RÉSUMÉ
Ticks are major vectors of various pathogens of health importance, such as bacteria, viruses and parasites. The problems associated with ticks and vector-borne pathogens are increasing in mountain areas, particularly in connection with global climate change. We collected ticks (n = 2,081) from chamois and mouflon in 4 mountainous areas of France. We identified 6 tick species: Ixodes ricinus, Rhipicephalus bursa, Rh. sanguineus s.l., Haemaphysalis sulcata, H. punctata and Dermacentor marginatus. We observed a strong variation in tick species composition among the study sites, linked in particular to the climate of the sites. We then analysed 791 ticks for DNA of vector-borne pathogens: Babesia/Theileria spp., Borrelia burgdorferi s.l., Anaplasma phagocytophilum, A. marginale, A. ovis, and Rickettsia of the spotted fever group (SFG). Theileria ovis was detected only in Corsica in Rh. bursa. Babesia venatorum (2 sites), Borrelia burgdorferi s.l. (B. afzelii and B. garinii; 2 sites) and Anaplasma phagocytophilum (3 sites) were detected in I. ricinus. Anaplasma ovis was detected at one site in I. ricinus and Rh. sanguineus s.l. SFG Rickettsia were detected at all the study sites: R. monacensis and R. helvetica in I. ricinus at the 3 sites where this tick is present; R. massiliae in Rh. sanguineus s.l. (1 site); and R. hoogstraalii and Candidatus R. barbariae in Rh. bursa in Corsica. These results show that there is a risk of tick-borne diseases for humans and domestic and wild animals frequenting these mountain areas.
Title: Prévalence d'agents pathogènes vectorisés chez des tiques collectées chez des ongulés sauvages (mouflons, chamois) dans 4 zones montagneuses en France. Abstract: Les tiques sont des vecteurs majeurs de différents agents pathogènes d'importance sanitaire, tels que des bactéries, des virus et des parasites. Les problématiques liées aux tiques et aux pathogènes vectorisés augmentent en zones de montagne, en lien notamment avec le réchauffement climatique. Nous avons collecté des tiques (n = 2 081) sur des chamois et des mouflons dans 4 zones montagneuses en France. Six espèces ont été identifiées : Ixodes ricinus, Rhipicephalus bursa, Rh. sanguineus s.l., Haemaphysalis sulcata, H. punctata et Dermacentor marginatus. Nous avons observé une forte variation de la composition en espèces de tiques entre les sites d'étude, en lien notamment avec le climat des sites. Nous avons ensuite recherché les ADN d'agents pathogènes vectorisés sur 791 tiques : Babesia/Theileria spp, Borrelia burgdorferi s.l., Anaplasma phagocytophilum, A. marginale, A. ovis, et de Rickettsia du groupe des fièvres boutonneuses (SFG). Theileria ovis a été détecté uniquement en Corse chez Rh. bursa. Babesia venatorum (2 sites), Borrelia burgdorferi s.l. (B. afzelii and B. garinii; 2 sites) et Anaplasma phagocytophilum (3 sites) ont été détectés chez I. ricinus. Anaplasma ovis a été détecté dans un site chez I. ricinus et Rh. sanguineus s.l.. Les Rickettsia SFG ont été détectées dans tous les sites d'étude : Rickettsia monacensis et R. helvetica chez I. ricinus dans les 3 sites où cette tique est présente; R. massiliae chez Rh. sanguineus s.l. (1 site); et R. hoogstraalii et Candidatus R. barbariae chez Rh. bursa en Corse. Ces résultats montrent un risque de transmission de maladies par les tiques pour les personnes et les animaux domestiques et sauvages fréquentant ces zones de montagne.
Sujet(s)
Anaplasma phagocytophilum , Babesia , Ixodes , Ixodidae , Rickettsia , Rupicapra , Theileria , Maladies transmises par les tiques , Humains , Animaux , Ovis , Ovis aries , Prévalence , Ixodes/microbiologie , Babesia/génétique , Theileria/génétique , Anaplasma phagocytophilum/génétique , Maladies transmises par les tiques/épidémiologie , Maladies transmises par les tiques/médecine vétérinaire , Maladies transmises par les tiques/microbiologieRÉSUMÉ
Ticks are important vectors of several human and animal pathogens. In this study, we estimated the prevalence of important tick-borne infections in questing ticks from an area in Southwestern France (Hautes-Pyrénées) inhabited by Pyrenean chamois (Rupicapra pyrenaica pyrenaica) experiencing high tick burden. We examined adult and nymph ticks collected by the flag dragging method from 8 to 15 sites in the Pic de Bazès during the years 2009, 2011, 2013 and 2015. PCR assays were conducted on selected ticks for the detection of Borrelia burgdorferi s.l., Babesia spp., Rickettsia spp., spotted fever group (SFG) Rickettsia and Anaplasma phagocytophilum. Randomly selected positive samples were submitted for sequence analysis. A total of 1971 questing ticks were collected including 95 males, 101 females and 1775 nymphs. All collected ticks were identified as Ixodes ricinus. Among them, 696 ticks were selected for pathogen detection and overall prevalence was 8.4% for B. burgdorferi s.l.; 0.4% for Babesia spp.; 6.1% for A. phagocytophilum; 17.6% for Rickettsia spp.; and 8.1% for SFG Rickettsia. Among the sequenced pathogens, we detected in this population of ticks the presence of Babesia sp. EU1 and Rickettsia helvetica, as well as Rickettsia monacensis for the first time in France. The detection of these pathogens in the Pic de Bazès highlights the potential infection risks for visitors to this area and the Pyrenean chamois population.
TITLE: Détection d'agents pathogènes présents chez les tiques errantes, Ixodes ricinus, dans les Pyrénées françaises et première identification de Rickettsia monacensis en France. ABSTRACT: Les tiques sont des vecteurs importants de plusieurs maladies animales et humaines. Dans cette étude, nous avons estimé la prévalence de maladies vectorisées chez les tiques errantes dans une région du sud-ouest de la France (Hautes-Pyrénées) occupée par des chamois des Pyrénées (Rupicapra pyrenaica pyrenaica) fortement infestés par les tiques. Nous avons utilisé des tiques adultes et des larves collectées par la technique du drapeau sur 815 sites du Pic de Bazès au cours des années 2009, 2011, 2013 et 2015. Des analyses PCR ont été menées sur des tiques sélectionnées pour la détection de Borrelia burgdorferi s.l., Babesia spp., Rickettsia spp., Rickettsia du groupe de la fièvre pourprée (GFP) et Anaplasma phagocytophilum. Des échantillons positifs sélectionnés au hasard ont été soumis à une analyse de séquences. Un total de 1971 tiques a été collecté dont 95 mâles, 101 femelles et 1775 larves. Toutes les tiques recueillies ont été identifiées comme étant Ixodes ricinus. Parmi celles-ci, 696 tiques ont été sélectionnées pour la détection des agents pathogènes et la prévalence globale était de 8,4 % pour B. burgdorferi s.l., 0,4 % pour Babesia spp., 6,1 % pour A. phagocytophilum, 17,6 % pour Rickettsia spp. et 8,1 % pour Rickettsia GFP. Parmi les agents pathogènes séquencés, nous avons détecté dans cette population de tiques la présence de Babesia sp. EU1, Rickettsia helvetica et, pour la première fois en France, Rickettsia monacensis. La détection de ces agents pathogènes dans le Pic de Bazès souligne les risques potentiels d'infection pour les visiteurs de cette région et pour la population de chamois des Pyrénées.
Sujet(s)
Ixodes/microbiologie , Ixodes/parasitologie , Rickettsia/isolement et purification , Maladies transmises par les tiques/diagnostic , Anaplasma phagocytophilum/génétique , Anaplasma phagocytophilum/isolement et purification , Animaux , Babesia/génétique , Babesia/isolement et purification , Borrelia burgdorferi/génétique , Borrelia burgdorferi/isolement et purification , Co-infection/microbiologie , Co-infection/parasitologie , ADN bactérien/génétique , ADN des protozoaires/génétique , Femelle , France , Humains , Mâle , Nymphe , Réaction de polymérisation en chaîne , Santé publique , Rickettsia/classification , Analyse de séquence d'ADN , Maladies transmises par les tiques/microbiologieRÉSUMÉ
The cost of current reproduction on survival or future reproduction is one of the most studied trade-offs governing resource distribution between fitness components. Results have often been clouded, however, by the existence of individual heterogeneity, with high-quality individuals able to allocate energy to several functions simultaneously, at no apparent cost. Surprisingly, it has also rarely been assessed within a breeding season by breaking down the various reproductive efforts of females from gestation to weaning, even though resource availability and energy requirements vary greatly. We filled this gap by using an intensively monitored population of Pyrenean chamois and by expanding a new methodological approach integrating robust design in a multi-event framework. We distinguished females that gave birth or not, and among reproducing females whether they lost their kid or successfully raised it until weaning. We estimated spring and summer juvenile survival, investigated whether gestation, lactation or weaning incurred costs on the next reproductive occasion, and assessed how individual heterogeneity influenced the detection of such costs. Contrary to expectations if trade-offs occur, we found a positive relationship between gestation and adult survival suggesting that non-breeding females are in poor condition. Costs of reproduction were expressed through negative relationships between lactation and both subsequent breeding probability and spring juvenile survival. Such costs could be detected only once individual heterogeneity (assessed as two groups contrasting good vs. poor breeders) and time variations in juvenile survival were accounted for. Early lactation decreased the probability of future reproduction, providing quantitative evidence of the fitness cost of this period recognized as the most energetically demanding in female mammals and critical for neonatal survival. The new approach employed made it possible to estimate two components of kid survival that are often considered practically unavailable in free-ranging populations, and also revealed that reproductive costs appeared only when contrasting the different stages of reproductive effort. From an evolutionary perspective, our findings stressed the importance of the temporal resolution at which reproductive cost is studied, and also provided insights on the reproductive period during which internal and external factors would be expected to have the greatest fitness impact.
Sujet(s)
Métabolisme énergétique , Lactation , Longévité , Reproduction , Rupicapra/physiologie , Animaux , FemelleRÉSUMÉ
In seasonal environments, birth dates are a central component for a species' life history, with potential long-term fitness consequences. Yet our understanding of selective pressures of environmental changes on birth dates is limited in wild mammals due to the difficulty of data collection. In a context of rapid climate change, the question of a possible mismatch between plant phenology and birth phenology also remains unanswered for most species. We assessed whether and how the timing of birth in a mountain mammal (isard, also named Pyrenean chamois, Rupicapra pyrenaica pyrenaica) tracked changes in plant growing season, accounting for maternal traits, individual heterogeneity and population density. We not only focused on spring conditions but also assessed to what extent onset of autumn can be a driver of phenological biological events and compared the magnitude of the response to the magnitude of the environmental changes. We relied on a 22-year study based on intensively monitored marked individuals of known age. Births were highly synchronized (80% of kids born within 25 days) and highly repeatable (84%; between-female variation of 9.6 days, within-female variation of 4.2 days). Individual phenotypic plasticity allows females to respond rapidly to interannual changes in plant phenology but did not prevent the existence of a mismatch: a 10-day advance in the autumn or spring plant phenology led to 3.9 and 1.3 days advance in birth dates, respectively. Our findings suggest that plant phenology may act as a cue to induce important stages of the reproductive cycle (e.g. conception and gestation length), subsequently affecting parturition dates, and stressed the importance of focusing on long-term changes during spring for which females may show much lower adaptive potential than during autumn. These results also question the extent to which individual plasticity along with high heterogeneity among individuals will allow species to cope with demographic consequences of climate changes.