Publications by authors named "Dania Richter"

To avoid potential adverse side effects of chemical plant protection products, microbial pest control products (MPCP) are commonly applied as biological alternatives. This study aimed to evaluate the biosafety of a MPCP with the active organism Bacillus thuringiensis ssp. aizawai (strain: ABTS-1857).

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This study was aimed at evaluating the effect of a microbial pest-controlling product (MPCP) with the active substance Bacillus thuringiensis ssp. aizawai (strain: ABTS-1857) on adults and larvae of honeybees. To determine the contamination levels of Bt spores in different matrices, a colony-feeding study under semi-field conditions was performed.

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Rats are a reservoir of human- and livestock-associated methicillin-resistant (MRSA). However, the composition of the natural population in wild and laboratory rats is largely unknown. Here, 144 nasal isolates from free-living wild rats, captive wild rats and laboratory rats were genotyped and profiled for antibiotic resistances and human-specific virulence genes.

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As the phylogenetic organization of mammalian polyomaviruses is complex and currently incompletely resolved, we aimed at a deeper insight into their evolution by identifying polyomaviruses in host orders and families that have either rarely or not been studied. Sixteen unknown and two known polyomaviruses were identified in animals that belong to 5 orders, 16 genera, and 16 species. From 11 novel polyomaviruses, full genomes could be determined.

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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.

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  • Wood ticks (Ixodes ricinus) are common in Central Europe and are known to spread various pathogens; their survival is influenced by environmental factors like humidity, temperature, and snow depth.
  • The study analyzed tick questing activity in relation to meteorological data collected hourly over six years in Berlin, finding significant annual variations in tick activity.
  • Key findings indicated that lower humidity and extreme cold temperatures during the winter months impacted the number of active ticks in spring, while snow cover played a protective role against harsh weather conditions.
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  • Small rodents, like wild mice, can carry tick-borne pathogens such as the bacteria that cause Lyme disease, and about 40% of mice in a study in Berlin were found to be infested with ticks and also infected with a type of nematode.
  • The study aimed to investigate how the presence of this nematode affects the immune response to tick feeding and the success of the tick-borne pathogen Borrelia afzelii.
  • Findings revealed that while mice coinfected with the nematode showed a stronger immune response (Th2) to ticks, this did not influence tick feeding success or increase susceptibility to Borrelia afzelii, suggesting that nematode infections do not impact Lyme disease risk significantly
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Background: We evaluated the potential of cholecalciferol as an enhancer of the first-generation anticoagulant coumatetralyl in the Westphalia anticoagulant-resistant strain of the Norway rat (Rattus norvegicus Berkenhout), characterised by the Tyr139Cys polymorphism on the VKOR enzyme. Because today only the most potent, but also most persistent anticoagulant rodenticides of the second generation remain available to control this strain, new rodenticide solutions are required.

Results: Feeding trials in the laboratory confirmed a significant level of efficacy, which was corroborated by field trials in the Münsterland resistance area.

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The reservoir competence and long life expectancy of edible dormice, Glis glis, suggest that they serve as efficient reservoir hosts for Lyme disease (LD) spirochetes. Their arboreality, however, may reduce the probability to encounter sufficient questing Ixodes ricinus ticks to acquire and perpetuate LD spirochetes. To define the potential role of this small arboreal hibernator in the transmission cycle of LD spirochetes, we examined their rate and density of infestation with subadult ticks throughout the season of activity.

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Article Synopsis
  • Six complete genomes of a polyomavirus were amplified and sequenced from feral and bred Norway rats.
  • *The virus is closely related to hamster and murine polyomaviruses.
  • *Studying this virus could help in understanding the evolutionary history of polyomaviruses in rodents.*
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  • Rodents in Austria are significant reservoirs for various zoonotic pathogens, including multiple viruses, bacteria, and parasites.
  • The study involved trapping 110 rodents from four species and performing tests to identify the presence of 11 different pathogens, revealing multiple infections in some specimens.
  • Findings suggest that these rodent populations not only harbor diverse pathogens but also raise critical questions about host-pathogen interactions and potential risks for transmission to humans and other animals.
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In Europe, dormice serve as competent reservoir hosts for particular genospecies of the tick-borne agent of Lyme disease (LD) and seem to support them more efficiently than do mice or voles. The longevity of edible dormice (Glis glis) and their attractiveness for ticks may result in a predominance of LD spirochetes in ticks questing in dormouse habitats. To investigate the role of edible dormice in the transmission cycle of LD spirochetes, we sampled skin tissue from the ear pinnae of dormice inhabiting five different study sites in south western Germany.

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The tick Ixodes ricinus uses its mouthparts to penetrate the skin of its host and to remain attached for about a week, during which time Lyme disease spirochaetes may pass from the tick to the host. To understand how the tick achieves both tasks, penetration and attachment, with the same set of implements, we recorded the insertion events by cinematography, interpreted the mouthparts' function by scanning electron microscopy and identified their points of articulation by confocal microscopy. Our structural dynamic observations suggest that the process of insertion and attachment occurs via a ratchet-like mechanism with two distinct stages.

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"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.

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Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato complex differ in their resistance to complement-mediated killing, particularly in regard to human serum. In the present study, we elucidate the serum and complement susceptibility of B.

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Despite a growing knowledge about the biological diversity of papillomaviruses (PV), only little is known about non-human PV in general and about PV mice models in particular. We cloned and sequenced the complete genomes of two novel PV types from the Norway rat (Rattus norvegicus; RnPV2) and the wood mouse (Apodemus sylvaticus; AsPV1) as well as a novel variant of the recently described MmuPV1 (originally designated as MusPV) from a house mouse (Mus musculus; MmuPV1 variant). In addition, we conducted phylogenetic analyses using a systematically representative set of 79 PV types, including the novel sequences.

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To determine whether the genospecies composition of Lyme disease spirochetes is spatially stratified, we collected questing Ixodes ricinus ticks in neighboring plots where rodents, birds, and lizards were present as reservoir host and compared the prevalence of various genospecies. The overall prevalence of spirochetes in questing ticks varied across the study site. Borrelia lusitaniae appeared to infect adult ticks in one plot at the same frequency as did Borrelia afzelii in the other plots.

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To determine whether Dermacentor reticulatus ticks are infected by Borrelia spp., Candidatus Neoehrlichia mikurensis, or Anaplasma phagocytophilum, we collected questing adults in the outskirts of Berlin, Germany, examined them for the presence of DNA of these pathogens, and compared the infection rates to those of sympatric Ixodes ricinus ticks. Questing D.

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To estimate the likelihood of people coming into contact with the recently described tick-borne agent "Candidatus Neoehrlichia mikurensis," we compared its prevalence to those of Lyme disease spirochetes and Anaplasma phagocytophilum in questing adult Ixodes ricinus ticks collected in various Central European sites and examined ticks, which had been removed from people, for the presence of these pathogens. Whereas spirochetes infected questing adult ticks most frequently (22.3%), fewer than a third as many ticks were infected by "Ca.

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To determine which kind of spirochete infects larval Ixodes ricinus, we examined questing larvae and larvae derived from engorged females for the presence of particular spirochetal DNA that permitted species differentiation. Borrelia miyamotoi was the sole spirochete detected in larval ticks sampled while questing on vegetation. Questing nymphal and adult ticks were infected mainly by Borrelia afzelii, whereas larval ticks resulting from engorged females of the same population were solely infected by B.

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To estimate relative risk for exposure to ticks infected with Lyme disease-causing spirochetes in different land-use types along a trail in Germany, we compared tick density and spirochete prevalence on ruminant pasture with that on meadow and fallow land. Risk was significantly lower on pasture than on meadow and fallow land.

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Polymorphisms in the vitamin K 2,3-epoxide reductase subcomponent 1 (vkorc1) of house mice (Mus musculus domesticus) can cause resistance to anticoagulant rodenticides such as warfarin [1-3]. Here we show that resistant house mice can also originate from selection on vkorc1 polymorphisms acquired from the Algerian mouse (M. spretus) through introgressive hybridization.

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To determine whether the pathogenic Lyme disease spirochete Borrelia spielmanii is adapted exclusively to garden dormice, we compared the reservoir competence of various rodent species for this spirochete, including sympatric and peridomestic rodents. The different kinds of rodents varied in their attractiveness to nymphal ticks and their level of susceptibility to tick-borne B. spielmanii infection, but only the edible dormouse appeared to be refractory.

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To determine whether and which spirochetes are cleared from Ixodes ricinus ticks during feeding on ruminants, ticks were removed from goats and cattle grazing on tick-infested pastures. Although about a quarter of ticks questing on the pasture were infected by spirochetes, no molted ticks that had previously engorged to repletion on ruminants harbored Lyme disease spirochetes. Borrelia miyamotoi spirochetes, however, appear not to be eliminated.

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