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[hal-04828846] Guild Dynamics and Pathogen Interactions in Hyalomma Ticks From Algerian Cattle
Ticks are pivotal in transmitting a variety of pathogens that affect both humans and animals. These pathogens often occur in guilds, groups of species that exploit similar resources in similar ways. Although the composition of tick‐borne pathogen (TBP) guilds is well‐documented, the interactions among pathogens within these guilds remain poorly understood. We hypothesized that abiotic and biotic factors significantly influence the patterns of occurrence and interactions among pathogens within these guilds. To investigate this, we analyzed microfluidic‐based high‐throughput data on microorganisms from 166 Hyalomma excavatum ticks (94 male and 72 female) collected across different seasons from cattle in the central Algerian steppe using network analysis to uncover complex pathogen–pathogen interaction patterns. We found that female ticks had a higher infection rate (63.9%) with common pathogens such as Rickettsia slovaca (26.4%), unclassified Apicomplexa (22.2%), and Borrelia afzelii (19.4%). Male ticks showed a 56.4% infection rate, with Rickettsia (31.1%) and R. slovaca (16%) being the most prevalent. Notable pathogen–pathogen interactions within guilds were identified, with positive associations such as between R. slovaca and Rickettsia conorii in males, and B. afzelii and Borrelia spielmanii in females, indicating cooperative interactions. Conversely, negative associations, such as between Anaplasma phagocytophilum and Francisella tularensis , suggested competitive exclusion. The observed variation in interaction patterns under different conditions indicates that ecological determinants, both biotic and abiotic, influence pathogen association dynamics within guilds. These findings have significant implications for understanding disease transmission and developing control strategies.
ano.nymous@ccsd.cnrs.fr.invalid (Salma Kaoutar Abdelali) 10 Dec 2024
https://hal.inrae.fr/hal-04828846v1
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[hal-04846136] The network MASCARA : Identification of local vector species involved in the transmission of arboviruses
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ano.nymous@ccsd.cnrs.fr.invalid (Barbara Viginier) 18 Dec 2024
https://hal.science/hal-04846136v1
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[hal-04828854] Wide spectrum of tick-borne pathogens in juvenile Ixodes ricinus collected from autumn-migrating birds in the Vistula River Valley, Poland
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ano.nymous@ccsd.cnrs.fr.invalid (Joanna Kulisz) 10 Dec 2024
https://hal.inrae.fr/hal-04828854v1
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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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[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-04846088] Le Réseau MASCARA en Auvergne-Rhône-Alpes : identification d’espèces vectrices locales impliquées dans la transmission d’arbovirus.
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Viginier Barbara) 18 Dec 2024
https://hal.science/hal-04846088v1
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[hal-04820568] Bien regarder les comptes rendus de cytologie : erreurs fréquentes d'interprétation
Le rapport de cytologie est le medium de communication entre le pathologiste et le clinicien dont la finalité est d’aboutir au diagnostic ou diagnostic différentiel pour un patient. Son importance est majeure puisque les informations qu’il contient vont dicter la prise en charge clinique du patient par le clinicien. Cependant, la communication d’informations peut être source de confusion, parfois au détriment du patient. Il est donc essentiel de s’assurer de la meilleure transmission de ces informations entre le clinicien et le pathologiste, pour que conjointement ils arrivent aussi loin que possible dans l’établissement d’un diagnostic pour le patient.
ano.nymous@ccsd.cnrs.fr.invalid (Pierre Lucien Deshuillers) 05 Dec 2024
https://hal.science/hal-04820568v1
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[hal-04820554] Jaune... rouge, verte, noire : que dit la couleur de l'urine ?
L’urine est normalement jaune clair, jaune ou légèrement ambrée, transparente à légèrement trouble. Ces couleurs et turbidités sont le résultat du volume d’urine et de sa concentration et donc de l’état d’hydratation du patient, ainsi que de la quantité de pigments qu’elle contient : urochrome et urobiline. Une couleur anormale peut provenir d’un changement d’état de santé, du régime alimentaire, de l’administration de médicaments ou de l’environnement aboutissant à un changement de composition des pigments d’origine endogène ou pigments exogènes. Dans tous les cas, lors d’une analyse d’urine, la couleur des urines doit être examinée et reportée parce qu’elle peut donner des indications sur les processus physiopathologiques en cours. Il est aussi important de noter ces changements de couleur car ils peuvent gêner l’interprétation des plages réactives colorées de la bandelette urinaire.
ano.nymous@ccsd.cnrs.fr.invalid (Pierre Lucien Deshuillers) 05 Dec 2024
https://hal.science/hal-04820554v1
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[hal-04820540] Culot urinaire : c'est quoi ce cristal ?
L’analyse physico-chimique des urines ne donne aucune information sur la présence de cristaux dans les urines et ne suffit pas à l’interprétation correcte des résultats obtenus grâce à la bandelette urinaire. L’examen du culot urinaire permet une évaluation semi-quantitative des éléments en suspension dans les urines en revanche, en l’absence de coloration, les détails cellulaires sont peu visibles.
ano.nymous@ccsd.cnrs.fr.invalid (Pierre Lucien Deshuillers) 05 Dec 2024
https://hal.science/hal-04820540v1
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[hal-04825248] Investigating contamination of ready-to-eat salads with Toxoplasma gondii oocysts in a European-wide multicenter survey
The majority of horizontal Toxoplasma gondii infections in humans are assumed to be foodborne. The relative contribution of the meat-borne (tissue cysts) versus environmental (oocyst-driven) routes of infections is largely unknown. The consumption of unwashed raw fruits or vegetables contaminated with T. gondii oocysts has been identified as a putative risk factor. Important methodological inconsistencies and limitations have been identified in the surveys carried out worldwide in fresh produce. The present study aimed to unravel the occurrence of T. gondii oocysts in commercially available ready-to-eat (RTE) salad mixes in ten European countries. For that purpose, the detection methodology was first validated in an interlaboratory ring trial. Next, a harmonized sampling strategy and the validated methodology were implemented by all participants. In this multicentre study, weekly sampling (from October 2021 to October 2022) was set to detect seasonal variations. Two categories of RTE salad mixes (baby leaves and cut leaves mixes) were sampled to explore potential associations between oocyst contamination and cultivation and growth conditions. In the study period, 3,329 RTE salad samples were tested using a standard operating procedure (SOP) that allows molecular detection of T. gondii oocysts in such matrices with a detection limit of 10 oocysts per 30 g of salad. Robustness and sensitivity of this SOP as well as the comparability of results among the laboratories had been confirmed in the ring trial before the start of the study. The key analytical steps include oocysts recovery by sample washing followed by pelleting of the eluate by centrifugation, DNA extraction and DNA detection by triplex qPCR, targeting two multicopy fragments (529RE, B1 gene) and an internal amplification control. Positive samples were confirmed by ITS-1 single tube nested PCR followed by Sanger sequencing. This is the first European-wide study to estimate the prevalence of T. gondii oocysts in RTE leafy green salads using a validated and standardized procedure to assess the associated potential risk for human infections. This work was done as part of TOXOSOURCES project, EU Horizon 2020 Research and Innovation programme under grant agreement No 773830: One Health European Joint Programme.
ano.nymous@ccsd.cnrs.fr.invalid (Nadja S. Bier) 07 Dec 2024
https://hal.science/hal-04825248v1
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[hal-04796956] Vaccination et santé publique, le cas du mpox.
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ano.nymous@ccsd.cnrs.fr.invalid (Nadia Haddad) 21 Nov 2024
https://hal.science/hal-04796956v1
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[hal-04802710] Tick-Borne Encephalitis Virus Infection in a Two-Year-Old Child Returning from Switzerland (July–August 2023): Is It Time for TBE Immunization of Serbian Travelers?
Tick-borne encephalitis (TBE) is a vaccine-preventable viral infection that poses significant public health challenges, particularly in regions where tick-borne diseases are endemic. This case report describes a 2-year-old boy with confirmed abortive TBEV infection following a tick bite during travel to Switzerland. The patient developed fever and mild symptoms but did not exhibit central nervous system involvement. The case underscores the importance of raising awareness among healthcare providers and travelers from non-endemic areas, such as Serbia, about TBE risk and the potential benefits of preventive vaccination. Strategic immunization campaigns could mitigate the public health impact of travel-related TBE.
ano.nymous@ccsd.cnrs.fr.invalid (Verica Simin) 25 Nov 2024
https://hal.science/hal-04802710v1
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[hal-04855042] Evaluation du niveau d'infestation des poulains par Parascaris spp. en Normandie
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ano.nymous@ccsd.cnrs.fr.invalid (Kenza Bourrier) 24 Dec 2024
https://hal.science/hal-04855042v1
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[hal-04807620] Stomoxys calcitrans : un potentiel vecteur mécanique d’Anaplasma phagocytophilum ?
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ano.nymous@ccsd.cnrs.fr.invalid (Clotilde Rouxel) 27 Nov 2024
https://hal.science/hal-04807620v1
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[hal-04791479] Diversity and Distribution of Bacterial and Parasitic Tick-Borne Pathogens in Armenia, Transcaucasia
Background: Variations in the distribution and prevalence of pathogens in ticks can have significant consequences for human health. Information on these variables in Transcaucasia is scarce, so the aim of our study was to conduct a large-scale study to detect selected tick-borne infectious agents in Armenia. Methods: Overall, 209 adult ticks were collected from different hosts including 4 samples from human clothes. We tested ticks using high-throughput microfluidic single-cell real-time PCR to detect 42 genospecies of pathogens. We used GIS to determine biotic and abiotic factors governing the prevalence of pathogens and applied statistical analyses to test the association between prevalence of pathogens depending on hosts, locality and environment. Results: From 209 samples, 134 were positive to targeted pathogens. Anaplasma phagocytophilum Foggie, 1949 was the most prevalent case (44%). The highest overall prevalence was observed in ticks from sheep (74%), followed by cows (67%) and calves (60%). The highest multiple infection rates were also detected in sheep (40%) and calves (40%) followed by cows (28%). One statistically significant association was found among co-infections (P<0.05). The prevalence of pathogens varied according to locality. The abundance of Anaplasma spp. is significantly correlated with “slope” and “vegetation” factors. Similar patterns were detected for other pathogens. Conclusion: This was the first large-scale survey of multiple tick-borne pathogens in Armenia and Transcaucasia. The results of this study shed light on spatial variations in pathogen infection rate among adult ticks found on hosts and underline a number of environmental determinants of pathogen distribution among ticks.
ano.nymous@ccsd.cnrs.fr.invalid (Sargis Aghayan) 19 Nov 2024
https://hal.science/hal-04791479v1
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[hal-04808997] Taxonomie intégrative des tiques d’Afrique tropicale : actualisation des connaissances et anticipation de potentielles émergences de maladies à tiques en Europe.
Les maladies émergentes sont en recrudescence en lien avec les changements globaux observés actuellement et près d’un quart sont des maladies vectorielles. Le transport passif via les oiseaux migrateurs d’Afrique vers l’Europe semble être aussi une voie majeure d’introduction de tiques et donc potentiellement d’agents pathogènes et de nouvelles maladies vectorielles. Ainsi, sur l’île de Malte, a été recensé récemment l’import par un passereau migrateur d’une espèce d’Ixodes, du sous-genre Afrixodes, en provenance d’Afrique tropicale. Ce sous genre comprend 62 espèces, représentées actuellement uniquement en Afrique (sauf 2 espèces d’Inde), dont 9 espèces endémiques de l’île de Madagascar. Or, la taxonomie de la grande majorité des espèces de ce sous genre Afrixodes reste largement à préciser. Il manque la description des mâles chez 47% des espèces de ce sous-genre, 69% pour les nymphes et 78% pour les larves. Seulement 9 espèces d’Afrixodes disposent d’au moins une séquence déposée dans Genbank. Basée sur une large collection de tiques (681 spécimens) prélevées sur des micromammifères (rongeurs et musaraignes) d’Afrique tropicale, le travail de taxonomie intégrative proposé dans le cadre de cette thèse vise notamment à développer de nouveaux outils d’identifications moléculaires et morphologiques. Une méthode d’extraction d’ADN non-destructive, adaptée ici pour les tiques, donne accès à des données moléculaires sur les tiques et les microorganismes qu’elles hébergent (endosymbiotes, pathogènes…) tout en conservant leur intégrité corporelle, permettant ainsi des investigations relevant de la morphométrie géométrique. Cette approche intégrative permet ainsi de caractériser ces espèces et de réviser leur systématique tout en recherchant des agents pathogènes qu’elles pourraient héberger.
ano.nymous@ccsd.cnrs.fr.invalid (Camille Lorang) 28 Nov 2024
https://hal.science/hal-04808997v1
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[hal-04805880] Two types of axonal muscarinic acetylcholine receptors mediate formation of saliva cocktail in the tick Ixodes ricinus
The secretion of salivary gland (SG) in ticks is effectively triggered by the muscarinic acetylcholine receptor (mAChR) agonist, the pilocarpine, known as a worldwide-preferred tool for obtaining copious saliva. Presently, all we know is, that injection or apical application of pilocarpine, into/on partially-fed tick females induces robust long-lasting salivary secretion, whereas it fails to induce salivation from isolated SG. Cutting neuronal connections between tick synganglion and SG, support the involvement of a neural mAChR in these processes. Based on these observations, it has been generally believed that tick synganglion neurons, mediates SG fluid secretion via unidentified non-cholinergic “secreto-motor nerves”, connecting neuronal cells with SG. Currently, the only known processes, associating specific tick neurons with SG are the neuropeptidergic axons innervating either type II or both type II/III saliva-producing acini. Here, based on agonistic/antagonistic assessments along mutant-based verifications, we revealed that Ixodes ricinus tick, possesses two pharmacologically distinct types (-A and -B) of mAChR. The synganglion was suggested to sense cholinomimetics via rich axonal arborizations at its surface, originating from two clusters of peptidergic neurosecretory cells, each expressing either mAChR-A or -B. Furthermore, both sets of neuropeptidergic SG-innervating cells also possess a cholinoceptive feature by expressing either of these two receptor types on their terminals in saliva producing type II and III acini. Following this model, the effects of in vivo-injected selective muscarinic agents, put forward that co-joint action of two different axonal mAChRs mediate a tandem cooperation of type II/III SG acini for saliva cocktail formation.
ano.nymous@ccsd.cnrs.fr.invalid (Ladislav Šimo) 26 Nov 2024
https://hal.inrae.fr/hal-04805880v1
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[hal-04826836] Professional carrer and lessons to learn
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ano.nymous@ccsd.cnrs.fr.invalid (Radu Blaga) 09 Dec 2024
https://hal.science/hal-04826836v1
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[hal-04803061] First evidence of circulation of multiple arboviruses in Algeria
Background Algeria like other North African countries is experiencing recurrent episodes of West Nile Virus (WNV) emergences and new health threats associated with the introduction of Aedes albopictus in 2010 are to be feared. To improve the surveillance of mosquito-borne pathogens, we performed a study using innovative tools based on multiplex molecular methods. Methods We combined two approaches: a high-throughput chip based on the BioMark Dynamic array system to detect arboviruses in mosquitoes, and a set of immunologic methods (ELISA, microsphere immunoassays (MIA) and virus microneutralization tests (MNT)) for serological surveys in animal hosts. We investigated two distinct regions: a first zone located in the coastal humid region and a second one in the Saharan desert region. Principal findings We collected a total of 1,658 mosquitoes belonging to nine different species and found predominantly Culex pipienss . l . (56.5%) and Cx . perexiguus (27.5%). From 180 pools of 10 mosquitoes, we detected four arboviruses: Banna virus (BAV), chikungunya virus (CHIKV), Sindbis virus (SINV), and Usutu virus (USUV). Moreover, we examined 389 blood samples from equids and poultry and found that 52.4% were positive for flavivirus antibodies in ELISA, while 30.8% were positive for WNV and two chickens and two equids were positive for USUV by MNT and MIA respectively. Conclusions To our knowledge, this is the first report of five arboviruses circulating in Algeria, with three reported for the first time (CHIKV, BAV, and USUV). Our study brings evidence that reinforcing surveillance using more discriminant tools may help in anticipating future emergences and propose adapted control measures.
ano.nymous@ccsd.cnrs.fr.invalid (Saïd Boubidi) 29 Nov 2024
https://hal.inrae.fr/hal-04803061v1
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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-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-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-04803235] Integrated protein-protein interaction and RNA interference screens reveal novel restriction and dependency factors for tick-borne encephalitis virus in its human host
In Europe, tick-borne encephalitis virus (TBEV) causes severe neurological disease in humans. As an obligate intracellular organism, TBEV relies on manipulating host metabolic processes and evading antiviral defenses for its survival. This is accomplished largely through binary interactions between specific viral proteins and host proteins. These protein-protein interactions (PPIs) constitute molecular determinants of critical pathobiologic traits of viruses, including host range, zoonotic potential and virulence, and making them realistic targets for antiviral therapies. To better understand the pathobiology of TBEV in humans, we mapped the network of PPIs between TBEV and its human host using interaction proteomics. We performed a high-throughput screen for virus-host PPIs by means of yeast two-hybrid methodology, utilizing the complete set of TBEV open reading frames and Homo sapiens cDNA libraries. This screen revealed a large number of human proteins that directly interact with TBEV viral proteins, many of which had not previously been associated with viral infections. We further investigated the functional significance of these host interactors in viral infection as viral dependency or restriction factors using RNA interference and bioinformatics analysis, identifying approximately 40% of the human proteins as having a significant impact on TBEV replication. These proteins are involved in diverse biological processes, some of which are expected to play a role in viral infection. Ongoing research is now focused on understanding the mechanisms of action of some of the most influential factors in the TBEV viral cycle. More broadly, this work aims to illuminate how tick-borne flaviviruses manipulate cellular processes to cause disease and to identify viral vulnerabilities that could be targeted therapeutically.
ano.nymous@ccsd.cnrs.fr.invalid (Marion Marion Sourisseau) 25 Nov 2024
https://hal.inrae.fr/hal-04803235v1
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[hal-04765006] Integrative approaches to Managing Tick-borne Diseases : Modelling coinfections and Harnessing Vector Microbiome Vaccines.
[...]
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
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Kenza Bourrier) 10 Oct 2024
https://hal.science/hal-04729931v1
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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-04724520] Octopamine and alpha2 adrenergic-like octopamine receptors in Ixodes ricinus salivary glands.
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Sabine Rakotobe) 07 Oct 2024
https://hal.inrae.fr/hal-04724520v1
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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-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-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-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-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-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-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-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-04723881] Midichloria mitochondri stimulates the sylvatic cycle of Lyme spirochetes in Ixodes ricinus instars.
[...]
ano.nymous@ccsd.cnrs.fr.invalid (C. F. Kohler) 07 Oct 2024
https://hal.inrae.fr/hal-04723881v1
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[hal-04815812] Rickettsia helvetica in C3H/HeN mice: A model for studying pathogen-host interactions
An infection with the tick-borne Rickettsia helvetica has been associated with a broad spectrum of clinical manifestations in humans, but patients are only seldomly reported. Understanding its disease etiology necessitates well-stablished infection models, improving to recognize and diagnose patients with R. helvetica infection and facilitating the development of effective control strategies. In this study, we used C3H/HeN mice as a model to establish R. helvetica infection, achieving a high infection prevalence (89-100 %). While the liver and the spleen DNA consistently tested positive for infection in all challenged mice, additional infected organs included the kidneys, heart, and the lungs. Notably, a low prevalence of infection was observed in I. ricinus nymphs fed on R. helvetica-challenged mice. In addition, larvae were refractory to infection, suggesting that ticks exhibit low susceptibility to the pathogen. To the best of our knowledge, this is the first study of an animal model for R. helvetica infection. It serves as a valuable tool for advancing research on the interactions among the bacterium and its vertebrate host.
ano.nymous@ccsd.cnrs.fr.invalid (Apolline Maitre) 16 Dec 2024
https://hal.science/hal-04815812v1
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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-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-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-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.
[...]
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-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-04677931] Differential nested patterns of Anaplasma marginale and Coxiella-like endosymbiont across Rhipicephalus microplus ontogeny
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Lianet Abuin-Denis) 27 Aug 2024
https://hal.science/hal-04677931v1
