First detection and low prevalence of Pearsonema spp. in wild raccoons (Procyon lotor) from Central Europe.

The urinary bladder and lower urinary tract of domestic and wild carnivores can be parasitised by filamentous nematodes from the genus Pearsonema (syn. Capillaria). Infestations are often asymptomatic, but severe courses in dogs and cats have been described. Hosts are infested through the ingestion of earthworms (Lumbricidae) which act as intermediate hosts. Epidemiological studies of Pearsonema in raccoons (Procyon lotor) in North America are scarce and previous studies of urinary bladder parasites of European raccoons did not provide evidence of infestation. We examined urine sediment or rinse water from urinary bladders of 499 wild raccoons from Luxembourg, Poland and five study sites in Germany. Pearsonema eggs were found in the urine sediment of 31 (6.2%) raccoons. Infested animals were found in all study areas with prevalence values ranging from 3.7% to 8.7%. No significant difference in prevalence was found either between animals in urban and rural areas or between sexes and age classes. Based on their morphology, the eggs were likely to be P. plica. Considering their increasing density in Central Europe, raccoons may play a previously overlooked role in environmental contamination with Personema eggs.

Chromosomally encoded ESBL genes in Escherichia coli of ST38 from Mongolian wild birds.

Objectives: ESBL genes in Escherichia coli are mainly plasmid encoded, although recent studies have also shown chromosomal integration, e.g. in clinical E. coli isolates of ST38. As ESBL-producing E. coli are also found in non-clinical settings, we were interested in determining whether chromosomally integrated ESBL genes occur in ST38 isolates from non-clinical habitats, e.g. wildlife. Methods: Four ESBL-producing E. coli isolates of ST38 originating from Mongolian birds of prey sampled in 2015 were subjected to a detailed analysis in terms of phenotypic resistance, plasmid profiling and WGS, followed by the determination of genotypic resistance factors including the chromosomal integration of ESBL and carbapenemase genes. Results: Results based on phenotypic and genotypic plasmid profiling, contiguous sequence (contig) sizes and PCR analysis of flanking insertion site regions showed that three of four ST38 isolates harboured chromosomally encoded bla CTX-M genes of three different types ( bla CTX-M-14 , bla CTX-M-15 and bla CTX-M-24 ) that were inserted into three different chromosomal locations. A comparison of WGS data with ST38 isolates from a clinical outbreak in the UK indicated only low numbers of core-genome SNPs detected among one Mongolian wild bird isolate and eight clinical isolates from the UK. Conclusions: The chromosomal integration of bla CTX-M genes in E. coli isolates of ST38 appears to be common and is likely independent of antimicrobial selective pressure in clinical environments. Our data corroborate the zoonotic potential of environmental isolates of ESBL-producing E. coli , which harbour stably integrated, chromosomally encoded resistance factors.

Nuclear and mitochondrial genetic structure in the Eurasian beaver (Castor fiber) - implications for future reintroductions.

Many reintroduction projects for conservation fail, and there are a large number of factors that may contribute to failure. Genetic analysis can be used to help stack the odds of a reintroduction in favour of success, by conducting assessment of source populations to evaluate the possibility of inbreeding and outbreeding depression and by conducting postrelease monitoring. In this study, we use a panel of 306 SNP (single nucleotide polymorphism) markers and 487-489 base pairs of mitochondrial DNA control region sequence data to examine 321 individuals from possible source populations of the Eurasian beaver for a reintroduction to Scotland. We use this information to reassess the phylogenetic history of the Eurasian beavers, to examine the genetic legacy of past reintroductions on the Eurasian landmass and to assess the future power of the genetic markers to conduct ongoing monitoring via parentage analysis and individual identification. We demonstrate the capacity of medium density genetic data (hundreds of SNPs) to provide information suitable for applied conservation and discuss the difficulty of balancing the need for high genetic diversity against phylogenetic best fit when choosing source population(s) for reintroduction.

Comparable high rates of extended-spectrum-beta-lactamase-producing Escherichia coli in birds of prey from Germany and Mongolia.

Frequent contact with human waste and liquid manure from intensive livestock breeding, and the increased loads of antibiotic-resistant bacteria that result, are believed to be responsible for the high carriage rates of ESBL-producing E. coli found in birds of prey (raptors) in Central Europe. To test this hypothesis against the influence of avian migration, we initiated a comparative analysis of faecal samples from wild birds found in Saxony-Anhalt in Germany and the Gobi-Desert in Mongolia, regions of dissimilar human and livestock population characteristics and agricultural practices. We sampled a total of 281 wild birds, mostly raptors with primarily north-to-south migration routes. We determined antimicrobial resistance, focusing on ESBL production, and unravelled the phylogenetic and clonal relatedness of identified ESBL-producing E. coli isolates using multi-locus sequence typing (MLST) and macrorestriction analyses. Surprisingly, the overall carriage rates (approximately 5%) and the proportion of ESBL-producers among E. coli (Germany: 13.8%, Mongolia: 10.8%) were similar in both regions. Whereas bla(CTX-M-1) predominated among German isolates (100%), bla(CTX-M-9) was the most prevalent in Mongolian isolates (75%). We identified sequence types (STs) that are well known in human and veterinary clinical ESBL-producing E. coli (ST12, ST117, ST167, ST648) and observed clonal relatedness between a Mongolian avian ESBL-E. coli (ST167) and a clinical isolate of the same ST that originated in a hospitalised patient in Europe. Our data suggest the influence of avian migratory species in the transmission of ESBL-producing E. coli and challenge the prevailing assumption that reducing human influence alone invariably leads to lower rates of antimicrobial resistance.

Mitochondrial genomes reveal slow rates of molecular evolution and the timing of speciation in beavers (Castor), one of the largest rodent species.

BACKGROUND: Beavers are one of the largest and ecologically most distinct rodent species. Little is known about their evolution and even their closest phylogenetic relatives have not yet been identified with certainty. Similarly, little is known about the timing of divergence events within the genus Castor. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced complete mitochondrial genomes from both extant beaver species and used these sequences to place beavers in the phylogenetic tree of rodents and date their divergence from other rodents as well as the divergence events within the genus Castor. Our analyses support the phylogenetic position of beavers as a sister lineage to the scaly tailed squirrel Anomalurus within the mouse related clade. Molecular dating places the divergence time of the lineages leading to beavers and Anomalurus as early as around 54 million years ago (mya). The living beaver species, Castor canadensis from North America and Castor fiber from Eurasia, although similar in appearance, appear to have diverged from a common ancestor more than seven mya. This result is consistent with the hypothesis that a migration of Castor from Eurasia to North America as early as 7.5 mya could have initiated their speciation. We date the common ancestor of the extant Eurasian beaver relict populations to around 210,000 years ago, much earlier than previously thought. Finally, the substitution rate of Castor mitochondrial DNA is considerably lower than that of other rodents. We found evidence that this is correlated with the longer life span of beavers compared to other rodents. CONCLUSIONS/SIGNIFICANCE: A phylogenetic analysis of mitochondrial genome sequences suggests a sister-group relationship between Castor and Anomalurus, and allows molecular dating of species divergence in congruence with paleontological data. The implementation of a relaxed molecular clock enabled us to estimate mitochondrial substitution rates and to evaluate the effect of life history traits on it.

Mitochondrial phylogeography of the Eurasian beaver Castor fiber L.

Nucleotide variation in an approximately 490 bp fragment of the mitochondrial DNA control region (mtDNA CR) was used to describe the genetic variation and phylogeographical pattern in the Eurasian beaver (Castor fiber) over its entire range. The sampling effort was focused on the relict populations that survived a drastic population bottleneck, caused by overhunting, at the end of the 19th century. A total of 152 individuals grouped into eight populations representing all currently recognized subspecies were studied. Sixteen haplotypes were detected, none of them shared among populations. Intrapopulation sequence variation was very low, most likely a result of the severe bottleneck. Extreme genetic structure could result from human-mediated extinction of intermediate populations, but it could also be an effect of prior substantial structuring of the beaver populations with watersheds of major Eurasian rivers acting as barriers to gene flow. Phylogenetic analysis revealed the presence of two mtDNA lineages: eastern (Poland, Lithuania, Russia and Mongolia) and western (Germany, Norway and France), the former comprising more divergent haplotypes. The low level of sequence divergence of the entire cytochrome b gene among six individuals representing six subspecies suggests differentiation during the last glacial period and existence of multiple glacial refugia. At least two evolutionary significant units (ESU) can be identified, the western and the eastern haplogroup. The individual relict populations should be regarded as management units, the eastern subspecies possibly also as ESUs. Guidelines for future translocations and reintroductions are proposed.