BackgroundBats receive increasing attention in infectious disease studies, because of their well recognized status as reservoir species for various infectious agents. This is even more important, as bats with their capability of long distance dispersal and complex social structures are unique in the way microbes could be spread by these mammalian species. Nevertheless, infection studies in bats are predominantly limited to the identification of specific pathogens presenting a potential health threat to humans. But the impact of infectious agents on the individual host and their importance on bat mortality is largely unknown and has been neglected in most studies published to date.Methodology/Principal FindingsBetween 2002 and 2009, 486 deceased bats of 19 European species (family Vespertilionidae) were collected in different geographic regions in Germany. Most animals represented individual cases that have been incidentally found close to roosting sites or near human habitation in urban and urban-like environments. The bat carcasses were subjected to a post-mortem examination and investigated histo-pathologically, bacteriologically and virologically. Trauma and disease represented the most important causes of death in these bats. Comparative analysis of pathological findings and microbiological results show that microbial agents indeed have an impact on bats succumbing to infectious diseases, with fatal bacterial, viral and parasitic infections found in at least 12% of the bats investigated.Conclusions/SignificanceOur data demonstrate the importance of diseases and infectious agents as cause of death in European bat species. The clear seasonal and individual variations in disease prevalence and infection rates indicate that maternity colonies are more susceptible to infectious agents, underlining the possible important role of host physiology, immunity and roosting behavior as risk factors for infection of bats.

We tested 55 deceased vespertilionid bats of 12 species from southern Germany for virus infections. A new adenovirus was isolated from tissue samples of 2 Pipistrellus pipistrellus bats, which represents the only chiropteran virus isolate found in Europe besides lyssavirus (rabies virus). Evidence was found for adenovirus transmission between bats.

From 1997-99 European brown hare (Lepus europaeus) population densities were estimated by spotlight surveys within different areas in Schleswig-Holstein, Germany. These areas showed a wide variation in local hare population densities. In addition, red fox (Vulpes vulpes) densities were estimated in 1997 by surveys of fox dens and litters. Sera of 321 hares (shot between 1998-2000) from four study areas were examined for antibodies against European brown hare syndrome virus (EBHSV) by enzyme linked immunosorbent assay (ELISA), Yersinia spp. (n = 299) and Francisella tularensis (n = 299) by western blotting, Brucella spp. by Rose Bengal test, and Toxoplasma gondii by Sabin-Feldman test (n = 318). Tissue samples comprising lung, liver, spleen, kidney, heart, and adrenal glands were collected for histopathology. Liver (n = 201) and spleen (n = 201) samples were processed for the detection of T. gondii-antigen in tissue sections and 321 liver and spleen samples were investigated for EBHSV-antigen by ELISA. Furthermore, 116 hares were examined macro- and microscopically for lungworms. Significant negative correlations between hare and fox densities were found in spring and autumn 1997. Antibodies against EBHSV were detected in 92 of 321 (29%), against Yersinia spp. in 163 of 299 (55%), and against T. gondii in 147 of 318 (46%) hares. We evaluated the potential influence of origin and hunting season on exposure rates of hares using logistic regression analysis. A strong association between hare densities and exposure rates was observed for various agents. One hundred and eight of 201 (57%) hares were positive for T. gondii-antigen. All sera were negative for antibodies against Brucella spp. and F. tularensis and all lung samples were negative for lungworms. In conclusion, variation in red fox densities may have an impact on the hare populations examined and the infectious diseases we studied seem to play a subordinate role in the dynamics of European brown hare populations from Schleswig-Holstein.

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A taxonomic study was performed on 13 bacterial strains isolated from preputial swabs of European bison (Bison bonasus) bulls suffering from balanoposthitis. The isolates were Gram-positive, non-motile, facultatively anaerobic, diphtheroid-shaped cells. Based on biochemical profiles and BOX-PCR-generated genomic fingerprints, the isolates were grouped into two clusters represented by four and nine strains, respectively. Strains 1(W3/01)T and 2(W106/04)T, selected as representatives of the two clusters, shared 97·2 % 16S rRNA gene sequence similarity. The highest gene sequence similarities found (95·5–96·4 %) were to Arcanobacterium pyogenes DSM 20630T and Arcanobacterium bernardiae DSM 9152T, demonstrating that the novel strains are members of the genus Arcanobacterium, but are not members of a recognized species. The polar lipid profiles of the two novel strains displayed the major characteristics also found in A. pyogenes DSM 20630T and Arcanobacterium haemolyticum DSM 20595T. Detection of a quinone system with MK-10(H4) as the predominant compound confirmed phylogenetic relatedness of the novel strains to A. pyogenes and separated them from the type species of the genus, A. haemolyticum, which contains MK-9(H4) as the predominant quinone. Results from DNA–DNA hybridizations clearly demonstrated that strains 1(W3/01)T and 2(W106/04)T represent separate species. Based on these data, two novel species of the genus Arcanobacterium are described, for which the names Arcanobacterium bialowiezense sp. nov. [type strain 1(W3/01)T=DSM 17162T=NCTC 13354T] and Arcanobacterium bonasi sp. nov. [type strain 2(W106/04)T=DSM 17163T=NCTC 13355T] are proposed.