Herpesvirus Infection in a Breeding Population of Two Coexisting Strix Owls.

Birds are a frequent host of a large variety of herpesviruses, and infections in them may go unnoticed or may result in fatal disease. In wild breeding populations of owls, there is very limited information about the presence, impact, and potential transmission of herpesvirus. The herpesvirus partial DNA polymerase gene was detected using polymerase chain reaction in oropharyngeal swabs of 16 out of 170 owls examined that were captured in or near nest boxes. Herpesvirus was detected in Ural owls (Strix uralensis), in both adults and young, but not in tawny owls (Strix aluco). In yellow-necked mice (Apodemus flavicollis), as the main prey of tawny owls and Ural owls in the area, herpesvirus was detected in the organs of 2 out of 40 mice captured at the same locations as the owls. Phylogenetic analysis showed that the herpesvirus sequences detected in the Ural owls differed from the herpesvirus sequences detected in the yellow-necked mice. The results indicate that herpesvirus infection exists in the breeding wild Ural owl population. However, herpesvirus-infected owls did not show any clinical or productivity deviances and, based on a phylogenetic comparison of detected herpesvirus sequences and sequences obtained from Genbank database, it seems that mice and other rodents are not the source of owl infections. The most probable transmission pathway is intraspecific, especially from adults to their chicks, but the origin of herpesvirus in owls remains to be investigated.

Concentration of Mercury in the Livers of Small Terrestrial Rodents from Rural Areas in Poland.

Small terrestrial mammals could be used as accumulative biomonitors of different environmental contaminants, but the knowledge of the level of Hg in their bodies is scant. The aim of our research was to verify the factors influencing Hg bioaccumulation and to analyze the concentration of total mercury (Hg) in the livers of four species of wild terrestrial rodents from different rural areas of Poland: the yellow-necked mouse (Apodemus flavicollis), striped field mouse (Apodemus agrarius), common vole (Microtus arvalis), and bank vole (Myodes glareolus). The concentration of total Hg was analyzed in liver tissue by atomic absorption spectrometry using a direct mercury analyzer. The concentration of Hg found in the livers of rodents ranged from <1 to 36.4 µg/kg of wet weight, differed between study sites, species, and sexes, and was related to body weight. We addressed feeding habits as potential causes of differences in liver Hg concentration among species.

A new fast real-time PCR method for the identification of three sibling Apodemus species (A. sylvaticus, A. flavicollis, and A. alpicola) in Italy.

The identification of field mice Apodemus flavicollis, Apodemus sylvaticus, and Apodemus alpicola represents a challenge for field scientists due to their highly overlapping morphological traits and habitats. Here, we propose a new fast real-time PCR method to discriminate the three species by species-specific TaqMan assays. Primers and probes were designed based on the alignment of 54 cyt-b partial sequences from 25 different European countries retrieved from GenBank. TaqMan assays were then tested on 133 samples from three different areas of Italy. Real-time PCR analysis showed 92 samples classified as A. flavicollis, 13 as A. sylvaticus, and 28 as A. alpicola. We did not observe any double amplification and DNA sequencing confirmed species assignment obtained by the TaqMan assays. The method is implementable on different matrices (ear tissues, tail, and blood). It can be used on dead specimens or on alive animals with minimally invasive sampling, and given the high sensitivity, the assay may be also suitable for degraded or low-DNA samples. The method proved to work well to discriminate between the species analyzed. Furthermore, it gives clear results (amplified or not) and it does not require any postamplification handling of PCR product, reducing the time needed for the analyses and the risk of carryover contamination. It therefore represents a valuable tool for field ecologists, conservationists, and epidemiologists.

Pathology of natural Francisella tularensis subsp. holarctica infection in two yellow-necked mice (Apodemus flavicollis).

BACKGROUND: Tularemia is a zoonosis caused by the bacterium Francisella tularensis. It has a wide host range, which includes mammals, birds and invertebrates. F. tularensis has often been isolated from various species of small rodents, but the pathology in naturally infected wild rodent species has rarely been reported. CASE PRESENTATION: Herein, we describe the pathology of tularemia in two naturally infected wild yellow-necked mice (Apodemus flavicollis). To visualize F. tularensis subsp. holarctica, indirect immunofluorescence and immunohistochemistry were applied on tissue sections. Real time polymerase chain reaction detected the bacterium in samples from liver and spleen in both mice. The only finding at necropsy was splenomegaly in one of the mice. Histological examination revealed necrotic foci in the liver associated with mild inflammation in both mice. Immunohistochemistry and indirect immunofluorescence showed bacteria disseminated in many organs, in the cytoplasm of macrophages, and intravascularly. CONCLUSIONS: The two yellow-necked mice died of an acute disease caused by tularemic infection disseminated to many organs. Further investigations of naturally infected small rodents are important to better understand the variability in pathological presentation caused by infection by F. tularensis subsp. holarctica, as well to elucidate the importance of small rodents as transmitters and/or reservoirs.