Malicious Mites-Sarcoptes scabiei in Raccoon Dogs (Nyctereutes procyonoides) in Schleswig-Holstein, Germany

Sarcoptic mange was detected in five free-ranging raccoon dogs (Nyctereutes procyonoides) in the federal state of Schleswig-Holstein, Germany, during a health assessment study of invasive species, including raccoon dogs, carried out between 2021 and 2022. Four raccoon dogs showed severe lesions, including extensive alopecia with thickening and hyperpigmentation of the skin (lichenification). The fifth animal was less affected, showing only thinning of the hair coat in multiple body locations. Skin scrapings were performed and confirmed the presence of Sarcoptes scabiei. Histopathology of the skin revealed diffuse epidermal hyperplasia and hyperkeratosis, mild eosinophilic dermatitis, and varying amounts of intralesional mites. Staphylococcus pseudintermedius and Corynebacterium auriscanis were detected in the skin samples of the affected animals, indicating a secondary bacterial infection. The source of sarcoptic mange remains unclear; interspecies transmission via direct or indirect contact seems likely. Raccoon dogs are therefore a potential vector for sarcoptic mange, and their behaviour could contribute to disease spread and persistence.

Genotyping-by-sequencing based SNP discovery in a non-model rodent, the endangered hazel dormouse

The hazel dormouse Muscardinus avellanarius presents an exemplary non-model species that is both locally threatened and whose genetic status is not fully understood owing to insufficient resolution of the currently available molecular tools. We performed normalized Genotyping-by-Sequencing (nGBS) on 48 hazel dormouse samples collected across the species European distribution, aiming at discovering useful single nucleotide polymorphism (SNP) markers for the assessment of population structure and genomic diversity. The analyses of > 24,000 SNPs showed a high divergence between the Eastern and Western lineage of the species with high rates of SNP allele fixation, consistent with previous studies suggesting the divergence of lineages occurred over 2 mya. These results indicate that investigating inter-lineage as well as within-lineage genetic composition will be a conclusive approach for identifying conservation strategies in the future. Results presented here indicate the highest genetic divergence in the Italian and Lithuanian populations. We document how nGBS allows the discovery of SNPs that can characterize patterns of genetic variation at multiple spatial scales in a non-model organism. We document how nGBS allows the discovery of SNPs that can characterize patterns of genetic variation at multiple spatial scales in a non-model organism, potentially informing monitoring and conservation strategies.

Geographic Distribution of Raccoon Roundworm, Baylisascaris procyonis, Germany and Luxembourg

Infestation with Baylisascaris procyonis, a gastrointestinal nematode of the raccoon, can cause fatal disease in humans. We found that the parasite is widespread in central Germany and can pose a public health risk. The spread of B. procyonis roundworms into nematode-free raccoon populations needs to be monitored.

Molecular survey of tick-borne pathogens reveals a high prevalence and low genetic variability of Hepatozoon canis in free-ranging grey wolves (Canis lupus) in Germany

Wild carnivores are important hosts for ixodid ticks and presumed reservoirs for several tick-borne pathogens (TBPs) of medical and veterinary importance. However, little is known about the role that the European grey wolf (Canis lupus) plays in the enzootic cycle of TBPs. The recent recolonization of Central European lowland, including some regions in Germany, by the grey wolf, opened up an excellent opportunity for studying the impact of the wolf population on pathogen diversity and transmission dynamics. Therefore, in the present study, we investigated spleen samples collected from 276 grey wolves in 11 federal states in Germany for common TBPs by molecular methods. In total, 127 grey wolves (46.0 %) were found to be positive for Hepatozoon canis. Only two genetic variants of this protozoan parasite (herein designated as G1 and G2) were found to circulate among the grey wolves, which can be potentially shared between populations of domestic and other wild carnivores in the country. Two grey wolves were positive for Anaplasma phagocytophilum (0.7 %), and both were co-infected with H. canis G1 genotype. The presence of other pathogens could not be confirmed by PCR and sequencing. This study represents the first one reporting H. canis in a grey wolf population worldwide, and it provides highly relevant information, which may contribute to a better understanding of the epidemiology of TBPs and the pathogen transmission dynamics among the reintroduced population of grey wolves and other carnivores.

Homogenous Population Genetic Structure of the Non-Native Raccoon Dog (Nyctereutes procyonoides) in Europe as a Result of Rapid Population Expansion

The extent of gene flow during the range expansion of non-native species influences the amount of genetic diversity retained in expanding populations. Here, we analyse the population genetic structure of the raccoon dog (Nyctereutes procyonoides) in north-eastern and central Europe. This invasive species is of management concern because it is highly susceptible to fox rabies and an important secondary host of the virus. We hypothesized that the large number of introduced animals and the species' dispersal capabilities led to high population connectivity and maintenance of genetic diversity throughout the invaded range. We genotyped 332 tissue samples from seven European countries using 16 microsatellite loci. Different algorithms identified three genetic clusters corresponding to Finland, Denmark and a large 'central' population that reached from introduction areas in western Russia to northern Germany. Cluster assignments provided evidence of long-distance dispersal. The results of an Approximate Bayesian Computation analysis supported a scenario of equal effective population sizes among different pre-defined populations in the large central cluster. Our results are in line with strong gene flow and secondary admixture between neighbouring demes leading to reduced genetic structuring, probably a result of its fairly rapid population expansion after introduction. The results presented here are remarkable in the sense that we identified a homogenous genetic cluster inhabiting an area stretching over more than 1500km. They are also relevant for disease management, as in the event of a significant rabies outbreak, there is a great risk of a rapid virus spread among raccoon dog populations.

High genetic structuring of Tula hantavirus

Tula virus (TULV) is a vole-associated hantavirus with low or no pathogenicity to humans. In the present study, 686 common voles (Microtus arvalis), 249 field voles (Microtus agrestis) and 30 water voles (Arvicola spec.) were collected at 79 sites in Germany, Luxembourg and France and screened by RT-PCR and TULV-IgG ELISA. TULV-specific RNA and/or antibodies were detected at 43 of the sites, demonstrating a geographically widespread distribution of the virus in the studied area. The TULV prevalence in common voles (16.7 %) was higher than that in field voles (9.2 %) and water voles (10.0 %). Time series data at ten trapping sites showed evidence of a lasting presence of TULV RNA within common vole populations for up to 34 months, although usually at low prevalence. Phylogenetic analysis demonstrated a strong genetic structuring of TULV sequences according to geography and independent of the rodent species, confirming the common vole as the preferential host, with spillover infections to co-occurring field and water voles. TULV phylogenetic clades showed a general association with evolutionary lineages in the common vole as assessed by mitochondrial DNA sequences on a large geographical scale, but with local-scale discrepancies in the contact areas.

Historical Invasion Records Can Be Misleading: Genetic Evidence for Multiple Introductions of Invasive Raccoons (Procyon lotor) in Germany

Biological invasions provide excellent study systems to understand evolutionary, genetic and ecological processes during range expansions. There is strong evidence for positive effects of high propagule pressure and the associated higher genetic diversity on invasion success, but some species have become invasive despite small founder numbers. The raccoon (Procyon lotor) is often considered as a typical example for such a successful invasion resulting from a small number of founders. The species' largest non-native population in Germany is commonly assumed to stem from a small number of founders and two separate founding events in the 1930s and 1940s. In the present study we analyzed 407 raccoons at 20 microsatellite loci sampled from the invasive range in Western Europe to test if these assumptions are correct. Contrary to the expectations, different genetic clustering methods detected evidence for at least four independent introduction events that gave rise to genetically differentiated subpopulations. Further smaller clusters were either artifacts or resulted from founder events at the range margin and recent release of captive individuals. We also found genetic evidence for on-going introductions of individuals. Furthermore a novel randomization process was used to determine the potential range of founder population size that would suffice to capture all the alleles present in a cluster. Our results falsify the assumption that this species has become widespread and abundant despite being genetically depauperate and show that historical records of species introductions may be misleading.

Adhesion patterns of commensal and pathogenic Escherichia coli from humans and wild animals on human and porcine epithelial cell lines

Background

Different strategies of colonization or infection by E. coli result in formation of certain adhesion patterns which help also in classifying intestinal E. coli into pathotypes. Little is known about adhesion patterns and host- and tissue adaption of commensal E. coli and about E. coli originating in clinically healthy hosts carrying pathotype-specific virulence-associated genes.

Findings

Adhesion pattern of E. coli (n = 282) from humans and from 18 animal species were verified on intestinal human Caco-2 and porcine IPEC-J2 cells and, furthermore, for comparison on human urinary bladder 5637, porcine kidney PK-15 epithelial and HEp-2 cells. The analysis was carried out on 150,000 images of adhesion assays.

Adhesion patterns were very diverse; 88 isolates were completely non-adherent, whereas 194 adhered to at least one cell line with the dominant adhesion patterns “diffusely distributed” and “microcolony formation”. Adhesion patterns “chains” and “clumps” were also visible. Chain formation was mediated by the presence of epithelial cells. Clump formation was very specific on only the 5637 cell line. All enteropathogenic (eae⁺) E. coli (EPEC; n = 14) were able to form microcolonies which was cell line specific for each isolate. Most EPEC formed microcolonies on intestinal IPEC-J2 and Caco-2 but several also on urinary tract cells. Shigatoxin-producing (stx⁺) E. coli (n = 10) showed no specific adhesion patterns.

Conclusions

E. coli isolates were highly diverse. Commensal and pathogenic isolates can adhere in various forms, including diffuse distribution, microcolonies, chains and clumps. Microcolony formation seems to be a global adhesion strategy also for commensal E. coli.

Detection of shrew-borne hantavirus in Eurasian pygmy shrew (Sorex minutus) in Central Europe

Recently, it was found that not only rodents but also shrews are reservoir hosts of hantaviruses. In Central Europe, only Seewis virus, associated with the Eurasian common shrew (Sorex araneus), has been recognized until now. In the present report, tissue samples from shrews belonging to Crocidurinae and Soricinae subfamilies, trapped in Czech Republic, Germany, and Slovakia, were screened for the presence of novel hantaviruses. Three new hantavirus partial L-segment sequences were obtained from pygmy shrews (Sorex minutus) trapped in Czech Republic and Germany. Complete nucleocapsid protein- and glycoprotein precursor-coding S- and M-segment sequences were then determined for the newly recognized hantavirus strains, CZ/Beskydy/412/2010/Sm, CZ/Drahany/420/2010/Sm, and DE/Dürrbach/1912/2009/Sm. Phylogenetic analyses showed that they represent strains of Asikkala virus (ASIV), a novel hantavirus also found in pygmy shrews from Finland. Our study reveals a broad geographic distribution of ASIV across Europe and indicates pygmy shrew as the primary reservoir host. Future studies will have to determine the pathogenic relevance of ASIV.

[Gingival fibromatosis (hereditary hyperplastic gingivitis) in a wild European red fox (Vulpes vulpes)]

This report describes a case of gingival fibromatosis in an otherwise healthy and well nourished wild European red fox (Vulpes vulpes), which was shot by a hunter and submitted to the state laboratory in the context of the rabies monitoring program of the federal state of Brandenburg, Germany. At necropsy, a severe papillomatous proliferation of the complete gingival tissue of the upper and lower jaw was present. This gingival proliferation had already resulted in malocclusion, loosening and loss of several incisival, premolar and molar teeth. Histologically, the primary lesion was a massive increase in the amount of collagen rich and relatively avascular connective tissue within the gingival lamina propria mucosae. A papillomavirus infection was excluded by electron microscopy, immunohistochemistry and molecular biological methods. The gingival lesions in the red fox are identical to those seen in hereditary hyperplastic gingivitis in farmed silver foxes and hereditary gingival fibromatosis in man. It is presumed that, in analogy to the genetic diseases in silver foxes and man, a still unidentified genetic defect is responsible for the development of the disease in the red fox, too.

Assessing non-metric skeleton characters as a morphological tool

The appearance of non-metric skeletal characters in vertebrates results mainly from basic genetic control, as proved and documented for house mice and humans. Although the heritability of non-metric traits, mainly the presence of foramina and similar structures for blood vessels and nerves or dental occlusal variants, have been evaluated as rather low, the simultaneous consideration of several traits allows estimation of epigenetic variation in time and space as a result of genetic relationship. Thus, the main use of non-metric characters has been aimed at assessing epigenetic variability and divergence among populations. Applications extend from the problem of genetic isolation of populations, the lack of reproductive contact, detection of genetic drift, systematic studies to clarify species taxonomy, to phylogenetic interpretation. Additionally, non-directional deviations from bilateral symmetry in non-metric characters, e.g. fluctuating asymmetry, could be caused by current environmental conditions in general. Fluctuating asymmetry is regarded as a measure of developmental instability to indicate the presence of genomic changes or the influence of contamination and/or habitat deterioration, and is also used as a further population parameter with integrated information. However, standpoints on the use of fluctuating asymmetry are quite inconsistent, fluctuating themselves between considering it a powerful biomonitoring tool to being merely a curious scientific toy.