCRs and agnostic metagenomics on skin biopsies and blood samples, no microorganisms other than Borrelia spp. was found.
ano.nymous@ccsd.cnrs.fr.invalid (Philippe Pérot) 12 Sep 2024
https://hal.inrae.fr/hal-04693283v1
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[hal-04693288] Contributions of birds to the feeding of ticks at host community level: Effects of tick burden, host density and yearly fluctuations
The eco-epidemiology of tick-borne diseases hinges on the abundance and distribution of hosts that sustain tick populations and the pathogens they carry. Research into the role of bird species in the feeding of Ixodes ricinus ticks, the primary tick species of veterinary and public health importance in Europe, remains scarce. This study endeavors to bridge these knowledge gaps by (i) assessing the density of feeding ticks (DFT) within a bird community to pinpoint species making substantial contributions, and (ii) exploring interannual variations in DFT over an extended timeline. Furthermore, we investigate whether variations in individual tick burden (TB) were more closely associated with the characteristics of bird species or interannual variations affecting the density of questing tick, using interannual TB variation as a surrogate. To fulfill these aims, we conducted a 13-year longitudinal study monitoring I. ricinus ticks feeding on a bird community in a periurban forest in France, covering breeding periods from 2007 to 2019. Within this community, we identified seven principal bird species significantly contributing to I. ricinus tick feeding: the Common Blackbird (Turdus merula), the Song Thrush (Turdus philomelos), the European Robin (Erithacus rubecula), the Dunnock (Prunella modularis), the Eurasian Blackcap (Sylvia atricapilla), the Great Tit (Parus major), and the Common Nightingale (Luscinia megarhynchos). Our results show that the bird community’s contribution to tick feeding remained relatively consistent from year-to-year, though certain years displayed higher or lower DFT values related to the average over the study period. Moreover, five out the seven major species accounted for 80 % to 95 % of DFT annually. Consequently, we emphasized the need to broaden the scope of future research on bird contributions to tick population dynamics beyond merely thrushes (Turdidae species), to encompass a more diverse range of species, particularly those common birds that engage in ground foraging activities. Furthermore, variations in individual tick burden were predominantly influenced by the characteristics of bird species rather than by interannual variability in infestation rates. This finding suggests a significant role for species-specific traits in determining tick exposure and susceptibility. In conclusion, our study offers new insights into the medium-term dynamics of tick-bird ecological systems, underscoring the need for future study of tick populations and their interactions with vertebrate hosts to improve our understanding of tick-borne disease circulation.
ano.nymous@ccsd.cnrs.fr.invalid (Amalia Rataud) 10 Sep 2024
https://hal.inrae.fr/hal-04693288v1
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[hal-04764916] Nested patterns of commensals and endosymbionts in microbial communities of mosquito vectors
Abstract Background Mosquitoes serve as vectors for numerous pathogens, posing significant health risks to humans and animals. Understanding the complex interactions within mosquito microbiota is crucial for deciphering vector-pathogen dynamics and developing effective disease management strategies. Here, we investigated the nested patterns of Wolbachia endosymbionts and Escherichia-Shigella within the microbiota of laboratory-reared Culex pipiens f. molestus and Culex quinquefasciatus mosquitoes. We hypothesized that Wolbachia would exhibit a structured pattern reflective of its co-evolved relationship with both mosquito species, while Escherichia-Shigella would display a more dynamic pattern influenced by environmental factors. Results Our analysis revealed different microbial compositions between the two mosquito species, although some microorganisms were common to both. Network analysis revealed distinct community structures and interaction patterns for these bacteria in the microbiota of each mosquito species. Escherichia-Shigella appeared prominently within major network modules in both mosquito species, particularly in module P4 of Cx. pipiens f. molestus , interacting with 93 nodes, and in module Q3 of Cx. quinquefasciatus , interacting with 161 nodes, sharing 55 nodes across both species. On the other hand, Wolbachia appeared in disparate modules: module P3 in Cx. pipiens f. molestus and a distinct module with a single additional taxon in Cx. quinquefasciatus , showing species-specific interactions and no shared taxa. Through computer simulations, we evaluated how the removal of Wolbachia or Escherichia-Shigella affects network robustness. In Cx. pipiens f. molestus , removal of Wolbachia led to a decrease in network connectivity, while Escherichia-Shigella removal had a minimal impact. Conversely, in Cx. quinquefasciatus , removal of Escherichia-Shigella resulted in decreased network stability, whereas Wolbachia removal had minimal effect. Conclusions Contrary to our hypothesis, the findings indicate that Wolbachia displays a more dynamic pattern of associations within the microbiota of Culex pipiens f. molestus and Culex quinquefasciatus mosquitoes, than Escherichia - Shigella . The differential effects on network robustness upon Wolbachia or Escherichia-Shigella removal suggest that these bacteria play distinct roles in maintaining community stability within the microbiota of the two mosquito species.
ano.nymous@ccsd.cnrs.fr.invalid (Justė Aželytė) 04 Nov 2024
https://hal.science/hal-04764916v1
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[hal-04764999] New TBV monitoring tools.
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ano.nymous@ccsd.cnrs.fr.invalid (Sara Moutailler) 04 Nov 2024
https://hal.inrae.fr/hal-04764999v1
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[hal-04752519] Culicoides biting midges among cattle in France: be wary of data in the literature
Culicoides are vectors that can transmit many different pathogens to mammals — including humans, and domestic and wild animals — and birds. In order to take preventive measures against any vector-borne disease, it is important to gather information on both the host and vector species. Culicoides species are mainly mammalophilic, ornithophilic or ornithophilic/mammalophilic, but females have also been found to occasionally feed on engorged insects. A recent systematic review based on three groups of key words investigated Culicoides on farms, and asserted that 92 species (including four not present species) have been reported among cattle in mainland France and Corsica. We have re-evaluated the presence of Culicoides species in cattle in France using the same data of the review. Our data show that only 18 species are reported among cattle. Furthermore, our research used molecular and indirect investigations to analyse Culicoides species that had been feeding on cattle. Our results demonstrate that 45 species feed on cattle out of 92 species present in France. The paper discusses the relevance of data in the literature when investigating hosts of Culicoides species.
ano.nymous@ccsd.cnrs.fr.invalid (Christine Millot) 24 Oct 2024
https://hal.science/hal-04752519v1
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[hal-04765006] Integrative approaches to Managing Tick-borne Diseases : Modelling coinfections and Harnessing Vector Microbiome Vaccines.
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ano.nymous@ccsd.cnrs.fr.invalid (Sara Moutailler) 04 Nov 2024
https://hal.inrae.fr/hal-04765006v1
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[hal-04746356] Non-destructive DNA extraction in ticks : a method to keep the shape !
“My DNA? At the price of my good shape? No way” it is what are thinking all of the ticks when we ask them for more information about their genetic and morphology. Even old specimens from Museum collection (the alcohol-preserved ticks), want to keep their integrity. That is why, to help researchers in their study and to preserve morphology (and mood) of these specimens, non-destructive DNA extraction protocol was applied on Ixodes ricinus (larvae, nymphs and adults -female and male) conserved since 2007 in alcohol 70%. The method can extract on average of 69ng of DNA (in a final volume of 30 µl). 16S fragments were successfully amplified and sequenced for all the stages. Photo shoot under stereomicroscope for all of the stages, reassures ticks and researchers that ticks keep there chitinous exoskeleton intact but clarified. Using the outline-based geometric morphometry approach, the contour of the first coxa of larvae, nymphs and adults, a diagnostic character frequently used to discriminate different species, was investigated. Our result shows that the coxa 1 is not altered by the DNA extraction. The method is fast, cheap. No body shaming for ticks: the non-destructive DNA extraction preserves the ticks and their morphological characteristics for future reference. It is a valuable aid for integrative taxonomy of ticks.
ano.nymous@ccsd.cnrs.fr.invalid (Camille Lorang) 21 Oct 2024
https://hal.science/hal-04746356v1
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[hal-04746026] Optimizing the production of the Anaplasma phagocytophilum genome, a crucial step in understanding virulence and host tropism
Introduction and Objectives Anaplasma phagocytophilum (Aph) is a strict intracellular bacterium transmitted by Ixodes spp. ticks. It infects humans, mainly in the USA, whereas in Europe, ruminants are strongly affected. Hosts and clinical signs are strain dependent. Genomes are too few on NCBI (33) and may have a questionable quality and completeness to identify genetic factors responsible for these differences. The lack of quality is hindered by the difficulty in isolating and cultivating Aph and separating Aph DNA from the vertebrate host genome. The goal of this project is to implement long read Oxford Nanopore Sequencing (ONS) to obtain more diverse genomes to compare them with those already published, for downstream applications such as phylogeny analysis, improvement of diagnosis. Material and Methods We performed ONS, which produces less fragmented genomes than short-read technology and increases genome completeness, on three samples: two Aph-infected cell cultures, with significantly higher Aph to host DNA ratios, and one blood sample from a naturally Aph-infected cow, with a low abundance of bacterial DNA. Sequencing results were filtered to eliminate host DNA and retain specific Aph sequences prior to assembly with Flye to obtain high-quality genomes. Assemblies were performed on subsampled reads at different coverage levels (10x to 100x) to evaluate the minimum number of reads required for high-quality genomes. Results, Discussion, and Conclusion For cultured samples, we obtained 88% and 30% Aph from total sequences, corresponding to a bacterial genome coverage exceeding 1000x. We found that at 20x coverage, assemblies had good quality with a median of 2 contigs, a genome size of 1.5 Mb, and a 41.66% GC content, like published reference genome. For the blood sample, the ratio of Aph to host DNA was much lower, with only 0.03% Aph sequences observed. Therefore, we will perform adaptive sampling, an ONS specific method that enriches or depletes samples during sequencing. It will help increase Aph sequences obtained from blood samples collected from different hosts and geographic locations. This will help to generate more Aph reference genomes and thus to elucidate its pathogenicity. It will also enable us to improve diagnostic sensitivity in infected animals and humans.
ano.nymous@ccsd.cnrs.fr.invalid (Harivel Thomas) 21 Oct 2024
https://hal.science/hal-04746026v1
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[hal-04764927] Differential impact of Paenibacillus infection on the microbiota of Varroa destructor and Apis mellifera
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ano.nymous@ccsd.cnrs.fr.invalid (Štefánia Skičková) 04 Nov 2024
https://hal.science/hal-04764927v1
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[hal-04729931] Assessment of the infection level of young equids by Parascaris spp. in Normandy
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ano.nymous@ccsd.cnrs.fr.invalid (Kenza Bourrier) 10 Oct 2024
https://hal.science/hal-04729931v1
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[hal-04724520] Octopamine and alpha2 adrenergic-like octopamine receptors in Ixodes ricinus salivary glands.
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ano.nymous@ccsd.cnrs.fr.invalid (Sabine Rakotobe) 07 Oct 2024
https://hal.inrae.fr/hal-04724520v1
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[hal-04724459] Two Types of Axonal Muscarinic Acetylcholine Receptors Mediate Formation of Saliva Cocktail in the Tick Ixodes ricinus.
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ano.nymous@ccsd.cnrs.fr.invalid (Ladislav Šimo) 07 Oct 2024
https://hal.inrae.fr/hal-04724459v1
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[hal-04709588] Enquête européenne multicentrique sur la contamination des salades prêtes à l’emploi (ready to eat salads) par les oocystes de Toxoplasma gondii
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ano.nymous@ccsd.cnrs.fr.invalid (Nadja S. Bier) 25 Sep 2024
https://hal.science/hal-04709588v1
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[hal-04707231] Les explants intestinaux félins comme modèle d’étude des interactions hôte/pathogène entre Toxoplasma gondii et la réponse immunitaire de la muqueuse intestinale de son hôte définitif.
Introduction : Toxoplasma gondii est considéré par la FAO/OMS comme le 3ème parasite d’origine alimentaire le plus menaçant pour la santé publique, parmis 31 identifiés en Europe. Le développement de vaccins ou de traitements contre la toxoplasmose, animale ou humaine, est fortement affecté par le manque de connaissances sur le cycle de reproduction sexuée du parasite, qui ne se produit que chez les félins, hôtes définitifs du parasite. Ainsi, l’objectif de notre projet est d’étudier les interactions entre T. gondii et le micro-environnement intestinal félin, afin de mieux comprendre la réponse immunitaire locale au niveau de la muqueuse et son impact sur le cycle du parasite. Méthodes : Les explants intestinaux ont déjà été utilisés pour l’étude des pathologies intestinales chez différentes espèces, mais jamais chez le chat, encore à l’heure actuelle. Nous proposons donc le développement d’un modèle d’explant intestinal félin, à partir de fragments de duodénum et d’iléon. Nous avons pu utiliser ce modèle en appliquant la technologie RNAscope® sur les tissus intestinaux afin d’étudier l’expression de diverses cytokines en fonction de différentes conditions de culture, ainsi qu’en présence ou en l’absence du parasite T. gondii. Résultats : Les entérocytes des explants peuvent être infectés par des tachyzoites de T. gondii dans les 24h post-infection, en conditions in-vitro et hyperoxiques. La production de cytokines en réaction à ces conditions a également pu être détectée. Cependant, l’incubation en conditions hyperoxiques induit des variations d’expression des cytokines, autant pour la voie Th1 que pour la voie Th2. Discussion / Conclusion : Ces premiers résultats confirment la possibilité d’utiliser le modèle des explants intestinaux ainsi que la technologie RNAscope® pour l’étude des interactions entre T. gondii et la muqueuse intestinale féline, ainsi que la réponse immunitaire associée. Une meilleure compréhension de ces interactions spécifiques à l’espèce de l’hôte définitif du parasite pourra aider au développement de stratégies vaccinales afin de mieux protéger la santé animale et la santé publique.
ano.nymous@ccsd.cnrs.fr.invalid (Julie Rouzet) 24 Sep 2024
https://hal.science/hal-04707231v1
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[hal-04716177] Cryptosporidium parvum et microbiote intestinal : une piste de recherche de nouvelles thérapies alternatives.
La cryptosporidiose est zoonose à l’origine de diarrhées chez l’Homme et chez l’animal notamment les jeunes ruminants. Elle est provoquée par des protozoaires à apicomplexe intracellulaires mais extracytoplasmiques dépendants de la cellule parasitée pour leur métabolisme, isolés des voies de délivrance de molécules actives et de la réponse immunitaire de l’hôte, et très résistants dans l’environnement. Il n’existe pas présentement de thérapies complètement efficaces disponibles aussi bien chez l’homme que chez l’animal. En étant impliquée dans la prévention et le traitement des diarrhées néonatales à Cryptosporidium chez les jeunes ruminants, la médecine vétérinaire joue un rôle crucial dans la limitation de la contamination environnementale par les oocystes parasitaires. Le microbiote intestinal est impliqué dans de nombreuses fonctions de l’organisme, car certaines molécules produites dans l’intestin passent dans la circulation sanguine et peuvent atteindre tous les organes y compris le cerveau. Le microbiote intestinal joue un rôle fondamental dans la digestion. Il dégrade les aliments complexes que l’organisme est incapable de digérer seul. Un autre rôle majeur est de protéger l’organisme des différents pathogènes en réagissant avec le système immunitaire. La perturbation du microbiote intestinal par Cryptosporidium a été rapportée chez des souris adultes immunodéprimées, mais aucune étude n’a été faite ni sur les souriceaux ni sur les chevreaux. L'objectif de cette étude est d'évaluer l'efficacité de la levure vivante Saccharomyces cerevisiae (Sc 5 et Sc 3-A) pour prévenir la cryptosporidiose expérimentale chez les chevreaux nouveau-nés infectés expérimentalement par la souche Iowa de Cryptosporidium parvum. Quarante chevreaux mâles âgés de 1 jour (race Alpine) ont été répartis en 4 groupes : 1) le groupe témoin non infecté 2) le groupe témoin infecté 3) le groupe infecté supplémenté avec Sc 3-A 4) le groupe infecté supplémenté avec Sc 5. Cette supplémentation a été effectuée quotidiennement pendant 26 jours. Les groupes infectés ont été inoculés par voie orale avec 106 oocystes de la souche Iowa de C. parvum. La supplémentation en levures vivantes a permis d'améliorer l'hydratation des animaux, de réduire l'intensité et la durée de la diarrhée et de l'infection. La supplémentation en Sc 5 a été plus efficace que la supplémentation en Sc 3-A pour maintenir la température des animaux dans une fourchette physiologique, pour améliorer le gain de poids quotidien et l'état général des animaux (score de santé et score de déshydratation). La supplémentation par les deux levures n'a pas retardé l'apparition de la diarrhée. L'examen histologique effectué 6 jours après l'infection a révélé des stades parasitaires et des changements microscopiques principalement limités à l'iléon. La supplémentation alimentaire en levures vivantes (Sc 5) module de manière bénéfique le profil du microbiote intestinal, directement ou indirectement, de telle sorte que la prolifération de C. parvum est défavorable pendant la période néonatale. Ces résultats indiquent que la supplémentation alimentaire en levures vivantes, principalement par Sc 5, réussit à prévenir la diarrhée et à restaurer la dysbiose. Par conséquent, l'utilisation d'une supplémentation en levures vivantes dans l'alimentation des ruminants pourrait être une méthode alternative intéressante pour lutter contre cette parasitose.
ano.nymous@ccsd.cnrs.fr.invalid (Mohamed Mammeri) 01 Oct 2024
https://hal.inrae.fr/hal-04716177v1
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[hal-04729698] Evaluation of Cryptocotyle lingua (Digenea) zoonotic potential by in vivo infestation
Marine fish are often speckled with “black spots” caused by host response to larval trematode infection. These unattractive spots and the presence of parasites may lead to important economic loss in fishery and may have impacts on public health. As many other zoonotic trematodes, Cryptocotyle (Lühe, 1899) are present in marine fish species. Human may be infected by consumption of raw or undercooked fish products. Characterized as zoonotic by Chai and Jung (2017) based on Babbott et al. (1961) human case description in 1999, its impact on human health is still unclear. For the first time, this study intends to characterize Cryptocotyle zoonotic potential. Beforehand conditions of conservation of Cryptocotyle metacercariae were set to organize scheduling of isolation of metacercariae from fish. Then, in vivo trials were performed on mice. After ingestion of 500 Cryptocotyle ligua metacercariae per mouse, daily monitoring of mice was undertaken by observation of their behavior, weight record and fecal time report. Mice were sacrificed twenty-one days post infection and organs were collected for observations of parasites or lesions. This survey constitutes the first analysis of Cryptocotyle lingua zoonotic potential by in vivo experiments. References: Babbott, F. L. J. , Frye, W. W., & Gordon, J. E. (1961). Intestinal parasites of man in Artic Greenland. The American journal of tropical medicine and hygiene, 10, 185-190. Chai, J. Y., & Jung, B.-K. (2017). Fishborne zoonotic heterophyid infections: An update [Article]. Food and Waterborne Parasitology, 8-9, 33-63.
ano.nymous@ccsd.cnrs.fr.invalid (Maureen Duflot) 10 Oct 2024
https://hal.science/hal-04729698v1
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[hal-04690776] Differential interactions of Rickettsia species with tick microbiota in Rh. sanguineus and Rh. turanicus
Tick-borne rickettsioses, caused by Gram-negative bacteria of the Rickettsia genus, pose a growing global threat, with various arthropod vectors contributing to their transmission. Understanding the complex interactions within tick microbiota, including the role of Rickettsia species, is crucial for elucidating the dynamics of rickettsial diseases. Here, we investigate the taxonomic profiles and co-occurrence networks of Rickettsia in Rh. sanguineus sensus lato (s.l.) and Rh. turanicus ticks, revealing significant differences in community composition and local connectivity of Rickettsia species. While the microbiota of both tick species share common taxa, distinct differences in relative abundance and network topology suggest unique ecological niches. Moreover, robustness analysis demonstrates varying resilience to perturbations, indicating different strategies for network organization. Our findings also highlight metabolic differences between tick species, suggesting potential implications for Rickettsia interactions. Overall, this study provides insights into the intricate microbial landscape within ticks, shedding light on the functional redundancy and metabolic pathways associated with Rickettsia, thus advancing our understanding of tick-borne diseases.
ano.nymous@ccsd.cnrs.fr.invalid (Apolline Maitre) 06 Sep 2024
https://hal.science/hal-04690776v1
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[hal-04691674] Peri-domestic entomological surveillance using private traps allows detection of dengue virus in Aedes albopictus during an autochthonous transmission event in mainland France, late summer 2023
While locally-acquired dengue virus (DENV) human infections occur in mainland France since 2010, data to identify the mosquito species involved and to trace the virus are frequently lacking. Supported by a local network gathering public health agencies and research laboratories, we analysed, in late summer 2023, mosquitoes from privately-owned traps within a French urban neighbourhood affected by a dengue cluster. The cluster, in Auvergne-Rhône-Alpes, comprised three cases, including two autochthonous ones. Upon return from a recent visit to the French Caribbean Islands, the third case had consulted healthcare because of dengue-compatible symptoms, but dengue had not been recognised. For the two autochthonous cases, DENV-specific antibodies in serum or a positive quantitative PCR for DENV confirmed DENV infection. The third case had anti-flavivirus IgMs. No DENV genetic sequences were obtained from affected individuals but Aedes albopictus mosquitoes trapped less than 200 m from the autochthonous cases’ residence contained DENV. Genetic data from the mosquito-derived DENV linked the cluster to the 2023–2024 dengue outbreak in the French Caribbean Islands. This study highlights the importance of raising mosquito-borne disease awareness among healthcare professionals. It demonstrates Ae. albopictus as a DENV vector in mainland France and the value of private mosquito traps for entomo−virological surveillance.
ano.nymous@ccsd.cnrs.fr.invalid (Barbara Viginier) 10 Sep 2024
https://hal.science/hal-04691674v1
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[hal-04690771] Disruption of bacterial interactions and community assembly in Babesia-infected Haemaphysalis longicornis following antibiotic treatment
Background : A previous study highlighted the role of antibiotic-induced dysbiosis in the tick microbiota, facilitating the transstadial transmission of Babesia microti from nymph to adult in Haemaphysalis longicornis. This study builds on previous findings by analyzing sequence data from an earlier study to investigate bacterial interactions that could be linked to enhanced transstadial transmission of Babesia in ticks. The study employed antibiotic-treated (AT) and control-treated (CT) Haemaphysalis longicornis ticks to investigate shifts in microbial community assembly. Network analysis techniques were utilized to assess bacterial interactions, comparing network centrality measures between AT and CT groups, alongside studying network robustness and connectivity loss. Additionally, functional profiling was conducted to evaluate metabolic diversity in response to antibiotic treatment. Results : The analysis revealed notable changes in microbial community assembly in response to antibiotic treatment. Antibiotic-treated (AT) ticks displayed a greater number of connected nodes but fewer correlations compared to control-treated (CT) ticks, indicating a less interactive yet more connected microbial community. Network centrality measures such as degree, betweenness, closeness, and eigenvector centrality, differed significantly between AT and CT groups, suggesting alterations in local network dynamics due to antibiotic intervention. Coxiella and Acinetobacter exhibited disrupted connectivity and roles, with the former showing reduced interactions in AT group and the latter displaying a loss of connected nodes, emphasizing their crucial roles in microbial network stability. Robustness tests against node removal showed decreased stability in AT networks, particularly under directed attacks, confirming a susceptibility of the microbial community to disturbances. Functional profile analysis further indicated a higher diversity and richness in metabolic capabilities in the AT group, reflecting potential shifts in microbial metabolism as a consequence of antimicrobial treatment.
ano.nymous@ccsd.cnrs.fr.invalid (Myriam Kratou) 06 Sep 2024
https://hal.science/hal-04690771v1
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[hal-04707053] Feline intestinal explant model to study interactions of Toxoplasma gondii with mucosal immune responses of its definitive host
Introduction : Toxoplasma gondii is considered the third most important of 31 foodborne parasites identified in Europe by the FAO/WHO, threatening public health. The development of effective vaccines or drugs against animal and human toxoplasmosis, has been hampered by a lack of data on the sexual reproductive cycle of T. gondii which occurs only in felids. Therefore, we aim to study the interactions of T. gondii with the feline intestinal microenvironment to decipher the local mucosal immune response and understand its impact on parasite life cycle. Methods: Intestinal explants have previously been used to study intestinal pathologies in various species, but until now cat specific models are lacking. Here we report the development of a feline intestinal explant model including both duodenum and ileum tissues. Using this model, we applied RNASCope® technology on the intestinal tissue to study cytokine expression in different culture conditions and in presence or not of T. gondii. Results : Explant enterocytes can be infected by T. gondii tachyzoites within 24h of infection in vitro in hyperoxic conditions and host cytokine responses can be detected. However, incubation in these hyperoxic conditions induced variations in both Th1 and Th2 cytokine expression. Discussion/Conclusion : These preliminary results validate the use of intestinal explants and the RNASCope® technology to study T. gondii interactions with the feline intestinal mucosa and the immune response of the definitive host. A better understanding of these species-specific interactions will help develop vaccine strategies for improved animal and public health.
ano.nymous@ccsd.cnrs.fr.invalid (Julie Rouzet) 24 Sep 2024
https://hal.science/hal-04707053v1
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[hal-04633489] Differential nested patterns of Anaplasma marginale and Coxiella-like endosymbiont across Rhipicephalus microplus ontogeny
Understanding the intricate ecological interactions within the microbiome of arthropod vectors is crucial for elucidating disease transmission dynamics and developing effective control strategies. In this study, we investigated the ecological roles of Coxiella-like endosymbiont (CLE) and Anaplasma marginale across larval, nymphal, and adult stages of Rhipicephalus microplus. We hypothesized that CLE would show a stable, nested pattern reflecting co-evolution with the tick host, while A. marginale would exhibit a more dynamic, non-nested pattern influenced by environmental factors and host immune responses. Our findings revealed a stable, nested pattern characteristic of co-evolutionary mutualism for CLE, occurring in all developmental stages of the tick. Conversely, A. marginale exhibited variable occurrence but exerted significant influence on microbial community structure, challenging our initial hypotheses of its non-nested dynamics. Furthermore, in silico removal of both microbes from the co-occurrence networks altered network topology, underscoring their central roles in the R. microplus microbiome. Notably, competitive interactions between CLE and A. marginale were observed in nymphal network, potentially reflecting the impact of CLE on the pathogen transstadial-transmission. These findings shed light on the complex ecological dynamics within tick microbiomes and have implications for disease management strategies.
ano.nymous@ccsd.cnrs.fr.invalid (Lianet Abuin-Denis) 03 Jul 2024
https://hal.science/hal-04633489v1
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[hal-04724448] Octopamine and alpha2 adrenergic-like octopamine receptors in Ixodes ricinus salivary glands.
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ano.nymous@ccsd.cnrs.fr.invalid (Sabine Rakotobe) 07 Oct 2024
https://hal.inrae.fr/hal-04724448v1
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[hal-04695205] Clinical and histopathological features of a chronic radiation-induced dermatitis in a dog and management with an ultra-hydrolysed collagen cream
<div><p>In this report, we present a case of chronic radiation-induced dermatitis, controlled with an ultra-hydrolysed marine collagen cream. We also describe the clinical and histopathological features of chronic radiation dermatitis in a dog.</p></div> <div>BACKGROUND<p>This article is of twofold interest. It describes for the first time, the clinical and histological aspects of chronic radiodermatitis (RD) in a dog and compares it with that described in humans. It also offers a treatment that has been shown to be effective, based on ultra-hydrolysed collagen, in a condition for which no treatment has been shown to be effective.</p></div>
ano.nymous@ccsd.cnrs.fr.invalid (Noëlle Cochet Faivre) 12 Sep 2024
https://hal.science/hal-04695205v1
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[hal-04708506] Tick-borne parasites in a high-throughput analysis era: usefulness of MALDI-TOF and Real-Time Microfluidic PCR in the study of parasite distribution in urban wildlife
The increasing abundance and distribution of hard ticks within Europe have been reported extensively over the last 10–20 years. Tick populations in urban and peri-urban environments are increasingly recognized as significant vectors for a wide array of pathogens that not only threaten the health of domestic animals but also pose a risk to public health. Urban wild animals are suitable hosts for ixodid vectors, and therefore they may play a role as reservoir of vector-borne pathogens. MALDI-TOF MS has recently been proposed as an accurate tool for arthropod identification, and this includes hard ticks’ identification. Urban wildlife is often parasitized with a wide species range of hard ticks. We decided to construct a main spectra library of ixodid ticks. For this purpose, we used specimens recovered from urban wild mammals (hedgehogs, roe deers and foxes) hosted at the Wildlife Hospital of the Veterinary College of Alfort (EnvA), in Paris, France. We succeeded to create an MSP database for the identification of Ixodes hexagonus and I. ricinus. The establishment of an Ixodes MSP bank at EnvA will allow further studies in wildlife or domestic hosts using a method considered faster and cheaper than conventional methods. This approach will increase the possibilities of vector identification by transporting specimens simply in ethanol, and will represent a valuable tool for ecological and epidemiological studies. Furthermore, we have started a preliminary study that aims to contribute to a better knowledge regarding the circulation of tick-borne pathogens in ticks recovered from urban wild mammals from Paris region. The presence of these pathogens in the blood meal ticks engorged on wild animals will provide insights into the role of urban wildlife as reservoir/sentinels for infectious diseases transmissible to domestic animals or to humans. Also, we assessed the circulation of tick-borne pathogens in urban wild mammals by blood sampling and high-throughput molecular screening.
ano.nymous@ccsd.cnrs.fr.invalid (Hélène Kpadonou) 25 Sep 2024
https://hal.science/hal-04708506v1
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[hal-04751952] Anaplasma phagocytophilum in passerines from Ile-de-France region (France), genetic characterization of variants by groEL, ankA and MLST typing
Anaplasma phagocytophilum (Aph) is a strict intracellular bacterium transmitted by ticks of the genus Ixodes. It causes granulocytic anaplasmosis (GA) in humans and various species of domestic mammals (dogs, cattle, sheep...) also called tick-borne fever (TBF) in ruminants. Contrary to TBF which is particularly prevalent in Europe and is the cause of significant economic losses, human GA is mainly found in the USA. Aph is characterized by high genetic diversity and complex epidemiological cycles, as it is also found in many wild animals (deer, rodents, birds...). Domestic species such as horses and dogs, as well as wild species such as wild boar, foxes and hedgehogs, harbor strains that are suspected of being zoonotic. Conversely, deer, rodents (voles) and shrews, as well as birds apparently, appear to harbor strains that are genetically distant from those that affect humans. Birds play an important role in the maintenance and spread of pathogens. Aph DNA has been identified in avian hosts in Europe, with prevalence rates ranging from 0% to 33.8%. However, few epidemiologic studies have been conducted on birds and Aph. Our project therefore aimed to investigating the presence of Aph in birds from urban and peri-urban areas of Ile-de-France and neighboring departments, particularly in passerines. Liver, spleen and skin samples from 680 passerines were tested for the presence of Aph DNA by qPCR targeting the msp2 gene. Three blackbirds (Turdus merula) were tested positive for Aph DNA. This corresponds to a detection rate of 0.4 % in all the birds tested and 3.3 % in the blackbirds. In a second phase, a phylogenetic study was performed targeting the groEL and ankA genes and using MLST (multilocus sequence typing). These results support the existence of an epidemiological cycle specific to birds, in France, in agreement with what is found in other European countries.
ano.nymous@ccsd.cnrs.fr.invalid (Clotilde Rouxel) 24 Oct 2024
https://hal.science/hal-04751952v1
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[hal-04677928] Tick-borne diseases at the crossroads of the Middle East and central Europe
Objectives: The Balkan Peninsula, acting as a crossroad between central Europe and the Middle East, presents diverse ecosystems supporting various tick species capable of transmitting TBDs. This study focuses on Serbia and North Macedonia, both endemic for TBDs, aiming to investigate human-biting ticks' prevalence, TBD prevalence, and major TBPs in blood samples. Patients and Methods: This prospective observational study was conducted in 2022 at two medical centers, involving 45 patients from Novi Sad, Serbia, and 17 patients from Skopje, North Macedonia. All participants had either a tick still attached or had had one removed within the preceding 48 h. The study consisted in clinical evaluations of patients and testing of patient samples and ticks for tick-borne pathogens using a High-Throughput pathogen detection system based on microfluidic real-time PCR. In addition, the study assessed the genetic diversity of the identified pathogens. Results: Ixodes ricinus was the most prevalent tick species, with varying infestation rates across various body parts. Tick species and feeding times differed between Novi Sad and Skopje. TBPs were prevalent, with Rickettsia spp. dominant in Skopje and a mix including Rickettsia aeschlimannii, , Rickettsia monacensis, , Anaplasma phagocytophilum, , and Borrelia afzelii in Novi Sad. Subclinical bacteremia occurred in 8.06% of cases, mostly involving Anaplasma spp. Clinical manifestations, primarily local hypersensitivity reactions, were observed in six patients. Phylogenetic analysis confirmed R. aeschlimannii and R. monacensis identity, highlighting genetic differences in gltA gene sequences. Conclusions: This study sheds light on the prevalence and diversity of TBPs in tick-infested individuals from Serbia and North Macedonia, contributing valuable insights into the epidemiology of TBDs in the Balkan region.
ano.nymous@ccsd.cnrs.fr.invalid (Pavle Banović) 26 Aug 2024
https://hal.science/hal-04677928v1
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[hal-04677931] Differential nested patterns of Anaplasma marginale and Coxiella-like endosymbiont across Rhipicephalus microplus ontogeny
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ano.nymous@ccsd.cnrs.fr.invalid (Lianet Abuin-Denis) 27 Aug 2024
https://hal.science/hal-04677931v1
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[hal-04724369] Novel neuropeptides involved in the salivary gland innervation of soft tick Ornithodoros moubata
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ano.nymous@ccsd.cnrs.fr.invalid (Livia Sofrankova) 07 Oct 2024
https://hal.inrae.fr/hal-04724369v1
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[hal-04724277] Activities of Two Types of Axonal Muscarinic Acetylcholine Receptors Mediate Formation of Saliva Cocktail in the Tick Ixodes ricinus.
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ano.nymous@ccsd.cnrs.fr.invalid (Caina Ning) 07 Oct 2024
https://hal.inrae.fr/hal-04724277v1
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[hal-04724331] Electromagnetic radiation alters the mRNA levels of neuropeptide genes in the Ixodes ricinus synganglion
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ano.nymous@ccsd.cnrs.fr.invalid (Livia Sofrankova) 07 Oct 2024
https://hal.inrae.fr/hal-04724331v1
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[hal-04711538] Rickettsia helvetica in C3H/HeN mice: A model for studying pathogen-host interactions
While locally-acquired dengue virus (DENV) human infections occur in mainland France since 2010, data to identify the mosquito species involved and to trace the virus are frequently lacking. Supported by a local network gathering public health agencies and research laboratories, we analysed, in late summer 2023, mosquitoes from privately-owned traps within a French urban neighbourhood affected by a dengue cluster. The cluster, in Auvergne-Rhône-Alpes, comprised three cases, including two autochthonous ones. Upon return from a recent visit to the French Caribbean Islands, the third case had consulted healthcare because of dengue-compatible symptoms, but dengue had not been recognised. For the two autochthonous cases, DENV-specific antibodies in serum or a positive quantitative PCR for DENV confirmed DENV infection. The third case had anti-flavivirus IgMs. No DENV genetic sequences were obtained from affected individuals but Aedes albopictus mosquitoes trapped less than 200 m from the autochthonous cases’ residence contained DENV. Genetic data from the mosquito-derived DENV linked the cluster to the 2023–2024 dengue outbreak in the French Caribbean Islands. This study highlights the importance of raising mosquito-borne disease awareness among healthcare professionals. It demonstrates Ae. albopictus as a DENV vector in mainland France and the value of private mosquito traps for entomo−virological surveillance.
ano.nymous@ccsd.cnrs.fr.invalid (Apolline Maitre) 27 Sep 2024
https://hal.inrae.fr/hal-04711538v1
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[hal-04715886] Non-destructive DNA extraction : a method to keep the shape !
“My DNA? At the price of my good shape? No way” it is what are thinking all of the ticks when we ask them for more information about their genetic and morphology. Even old specimens from Museum collection (the alcohol-preserved ticks), want to keep their integrity. That is why, to help researchers in their study and to preserve morphology (and mood) of these specimens, non-destructive DNA extraction protocol was applied on Ixodes ricinus (larvae, nymphs and adults -female and male) conserved since 2007 in alcohol 70%. The method can extract on average of 69ng of DNA (in a final volume of 30 µl). 16S fragments were successfully amplified and sequenced for all the stages. Photo shoot under stereomicroscope for all of the stages, reassures ticks and researchers that they are keeping their shape but whiten. The contour of the first coxa of larvae, nymphs and adults, a diagnostic character frequently used to discriminate different species was investigated using the outline-based geometric morphometric approach. Our result shows that the coxa 1 is not altered by the DNA extraction. The method is fast, cheap. No body shaming for ticks: the non-destructive DNA extraction preserves the ticks and their morphological characteristics for future reference. It is a valuable aid for integrative taxonomy of ticks.
ano.nymous@ccsd.cnrs.fr.invalid (Camille Lorang) 01 Oct 2024
https://hal.science/hal-04715886v1
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[hal-04713906] Co-infection dynamics of B. afzelii and TBEV in C3H mice
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ano.nymous@ccsd.cnrs.fr.invalid (Stefania Porcelli) 30 Sep 2024
https://hal.science/hal-04713906v1
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[hal-04710798] Intérêt et interprétation de la coproscopie chez le chien et le chat
La coproscopie vise à détecter les éléments parasitaires dans les matières fécales. Il s'agit d'un examen complémentaire qu'il faut associer à l'analyse de risque, en vue de mettre en œuvre un traitement adapté. Les connaissances actuelles permettent l'interprétation des résultats obtenus, positifs comme négatifs. Cette interprétation doit alors prendre en compte les caractéristiques des parasites, la qualité des prélèvements et la méthode utilisée. Cette étape est importante pour mettre en lien ce résultat avec l'analyse de risque réalisée par le praticien.
ano.nymous@ccsd.cnrs.fr.invalid (Marie-Pierre Callait-Cardinal) 26 Sep 2024
https://vetagro-sup.hal.science/hal-04710798v1
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[hal-04710884] Traitements des helminthoses digestives chez le chien et le chat
Il existe de nombreuses spécialités actives contre les nématodes et les cestodes, les parasites digestifs du chien ou du chat. Les experts en parasitologie, comme ceux appartenant à l'European Scientific Counsel Companion Animal Parasites (Esscap), préconisent l'utilisation de ces produits dans le cadre de programmes de traitements antiparasitaires fondés sur l'évaluation individuelle du risque d'infestation. Pour les animaux adultes, les conseils sont répartis en quatre catégories pour le chien et deux catégories pour le chat, en lien avec les risques parasitaires associés au mode de vie. Des recommandations sont fournies pour les situations particulières. La solution alternative aux traitements systématiques passe par des examens de fèces réguliers, suivis d'un traitement en cas de résultat positif.
ano.nymous@ccsd.cnrs.fr.invalid (Jacques Guillot) 26 Sep 2024
https://vetagro-sup.hal.science/hal-04710884v1
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[hal-04711546] High-throughput nanotechnologies for tick-borne pathogens detection (KeyNote Speaker)
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ano.nymous@ccsd.cnrs.fr.invalid (Sara Moutailler) 27 Sep 2024
https://hal.inrae.fr/hal-04711546v1
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[hal-04723881] Midichloria mitochondri stimulates the sylvatic cycle of Lyme spirochetes in Ixodes ricinus instars.
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ano.nymous@ccsd.cnrs.fr.invalid (C. F. Kohler) 07 Oct 2024
https://hal.inrae.fr/hal-04723881v1
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[hal-04724402] Kinin neuropeptide in the midgut endocrine cells and innervation of salivary glands of Ixodes ricinus.
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ano.nymous@ccsd.cnrs.fr.invalid (Lianet Abuin-Denis) 07 Oct 2024
https://hal.inrae.fr/hal-04724402v1
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[hal-04750531] Are our pets at risk of being infected and/or transmitting the new clade (Ib) of the Mpox virus (formerly Monkeypox)?
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ano.nymous@ccsd.cnrs.fr.invalid (Nadia Haddad) 23 Oct 2024
https://hal.science/hal-04750531v1
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[hal-04690296] Last years emerging parasites in Europe - a challenge on how to anticipate
According to WHOA, emerging diseases are new infections caused by the evolution or modification of an existing pathogen, such as a parasite, due to a change of host, vector, pathogenicity or strain. These diseases could become more numerous in the context of global warming, which could alter the range of certain parasites and/or their potential vectors. With regard to emerging parasites, the concept of emergence is associated either with a new parasite described by science or with a parasite whose area of incidence or host range is expanding. Very often, the mechanism of the emergence consists of two steps: first, the introduction of a new parasitic agent and second, its spread to a more susceptible or immunologically unadapted population. The emergence of parasites is often linked to their reservoir hosts, often found in wildlife (e.g. foxes in the case of Echinococcus multilocularis). More recently, some parasite introductions or expansion into new areas have been associated with an increase in vectors such as the recent increase of Dirofilaria repens, which emerged recently in Northern European countries. Regarding vectors, people think about biting arthropods. What about gastropods? They host many parasites, including some emerging ones. The recent emergence of Angiostrongylus cantonensis in Spain, first in Tenerife, then in Majorca and finally in mainland Spain in and around Valencia, is evidence of their importance. In addition to Human diseases, an important point is the increase in parasitic diseases also in domestic animals such as pulmonary infections in cats due to Aelurostrongylus abstrusus, Troglostrongylus brevior … Moreover, the increase and spread of Angiostrongylus chabaudi, A. vasorum, as well as the recent cases caused by A. dujardini show the importance of t aking into account terrestrial gastropods. The impact of these parasites/hosts on Global Health highlights the need for a European network, which we are currently building.
ano.nymous@ccsd.cnrs.fr.invalid (Grégory Karadjian) 06 Sep 2024
https://hal.science/hal-04690296v1
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[hal-04690313] Epidemiology of cryptosporidiosis in France and new insights on parasitic viruses - importance of one health approach
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ano.nymous@ccsd.cnrs.fr.invalid (Damien Costa) 06 Sep 2024
https://hal.science/hal-04690313v1
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[hal-04690302] In vivo study on the zoonotic potential of Cryptocotyle lingua (Digenea)
Over the last two decades, the diffusion of new eating habits and the increase of fish products demand lead to a raising risk for consumers due to fish-borne parasitic zoonosis. Cryptocotyle (Lühe, 1899) are present in marine fish species. Human may be infected by consumption of raw or undercooked fish products. Characterized as zoonotic by Chai and Jung (2017) based on Babbott et al. (1961) human case description in 1999, its impact on human health is still unclear. For the first time, this study intends to characterize Cryptocotyle zoonotic potential. Beforehand conditions of conservation of Cryptocotyle metacercariae were set to organize scheduling of isolation of metacercariae from fish. Then, in vivo trials were performed on mice. After ingestion of 500 Cryptocotyle ligua metacercariae per mouse, daily monitoring of mice was undertaken by observation of their behavior, weight record and fecal time report. Mice were sacrificed twenty-one days post infection and organs were collected for observations of parasites or lesions. This survey constitutes the first analysis of Cryptocotyle lingua zoonotic potential by in vivo experiments. References: Babbott, F. L. J. , Frye, W. W., & Gordon, J. E. (1961). Intestinal parasites of man in Artic Greenland. The American journal of tropical medicine and hygiene, 10, 185-190. Chai, J. Y., & Jung, B.-K. (2017). Fishborne zoonotic heterophyid infections: An update. Food and Waterborne Parasitology, 8-9, 33-63. Acknowledgements: The authors want to thank the Hauts-de-France region of France for financial support.
ano.nymous@ccsd.cnrs.fr.invalid (Maureen Duflot) 06 Sep 2024
https://hal.science/hal-04690302v1
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[hal-04677925] Diversity of bartonellae in mites ( Acari: Mesostigmata: Macronyssidae and Spinturnicidae ) of boreal forest bats: Association of host specificity of mites and habitat selection of hosts with vector potential
Abstract Research into various bacterial pathogens that can be transmitted between different animals and may have zoonotic potential has led to the discovery of different strains of Bartonella sp. in bats and their associated ectoparasites. Despite their enormous species diversity, only a few studies have focussed on the detection of bacterial pathogens in insectivorous bats of boreal forests and their associated Macronyssidae and Spinturnicidae mites. We collected and molecularly analysed mite samples from forest‐dwelling bat species distributed all along the boreal belt of the Palearctic, from Central Europe to Far East. Ectoparasitic mites were pooled for DNA extraction and DNA amplification polymerase chain reaction (PCRs) were conducted to detect the presence of various bacterial (Anaplasmataceae, Bartonella sp., Rickettsia sp., Mycoplasma sp.) and protozoal ( Hepatozoon sp.) pathogens. Bartonella sp. DNA was detected in four different mite species (Macronyssidae: Steatonyssus periblepharus and Spinturnicidae: Spinturnix acuminata , Sp. myoti and Sp. mystacinus ), with different prevalences of the targeted gene ( glt A, 16‐23S ribosomal RNA intergenic spacer and fts Z). Larger pools (&gt;5 samples pooled) were more likely to harbour Bartonella sp. DNA, than smaller ones. In addition, cave‐dwelling bat hosts and host generalist mite species are more associated with Bartonella spp. presence. Spinturnicidae mites may transmit several distinct Bartonella strains, which cluster phylogenetically close to Bartonella species known to cause diseases in humans and livestock. Mites with ubiquitous presence may facilitate the long‐term maintenance (and even local recurrence) of Bartonella ‐infestations inside local bat populations, thus acting as continuous reservoirs for Bartonella spp in bats.
ano.nymous@ccsd.cnrs.fr.invalid (Attila Sándor) 26 Aug 2024
https://hal.science/hal-04677925v1
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[hal-04693556] Anthropogenic electromagnetic radiation alters the transcription levels of the genes encoding the SIFamide and myoinhibitory peptide and their receptors in Ixodes ricinus synganglion
The research of the influences of man-made electromagnetic fields on tick physiology has been very sparse and long neglected since the pioneer studies published in 1996 and 2000. Once multiple behavioral tests confirmed an attraction and possible perception of electromagnetic fields in ticks, a new interest in this topic erupted in recent years. In this study, qRT-PCR is utilized to determine the changes in the mRNA transcript levels of neuropeptides SIFamide and myoinhibitory peptide ( mip and sifa ) and their representative receptors ( mip-r1 and sifa-r1 ) in the synganglia of the tick Ixodes ricinus irradiated by 900 MHz radiofrequency electromagnetic field. It was determined that 40 V/m intensity has a significant suppressory effect on the transcript levels of all genes after at least 60 minutes of constant exposure in both sexes. Commonly occurring intensity of radiation in urban areas (2 V/m) produced an elevation in mRNA levels after various timespans in every gene. A significant decrease of transcript abundances was detected in females after one hour of exposure to 2 V/m. Results of this study widen the knowledge of EMF-induced alterations in the neurophysiology of I. ricinus , the most commonly distributed hard tick in Europe.
ano.nymous@ccsd.cnrs.fr.invalid (Lívia Šofranková) 10 Sep 2024
https://hal.inrae.fr/hal-04693556v1
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[hal-04688364] Microbiota‐driven vaccination in soft ticks: Implications for survival, fitness and reproductive capabilities in Ornithodoros moubata
Abstract The Ornithodoros moubata (Om) soft tick, a vector for diseases like tick‐borne human relapsing fever and African swine fever, poses challenges to conventional control methods. With diminishing insecticide efficacy, harnessing the tick's microbiota through innovative approaches like microbiota‐driven vaccination emerges as a promising strategy for sustainable and targeted disease control. This study investigated the intricate relationship between Pseudomonas , a keystone taxon in the Om microbiome, and its impact on tick fitness, microbiome structure and network dynamics. Utilizing in silico analyses and empirical vaccination experiments, the role of Pseudomonas within microbial networks in the tick midguts (MG) and salivary glands (SG) of Om was studied. Additionally, the consequences of anti‐microbiota vaccines targeting Pseudomonas and Lactobacillus on tick fitness, microbiome diversity and community assembly were explored. The result of the study shows that in Om, Pseudomonas plays a central role in microbial networks, influencing keystone species despite being categorized as peripheral (interacting with 47 different taxa, 13 of which are keystone species). Anti‐microbiota vaccination targeting Pseudomonas and Lactobacillus yields distinct effects on tick fitness, with Pseudomonas vaccination significantly impacting female tick survival, while Lactobacillus significantly reduced oviposition and fertility. Microbiome changes post‐vaccination reveal diversity alterations, emphasizing the impact of vaccine choice. Community assembly dynamics and network robustness analyses highlight Pseudomonas ' pivotal role, in influencing topological features and network resilience. The findings of the study provide comprehensive insights into the intricate dynamics of Om microbial networks and the potential of targeted microbiota‐driven vaccines for tick control.
ano.nymous@ccsd.cnrs.fr.invalid (Ana Laura Cano-Argüelles) 05 Sep 2024
https://hal.science/hal-04688364v1
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[hal-04709526] Toxoplasma gondii genotypes and frequency in domestic cats from Romania
Background Toxoplasma gondii is a zoonotic protozoan parasite with a heteroxenus life cycle that involves felids as the definitive hosts and any warm-blooded animal, including humans, as intermediate hosts. Cats are key players in parasite transmission as they are capable of shedding high numbers of oocysts in their feces that contaminate the environment. Methods The study was performed on 31 domestic cats (31.23 +/- 27.18 months old) originating from rural and urban areas (5.17:1) in the center and north-west Romania. Feces (n = 31), blood (n = 28), and heart samples (n = 27) were collected. Fecal samples were analyzed by flotation technique, and PCR (529 bp repetitive element). Fecal samples with T. gondii oocysts were bioassayed in mice. Serum samples were analyzed by modified agglutination test and ImmunoComb for the detection of specific anti-T. gondii IgG antibodies. Heart samples were bioassayed in mice, and analyzed by PCR. Toxoplasma gondii positive samples were genotyped by nPCR-RFLP targeting eleven genetic loci (SAG1, SAG2, alt-SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Results Toxoplasma gondii oocysts were found in 2 out of 31 fecal samples collected from a 3-months old stray kitten, and a 4-years old female. In total, 17 out of 27 sera were positive for T. gondii IgG antibodies. The antibody titers in MAT ranged from 1:6 to 1:384. Toxoplasma gondii DNA was detected in 7 out of 27 heart samples, and four of them were positive also by bioassay. Six T. gondii DNA samples from bioassayed mice could be assigned to ToxoDB PCR-RFLP genotype #1 or #3 (Type II) and one T. gondii DNA from heart digest to genotype #2 (Type III). Both of these genotypes are common in Europe. Conclusions Our results revealed that the infection with T. gondii is still high in cats from Romania. The oocysts shedded by these cats represent an important source of infection for intermediate hosts, including humans. Further studies on a wider range of cases are necessary for a more exhaustive definition of the T. gondii genotypes circulating in Romania.
ano.nymous@ccsd.cnrs.fr.invalid (Adriana Györke) 26 Sep 2024
https://hal.science/hal-04709526v1
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[hal-04664424] Infection dynamics following experimental challenge of pigs orally dosed with different stages of two archetypal genotypes of Toxoplasma gondii
Toxoplasma gondii is a food-borne zoonotic parasite widespread in a variety of hosts, including humans. With a majority of infections in Europe estimated to be meat-borne, pork, as one of the most consumed meats worldwide, represents a potential risk for consumers. Therefore, we aimed to investigate the progress of T. gondii infection and tissue tropism in experimentally infected pigs, using different T. gondii isolates and infectious stages, i.e. tissue cysts or oocysts. Twenty-four pigs were allocated to treatment in four groups of six, with each group inoculated orally with an estimated low dose of either 400 oocysts or 10 tissue cysts of two European T. gondii isolates, a type II and a type III isolate. The majority of pigs seroconverted two weeks post-inoculation. Pigs infected with the type III isolate had significantly higher levels of anti-T. gondii antibodies compared to those infected with the type II isolate. Histopathological exams revealed reactive hyperplasia of the lymphatic tissue of all pigs. Additionally, a selected set of nine tissues was collected during necropsy at 50 dpi from each of the remaining 22 pigs for T. gondii DNA detection by quantitative real-time PCR. A positive result was obtained in 29.8 % (59/139) of tested tissues. The brain was identified as the most frequently positive tissue in 63.6 % (14/ 22) of the animals. In contrast, liver samples tested negative in all animals. The highest mean parasite load, calculated by interpolating the average Cq values on the standard curve made of ten-fold serial dilutions of the genomic DNA, corresponding to 100 to 104 tachyzoites/mu L, was observed in shoulder musculature with an estimated concentration of 84.4 [0.0-442.5] parasites per gram of tissue. The study highlights the variability in clinical signs and tissue distribution of T. gondii in pigs based on the combination of parasite stages and strains, with type III isolates, particularly oocysts, causing a stronger antibody response and higher tissue parasite burden. These findings suggest the need for further investigation of type III isolates to better understand their potential risks to humans.
ano.nymous@ccsd.cnrs.fr.invalid (Filip Dámek) 30 Jul 2024
https://hal.science/hal-04664424v1
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[hal-04646179] Co-infection dynamics of B. afzelii and TBEV in C3H mice: insights and implications for future research
ABSTRACT Ticks are important vectors of disease, particularly in the context of One Health, where tick-borne diseases (TBDs) are increasingly prevalent worldwide. TBDs often involve co-infections, where multiple pathogens co-exist in a single host. Patients with chronic Lyme disease often have co-infections with other bacteria or parasites. This study aimed to create a co-infection model with Borrelia afzelii and tick-borne encephalitis virus (TBEV) in C3H mice and to evaluate symptoms, mortality, and pathogen level compared to single infections. Successful co-infection of C3H mice with B. afzelii and TBEV was achieved. Outcomes varied, depending on the timing of infection. When TBEV infection followed B. afzelii infection by 9 days, TBEV symptoms worsened and virus levels increased. Conversely, mice infected 21 days apart with TBEV showed milder symptoms and lower mortality. Simultaneous infection resulted in mild symptoms and no deaths. However, our model did not effectively infect ticks with TBEV, possibly due to suboptimal dosing, highlighting the challenges of replicating natural conditions. Understanding the consequences of co-infection is crucial, given the increasing prevalence of TBD. Co-infected individuals may experience exacerbated symptoms, highlighting the need for a comprehensive understanding through refined animal models. This study advances knowledge of TBD and highlights the importance of exploring co-infection dynamics in host-pathogen interactions.
ano.nymous@ccsd.cnrs.fr.invalid (Stefania Porcelli) 12 Jul 2024
https://hal.inrae.fr/hal-04646179v1
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[hal-04629155] EDA Missense Variant in a Cat with X-Linked Hypohidrotic Ectodermal Dysplasia
Hypohidrotic ectodermal dysplasia is a developmental defect characterized by sparse or absent hair, missing or malformed teeth and defects in eccrine glands. Loss-of-function variants in the X-chromosomal EDA gene have been reported to cause hypohidrotic ectodermal dysplasia in humans, mice, dogs and cattle. We investigated a male cat exhibiting diffuse truncal alopecia with a completely absent undercoat. The cat lacked several teeth, and the remaining teeth had an abnormal conical shape. Whole-genome sequencing revealed a hemizygous missense variant in the EDA gene, XM_011291781.3:c.1042G&gt;A or XP_011290083.1:p.(Ala348Thr). The predicted amino acid exchange is located in the C-terminal TNF signaling domain of the encoded ectodysplasin. The corresponding missense variant in the human EDA gene, p.Ala349Thr, has been reported as a recurring pathogenic variant in several human patients with X-linked hypohidrotic ectodermal dysplasia. The identified feline variant therefore represents the likely cause of the hypohidrotic ectodermal dysplasia in the investigated cat, and the genetic investigation confirmed the suspected clinical diagnosis. This is the first report of an EDA-related hypohidrotic ectodermal dysplasia in cats.
ano.nymous@ccsd.cnrs.fr.invalid (Stefan J Rietmann) 28 Jun 2024
https://hal.science/hal-04629155v1
