Borrelia afzeliialters reproductive success in a rodent host

The impact of a pathogen on the fitness and behaviour of its natural host depends upon the host–parasite relationship in a given set of environmental conditions. Here, we experimentally investigated the effects ofBorrelia afzelii,one of the aetiological agents of Lyme disease in humans, on the fitness of its natural rodent host, the bank vole (Myodes glareolus), in semi-natural conditions with two contrasting host population densities. Our results show thatB. afzeliican modify the reproductive success and spacing behaviour of its rodent host, whereas host survival was not affected. Infection impaired the breeding probability of large bank voles. Reproduction was hastened in infected females…

Urban forest soils harbour distinct and more diverse communities of bacteria and fungi compared to less disturbed forest soils.

Anthropogenic changes to land use drive concomitant changes in biodiversity, including that of the soil microbiota. However, it is not clear how increasing intensity of human disturbance is reflected in the soil microbial communities. To address this issue, we used amplicon sequencing to quantify the microbiota (bacteria and fungi) in the soil of forests (n=312) experiencing four different land uses, national parks (set aside for nature conservation), managed (for forestry purposes), suburban (on the border of an urban area) and urban (fully within a town or city), which broadly represent a gradient of anthropogenic disturbance. Alpha diversity of bacteria and fungi increased with increasin…

Sympatric Ixodes-tick species: pattern of distribution and pathogen transmission within wild rodent populations

AbstractThe generalist tick Ixodes ricinus is the most important vector for tick-borne pathogens (TBP), including Borrelia burgdorferi sensu lato, in Europe. However, the involvement of other sympatric Ixodes ticks, such as the specialist vole tick I. trianguliceps, in the enzootic circulations of TBP remains unclear. We studied the distribution of I. ricinus and I. trianguliceps in Central Finland and estimated the TBP infection likelihood in the most common rodent host in relation with the abundance of the two tick species. Ixodes trianguliceps was encountered in all 16 study sites whereas I. ricinus was frequently observed only at a quarter of the study sites. The abundance of I. ricinus…

Code from Competition between strains of Borrelia afzelii inside the rodent host and the tick vector

R code used to analyze the data

Susceptibility to infection with Borrelia afzelii and TLR2 polymorphism in a wild reservoir host

AbstractThe study of polymorphic immune genes in host populations is critical for understanding genetic variation in susceptibility to pathogens. Controlled infection experiments are necessary to separate variation in the probability of exposure from genetic variation in susceptibility to infection, but such experiments are rare for wild vertebrate reservoir hosts and their zoonotic pathogens. The bank vole (Myodes glareolus) is an important reservoir host of Borrelia afzelii, a tick-borne spirochete that causes Lyme disease. Bank vole populations are polymorphic for Toll-like receptor 2 (TLR2), an innate immune receptor that recognizes bacterial lipoproteins. To test whether the TLR2 polym…

Temporal dynamics of the tick Ixodes ricinus in northern Europe : epidemiological implications

Background Tick-borne pathogens pose an increasing threat to human and veterinary health across the northern hemisphere. While the seasonal activity of ticks is largely determined by climatic conditions, host-population dynamics are also likely to affect tick abundance. Consequently, abundance fluctuations of rodents in northern Europe are expected to be translated into tick dynamics, and can hence potentially affect the circulation of tick-borne pathogens. We quantified and explained the temporal dynamics of the tick Ixodes ricinus in the northernmost part of its European geographical range, by estimating (i) abundance in vegetation and (ii) infestation load in the most common rodent speci…

Supplementary material from Competition between strains of Borrelia afzelii inside the rodent host and the tick vector

Supplementary material supporting the paper

cayol_texte_tables_figures_ESM from Borrelia afzelii alters reproductive success in a rodent host

Supplementary material from "Borrelia afzelii alters reproductive success in a rodent host". Detailed material and methods, supplementary tables, figures and results.

Competition between strains of Borrelia afzelii inside the rodent host and the tick vector

Multiple-strain pathogens often establish mixed infections inside the host that result in competition between strains. In vector-borne pathogens, the competitive ability of strains must be measured in both the vertebrate host and the arthropod vector to understand the outcome of competition. Such studies could reveal the existence of trade-offs in competitive ability between different host types. We used the tick-borne bacteriumBorrelia afzeliito test for competition between strains in the rodent host and the tick vector, and to test for a trade-off in competitive ability between these two host types. Mice were infected via tick bite with either one or two strains, and these mice were subse…

Additional file 1: Figure S1. of Temporal dynamics of the tick Ixodes ricinus in northern Europe: epidemiological implications

Average monthly saturation deficit and temperature during the monitoring years. Figure S2. Observed mean abundance of ticks in vegetation per session, from May 2012 to October 2015. Figure S3. Mean number of vole captured per trap-night at each session and in each site, from May 2012 to October 2015. Table S1. Selection table for models explaining the abundance of ticks questing in the vegetation. Figure S4. Predicted number of larvae, nymphs and pooled nymphs and females per 100Â m2 of vegetation explained by bank vole abundance. Table S2. Selection table for models explaining the abundance of ticks questing in the vegetation. Table S3. Total number of ticks (per species and stage) collect…

Eco-epidemiology of tick- and rodent-borne pathogens in boreal forests

Infectious diseases are amongst the ten major causes of human mortality worldwide, 60% of them being animal-borne. Variations of abiotic and biotic conditions are likely to modify the transmission of parasites and pathogens within reservoir species, and, as a consequence, alter the zoonotic risk for human. My thesis aims at elucidating the dynamics and mechanisms of the maintenance of ticks, tick-borne pathogens (TBPs) and the Puumala hantavirus (PUUV) in the reservoir host, the bank vole (Myodes glareolus, BV). In Northern Europe, tick-borne diseases are growing in importance to human because of the latitudinal expansion of the tick Ixodes ricinus. Field monitoring revealed that I. ricinus…

Data from Competition between strains of Borrelia afzelii inside the rodent host and the tick vector

Data used for the analyses

Research data of article: "Borrelia afzelii alters reproductive success in a rodent host"

Research data of article: "Sympatric Ixodes-tick species: pattern of distribution and pathogen transmission within wild rodent populations"

Longitudinal monitoring of bank voles as well as their ticks and tick-borne pathogens in Central Finland, carried out in 2012.