Lyme borreliosis in Europe.

Despite improvements in prevention, diagnosis and treatment, Lyme borreliosis (LB) is still the most common arthropod-borne disease in temperate regions of the northern hemisphere, with risk of infection associated with occupation (e.g. forestry work) and certain outdoor recreational activities (e.g. mushroom collecting). In Europe, LB is caused by infection with one or more pathogenic European genospecies of the spirochaete Borrelia burgdorferi sensu lato, mainly transmitted by the tick Ixodes ricinus. Recent surveys show that the overall prevalence of LB may be stabilising, but its geographical distribution is increasing. In addition, much remains to be discovered about the factors affecting genospecific prevalence, transmission and virulence, although avoidance of tick bite still appears to be the most efficient preventive measure. Uniform, European-wide surveillance programmes (particularly on a local scale) and standardisation of diagnostic tests and treatments are still urgently needed, especially in the light of climate change scenarios and land-use and socio-economic changes. Improved epidemiological knowledge will also aid development of more accurate risk prediction models for LB. Studies on the effects of biodiversity loss and ecosystem changes on LB emergence may identify new paradigms for the prevention and control of LB and other tick-borne diseases

Current and future distribution of a parasite with complex life cycle under global change scenarios: Echinococcus multilocularis in Europe

Global change is expected to have complex effects on the distribution and transmission patterns of zoonotic parasites. Modelling habitat suitability for parasites with complex life cycles is essential to further our understanding of how disease systems respond to environmental changes, and to make spatial predictions of their future distributions. However, the limited availability of high quality occurrence data with high spatial resolution often constrains these investigations. Using 449 reliable occurrence records for Echinococcus multilocularis from across Europe published over the last 35 years, we modelled habitat suitability for this parasite, the aetiological agent of alveolar echinococcosis, in order to describe its environmental niche, predict its current and future distribution under three global change scenarios, and quantify the probability of occurrence for each European country. Using a machine learning approach, we developed large-scale (25 × 25 km) species distribution models based on seven sets of predictors, each set representing a distinct biological hypothesis supported by current knowledge of the autecology of the parasite. The best-supported hypothesis included climatic, orographic and land-use/land-cover variables such as the temperature of the coldest quarter, forest cover, urban cover and the precipitation seasonality. Future projections suggested the appearance of highly suitable areas for E. multilocularis towards northern latitudes and in the whole Alpine region under all scenarios, while decreases in habitat suitability were predicted for central Europe. Our spatially explicit predictions of habitat suitability shed light on the complex responses of parasites to ongoing global change

Gut microbiota variations in wild yellow baboons (Papio cynocephalus) are associated with sex and habitat disturbance

Although male and female mammals differ in biological traits and functional needs, the contribution of this sexual dimorphism to variations in gut bacteria and fungi (gut microbiota) in relation to habitat type has not been fully examined. To understand whether the combination of sex and habitat affects gut microbiota variation, we analyzed 40 fecal samples of wild yellow baboons (Papio cynocephalus) living in contrasting habitat types (intact, well-protected vs. fragmented, less protected forests) in the Udzungwa Mountains of Tanzania. Sex determination was performed using the marker genes SRY (Sex-determining Region Y) and DDX3X-DDX3Y (DEAD-Box Helicase 3). Samples were attributed to 34 individuals (19 females and 15 males) belonging to five social groups. Combining the results of sex determination with two amplicon sequencing datasets on bacterial (V1-V3 region of the 16S rRNA gene) and fungal (ITS2) gut communities, we found that overall, baboon females had a significantly higher gut bacterial richness compared to males. Beta diversity estimates indicated that bacterial composition was significantly different between males and females, and this was true for individuals from both well- and less protected forests. Our results highlight the combined role of sex and habitat type in shaping variation in gut microbial communities in wild non-human primates

Gut microbial functions are impacted by habitat: implications for the conservation of non-human primates

We investigate the effect of forest fragmentation on gut microbiota functions and dietary adaptations of two non-human primate species in the Udzungwa Mountains of Tanzania using whole-genome shotgun sequencing. The Udzungwa red colobus (Procolobus gordonorum) is an endangered species with a restricted folivorous (leaf-eating) diet, while the yellow baboon (Papio cynocephalus) is a species of least concern with a highly diverse omnivorous diet. We identified several microbial pathways that were enriched or decreased in a fragmented forest patch compared to an intact forest, indicating functional adaptations of gut bacteria. The gut microbiota of the Udzungwa red colobus, in particular, shows a high sensitivity to habitat changes, which may be linked to its strictly folivorous feeding strategy. By contrast, the yellow baboon displays greater tolerance to habitat changes by showing a lower impact on their gut microbes, which is likely caused by its more varied diet. To investigate habitat-associated diet in detail, in an ongoing analysis, we aim to reconstruct dietary composition from the same shotgun sequencing samples. We will also present novel results showing the potential and the limits of identifying diet and host characteristics from faecal samples, and hence, the usefulness of this shotgun approach to conservation issues

Interactions between parasitic helminths and gut microbiota in wild tropical primates from intact and fragmented habitats

7openInternationalBothThe mammalian gastrointestinal tract harbours a highly complex ecosystem composed of a variety of micro- (bacteria, fungi, viruses, protozoans) and macro-organisms (helminths). Although most microbiota research focuses on the variation of single gut components, the crosstalk between components is still poorly characterized, especially in hosts living under natural conditions. We investigated the gut micro-biodiversity (bacteria, fungi and helminths) of 158 individuals of two wild non-human primates, the Udzungwa red colobus (Procolobus gordonorum) and the yellow baboon (Papio cynocephalus). These species have contrasting diets and lifestyles, but live sympatrically in both human-impacted and pristine forests in the Udzungwa Mountains of Tanzania. Using non-invasive faecal pellets, helminths were identified using standard microscopy while bacteria and fungi were characterized by sequencing the V1–V3 variable region of the 16S rRNA gene for bacteria and the ITS1–ITS2 fragment for fungi. Our results show that both diversity and composition of bacteria and fungi are associated with variation in helminth presence. Although interactions differed by habitat type, in both primates we found that Strongyloides was negatively associated and Trichuris was positively associated with bacterial and fungal richness. To our knowledge, this is one of the few studies demonstrating an interaction between helminth and gut microbiota communities in wild non-human primates.openBarelli, Claudia; Donati, Claudio; Albanese, Davide; Pafčo, Barbora; Modrý, David; Rovero, Francesco; Hauffe, Heidi C.Barelli, C.; Donati, C.; Albanese, D.; Pafčo, B.; Modrý, D.; Rovero, F.; Hauffe, H.C

Sex predicts gut microbiota variations in wild yellow baboons (Papio cynocephalus)

The role of gut microbiota diversity in animal ecology and conservation has become a key topic, especially since the contribution of these bacterial and fungal communities to host growth and health has been recently recognized. Most investigations in wildlife have focused on the study of extrinsic (e.g., diet, habitat) rather than intrinsic factors (e.g., sex, genetic background) affecting variation in animal gut communities. However, since male and female mammals often differ in biological traits and functional needs, sex is likely to play a major role in gut microbiota variation. Here, we evaluated if and how sex is associated with the gut microbiota richness and composition of wild yellow baboons (Papio cynocephalus) living in two habitat types, protected and unprotected forests of the Udzungwa Mountains in Tanzania. To understand whether sex and habitat type affect gut microbiota variation, we determined the sex of 34 yellow baboons (19 females and 15 males) from fecal pellets collected non-invasively using two marker genes (SRY and DDX3X). We then combined these results with amplicon sequencing datasets focusing on bacterial (V3-V4 region of the 16S rRNA gene) and fungal (ITS1-ITS2) communities of the same pellets. We found that females had gut microbiotas with a higher bacterial richness [Kruskal test; Shannon (alpha diversity): P = 0.010] and different composition [ANOVA; weighted Unifrac (beta diversity): P = 0.030] compared to males, in agreement with the strong morphological and behavioural dimorphisms shown between sexes of this species. Furthermore, forest type had a greater impact on females than males, such that the gut microbiotas of females from the two forests differed significantly in fungal composition [pairwise adonis test; Bray-Curtis: P = 0.02] and bacterial richness [pairwise Wilcoxon Rank Sum test; Shannon: P = 0.023], while those of males did not. These results indicated that the impact of habitat disturbance varied with sex, suggesting that intrinsic biological factors should be carefully considered when investigating wild animal biodiversity at any scale, and that such intraspecific variation could impact the outcome of conservation actions. However, research on the metabolic pathways, through shotgun sequencing, are encouraged to verify whether greater gut bacterial richness, such as those observed in baboon females, may translate into a greater diversity of metabolic functions

Comparison of DNA extraction methods on different sample matrices within the same terrestrial ecosystem

Metataxonomic studies of ecosystem microbiotas require the simultaneous processing of samples with contrasting physical and biochemical traits. However, there are no published studies of comparisons of different DNA extraction kits to characterize the microbiotas of the main components of terrestrial ecosystems. Here, and to our knowledge for the first time, five DNA extraction kits were used to investigate the composition and diversity of the microbiota of a subset of samples typically studied in terrestrial ecosystems such as bulk soil, rhizosphere soil, invertebrate taxa and mammalian feces. DNA extraction kit was associated with changes in the relative abundance of hundreds of ASVs, in the same samples, resulting in significant differences in alpha and beta diversity estimates of their microbiotas. Importantly, the impact of DNA extraction kit on sample diversity varies according to sample type, with mammalian feces and soil samples showing the most and least consistent diversity estimates across DNA extraction kits, respectively. We show that the MACHEREY-NAGEL NucleoSpin® Soil kit was associated with the highest alpha diversity estimates, providing the highest contribution to the overall sample diversity, as indicated by comparisons with computationally assembled reference communities, and is recommended to be used for any large-scale microbiota study of terrestrial ecosystem

Diet-driven mercury contamination is associated with polar bear gut microbiota

7openInternationalInternational coauthor/editorThe gut microbiota may modulate the disposition and toxicity of environmental contaminants within a host but, conversely, contaminants may also impact gut bacteria. Such contaminant-gut microbial connections, which could lead to alteration of host health, remain poorly known and are rarely studied in free-ranging wildlife. The polar bear (Ursus maritimus) is a long-lived, wide-ranging apex predator that feeds on a variety of high trophic position seal and cetacean species and, as such, is exposed to among the highest levels of biomagnifying contaminants of all Arctic species. Here, we investigate associations between mercury (THg; a key Arctic contaminant), diet, and the diversity and composition of the gut microbiota of polar bears inhabiting the southern Beaufort Sea, while accounting for host sex, age class and body condition. Bacterial diversity was negatively associated with seal consumption and mercury, a pattern seen for both Shannon and Inverse Simpson alpha diversity indices (adjusted R2 = 0.35, F1,18 = 8.00, P = 0.013 and adjusted R2 = 0.26, F1,18 = 6.04, P = 0.027, respectively). No association was found with sex, age class or body condition of polar bears. Bacteria known to either be involved in THg methylation or considered to be highly contaminant resistant, including Lactobacillales, Bacillales and Aeromonadales, were significantly more abundant in individuals that had higher THg concentrations. Conversely, individuals with higher THg concentrations showed a significantly lower abundance of Bacteroidales, a bacterial order that typically plays an important role in supporting host immune function by stimulating intraepithelial lymphocytes within the epithelial barrier. These associations between diet-acquired mercury and microbiota illustrate a potentially overlooked outcome of mercury accumulation in polar bears.openWatson, S.; McKinney, M.A.; Pindo, M.; Bull, M.; Atwood, T.C.; Hauffe, H.C.; Perkins, S.E.Watson, S.; Mckinney, M.A.; Pindo, M.; Bull, M.; Atwood, T.C.; Hauffe, H.C.; Perkins, S.E