Die gängige Entwurmungspraxis - noch zeitgemäß?

Die gängige Entwurmungspraxis – noch zeitgemäß? Dieser Frage sind Dr. med. vet. Regine Koopmann, Institut für ökologischen Landbau der Bundesforschungsanstalt für Landwirtschaft, und Dr. med. vet. Christian Epe, Institut für Parasitologie der Tierärztlichen Hochschule Hannover, nachgegangen

Der Mikropilz Duddingtonia flagrans zur biologischen Bekämpfung von Magen-Darm-Nematoden der Nutztiere – Übersicht zu Feldstudien 1994 bis 2006

An overview is given on some of the published works concerning the use of Dudding-tonia flagrans as an organism for biological control of parasitic nematodes with em-phasis on field studies with different farm animals

Larval migration in PERL chambers as an in vitro model for percutaneous infection stimulates feeding in the canine hookworm Ancylostoma caninum

<p>Abstract</p> <p>Background</p> <p><it>Ancylostoma caninum </it>third-stage larvae are the non-feeding infective stage of this parasite and are able to infect potential hosts via different infection routes. Since percutaneous infection is one of the most important routes and skin penetration is the first step into parasitic life, an existing <it>in vitro </it>model for percutaneous migration was modified and evaluated. The main parameter used to evaluate migration was the migration ratio (migrated larvae as a percentage of total number of larvae recovered). Additionally, the skin lag was calculated, expressing the percentage of larvae remaining in the skin and therefore not being recovered. Since initiation of feeding is proposed to be an important step in the transition from free-living to parasitic <it>A. caninum </it>larvae, feeding assays were performed with <it>in vitro </it>percutaneously migrated larvae. Additionally, infective larvae of <it>A. caninum </it>were activated via serum-stimulation and feeding behaviour was analysed and compared between percutaneously migrated and serum-stimulated larvae.</p> <p>Results</p> <p>Maximum skin migration levels of infective larvae were observed at temperatures above 32°C when larvae were placed on the epidermal side of skin for more than 12 hours. The medium beneath the skin had no effect on migration ratio, and no significant difference between the migration ratios through fresh and frozen/thawed skin was observed.</p> <p>Maximum feeding levels of 93.2% were observed for percutaneously migrated larvae after 48 h incubation, whereas serum-stimulated larvae reached the maximum of 91.0% feeding larvae after 24 h.</p> <p>Conclusions</p> <p>The PERL chamber system was optimised and standardised as an <it>in vitro </it>model for percutaneous migration. The larvae recovered after percutaneous migration showed characteristic signs of activation similar to that of serum-stimulated larvae. The observed difference in time course of resumption of feeding indicates that percutaneously migrated larvae are not identical to serum-stimulated larvae, which are currently representing the model for early parasitic stages.</p

Establishment of a minor groove binder-probe based quantitative real time PCR to detect Borrelia burgdorferi sensu lato and differentiation of Borrelia spielmanii by ospA-specific conventional PCR

<p>Abstract</p> <p>Background</p> <p><it>Borrelia burgdorferi </it>sensu lato (sl), the causative agent of Lyme borreliosis, is transmitted by ticks of the genus <it>Ixodes </it>as vector. For identification of <it>Borrelia </it>infections in ticks a TaqMan™ minor groove binder (MGB) probe-based quantitative real time PCR (qPCR) was established targeting the 5S-23S intergenic spacer. Extension to a duplex qPCR included an <it>Ixodes </it>spp. positive control to verify successful DNA isolation. Besides qPCR, an <it>osp</it>A-specific conventional PCR for species-specific identification of <it>B. spielmanii </it>was established. Afterwards 1000 <it>I. ricinus </it>flagged in the city of Hanover, Germany, were investigated for <it>B. burgdorferi </it>sl infections followed by species identification. Furthermore, <it>I. hexagonus </it>ticks were investigated to proof applicability of the PCRs.</p> <p>Results</p> <p>Quantitative real time PCR (qPCR) identifying <it>B. burgdorferi </it>sl in ticks was able to detect 1-10 copies per reaction. <it>B. spielmanii osp</it>A-specific conventional PCR was also highly specific and showed no cross reactions with the other tested <it>Borrelia </it>species. From 1000 hanoveranian ticks 24.3% were positive compared to only 7.4% positives by dark-field microscopy. Related to tick stage 1.7% larvae, 18.1% nymphs, and 34.6% adults were positive. The most frequent species was <it>B. garinii</it>, followed by <it>B. afzelii</it>, <it>B. spielmanii</it>, <it>B. valaisiana </it>and <it>B. burgdorferi </it>sensu stricto (ss). 70.6% of <it>I. ricinus </it>were mono-infected, whereas 28.0% and 1.4% were infected with two and three <it>Borrelia </it>species, respectively. From 232 <it>I. hexagonus </it>collected from hedgehogs in different sites of Germany, qPCR detected 5.7% to be infected with <it>B. burgdorferi </it>sl, which were identified as <it>B. afzelii</it>, <it>B. garinii </it>and <it>B. spielmanii</it>.</p> <p>Conclusions</p> <p>The evaluated qPCR to detect <it>B. burgdorferi </it>sl in <it>Ixodes </it>spp. is highly specific and sensitive. As a duplex qPCR including detection of <it>Ixodes </it>spp. DNA it is the first DNA based technique incorporating a control for successful DNA isolation from the vector tick. Establishment of a <it>B. spielmanii </it>specific conventional PCR filled the gap in PCR identification of principal European <it>Borrelia </it>genospecies. Practical application showed that all European pathogenic <it>Borrelia </it>spp. were present in <it>I. ricinus </it>flagged in recreational areas of the city of Hanover and confirmed <it>I. hexagonus </it>as reservoir for pathogenic <it>Borrelia </it>spp.</p

The genetic consequences of dog breed formation-Accumulation of deleterious genetic variation and fixation of mutations associated with myxomatous mitral valve disease in cavalier King Charles spaniels

Selective breeding for desirable traits in strictly controlled populations has generated an extraordinary diversity in canine morphology and behaviour, but has also led to loss of genetic variation and random entrapment of disease alleles. As a consequence, specific diseases are now prevalent in certain breeds, but whether the recent breeding practice led to an overall increase in genetic load remains unclear. Here we generate whole genome sequencing (WGS) data from 20 dogs per breed from eight breeds and document a similar to 10% rise in the number of derived alleles per genome at evolutionarily conserved sites in the heavily bottlenecked cavalier King Charles spaniel breed (cKCs) relative to in most breeds studied here. Our finding represents the first clear indication of a relative increase in levels of deleterious genetic variation in a specific breed, arguing that recent breeding practices probably were associated with an accumulation of genetic load in dogs. We then use the WGS data to identify candidate risk alleles for the most common cause for veterinary care in cKCs-the heart disease myxomatous mitral valve disease (MMVD). We verify a potential link to MMVD for candidate variants near the heart specific NEBL gene in a dachshund population and show that two of the NEBL candidate variants have regulatory potential in heartderived cell lines and are associated with reduced NEBL isoform nebulette expression in papillary muscle (but not in mitral valve, nor in left ventricular wall). Alleles linked to reduced nebulette expression may hence predispose cKCs and other breeds to MMVD via loss of papillary muscle integrity

Seroprevalence of Babesia Infections in Humans Exposed to Ticks in Midwestern Germany

Babesiosis is considered to be an emerging tick-borne disease in humans worldwide. However, most studies on the epidemiology of human babesiosis to date have been carried out in North America, and there is little knowledge on the prevalence of infection and frequency of disease in other areas. The aim of this study was to investigate the prevalence of Babesia infections in a human population in Germany. A total of 467 sera collected between May and October 1999 from individuals living in the Rhein-Main area were tested for the presence of immunoglobulin G (IgG) and IgM antibodies to antigens of Babesia microti and Babesia divergens by indirect fluorescent-antibody (IFA) tests. These sera were derived from 84 Lyme borreliosis patients suffering from erythema migrans, 60 asymptomatic individuals with positive borreliosis serology, and 81 individuals with a history of tick bite. Cutoff values for discrimination between seronegative and seropositive results in the IFA tests were determined using sera from 120 healthy blood donors and 122 patients suffering from conditions other than tick-borne diseases (malaria, n = 40; toxoplasmosis, n = 22; syphilis, n = 20; Epstein-Barr virus infection, n = 20; and presence of antinuclear antibodies, n = 20). The overall specificities of the IFA tests for B. microti and B. divergens were estimated to be ≥97.5%. Positive IgG reactivity against B. microti antigen (titer, ≥1:64) or B. divergens antigen (titer, ≥1:128) was detected significantly more often (P < 0.05) in the group of patients exposed to ticks (26 of 225 individuals; 11.5%) than in the group of healthy blood donors (2 of 120 individuals; 1.7%). IgG antibody titers of ≥1:256 against at least one of the babesial antigens were found significantly more often (P < 0.05) in patients exposed to ticks (9 of 225) than in the control groups (1 of 242). In the human population investigated here, the overall seroprevalences for B. microti and B. divergens were 5.4% (25 of 467) and 3.6% (17 of 467), respectively. The results obtained here provide evidence for concurrent infections with Borrelia burgdorferi and Babesia species in humans exposed to ticks in midwestern Germany. They also suggest that infections with Babesia species in the German human population are more frequent than believed previously and should be considered in the differential diagnosis of febrile illness occurring after exposure to ticks or blood transfusions, in particular in immunocompromised patients