Cause and Effect Analysis between Influencing Factors Related to Environmental Conditions, Hunting and Handling Practices and the Initial Microbial Load of Game Carcasses.

Environmental, hunting and handling factors affect the microbial load of hunted game and the resulting meat products. The aim of this study was to systematically investigate the influence of several factors on the initial microbial load (IML) of game carcasses during the early hunting chain. Eviscerated roe deer body cavities (n = 24) were investigated in terms of total viable count and the levels of Pseudomonas spp., Lactobacillus spp., Enterobacteriaceae and Escherichia coli (E. coli). Furthermore, a risk analysis based on the obtained original IML data, literature search and a Failure Mode and Effects Analysis (FMEA) was performed. The IML could be explained in a regression model by factors including the higher body weight (BW), damaged gastrointestinal tract by the shot, ambient temperature or rain. The levels of Lactobacillus spp. (p = 0.0472), Enterobacteriaceae (p = 0.0070) and E. coli (p = 0.0015) were lower on the belly flap surface when gloves were used during evisceration. The literature search revealed that studies examining influencing factors (IF) on the IML of game carcasses found contradictory effects of the comparable IF on IML. Potential handling failures may lead to a higher IML of game carcasses during the early hunting chain ranked by FMEA. Several handling practices for game carcasses are recommended, such as ensuring efficient cooling of heavier BW carcasses to limit bacterial growth or eviscerating heavier carcasses before lighter ones.

Evaluation of the Occurrence of Staphylococcaceae with Reduced Susceptibility to Cefoxitin in Wild Ungulates in Brandenburg, Germany, Based on Land Use-Related Factors.

Interactions between natural and human-used environments have a significant influence on the spread of antimicrobial resistance in wild ecosystems. Despite current knowledge, fundamental questions about the degree of impact of land use-related factors on the spread of antimicrobial-resistant staphylococci in European wild game animal populations have not yet been answered with certainty. In this study, we evaluated the occurrence of Staphylococcaceae showing reduced susceptibility to cefoxitin in nasal swabs of fallow deer (Dama dama), red deer (Cervus elaphus), roe deer (Capreolus capreolus), and wild boar (Sus scrofa) hunted in Brandenburg, Germany. Evaluations were focused on the use of open-source data regarding the extent as well as the degree of land use, especially for settlement or animal husbandry. Results showed that the detection rate of Staphylococcaceae showing a non-wild-type phenotype for cefoxitin differed between animal species of the studied hunting districts. Statistical analyses of results combined with data on land use features revealed that a high density of cattle or poultry in a county may be associated with an increased detection rate in roe deer or wild boar, respectively. Furthermore, positive correlations were determined between the prevalence of non-wild-type Staphylococcaceae in roe deer or fallow deer and the proportional extent of surface water bodies in the corresponding area. The presented approach establishes a general basis for a risk-oriented assessment of the effects of human activities on the epidemiology of transmissible microorganisms in the human-animal-environment interface, including antimicrobial-resistant bacteria. IMPORTANCE Intensive research regarding the impact of land use-related factors on the prevalence and distribution of antimicrobial-resistant Staphylococcaceae in game ungulate populations is necessary for adequately determining risks related to interactions between wild animals, domestic animals, and humans in common geographic locations. This systematic approach for the analysis of the observations in specific hunting districts of Brandenburg, Germany, adds an innovative value to the research strategy of antimicrobial resistance in wild game animals, which is in accordance with current recommendations worldwide. Thus, results and information obtained in this study build a relevant foundation for future risk assessment regarding the safety of game products. Furthermore, the data generated represent an important basis for improving existing guidelines in land use practices and hunting practices. The use of existing open source data collections provided by official governmental and nongovernmental entities increases not only the impact but also the applicability and comparability of information beyond the regional level.

Standardised Sampling Approach for Investigating Pathogens or Environmental Chemicals in Wild Game at Community Hunts.

Wildlife may host pathogens and chemicals of veterinary and public health relevance, as well as pathogens with significant economic relevance for domestic livestock. In conducting research on the occurrence and distribution of these agents in wildlife, a major challenge is the acquisition of a sufficient number of samples coupled with efficient use of manpower and time. The aim of this article is to present the methodology and output of a sampling approach for game animals, which was implemented from 2017/18 to 2020/21 at drive hunts in Brandenburg, Germany. The central element was a framework agreement with the BImA, whereby federal forest officials and other hunters collected most of the samples during field dressing. Further samples of game carcasses were obtained by scientists during subsequent gathering at a collection point. Altogether, 3185 samples from 938 wild ungulates of four species were obtained for various studies analysing-in this case-food-borne agents in game animals. Sampling was representative and reflected the proportional distribution of ungulate species hunted in Brandenburg. Hunting district and hunting season strongly influenced hunting bag and hence sampling success. This sampling approach was demonstrated to be a suitable basis for monitoring programs, that can be adapted to other regions.

Factors associated with diversity, quantity and zoonotic potential of ectoparasites on urban mice and voles.

Wild rodents are important hosts for tick larvae but co-infestations with other mites and insects are largely neglected. Small rodents were trapped at four study sites in Berlin, Germany, to quantify their ectoparasite diversity. Host-specific, spatial and temporal occurrence of ectoparasites was determined to assess their influence on direct and indirect zoonotic risk due to mice and voles in an urban agglomeration. Rodent-associated arthropods were diverse, including 63 species observed on six host species with an overall prevalence of 99%. The tick Ixodes ricinus was the most prevalent species, found on 56% of the rodents. The trapping location clearly affected the presence of different rodent species and, therefore, the occurrence of particular host-specific parasites. In Berlin, fewer temporary and periodic parasite species as well as non-parasitic species (fleas, chiggers and nidicolous Gamasina) were detected than reported from rural areas. In addition, abundance of parasites with low host-specificity (ticks, fleas and chiggers) apparently decreased with increasing landscape fragmentation associated with a gradient of urbanisation. In contrast, stationary ectoparasites, closely adapted to the rodent host, such as the fur mites Myobiidae and Listrophoridae, were most abundant at the two urban sites. A direct zoonotic risk of infection for people may only be posed by Nosopsyllus fasciatus fleas, which were prevalent even in the city centre. More importantly, peridomestic rodents clearly supported the life cycle of ticks in the city as hosts for their subadult stages. In addition to trapping location, season, host species, body condition and host sex, infestation with fleas, gamasid Laelapidae mites and prostigmatic Myobiidae mites were associated with significantly altered abundance of I. ricinus larvae on mice and voles. Whether this is caused by predation, grooming behaviour or interaction with the host immune system is unclear. The present study constitutes a basis to identify interactions and vector function of rodent-associated arthropods and their potential impact on zoonotic diseases.

Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany.

Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1) and specifically Toxoplasma gondii (repetitive element) in brain and ascarids (ITS-2) in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented) had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8), Toxocara cati (4) and Parascaris sp. (1) were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to estimate the health risks arising from wild and domesticated carnivores.

Susceptibility to Ticks and Lyme Disease Spirochetes Is Not Affected in Mice Coinfected with Nematodes.

Small rodents serve as reservoir hosts for tick-borne pathogens, such as the spirochetes causing Lyme disease. Whether natural coinfections with other macroparasites alter the success of tick feeding, antitick immunity, and the host's reservoir competence for tick-borne pathogens remains to be determined. In a parasitological survey of wild mice in Berlin, Germany, approximately 40% of Ixodes ricinus-infested animals simultaneously harbored a nematode of the genus Heligmosomoides We therefore aimed to analyze the immunological impact of the nematode/tick coinfection as well as its effect on the tick-borne pathogen Borrelia afzelii Hosts experimentally coinfected with Heligmosomoides polygyrus and larval/nymphal I. ricinus ticks developed substantially stronger systemic type 2 T helper cell (Th2) responses, on the basis of the levels of GATA-3 and interleukin-13 expression, than mice infected with a single pathogen. During repeated larval infestations, however, anti-tick Th2 reactivity and an observed partial immunity to tick feeding were unaffected by concurrent nematode infections. Importantly, the strong systemic Th2 immune response in coinfected mice did not affect susceptibility to tick-borne B. afzelii An observed trend for decreased local and systemic Th1 reactivity against B. afzelii in coinfected mice did not result in a higher spirochete burden, nor did it facilitate bacterial dissemination or induce signs of immunopathology. Hence, this study indicates that strong systemic Th2 responses in nematode/tick-coinfected house mice do not affect the success of tick feeding and the control of the causative agent of Lyme disease.

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.

Pathogens in ticks collected from dogs in Berlin/Brandenburg, Germany.

BACKGROUND: Tick-borne diseases are a major health risk for humans and dogs. In addition to collection and analysis of questing ticks, analysis of host-associated ticks for the presence of pathogens is a valuable method to gain insight into transmission patterns of tick-borne diseases. METHODS: Ticks were collected from dogs living in the Berlin/Brandenburg area. The three tick species Ixodes ricinus, Ixodes hexagonus and Dermacentor reticulatus were examined for the presence of Babesia spp., Borrelia spp., Rickettsia spp. and Anaplasmataceae. Conventional PCR followed by sequencing was used for pathogen detection and characterization. RESULTS: Babesia spp. were found in 2.5% and 3% of I. ricinus and I. hexagonus, respectively. Sequencing revealed the presence of Babesia microti, Babesia capreoli and Babesia venatorum. D. reticulatus were free of Babesia canis. Rickettsia spp. were detected in 61% of I. ricinus, 44% of I. hexagonus and 39% of D. reticulatus. Specifically detected were Rickettsia raoulti in D. reticulatus and I. hexagonus, Rickettsia helvetica in I. ricinus and I. hexagonus and Rickettsia monacensis in I. hexagonus. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis have been reported previously in I. ricinus (6.5% and 4.3%, respectively) and I. hexagonus (3.9% and 5.9%). Borrelia spp. were found in 11.6% of I. ricinus and 11.2% of I. hexagonus. Subsequent genospecies analysis revealed Borrelia afzelii, Borrelia garinii, Borrelia burgdorferi sensu stricto and Borrelia miyamotoi. Simultanous presence of more than one pathogen was found in 20% of I. ricinus and in 59% of I. hexagonus whereas the total frequency of any pathogen was 65% in I. ricinus, 59% in I. hexagonus and 64% in D. reticulatus. Ticks in which A. phagocytophilum was detected had a significantly increased risk of also containing Rickettsia. Ticks harbouring a pathogen had significantly higher scutal indices than ticks without presence of any pathogen. CONCLUSIONS: Frequencies of potential human or canine pathogens in ticks were considerable and DNA of all four groups of pathogens was detected. Differences in scutal indices might suggest that pathogens are frequently taken up by ticks when feeding on dogs in Berlin/Brandenburg.

A novel high-resolution melt PCR assay discriminates Anaplasma phagocytophilum and "Candidatus Neoehrlichia mikurensis".

"Candidatus Neoehrlichia mikurensis" (Anaplasmataceae) is an emerging pathogen transmitted by Ixodes ticks. Conventional PCR and the newly developed high-resolution melt PCR were used to detect and discriminate "Candidatus Neoehrlichia mikurensis" and Anaplasma phagocytophilum. Both bacterial species were frequently found in Ixodes ricinus and Ixodes hexagonus but virtually absent from Dermacentor reticulatus. In rodents, "Candidatus N. mikurensis" was significantly more prevalent than A. phagocytophilum, whereas in cats, only A. phagocytophilum was found.