Institute of Parasitology

Vienna, Austria

Institute of Parasitology

Vienna, Austria
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Liu J.,IDEXX Laboratories | Schnyder M.,Institute of Parasitology | Willesen J.L.,Copenhagen University | Potter A.,IDEXX Laboratories | Chandrashekar R.,IDEXX Laboratories
Veterinary Parasitology: Regional Studies and Reports | Year: 2017

Angiostrongylosis is a crucial differential diagnosis in any dog with respiratory, bleeding, neurological, or syncopal signs of unknown etiology in endemic areas. Many cases of angiostrongylosis have a fatal outcome; subclinical angiostrongylosis also has been reported. The most common method for supporting diagnosis of angiostrongylosis has been identification of Angiostrongylus vasorum first stage larvae in the feces by the Baermann-Wetzel method. Although considered as gold standard, this method has technical and sampling challenges and cannot detect infections during prepatency or in case of intermittent shedding of the larvae. A rapid in-clinic antigen test has been developed for serologic detection of A. vasorum infections using blood samples (Angio Detect™, IDEXX Laboratories Inc., Westbrook, Maine, USA). The study reported here was conducted to determine diagnostic sensitivity and specificity of the Angio Detect test kit by comparing Angio Detect testing results using serum or plasma samples with the results of Baermann-Wetzel testing using matched fecal samples. Samples from 214 dogs [with clinically suspected (N = 195) or diagnosed angiostrongylosis (N = 19)] were used for this evaluation. Baermann-Wetzel testing was performed independently at commercial reference laboratories or at university hospitals. All serum/plasma samples were blinded and randomized before testing with Angio Detect. The Angio Detect test was positive for 34 of the 35 cases found positive by the Baermann-Wetzel method; sensitivity of the Angio Detect test was 97.1% (95%CI: 85.1%–99.9%). The Angio Detect test was negative for 177 of 179 samples that were negative by the Baermann-Wetzel test; specificity was 98.9% (95%CI: 96.0%–99.9%). In cross-reactivity testing, all 89 samples from dogs confirmed to be infected with other common nematodes (Dirofilaria immitis, D. repens, Crenosoma vulpis, hookworms, ascarids, or whipworms) were all negative for A. vasorum by the Angio Detect antigen test. Angio Detect provides a rapid and reliable method for diagnosis of A. vasorum in clinically suspected dogs at risk for infection. The test requires minimal steps by the operator and provides results in 15 min, allowing the clinician to initiate treatment for positive dogs before leaving the clinic. © 2016 The Authors

Silbermayr K.,Institute of Parasitology | Joachim A.,Institute of Parasitology | Litschauer B.,Clinical Unit of Internal Medicine Small Animals | Panakova L.,Clinical Unit of Internal Medicine Small Animals | And 2 more authors.
Parasitology Research | Year: 2013

Feline demodicosis is a rare parasitic condition caused by three different species of mites (Demodex cati, Demodex gatoi, and an unnamed species). D. gatoi inhabits the superficial skin layer (stratum corneum) and is easily transmitted between individual cats. A 2-year-old female spayed Cornish Rex was presented with alopecia and pruritus. The dermatological examination revealed bilateral alopecia and excoriations on trunk, limbs, and belly. The second cat in the household, a 3-year-old female spayed Thai, showed no clinical signs. Superficial and deep skin scrapings were performed and cellophane tapes applied, and living D. gatoi mites could be detected in both cats. Oral ivermectin (0.25 mg/kg every other day) was subscribed. Feces were collected from both cats and fecal flotation with sugar and zinc solutions performed. When compared to skin scrapings and cellophane tapes, D. gatoi was detected more frequently and in higher numbers in fecal samples. Our findings suggest that D. gatoi can be efficiently diagnosed with coproscopy, particularly in asymptomatic carrier animals. DNA was extracted from the flotation liquid, and a PCR protocol for the species verification was designed. A fragment targeting a 325-bp DNA fragment of the D. gatoi mitochondrial 16S rDNA gene was amplified with a 100 % similarity to the D. gatoi entry in GenBank® (GI 421920216). We report the first finding of D. gatoi in Austria and propose fecal flotation as a valuable tool for mite detection. Fecal flotation liquid is suitable for DNA extraction and PCR-based species verification of D. gatoi. © 2013 Springer-Verlag Berlin Heidelberg.

PubMed | University of East London, Institute of Parasitology, Luxembourg Institute of Health, 4 Scientific Veterinary Institute Novi Sad and 6 National Institute for Agrarian and Veterinarian Research INIAV
Type: Journal Article | Journal: Vector borne and zoonotic diseases (Larchmont, N.Y.) | Year: 2017

Borrelia species fall into two groups, the Borrelia burgdorferi sensu lato (Bbsl) complex, the cause of Lyme borreliosis (also known as Lyme disease), and the relapsing fever group. Both groups exhibit inter- and intraspecies diversity and thus have variations in both clinical presentation and diagnostic approaches. A further layer of complexity is derived from the fact that ticks may carry multiple infectious agents and are able to transmit them to the host during blood feeding, with potential overlapping clinical manifestations. Besides this, pathogens like Borrelia have developed strategies to evade the host immune system, which allows them to persist within the host, including humans. Diagnostics can be applied at different times during the clinical course and utilize sample types, each with their own advantages and limitations. These differing methods should always be considered in conjunction with potential exposure and compatible clinical features. Throughout this review, we aim to explore different approaches providing the reader with an overview of methods appropriate for various situations. This review will cover human pathogenic members of Bbsl and relapsing fever borreliae, including newly recognized Borrelia miyamotoi spirochetes.

Schnyder M.,Institute of Parasitology | Stebler K.,Institute of Parasitology | Naucke T.J.,University of Hohenheim | Naucke T.J.,Laboklin GmbH and Co. KG | And 2 more authors.
Parasites and Vectors | Year: 2014

Background: Angiostrongylus vasorum is a potentially fatal canine nematode. Due to the high variability of clinical signs and the often chronic and subtle course of the infections, the diagnosis is particularly challenging. A rapid in-clinic assay (Angio Detect™ Test, IDEXX Laboratories, Westbrook, Maine, USA) for the serological detection of circulating antigen and intended for routine in-clinic diagnosis has been evaluated. Methods. Sensitivity was calculated with sera from 39 naturally infected dogs confirmed by Baermann-Wetzel analysis, while sera of 38 experimentally infected dogs were used for follow-up analyses, of which 10 were treated with imidacloprid/ moxidectin. Cross-reactivity was tested with a total of 123 samples from dogs with proven parasitic infections with Toxocara canis (n = 21), Ancylostoma caninum (n = 4), Crenosoma vulpis (n = 18), Oslerus osleri (n = 3), Eucoleus aerophilus, (n = 6), Dirofilaria immitis (n = 28), Dirofilaria repens (n = 20), Acantocheilonema reconditum (n = 10) or Dipetalonema dracunculoides (n = 10) or multiple infections (n = 3). All sera were tested with the Angio Detect™ Test and with an ELISA for detection of circulating antigen of A. vasorum. Results: The sensitivity of the Angio Detect™ Test was 84.6% (95% C.I. 69.5 - 94.1%), while specificity was 100% (95% C.I. 97.6 - 100%). The sensitivity of the ELISA (94.9%, 95% C.I. 82.7 - 99.3%) was comparable with previous evaluations. In experimentally infected dogs, earliest positive results with the Angio Detect™ Test were observed 9 weeks post inoculation and 5 weeks later all sera were Angio Detect™ Test positive. After anthelmintic treatment, seropositive dogs turned negative again within 3 to 7 weeks after treatment. The evaluation of the colour intensity of the test strips confirmed the delay of approximately 3-4 weeks for antigen detection by the Angio Detect™ Test compared to the ELISA and its correlation with the time after infection. Conclusions: This study provided evidence of a good sensitivity and a very high specificity of the rapid device Angio Detect™ Test for detection of circulating A. vasorum antigen in dogs with suspected canine angiostrongylosis, representing a very simple and useful tool to be broadly applied in veterinary practices. The rapid detection of infected dogs is a key point for initiating an indispensable and urgent therapy. © 2014 Schnyder et al.; licensee BioMed Central Ltd.

Silbermayr K.,Institute of Parasitology | Li F.,University of Alberta | Soudre A.,University of Natural Resources and Life Sciences, Vienna | Muller S.,Institute of Animal Breeding and Genetics | Solkner J.,University of Natural Resources and Life Sciences, Vienna
PLoS Neglected Tropical Diseases | Year: 2013

This study was conducted to (i) determine the prevalence of African Animal Trypanosomosis (AAT) in tsetse challenged areas, (ii) compare conventional with qPCR detection systems and (iii) evaluate the host genetic background and biology as risk factors. AAT prevalence studies are often confronted with low levels of parasitaemia. Hence, we designed a novel qPCR assay using primers and species specific probes amplifying the Internal Transcribed Spacer 1 (ITS1) gene. Thereby all three AAT species could be detected simultaneously. 368 individuals from three cattle types (Baoulé, Zebu and hybrids) originating from 72 farms in Burkina Faso were analysed. Farmers were interviewed and morphometric measurements of the cattle taken. A chi-squared test and a logistic regression model were calculated to detect associations with infection. In our study, the overall rate of prevalence detected with the novel qPCR assay was 11.14%. Compared to conventional PCR we identified a concordance of 91.30%. We tested 41 animals positive for trypanosome DNA, five animals showed multiple infections. Zebus were twice as often infected (21.74%) compared to Baoulé (9.70%) and hybrids (9.57%). Trypanosoma vivax is the dominant species (9.24%), as compared to T. congolense (2.44%) and T. brucei (0.82%). The chi-squared tests linking the infection events to the breeds (Zebu vs. Baoulé and Zebu vs. hybrids) were on the border of significance. No significant association with other tested parameters could be detected. We introduce a novel qPCR technique for the fast, sensitive and simultaneous detection of the three AAT species. Our results suggest that associations with breed and infection exist since Zebu cattle are more likely to be infected compared to Baoulé and hybrids. Indigenous taurine cattle breeds, like the Baoulé, therefore provide a unique and valuable genetic resource. © 2013 Silbermayr et al.

News Article | November 27, 2015

The bacterium might be transmitted by ticks. Credit: Philipp Berger/Vetmeduni Vienna Ticks can transmit various diseases to people and animals. Some well-known diseases spread by ticks include tick-borne encephalitis (TBE) and Lyme disease. Researchers at the Vetmeduni Vienna are hot on the trail of pathogens carried by ticks. The parasitologists recently discovered a new form of the bacterium Candidatus Neoehrlichia in a red fox from the Austrian state of Vorarlberg. The pathogen might also be transmittable to humans. The results were published in the journal Parasites & Vectors. Adnan Hodžić from the Institute of Parasitology at the Vetmeduni Vienna is searching for pathogens transmitted by ticks. He is especially interested in wild carnivores (foxes and wolves) which could be a possible reservoir and source of infection for humans and other animals. One special pathogen, first discovered in 1999 in Ixodes ricinus ticks, is the bacterium Candidatus Neoehrlichia mikurensis (CNM). The first case of CNM causing illness in a person was identified in the year 2010 in Sweden. Since then, the bacterium has been found several times in humans as well as in animals such as dogs, hedgehogs, shrews, bears, badgers, chamois and mouflons. In people, an infection with CNM bacteria causes fever, muscle and joint pain, and a higher risk for thrombosis and embolisms. Older and immunocompromised people are especially at risk. A second, related pathogen is Candidatus Neoehrlichia lotoris (CNL). So far, however, CNL has only been found in raccoons in the USA. Now Hodžić and his colleagues have discovered a new strain of Candidatus Neoehrlichia in a red fox from Vorarlberg, Austria. Genetically, the new find is situated somewhere between the two previously recognized forms. "Further study will be required for proper phylogenetic placement of the bacterium. What is certain, however, is that this could be a potential zoonotic pathogen, meaning that it could be transmittable to humans. But we still do not know the possible route of an infection and consequences on humans or pets," explains study leader Hans-Peter Führer. In 2014, the researchers collected 164 spleen samples from red foxes during routine hunting events in Tyrol and Vorarlberg. Genetic analysis revealed a female fox from Feldkirch as carrying the new bacterial strain. Candidatus Neoehrlichia mikurensis causes flu-like symptoms in humans and pets such as dogs. "The illness is not yet well-known among physicians, however, and therefore often remains undiagnosed," says Hodžić. "We want to raise awareness of this pathogen. Given the relevant symptoms, physicians should know what to do. An infection is best treated with the antibiotic Doxycyclin." The parasitologist Hodžić plans to conduct further research on wild animals in the future. The distribution of ticks in Europe will also require further study. "The monitoring of tick-borne diseases is becoming increasingly important," Hodžić points out. More information: Adnan Hodžić et al. Candidatus Neoehrlichia sp. in an Austrian fox is distinct from Candidatus Neoehrlichia mikurensis, but closer related to Candidatus Neoehrlichia lotoris, Parasites & Vectors (2015). DOI: 10.1186/s13071-015-1163-0

Bernies D.,Fishery Research Station | Bernies D.,Institute of Parasitology | Brinker A.,Fishery Research Station | Daugschies A.,Institute of Parasitology
Journal of Fish Biology | Year: 2011

This study is the first account of the establishment and development of the neozoic nematode parasite Anguillicoloides crassus in its host, the European eel Anguilla anguilla, in a deep, cold-monomictic lake. A 21 year study of A. crassus took place in Upper Lake Constance (ULC), Europe's second largest pre-alpine lake. The study included two extensive surveys, one in 1991 during the initial parasite invasion phase and the second in 2006 when the infection was well established. The subtropical swimbladder nematode A. crassus was first recorded in A. anguilla in ULC in 1989. Prevalence reached 60% in 1992 and remained at this level until 2007. In 2008, prevalence decreased to 48%. Infection intensity peaked in 1993 at a mean value of 16 adult parasites per host fish. Around 90% of all A. anguilla examined displayed swimbladder lesions, with a significant trend to increasing severity over time. Moreover, heavy swimbladder lesions were seen in c. 10% of A. anguilla ready to migrate to their spawning habitat. Both ruffe Gymnocephalus cernuus and sunfish Lepomis gibbosus serve as paratenic hosts for A. crassus in ULC. Gymnocephalus cernuus seems to be the main vector, and infection is especially frequent in spring possibly caused by reduced immune system efficacy of G. cernuus during winter. In 1991, hypochromic anaemia was prevalent in ULC A. anguilla acutely infected with A. crassus, whereas in 2006 blood values were indicative of chronic infection. The growth and survival rates of A. anguilla during their continental phase were not noticeably altered in infected fish, but damage to the swimbladder probably impairs migration potential and thus the subsequent breeding success of the oceanic phase. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Schnyder M.,Institute of Parasitology | Deplazes P.,Institute of Parasitology
Parasites and Vectors | Year: 2012

Background: Dirofilaria immitis and Angiostrongylus vasorum are both important potentially fatal canine nematodes with overlapping endemic areas, especially in Europe. The preadult and adult stages of both species are living in the Arteria pulmonalis and the right heart, and diagnostically detectable circulating parasite antigens have been demonstrated for both species. For the detection of D. immitis infections, a variety of commercial tests have been developed, however, they have not been evaluated for cross-reactions against circulating antigens of A. vasorum. Methods. In this study, potential cross-reactions of sera from 16 dogs, which were experimentally infected with A. vasorum and which had circulating antigens as confirmed by a species-specific ELISA, were evaluated for the detection of A. vasorum antigen in six commercially available D. immitis test kits. Results: In three fast tests (Witness Dirofilaria, SensPERT Canine Heartworm, SNAP 4Dx Plus), all sera were negative. One fast membrane ELISA (SNAP HTWM RT Test) was positive with four sera (25%), and one serum delivered a non-valid result twice. In the PetChek HTWM PF Test, depending on the interpretation protocol, 5 or 8 dogs (31.2 - 50%) were positive. With the DiroCHEK-ELISA, a single A. vasorum-infected dog (6.2%) tested positive. Conclusions: Due to potential cross-reactions with A. vasorum in commercially available test kits for the detection of D. immitis antigen, the simultaneous use of highly specific diagnostic methods for the differentiation of these two canine heart worms is recommended. © 2012 Schnyder and Deplazes; licensee BioMed Central Ltd.

Kim E.-J.,Institute of Parasitology | Bauer C.,Institute of Parasitology | Grevelding C.G.,Institute of Parasitology | Quack T.,Institute of Parasitology
Ticks and Tick-borne Diseases | Year: 2013

Most epidemiological studies on tick-borne pathogens employ PCR approaches. Prevalences determined by this method particularly depend on the efficiency and sensitivity of the applied protocol, which can be influenced by various factors. In the current study, we examined crucial points to improve PCR strategies with respect to sensitivity as well as specificity and developed optimized and easily practicable PCR/nested PCR approaches for the detection of different tick-borne pathogens. Among them were Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato complex, and Babesia spp., for which the novel protocol was successfully applied to perform species determination by direct sequencing of PCR amplicons. The occurrence of double and multiple infections of different species of the same genus were detected by chromatogram analyses exhibiting mixed sequences. Furthermore, we suggest employing a standard plasmid containing the appropriate target sequence followed by verification of the encountered detection limit with an addition of tick DNA spiked with the appropriate pathogen DNA. Approaches standardized in this manner would facilitate the comparison of prevalence studies. © 2013 Elsevier GmbH.

Shaneh A.,Institute of Parasitology | Salavati R.,Institute of Parasitology
Journal of Molecular Modeling | Year: 2010

Kinetoplastid RNA editing ligases 1 and 2 (KREL1 and KREL2) share a significant degree of sequence homology. However, biochemical experiments have reported that KREL1 and KREL2 differ in their functional roles during the RNA editing process. In this study, we hypothesize that dissimilar roles for KREL1 and KREL2 proteins arise from their different physicochemical characteristics. To test our hypothesis at sequence level, we plotted theoretical titration curves for KREL1, KREL2 and their binding partner proteins. The plots showed a lower isoelectric point for KREL1 compared to that for KREL2 as well as more relative alkalinity and acidity for binding partner proteins of KREL1 and KREL2 at net charge zero, respectively. At structure level, based on the available high resolution structure of KREL1 N-terminal domain and strong sequence similarity between KRELs and other ligases, we built the homology model of KREL2 N-terminal domain. Using Poisson-Boltzmann continuum approach, we calculated the electrostatic potential isosurfaces of KREL1 structure and KREL2 model. KREL1 and KREL2 coordinates differed in their electrostatic isopotential patterns. A wider negative patch on the surface of KREL1 suggests differential affinity for another protein compared to KREL2. In contrast, a larger positive patch on the KREL2 surface predicts its differential affinity and/or specificity for its RNA substrate. Subsequently, we employed in silico mutational scanning and identified the surface-exposed residues contributing to the long-range electrostatic energy of KRELs. We predict that two structurally conserved loops of KRELs, not previously reported in the literature, also recognize their RNA substrates. Our results provide important information about the physicochemical properties of RNA editing ligases that could contribute to the ligation step of RNA editing. © 2009 Springer-Verlag.

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