RESUMEN
Research into various bacterial pathogens that can be transmitted between different animals and may have zoonotic potential has led to the discovery of different strains of Bartonella sp. in bats and their associated ectoparasites. Despite their enormous species diversity, only a few studies have focussed on the detection of bacterial pathogens in insectivorous bats of boreal forests and their associated Macronyssidae and Spinturnicidae mites. We collected and molecularly analysed mite samples from forest-dwelling bat species distributed all along the boreal belt of the Palearctic, from Central Europe to Far East. Ectoparasitic mites were pooled for DNA extraction and DNA amplification polymerase chain reaction (PCRs) were conducted to detect the presence of various bacterial (Anaplasmataceae, Bartonella sp., Rickettsia sp., Mycoplasma sp.) and protozoal (Hepatozoon sp.) pathogens. Bartonella sp. DNA was detected in four different mite species (Macronyssidae: Steatonyssus periblepharus and Spinturnicidae: Spinturnix acuminata, Sp. myoti and Sp. mystacinus), with different prevalences of the targeted gene (gltA, 16-23S ribosomal RNA intergenic spacer and ftsZ). Larger pools (>5 samples pooled) were more likely to harbour Bartonella sp. DNA, than smaller ones. In addition, cave-dwelling bat hosts and host generalist mite species are more associated with Bartonella spp. presence. Spinturnicidae mites may transmit several distinct Bartonella strains, which cluster phylogenetically close to Bartonella species known to cause diseases in humans and livestock. Mites with ubiquitous presence may facilitate the long-term maintenance (and even local recurrence) of Bartonella-infestations inside local bat populations, thus acting as continuous reservoirs for Bartonella spp in bats.
RESUMEN
Four Ixodes species represent the subgenus Scaphixodes Schulze, 1941 in Europe, but none of them were reported to be compared in a molecular-phylogenetic context. This study compensates for this lack of data. A tick larva, morphologically identified as Ixodes (Scaphixodes) caledonicus Nuttall, 1910, was collected from an Alpine swift (Tachymarptis melba) during its nesting period in Transylvania, Romania. Following DNA extraction, PCR analyses and sequencing in part with newly designed primers, three genetic markers of this specimen were amplified and compared to GenBank data, and two were analyzed phylogenetically. Based on sequence comparisons of its mitochondrial cytochrome c oxidase subunit I (cox1) and nuclear 28S rRNA genes I. caledonicus appeared to be closely related to members of the subgenus Pholeoixodes. However, the topology of the concatenated cox1 and 16S rRNA gene phylogenetic tree clearly showed its clustering with Ixodes (Scaphixodes) philipi. In conclusion, I. caledonicus is part of the tick fauna of Romania and is expected to occur also in other countries of the Carpathian Basin where rocky cliffs are available for nesting of swifts and other birds. This is the first species of the subgenus Scaphixodes in Europe, for which the traditional (morphology-based) taxonomic assignment is confirmed by molecular-phylogenetic analyses.
Asunto(s)
Ixodes , Animales , Filogenia , ARN Ribosómico 16S/genética , Europa (Continente) , RumaníaRESUMEN
Bat flies are one of the most abundant ectoparasites of bats, showing remarkable morphological adaptations to the parasitic habit, while the relationship with their hosts is characterized by a high level of specificity. By collecting bat flies from live hosts, our intention was to elucidate the seasonal differences in bat fly occurrence and to describe factors regulating the level of incipient host specificity. Our results indicate that the prevalence and the intensity of infestation is increasing from spring to autumn for most host species, with significant differences among different fly species. Males showed higher infestation levels than females in autumn, suggesting a non-random host choice by flies, targeting the most active host sex. Bat-bat fly host specificity shows seasonal changes and host choice of bat flies are affected by the seasonal differences in hosts' behavior and ecology, the intensity of infestation and the species composition of the local host community. Nycteribiid bat flies showed lower host specificity in the swarming (boreal autumn) period, with higher prevalence recorded on non-primary hosts. Choosing a non-primary bat host may be an adaptive choice for bat flies in the host's mating period, thus increasing their dispersive ability in a high activity phase of their hosts.
Asunto(s)
Quirópteros , Dípteros , Parásitos , Animales , Femenino , Masculino , Interacciones Huésped-Parásitos , Estaciones del Año , Parásitos/fisiología , Ecología , Especificidad del HuéspedRESUMEN
Evidence for divergent selection and adaptive variation across the landscape can provide insight into a species' ability to adapt to different environments. However, despite recent advances in genomics, it remains difficult to detect the footprints of climate-mediated selection in natural populations. Here, we analysed ddRAD sequencing data (21,892 SNPs) in conjunction with geographic climate variation to search for signatures of adaptive differentiation in twelve populations of the bank vole (Clethrionomys glareolus) distributed across Europe. To identify the loci subject to selection associated with climate variation, we applied multiple genotype-environment association methods, two univariate and one multivariate, and controlled for the effect of population structure. In total, we identified 213 candidate loci for adaptation, 74 of which were located within genes. In particular, we identified signatures of selection in candidate genes with functions related to lipid metabolism and the immune system. Using the results of redundancy analysis, we demonstrated that population history and climate have joint effects on the genetic variation in the pan-European metapopulation. Furthermore, by examining only candidate loci, we found that annual mean temperature is an important factor shaping adaptive genetic variation in the bank vole. By combining landscape genomic approaches, our study sheds light on genome-wide adaptive differentiation and the spatial distribution of variants underlying adaptive variation influenced by local climate in bank voles.