[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.
email@example.com (Alejandro Cabezas-Cruz) 08 Feb 2024
[anses-04467525] Four powdered plants for prevention of <i>Aeromonas hydrophila</i> disease in Nile tilapia (<i>Oreochromis niloticus</i>)
As alternatives to antibiotics and growth promoters, herbs and medicinal plants can contribute to new strategies for aquatic health management, and have great potential for more sustainable aquaculture. Four plants, Pelargonium roseum, Schinus terenbinthifolius, Murraya koenigii and Aphloia theiformis, widely distributed in tropical countries were studied to assess their efficacy in the prevention and reduction of mortality caused by experimental infection with Aeromonas hydrophila on Nile tilapia, Oreochromis niloticus. Powdered plants were incorporated into fish feed, and fish were fed with an enriched diet for 40 days before a challenge with the pathogen. No negative impact on the condition factor, weight gain or specific growth rate was observed in fish fed with the plant supplements, and the best growth was observed in fish fed with P. roseum. Mortality was significantly reduced in fish treated with A. theiformis compared to other fish from plant species and control, with a relative survival rate (RPS) of up to 30%.
firstname.lastname@example.org (Domenico Caruso) 20 Feb 2024
[hal-04446370] Quels sont les facteurs associés aux niveaux de parasitisme interne chez les porcs dans les systèmes d'élevage alternatifs ?
Une étude a été menée dans 112 élevages porcins alternatifs français (sur litière ou avec accès à l'extérieur) où des échantillons fécaux et sanguins ont été prélevés sur 10 truies, 10 porcs de 10-12 semaines d’âge et/ou 10 porcs en fin d'engraissement pour une analyse coprologique ainsi que pour des recherches d’anticorps dirigés contre Ascaris suum et Toxoplasma gondii. Des informations concernant la structure et la conduite de l’élevage ont été collectées lors de la visite de l'exploitation et ont fait l’objet d’analyses multidimensionnelles afin de déterminer des profils d’élevages au regard de l'infestation parasitaire et les caractéristiques de l'exploitation qui leur sont associés. Des oocystes de coccidies ont été observés dans les fèces de porcs dans la majorité des élevages (84 %), suivis par des œufs de strongles (55 %), Trichuris suis (32 %) et A. suum (16 %). Les taux d'élevages séropositifs pour A. suum et T. gondii étaient respectivement de 80 % et 56 %. L'hygiène et notamment la décontamination des installations sont des facteurs associés à un faible niveau de parasitisme. À l'inverse, l'élevage en plein air ou sur litière, un entretien médiocre des bâtiments, les élevages de petite taille ainsi que la saison (été) sont des paramètres associés à des niveaux élevés de parasitisme. L'utilisation de traitements anthelminthiques multiples sur les porcs en croissance était associée à une faible excrétion d’œufs de T. suis mais à des niveaux élevés de séroprévalence pour A. suum. Même si certains facteurs ne sont pas sous le contrôle des éleveurs (e.g. saison), des marges d'amélioration existent concernant l'hygiène et l'utilisation appropriée de traitements antiparasitaires.
email@example.com (Maxime Delsart) 08 Feb 2024
[hal-04434326] Aptamer selection against cell extracts containing the zoonotic obligate intracellular bacterium, Anaplasma phagocytophilum
Abstract A. phagocytophilum is a zoonotic and tick-borne bacterium, threatening human and animal health. Many questions persist concerning the variability of strains and the mechanisms governing the interactions with its different hosts. These gaps can be explained by the difficulty to cultivate and study A. phagocytophilum because of its strict intracellular location and the lack of specific tools, in particular monoclonal antibodies, currently unavailable. The objective of our study was to develop DNA aptamers against A. phagocytophilum, or molecules expressed during the infection, as new study and/or capture tools. Selecting aptamers was a major challenge due to the strict intracellular location of the bacterium. To meet this challenge, we set up a customized selection protocol against an enriched suspension of A. phagocytophilum NY18 strain, cultivated in HL-60 cells. The implementation of SELEX allowed the selection of three aptamers, characterized by a high affinity for HL-60 cells infected with A. phagocytophilum NY18 strain. Interestingly, the targets of these three aptamers are most likely proteins expressed at different times of infection. The selected aptamers could contribute to increase our understanding of the interactions between A. phagocytophilum and its hosts, as well as permit the development of new diagnostic, therapeutic or drug delivery appliances.
firstname.lastname@example.org (Lisa Lucie Le Dortz) 08 Feb 2024
[hal-04442106] Exploring the Coinfection and Genetic Diversity of Multiple Tick-Borne Pathogens in Livestock Population of Punjab, Pakistan
Tick-borne diseases affecting domestic animals and humans have increased globally in recent years. Pakistan, in particular, faces a significant economic threat from ticks, where two specific species, Rhipicephalus microplus and Hyalomma anatolicum, act as vectors for various pathogens such as piroplasma, Anaplasma, Ehrlichia, and Rickettsia that pose a significant burden on livestock production in the country. To better understand the risk that tick-borne pathogens (TBPs) pose to livestock in Pakistan, we conducted a cross-sectional study of the occurrence, diversity, and coinfection of these pathogens in small and large ruminants owned by small farms as well as in ticks collected from these animals. We collected blood samples from 224 cattle, 224 buffalo, 69 goats, and 56 sheep, gathered from 112 farms located in seven districts of Punjab, one of Pakistan’s largest province. In addition, we collected a total of 476 ticks attached to these animals. Based on the identification of tick species through morphology and sequence analysis of the 16S rRNA and cytochrome c oxidase subunit 1 (cox1) gene, we confirmed that the most commonly collected tick species were Rh. microplus (38.65% of all individuals), H. anatolicum (31.93%), and Rh. decoloratus (8.40%). Notable pathogens detected in the collected ticks included Theileria annulata (18.4% prevalence), Anaplasma ovis (15.79%), A. centrale (13.16%), and Rickettsia slovaca (13.16%). In blood samples, the most frequently detected pathogens were T. annulata (n = 8), Babesia bovis (n = 7), A. centrale (n = 6), and B. bigemina (n = 5). In some cases, both cattle and buffaloes were found to be coinfected with B. bovis, T. annulata, and A. centrale. These findings provide valuable insights into the circulation of TBPs in livestock and highlight the need for further research on the epidemiological risk that these pathogens pose to ruminants in Pakistan.
email@example.com (Sabir Hussain) 06 Feb 2024
[hal-04010177] Seasonality of host-seeking Ixodes ricinus nymph abundance in relation to climate
Abstract There is growing concern about climate change and its impact on human health. Specifically, global warming could increase the probability of emerging infectious diseases, notably because of changes in the geographical and seasonal distributions of disease vectors such as mosquitoes and ticks. For example, the range of Ixodes ricinus, the most common and widespread tick species in Europe, is currently expanding northward and at higher altitudes. However, little is known about the seasonal variation in tick abundance in different climates. Seasonality of I. ricinus is often based on expert opinions while field surveys are usually limited in time. Our objective was to describe seasonal variations in I. ricinus abundance under different climates. To this end, a seven-year longitudinal study, with monthly collections of I. ricinus host-seeking nymphs, was carried out in France, in six locations corresponding to different climates. Tick data were log-transformed and grouped between years so as to obtain seasonal variations for a typical year. Daily average temperature was measured during the study period. Seasonal patterns of nymph abundance were established for the six different locations using linear harmonic regression. Model parameters were estimated separately for each location. Seasonal patterns appeared different depending on the climate considered. Western temperate sites showed an early spring peak, a summer minimum and a moderate autumn and winter abundance. More continental sites showed a later peak in spring, and a minimum in winter. The peak occurred in summer for the mountainous site, with an absence of ticks in winter. In all cases except the mountainous site, the timing of the spring peak could be related to the sum of degree days since the beginning of the year. Winter abundance was positively correlated to the corresponding temperature. Our results highlight clear patterns in the different sites corresponding to different climates, which allow further forecast of tick seasonality under changing climate conditions.
firstname.lastname@example.org (Thierry Hoch) 17 Jan 2024
[hal-04400072] Microfluidic PCR and network analysis reveals complex tick-borne pathogen interactions in the tropics
Background Ixodid ticks, particularly Rhipicephalus sanguineus s.l., are important vectors of various disease-causing agents in dogs and humans in Cuba. However, our understading of interactions among tick-borne pathogens (TBPs) in infected dogs or the vector R. sanguineus s.l. remains limited. This study integrates microfluidic-based high-throughput real-time PCR data, Yule's Q statistic, and network analysis to elucidate pathogen-pathogen interactions in dogs and ticks in tropical western Cuba. Methods A cross-sectional study involving 46 client-owned dogs was conducted. Blood samples were collected from these dogs, and ticks infesting the same dogs were morphologically and molecularly identified. Nucleic acids were extracted from both canine blood and tick samples. Microfluidic-based high-throughput real-time PCR was employed to detect 25 bacterial species, 10 parasite species, 6 bacterial genera, and 4 parasite taxa, as well as to confirm the identity of the collected ticks. Validation was performed through end-point PCR assays and DNA sequencing analysis. Yule's Q statistic and network analysis were used to analyse the associations between different TBP species based on binary presence-absence data. Results The study revealed a high prevalence of TBPs in both dogs and R. sanguineus s.l., the only tick species found on the dogs. Hepatozoon canis and Ehrlichia canis were among the most common pathogens detected. Co-infections were observed, notably between E. canis and H. canis . Significant correlations were found between the presence of Anaplasma platys and H. canis in both dogs and ticks. A complex co-occurrence network among haemoparasite species was identified, highlighting potential facilitative and inhibitory roles. Notably, H. canis was found as a highly interconnected node, exhibiting significant positive associations with various taxa, including A. platys , and E. canis , suggesting facilitative interactions among these pathogens. Phylogenetic analysis showed genetic diversity in the detected TBPs. Conclusions Overall, this research enhances our understanding of TBPs in Cuba, providing insights into their prevalence, associations, and genetic diversity, with implications for disease surveillance and management. Graphical abstract
email@example.com (Cristian Díaz-Corona) 08 Feb 2024
[hal-04398431] Real-Time Microfluidic PCRs: A High-Throughput Method to Detect 48 or 96 Tick-borne Pathogens in 48 or 96 Samples
Tick-borne pathogens (TBPs) are often detected through classical molecular tools (PCR, nested PCR, real-time PCR), but these are limited in terms of the number of targeted pathogens due to the volume of DNA available for analysis. To solve this problem, in 2014 we developed a new high-throughput method based on real-time microfluidic PCRs that can detect 48 or 96 pathogens in 48 or 96 samples in a single run, such as ten species from the Borrelia burgdorferi sensu lato group. We then used this technique for large-scale epidemiological studies of TBPs in tick and animal samples on an international scale through numerous collaborative projects.
firstname.lastname@example.org (Sara Moutailler) 16 Jan 2024
[hal-04318501] Chapter 89 - Anaplasma
Anaplasma phagocytophilum is a rickettsial pathogen transmitted by ixodid ticks. A. phagocytophilum colonizes myeloid and nonmyeloid cells and causes human granulocytic anaplasmosis—an important disease in the United States, Europe, and Asia. Research has illustrated how A. phagocytophilum successfully invades and proliferates inside host cells, causing a systemic disease. Major advances have been made in understanding the molecular interactions between A. phagocytophilum and host cells. Here, we address A. phagocytophilum biology and the underlying mechanisms involved in bacterial pathogenesis and vector–pathogen interactions. Clinical features, eco-epidemiology, diagnostics, and treatment are also discussed.
email@example.com (Alejandro Cabezas-Cruz) 01 Dec 2023
[hal-04314233] High-throughput screening of pathogens in Ixodes ricinus removed from hosts in Lombardy, northern Italy
Ticks are important vectors of many pathogens in Europe, where the most impactful species is Ixodes ricinus. Recently, the geographical distribution of this tick species has been expanding, resulting in an increased risk of human exposure to tick bites. With the present study, we aimed to screen 350 I. ricinus specimens collected from humans and wild animals (mainly ungulates), to have a broader understanding of the tick-borne pathogens circulating in the Lombardy region, in northern Italy. To do so, we took advantage of a high-throughput real-time microfluidic PCR approach to screen ticks in a cost-effective and time-saving manner. Molecular analysis of the dataset revealed the presence of four genera of bacteria and two genera of protozoa: in ungulates, 77 % of collected ticks carried Anaplasma phagocytophilum, while the most common pathogen species in ticks removed from humans were those belonging to Borrelia burgdorferi sensu lato group (7.6 %). We also detected other pathogenic microorganisms, such as Rickettisa monacensis, Rickettsia helvetica, Neoehrlichia mikurensis, Babesia venatorum, and Hepatozoon martis. Besides, we also reported the presence of the pathogenic agent Borrelia miyamotoi in the area (1.4 % overall). The most common dual co-infection detected in the same tick individual involved A. phagocytophilum and Rickettsia spp. Our study provided evidence of the circulation of different tick-borne pathogens in a densely populated region in Italy.
firstname.lastname@example.org (Sophie Melis) 29 Nov 2023
[hal-04398392] New insights regarding tick co-infections?
email@example.com (Stefania Porcelli) 16 Jan 2024
[anses-04373000] Hierarchical shift of the Aedes albopictus microbiota caused by antimicrobiota vaccine increases fecundity and egg-hatching rate in female mosquitoes
Recent studies show that mosquito–microbiota interactions affects vector competence and fitness. We investigated if host antibodies modifying microbiota impact mosquito physiology. We focused on three prevalent bacteria (Acinetobacter, Pantoea, and Chryseobacterium), originally isolated from the Asian tiger mosquito Aedes albopictus. Our goal was to assess the impact of host antibodies on mosquito microbiota and life traits. Female mosquitoes were fed with blood from rabbits immunized with each bacterium or a mock vaccine. We compared various factors, including feeding behavior, survival rates, and reproductive success of the mosquitoes. Interestingly, mosquitoes fed with blood from a Chryseobacterium-immunized rabbit showed a significant increase in fecundity and egg-hatching rate. This outcome correlated with a decrease in the abundance of Chryseobacterium within the mosquito microbiota. While no significant changes were observed in the alpha and beta diversity indexes between the groups, our network analyses revealed an important finding. The antimicrobiota vaccines had a considerable impact on the bacterial community assembly. They reduced network robustness, and altered the hierarchical organization of nodes in the networks. Our findings provide the basis for the rational design of antimicrobiota vaccines to reduce mosquito fitness and potentially induce infection-refractory states in the microbiota to block pathogen transmission.
firstname.lastname@example.org (Lourdes Mateos-Hernández) 04 Jan 2024
[hal-04372859] Evidence of tick-borne encephalitis virus neutralizing antibodies in Serbian individuals exposed to tick bites
Introduction Tick-borne encephalitis (TBE) is an emerging vector-borne and food-borne disease caused by the tick-borne encephalitis virus (TBEV; Orthoflavivirus encephalitidis ), with a distribution spanning the Eurasian continent. Despite its significant public health impact in various European regions, TBE remains largely underdiagnosed in Serbia due to limited awareness and diagnostic challenges. In response to this, our study aimed to comprehensively assess TBEV exposure in individuals infested with ticks and to identify potential TBEV foci within Serbia. Materials and methods From 2019 to 2021, we conducted an observational study involving 450 patients who reported tick infestations. Results Our demographic analysis revealed a median age of 38 years, with a slight male predominance among the participants. We documented tick infestations in 38 municipalities across 14 districts of Serbia, with a notable concentration in proximity to Fruška Gora Mountain. The ticks most frequently removed were Ixodes ricinus , with nymphs and adult females being the predominant stages. On average, nymphs were removed after about 27.1 hours of feeding, while adult females remained attached for approximately 44.4 hours. Notably, we found age as a significant predictor of infestation time for both nymphs and adult females. Furthermore, we detected TBEV-neutralizing antibodies in 0.66% of the serum samples, shedding light on potential TBEV foci, particularly in Fruška Gora Mountain and other regions of Serbia. Conclusion Our study emphasizes the urgent need for active TBE surveillance programs, especially in areas suspected of hosting TBEV foci, in order to assess the true TBE burden, identify at-risk populations, and implement effective preventive measures.
email@example.com (Pavle Banović) 04 Jan 2024
[anses-04373040] Arthropod microbiota: shaping pathogen establishment and enabling control
Vector-borne diseases (VBDs) pose significant global health threats. The microbiota of arthropod vectors influences their fitness and pathogen acquisition and/or transmission. Here, we review the intricate interplay among the arthropod immune system, the microbiota, and pathogens that limits or favors infection. We focused on the most important arthropod vectors, namely mosquitos, phlebotomines, tsetse flies, triatomines, and ticks, and expanded our analysis to include the nonvector model Drosophila melanogaster for comparison. The microbiota and immune system of arthropod vectors are targets for the development of promising control strategies, such as paratransgenesis and anti‐microbiota vaccines. Further research should focus on elucidating the underlying mechanisms of vector–pathogen–microbiota interactions and optimizing anti-microbiota strategies. These approaches have the potential to combat VBDs and reduce their global impact.
firstname.lastname@example.org (Daniel Pavanelo) 04 Jan 2024
[hal-04150498] Disparate dynamics of pathogen prevalence in Ixodes ricinus and Dermacentor reticulatus ticks occurring sympatrically in diverse habitats
Ixodes ricinus and Dermacentor reticulatus ticks are important reservoirs and vectors of pathogens. The aim of the present study was to investigate the dynamic of the prevalence and genetic diversity of microorganisms detected in these tick species collected from two ecologically diverse biotopes undergoing disparate long-term climate condition. High-throughput real time PCR confirmed high prevalence of microorganisms detected in sympatrically occurring ticks species. D. reticulatus specimens were the most often infected with Francisella -like endosymbiont (FLE) (up to 100.0%) and Rickettsia spp. (up to 91.7%), while in case of I. ricinus the prevalence of Borreliaceae spirochetes reached up to 25.0%. Moreover, pathogens belonging to genera of Bartonella , Anaplasma , Ehrlichia and Babesia were detected in both tick species regardless the biotope. On the other hand, Neoehrlichia mikurensis was conformed only in I. ricinus in the forest biotope, while genetic material of Theileria spp. was found only in D. reticulatus collected from the meadow. Our study confirmed significant impact of biotope type on prevalence of representatives of Borreliaceae and Rickettsiaceae families. The most common co-infection detected in D. reticulatus was Rickettsia spp. + FLE, while Borreliaceae + R. helvetica was the most common in I. ricinus . Additionally, we found significant genetic diversity of R. raoultii gltA gene across studied years, however such relationship was not observed in ticks from studied biotopes. Our results suggest that ecological type of biotope undergoing disparate long-term climate conditions have an impact on prevalence of tick-borne pathogens in adult D. reticulatus and I. ricinus .
email@example.com (Zbigniew Zając) 12 Sep 2023
[anses-04185936] First identification of Cryptosporidium parvum virus 1 (CSpV1) in various subtypes of Cryptosporidium parvum from diarrheic calves, lambs and goat kids from France
Cryptosporidium spp. remain a major cause of waterborne diarrhea and illness in developing countries and represent a significant burden to farmers worldwide. Cryptosporidium parvum virus 1 (CSpV1), of the genus Cryspovirus , was first reported to be present in the cytoplasm of C. parvum in 1997. Full-length genome sequences have been obtained from C. parvum from Iowa (Iowa), Kansas (KSU) and China. We aimed at characterizing the genome of CSpV1 from France and used sequence analysis from Cryptosporidium isolates to explore whether CSpV1 genome diversity varies over time, with geographical sampling location, C. parvum genetic diversity, or ruminant host species. A total of 123 fecal samples of cattle, sheep and goats were collected from 17 different French departments (57 diseased animal fecal samples and 66 healthy animal fecal samples). Subtyping analysis of the C. parvum isolates revealed the presence of two zoonotic subtype families IIa and IId. Sequence analysis of CSpV1 revealed that all CSpV1 from France, regardless of the subtype of C. parvum (IIaA15G2R1, IIaA17G2R1 and IIdA18G1R1) are more closely related to CSpV1 from Turkey, and cluster on a distinct branch from CSpV1 collected from C. parvum subtype IIaA15G2R1 from Asia and North America. We also found that samples collected on a given year or successive years in a given location are more likely to host the same subtype of C. parvum and the same CSpV1 strain. Yet, there is no distinct clustering of CSpV1 per French department or ruminants, probably due to trade, and transmission of C. parvum among host species. Our results point towards (i) a close association between CSpV1 movement and C. parvum movement, (ii) recent migrations of C. parvum among distantly located departments and (iii) incidental transmission of C. parvum between ruminants. All together, these results provide insightful information regarding CSpV1 evolution and suggest the virus might be used as an epidemiological tracer for C. parvum . Future studies need to investigate CSpV1’s role in C. parvum virulence and on subtype ability to infect different species.
firstname.lastname@example.org (Karim Tarik Adjou) 23 Aug 2023
[hal-04146750] Structural differences in the gut microbiome of bats using terrestrial vs. aquatic feeding resources
Bat gut microbiomes are adapted to the specific diets of their hosts. Despite diet variation has been associated with differences in bat microbiome diversity, the influence of diet on microbial community assembly have not been fully elucidated. In the present study, we used available data on bat gut microbiome to characterize the microbial community assembly of five selected bat species (i.e., Miniopterus schreibersii , Myotis capaccinii , Myotis myotis , Myotis pilosus , and Myotis vivesi ), using network analysis. These bat species with contrasting habitat and food preferences (i.e., My. capaccinii and My. pilosus can be piscivorous and/or insectivorous; Mi. schreibersii and My. myotis are exclusively insectivorous; while My. vivesi is a marine predator) offer an invaluable opportunity to test the impact of diet on bat gut microbiome assembly. The results showed that My. myotis showed the most complex network, with the highest number of nodes, while My. vivesi has the least complex structured microbiome, with lowest number of nodes in its network. No common nodes were observed in the networks of the five bat species, with My. myotis possessing the highest number of unique nodes. Only three bat species, My. myotis , My. pilosus and My. vivesi , presented a core microbiome and the distribution of local centrality measures of nodes was different in the five networks. Taxa removal followed by measurement of network connectivity revealed that My. myotis had the most robust network, while the network of My. vivesi presented the lowest tolerance to taxa removal. Prediction of metabolic pathways using PICRUSt2 revealed that Mi. schreibersii had significantly higher functional pathway’s richness compared to the other bat species. Most of predicted pathways (82%, total 435) were shared between all bat species, while My. capaccinii , My. myotis and My. vivesi , but no Mi. schreibersii or My. pilosus , showed specific pathways. We concluded that despite similar feeding habits, microbial community assembly can differ between bat species. Other factors beyond diet may play a major role in bat microbial community assembly, with host ecology, sociality and overlap in roosts likely providing additional predictors governing gut microbiome of insectivorous bats.
email@example.com (Alexandra Corduneanu) 30 Jun 2023
[hal-04352927] Expansion des maladies à tiques, implication de la société civile dans la surveillance (sciences participatives) et développement d’outils innovants pour leur détection
firstname.lastname@example.org (Sara Moutailler) 19 Dec 2023
[hal-03964649] Survey of ticks and tick-borne pathogens in wild chimpanzee habitat in Western Uganda
Background Ticks and tick-borne pathogens significantly impact both human and animal health and therefore are of major concern to the scientific community. Knowledge of tick-borne pathogens is crucial for prescription of mitigation measures. In Africa, much research on ticks has focused on domestic animals. Little is known about ticks and their pathogens in wild habitats and wild animals like the endangered chimpanzee, our closest relative. Methods In this study, we collected ticks in the forested habitat of a community of 100 chimpanzees living in Kibale National Park, Western Uganda, and assessed how their presence and abundance are influenced by environmental factors. We used non-invasive methods of flagging the vegetation and visual search of ticks both on human team members and in chimpanzee nests. We identified adult and nymph ticks through morphological features. Molecular techniques were used to detect and identify tick-borne piroplasmids and bacterial pathogens. Results A total of 470 ticks were collected, which led to the identification of seven tick species: Haemaphysalis parmata (68.77%), Amblyomma tholloni (20.70%), Ixodes rasus sensu lato (7.37%), Rhipicephalus dux (1.40%), Haemaphysalis punctaleachi (0.70%), Ixodes muniensis (0.70%) and Amblyomma paulopunctatum (0.35%). The presence of ticks, irrespective of species, was influenced by temperature and type of vegetation but not by relative humidity. Molecular detection revealed the presence of at least six genera of tick-borne pathogens (Babesia, Theileria, Borrelia, Cryptoplasma, Ehrlichia and Rickettsia). The Afrotopical tick Amblyomma tholloni found in one chimpanzee nest was infected by Rickettsia sp. Conclusions In conclusion, this study presented ticks and tick-borne pathogens in a Ugandan wildlife habitat whose potential effects on animal health remain to be elucidated.
email@example.com (Camille Lacroux) 01 Mar 2023
[hal-04311327] Effects of Electromagnetic Radiation on Neuropeptide Transcript Levels in the Synganglion of Ixodes ricinus
Anthropogenic electromagnetic radiation is an important environmental factor affecting the functionality of biological systems. Sensitivity to various frequencies of electromagnetic radiation has been detected in ixodid ticks in the past. However, the physiological aspects of radiation effects have not yet been studied in ticks. In the presented experiment, 360 Ixodes ricinus ticks, 180 males and 180 females, were divided into 16 irradiated and 8 control groups. The irradiated groups were exposed to two different intensities of electromagnetic radiation with a frequency of 900 MHz at different lengths of exposure time. RT-PCR was utilized to determine the changes in mRNA levels in tick synganglia after irradiation. Four randomly selected neuropeptide genes were tested-allatotropin (at), FGLa-related allatostatins (fgla/ast), kinin, and arginine-vasopressin-like peptide (avpl). A significant decrease in transcript levels in all female groups exposed to higher intensity radiofrequency radiation for 1 to 3 h was found. After one hour of radiofrequency exposure, a significant downregulation in allatotropin expression in males was detected. A consistent downregulation of the at gene was detected in males irradiated with at a higher intensity. Unfortunately, the specific functions of the studied neuropeptides in ticks are not known yet, so a more comprehensive study is necessary to describe the effects of EMF on observed neuropeptides. This study represents the first report on the effects of the abiotic environment on tick neurophysiology.
firstname.lastname@example.org (Lívia Šofrankova) 28 Nov 2023
[hal-04314227] Diversity of Viruses in Ixodes ricinus in Europe including Novel and Potential Arboviruses
Tick-borne pathogens are responsible for many vector-borne diseases in Europe, causing important problems for human and animal health. The composition of viral communities in ticks and their interactions with pathogens is little understood, especially in Eastern Europe, an area that represents a major hub for animal-arthropod vectors exchanges. In this study, we used metatranscriptomics to characterize the virome of 2,753 Ixodes ricinus ticks collected from France and Romania, focusing on viruses that could potentially have implications for human or animal health. Among the great viral diversity of viruses identified, we reported a novel strain of Tribec virus, an important human pathogen that was found in Romanian ticks. We detected viruses belonging to the Phenuiviridae and Nairoviridae families close to human and animal pathogens, suggesting that these viruses could constitute novel arboviruses. We used luciferase immunoprecipitation system targeting external viral proteins of viruses identified among the Sedoreoviridae, Phenuiviridae, and Nairoviridae families to screen serum samples from small ruminants’ exposed to tick bites. The results suggest that part (approximately 12%, 95% CI 9.1–16.2) of the small ruminant population from Danube Delta, was exposed to viruses related to bi- or tri-segmented nairoviruses, but cross-reactive viruses could not be confirmed with certainly. The strategy developed in this study serves as a key step in predicting potential new disease outbreaks and can be readily adapted to study other reservoirs, vectors, and interfaces involving susceptible hosts.
email@example.com (Bianca Elena Bratuleanu) 29 Nov 2023
[anses-04370008] First molecular characterization of Dirofilaria Immitis in Cuba
Background Dirofilarioses are widespread diseases caused by mosquito-borne nematodes of the family Onchocercidae, genus Dirofilaria . The major etiologic agent of canine dirofilariosis in the American continent is the zoonotic parasite Dirofilaria immitis . Existing reports of filarioid nematodes in Cuba are based solely on morphological and immunological analysis which do not allow unambiguous identification and/or direct detection of causal agents. Results Here we present the molecular characterization of filarioid nematodes found in a dog in Cuba. Based on the molecular and phylogenetic analysis of the 5.8S-ITS2-28S region and cox1 gene fragments, the worms were unambiguously classified as D. immitis . Sequence analysis showed high identity of the gene fragments in this study with others previously obtained from D. immitis found in dogs, wolfs and jackals but also from mosquito vectors of D. immitis . Conclusions Further studies are guarantee to better understand the epidemiological impact of canine dirofilariosis in Cuba as well as the competence of different species of culicid mosquitoes as vectors of Dirofilaria in the country.
firstname.lastname@example.org (Lisset Roblejo-Arias) 02 Feb 2024
[hal-04314251] Exploring the Susceptibility of C3H Mice to Tick-Borne Encephalitis Virus Infection: Implications for Co-Infection Models and Understanding of the Disease
Ticks and tick-borne diseases (TBDs) are increasingly recognized as a critical One Health concern. Tick-borne encephalitis (TBE), a severe neuro infection caused by the tick-borne encephalitis virus (TBEV), has emerged as a significant global public health threat. Laboratory animals, particularly mice, have played a pivotal role in advancing our understanding of TBD pathogenesis. Notably, BALB/c mice have been employed as models due to their heightened susceptibility to TBEV. However, the use of C3H mice, valued for other tick-borne pathogens, has remained unexplored for TBEV until now. This study aimed to assess the susceptibility of C3H mice to TBEV infection, laying the groundwork for future co-infection models involving TBEV and Borrelia. Experiments revealed that C3H mice are susceptible to TBEV infection through subcutaneous inoculation. While 102 PFU/mouse appeared necessary for full infection, 103 PFU/mouse induced consistent symptoms. However, subsequent assessment of ticks’ acquisition of TBEV from infected mice met with limited success, raising questions about optimal infectious doses for natural infection. These findings suggest the potential of C3H mice for studying TBEV and co-infections with other pathogens, particularly Borrelia. Further exploration of the interplay between these pathogens, their transmission dynamics, and disease severity could enhance prevention and control strategies.
email@example.com (Porcelli Stefania) 29 Nov 2023
[anses-04373028] Identification of <em>Cryptosporidium parvum</em> IIa and IId zoonotic subtype families and <em>Cryptosporidium bovis</em> from calves in Algeria
Cryptosporidiosis is a significant disease in calves caused by the parasitic protist Cryptosporidium. The infection results in severe symptoms such as diarrhea, dehydration, delayed growth, and weight loss, often leading to mortality and economic losses. This study aimed to detect Cryptosporidium spp. in fecal samples from calves in five Algerian provinces. A total of 65 fecal samples from calves were collected from 12 dairy cattle farms in the north-east of Algeria. The presence of the parasites was established by microscopic screening of the oocysts following an immunofluorescence assay (IFA). IFA-positive samples were analyzed by 18S rRNA PCR-RFLP (restriction fragment length polymorphism) to determine the species. Cryptosporidium parvum was subtyped by sequence analysis of the 60 kDa glycoprotein gene. Cryptosporidium oocysts were detected microscopically in 41/65 (63%) samples, of which 26/41 (63.4%) were positive by 18S rRNA PCR-RFLP. Two Cryptosporidium species were detected in 24 samples; C. parvum (20/24) and C. bovis (4/24). C. parvum isolates from IIa and IId zoonotic subtype families were detected: IIaA16G2R1 (9/24), IIdA16G1 (4/24), and IIaA15G2R1 (1/24). Thus, calves are reservoirs of zoonotic C. parvum subtypes and represent a public health concern.
firstname.lastname@example.org (Lynda Sahraoui) 05 Jan 2024
[anses-04372958] Ticking off the Tick Vectors: Rhipicephalus microplus Fails to Transmit Theileria orientalis
Theileria (T [...]
email@example.com (Abdul Ghafar) 04 Jan 2024
[anses-04309487] Functional characterization of three G protein-coupled acetylcholine receptors in parasitic nematode Trichinella spiralis
The physiological significance of metabotropic acetylcholine receptors in parasitic nematodes remains largely unexplored. Here, three different Trichinella spiralis G protein-coupled acetylcholine receptors (TsGAR-1, -2, and -3) were identified in the genome of T. spiralis. The phylogenetic analyses showed that TsGAR-1 and -2 receptors belong to a distinct clade specific to invertebrates, while TsGAR-3 is closest to the cluster of mammalian-type muscarinic acetylcholine receptors (mAChR). The mRNA of TsGAR-1, -2, and -3 was detected in muscle larvae, newborn larvae, and adults. The functional aequorin-based assay in Chinese hamster ovary cells revealed that all three types of T. spiralis GARs trigger the Gq/11 pathway upon activation of the receptor with the acetylcholine ligand. TsGAR-1 and TsGAR-2 showed atypical affinity with classical muscarinic agonists, while TsGAR-3 was sensitive to all muscarinic agonists tested. High concentrations of propiverine antagonist blocked the activities of all three TsGARs, while atropine and scopolamine antagonists effectively inhibited only TsGAR-3. Our data indicate that the distinct pharmacological profile of TsGAR-1 and -2 receptors, as well as the phylogenetic distance between them and their mammalian orthologs, place them as attractive targets for the development of selective anthelmintic drugs interfering with nematodes’ cholinergic system.
firstname.lastname@example.org (Caina Ning) 27 Nov 2023
[anses-04369914] FRET with MoS2 nanosheets integrated CRISPR/Cas12a sensors for robust and visual food-borne parasites detection
Recently, CRISPR/Cas associated biosensors have been shown to have great potential in sensing applications due to their high sensitivity and high base resolution. However, the signal reporter system containing two organic fluorescent dye pair is limited by high cost and less stability. In contrast, functional nanomaterials exhibit robust stability, excellent optical properties and low preparation cost, making them suitable reporters. In this study, a MoS2 nanosheets (NSs) improved CRISPR/Cas12a-based biosensing platform was constructed for the first time to detect food-borne parasites. MoS2 NSs were used as fluorescence quenchers and single-stranded DNA (ssDNA) discriminated carrier to construct CRISPR/Cas signal reporter system. The combination of recombinase polymerase amplification with MoS2 NSs modulated CRISPR/Cas12a helped achieve attomolar sensitivity for nucleic acid detection within 35 min. Moreover, the results were obtained using a portable apparatus, enabling visual detection at the point of care. The practical applicability of this biosensing platform was successfully achieved through the detection of anisakis in real samples. This study provides novel insights into exploring the feasibility of two-dimensional nanomaterials based reporter in the CRISPR/Cas12a system, as well as offers a reliable tool for on-site monitoring of parasites.
email@example.com (Xiuqin Chen) 02 Jan 2024
[hal-04380653] Isolation of bovine CD34+ bone marrow stem and progenitor cells using a monoclonal antibody against CD34 protein
Background: There is currently no commercially available bovine anti-CD34 monoclonal antibody. Bovine Hematopoietic Stem and Progenitor Cells (BHSPC) isolation in vitro has had mixed results. Methods: CD34 protein sequences from multiple species were compared in silico to the bovine sequence. A suitable antibody was selected and coupled to R-PhycoErythrin (R-PE). Bone marrow samples from 7 Prim’Holstein calves were collected in EDTA and mononuclear cells were isolated using a density gradient. Antibody binding to BHSPC was monitored by flow cytometry. Labeled BHSPC were separated with anti-PE magnetic beads. Enrichment was evaluated by flow cytometry. Results and discussion: A monoclonal antibody against ovine CD34 was selected based on high homology between bovine and ovine CD34. CD34+ cells accounted for 4.4 to 27.6 % of BHSPC. Variation in CD34+ cells proportion may relate to an individual variation of positive cells in the marrow; however, polymorphism in the coding region of the protein is possible (previously described). Magnetic beads increased CD34+ cells concentration by a 1.96-fold (n = 10, σ = 0.95), but with a weak recovery rate of 1.54 % (n = 8). Conclusions: This experiment describes a new potential commercial anti-CD34 monoclonal antibody for isolation or identification of BHSPC. Although the enrichment may appear low, the increase in cell purity is sufficient for culture and immortalization.
firstname.lastname@example.org (Quentin Leroy) 08 Jan 2024
[hal-04314268] Detection of bacterial and protozoan pathogens in individual bats and their ectoparasites using high-throughput microfluidic real-time PCR
ABSTRACT Among the most studied mammals in terms of their role in the spread of various pathogens with possible zoonotic effects are bats. These are animals with a very complex lifestyle, diet, and behavior. They are able to fly long distances, thus maintaining and spreading the pathogens they may be carrying. These pathogens also include vector-borne parasites and bacteria that can be spread by ectoparasites such as ticks and bat flies. In the present study, high-throughput screening was performed and we detected three bacterial pathogens: Bartonella spp., Neoehrlichia mikurensis and Mycoplasma spp., and a protozoan parasite: Theileria spp. in paired samples from bats (blood and ectoparasites). In the samples from the bat-arthropod pairs, we were able to detect Bartonella spp. and Mycoplasma spp. which also showed a high phylogenetic diversity, demonstrating the importance of these mammals and the arthropods associated with them in maintaining the spread of pathogens. Previous studies have also reported the presence of these pathogens, with one exception, Neoehrlichia mikurensis , for which phylogenetic analysis revealed less genetic divergence. High-throughput screening can detect more bacteria and parasites at once, reduce screening costs, and improve knowledge of bats as reservoirs of vector-borne pathogens. IMPORTANCE The increasing number of zoonotic pathogens is evident through extensive studies and expanded animal research. Bats, known for their role as reservoirs for various viruses, continue to be significant. However, new findings highlight the emergence of Bartonella spp., such as the human-infecting B. mayotimonensis from bats. Other pathogens like N. mikurensis , Mycoplasma spp., and Theileria spp. found in bat blood and ectoparasites raise concerns, as their impact remains uncertain. These discoveries underscore the urgency for heightened vigilance and proactive measures to understand and monitor zoonotic pathogens. By deepening our knowledge and collaboration, we can mitigate these risks, safeguarding human and animal well-being.
email@example.com (Alexandra Corduneanu) 29 Nov 2023
[anses-04370024] Can Tick Microbiome Explain Nonlinear Relationship between Tick Abundance and Lyme Disease Incidence?
Ticks (Acari: Ixodida) are hematophagous ectoparasitic arachnids that feed on the blood of vertebrate hosts, posing significant concern due to their unrivaled capacity to transmit various pathogens, which surpasses those of all other known arthropod vectors [...]
firstname.lastname@example.org (Miray Tonk-Rügen) 02 Jan 2024
[hal-04372028] Phylogénie et distribution géographique de Borrelia garinii chez des oiseaux communs en France
La maladie de Lyme est une maladie transmise à l’humain via la piqûre d’une tique. Elle est due à des bactéries du genre Borrelia appartenant au complexe Borrelia burgdorferi sensu lato (Bbsl). Borrelia garinii, appartenant à ce complexe et majoritairement responsable de neuroborrélioses chez l’humain en Europe, a pour réservoir les oiseaux. Le but de notre étude était d’étudier la diversité génétique et la répartition spatiale des Bbsl détectées chez des larves gorgées collectées sur 70 oiseaux appartenant à 15 espèces en période de reproduction en France, en se concentrant principalement sur B. garinii. Pour ce faire, nous avons utilisé les séquences génétiques de 96 Bbsl (dont 74 B. garinii), correspondant à un fragment du gène flaB. B. garinii a été identifiée dans toute la France. Les séquences étudiées étaient génétiquement proches. L’arbre phylogénétique construit par la méthode du maximum de parcimonie n’a pas mis en évidence de clades spécifiques à une espèce d’oiseau. Aucune relation entre les clades identifiés dans l’arbre phylogénétique et la distribution spatiale n’a pu être mise en évidence. Le gène séquencé (flaB) est un gène conservé au sein des espèces de Bbsl, ce qui explique la faible diversité génétique observée pour les séquences de Bbsl étudiées. De ce fait, la diversité génétique observée dans cette étude pour le gène flaB ne reflète pas la diversité génétique existant pour l’ensemble du génome des Bbsl. L’utilisation de méthodes de séquençage plus discriminantes serait à privilégier pour l’étude de la phylogénie des Bbsl.
email@example.com (François Margaux) 04 Jan 2024
[hal-04356492] Conserved core microbiota in managed and free-ranging Loxodonta africana elephants
The gut microbiota plays a crucial role in animal health and homeostasis, particularly in endangered species conservation. This study investigated the fecal microbiota composition of European captive-bred African savanna elephants ( Loxodonta africana ) housed in French zoos, and compared it with wild African savanna elephants. Fecal samples were collected and processed for DNA extraction and amplicon sequencing of the 16S rRNA gene. The analysis of α and β diversity revealed significant effects of factors such as diet, daily activity, and institution on microbiota composition. Specifically, provision of branches as part of the diet positively impacted microbiota diversity. Comparative analyses demonstrated distinct differences between captive and wild elephant microbiomes, characterized by lower bacterial diversity and altered co-occurrence patterns in the captive population. Notably, specific taxa were differentially abundant in captive and wild elephants, suggesting the influence of the environment on microbiota composition. Furthermore, the study identified a core association network shared by both captive and wild elephants, emphasizing the importance of certain taxa in maintaining microbial interactions. These findings underscore the impact of environment and husbandry factors on elephant gut microbiota, highlighting the benefits of dietary enrichment strategies in zoos to promote microbiome diversity and health. The study contributes to the broader understanding of host-microbiota interactions and provides insights applicable to conservation medicine and captive animal management.
firstname.lastname@example.org (Milan Thorel) 20 Dec 2023
[hal-04441732] New perspectives for the detection of Anaplasma phagocytophilum infection using aptamers
email@example.com (Lisa Lucie Le Dortz) 06 Feb 2024
[hal-04398418] Establishment of co-infection models in mice with B. afzelii and TBEV
firstname.lastname@example.org (Stefania Porcelli) 16 Jan 2024
[hal-04253031] Isolation and electrophysiological recording of Ixodes ricinus synganglion neurons
email@example.com (Khalid Boussaine) 21 Oct 2023
[anses-04369969] Optimization of the most widely used serological tests for a harmonized diagnosis of Toxoplasma gondii infection in domestic pigs
firstname.lastname@example.org (Nadia María López-Ureña) 02 Jan 2024
[hal-04253067] Cholinergic control of Ixodes salivary glands
email@example.com (Caina Ning) 21 Oct 2023
[hal-04267679] Studies on the circulation of tick-borne pathogens
firstname.lastname@example.org (Angélique Foucault-Simonin) 02 Nov 2023
[hal-04253055] Insight into the tick neurosecretory system
email@example.com (Ladislav Šimo) 21 Oct 2023
[hal-04253059] Do ticks utilize functional adrenergic system?
firstname.lastname@example.org (Sabine Rakotobe) 21 Oct 2023
[hal-04398377] Establishment of co-infection models in mice with B. afzelii and TBEV
email@example.com (Stefania Porcelli) 16 Jan 2024
[hal-04314297] High-throughput nanotechnologies for tick-borne pathogens detection.
firstname.lastname@example.org (Sara Moutailler) 29 Nov 2023
[hal-04181142] Comparative mapping of protein-protein interactions between tick-borne flaviviruses and their mammalian hosts reveals virus- and mammalian host-specific interactions
email@example.com (Marion Sourisseau) 15 Aug 2023
[hal-04314258] Fill in one gap in our understanding of CHIKV intra-vector dynamics
firstname.lastname@example.org (Sara Moutailler) 02 Feb 2024
[hal-04314261] Tick Activity, Host Range, and Tick-Borne Pathogen Prevalence in Mountain Habitats of the Western Carpathians, Poland
In mountainous regions, diverse ecosystems provide a habitat for numerous species of organisms. In this study, we focused on ixodid ticks and their presence in the Western Carpathians, Poland. Our objectives were to investigate the impact of environmental factors on tick occurrence and activity, the prevalence of vectored pathogens, and tick hosts, and their role as reservoir organisms for tick-borne pathogens (TBPs). To this end, we collected ticks from the vegetation and from animals (Apodemus agrarius, A. flavicollis, Capreolus capreolus, Microtus spp., Myodes glareolus, Ovis aries). In addition, we collected blood samples from rodents. The collected material underwent molecular analysis, utilizing the high-throughput microfluidic real-time PCR technique, to detect the presence of TBPs. Our findings confirmed the occurrence of only two species of ixodid ticks in the study area: the dominant Ixodes ricinus, and Dermacentor reticulatus with very limited abundance. Temperature significantly influenced tick activity, and the number of I. ricinus nymphs varied with altitude. We also observed a circadian pattern of questing activity in I. ricinus ticks. The main hosts for juvenile tick stages were M. glareolus and A. agrarius, while adult stages were frequently found on C. capreolus. I. ricinus ticks collected from the vegetation were often infected with Rickettsia helvetica (up to 35.71%), Borrelia afzelii (up to 28.57%), and Ehrlichia spp. (up to 9.52%). In contrast, juvenile stages frequently carried Bartonella spp. (up to 10.00%), Mycoplasma spp. (up to 16.67%) and R. helvetica (up to 16.67%). Moreover, we detected genetic material of Mycoplasma spp. (up to 100.00%), Ehrlichia spp. (up to 35.71%), Bartonella spp. (up to 25.00%), and Borrelia spp. (up to 6.25%) in rodent blood samples. The obtained results indicate A. agrarius and M. glareolus as reservoir animals for TBPs in the studied region.
email@example.com (Zbigniew Zając) 20 Dec 2023
[hal-04441660] Détection d’Anaplasma phagocytophilum chez des passereaux d’Ile de France et caractérisation génétique des variants identifiés par différentes méthodes (typage groEL, ankA et MLST)
firstname.lastname@example.org (Clotilde Rouxel) 06 Feb 2024
[hal-04441703] Sélection et développement d’aptamères dirigés contre A. phagocytophilum
email@example.com (Lisa Lucie Le Dortz) 06 Feb 2024
[hal-04398414] Establishment of co-infection models in mice with B. afzelii and TBEV
firstname.lastname@example.org (Stefania Porcelli) 16 Jan 2024
[hal-04398403] Establishment of co-infection models in mice with B. afzelii and TBEV
email@example.com (Stefania Porcelli) 16 Jan 2024
[hal-04441471] Détection d’Anaplasma phagocytophilum chez des passereaux d’Ile de France et caractérisation génétique des variants identifiés par différentes méthodes (typage groEL, ankA et MLST)
firstname.lastname@example.org (Clotilde Rouxel) 06 Feb 2024