Sandra Wiedermann

Mrs. Sandra Wiedermann

University of Veterinary Medicine Vienna, Vienna, Wien, Austria
orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 April 2022 in Pathogens
Verified
Journal Article
Open access
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BHBarbara Hinney
Barbara Hinney
SWSandra Wiedermann
Sandra Wiedermann
WKWaltraud Kaiser
Waltraud Kaiser
JKJürgen Krücken
Jürgen Krücken
Anja JoachimAnja Joachim
Anja Joachim
Anthelmintic resistance (AR) of trichostrongyloids is widespread in Europe, but there is no up-to-date information on the spread of AR in caprine parasites in Austria. Eprinomectin (EPR) is currently the only anthelmintic drug of the macrocyclic lactones registered for goats in Europe. The aim of the present study was to gather information regarding the efficacy of anthelmintics against trichostrongyloids on a dairy goat farm in Austria with reported treatment failure of macrocyclic lactones and to determine the presence of different trichostrongyloid genera. Faecal egg count reduction tests (FECRT) using Mini-FLOTAC were performed with eprinomectin (EPR) and moxidectin (MOX). Egg count reduction, calculated with the R package egg-Counts, was 44% for EPR and 86% for MOX, confirming AR of trichostrongyloids for both compounds. The most frequently detected genus in larval cultures was Haemonchus, followed by Trichostrongylus. This is the first report of MOX resistance in caprine trichostrongyloids in Europe. Failure of EPR and MOX to control trichostrongyloid infections is a severe threat to dairy goat farming, since other compounds must not be applied in goats used for milk production. Haemonchus contortus is one of the most pathogenic parasites of small ruminants and can quickly develop AR. Thus, immediate action should be taken to slow the further spread of AR in this and other roundworm species of ruminants in Austria.

13 October 2023 in Animals
Verified
Journal Article
Open access
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FSFloriana Sajovitz
Floriana Sajovitz
IAIsabella Adduci
Isabella Adduci
SYShi Yan
Shi Yan
SWSandra Wiedermann
Sandra Wiedermann
ATAlexander Tichy
Alexander Tichy
KLKatharina Lichtmannsperger
Katharina Lichtmannsperger
Gastrointestinal nematodes, most notably trichostrongylids, are known to cause significant losses in sheep production. Previous studies have shown that monitoring parameters (e.g., FAMACHA©, BCS, dag score) change with increasing egg excretion. These parameters are well known and frequently used for targeted selective treatment. Based on the willingness to participate in this study (based on a previous questionnaire distribution among sheep farmers in Austria) we investigated the associations between faecal egg counts and the FAMACHA©, BCS, and dag scores of 1195 dairy ewes. Faecal samples were analysed using the Mini-FLOTAC technique I and larval culture. Three raters assessed the FAMACHA©, BCS, and dag scores in sheep to calculate the inter-rater agreement and intraclass correlation coefficient. The responses to the questionnaire of 23 farms were used for the evaluation, of which 16 farms were visited. Trichostrongylid eggs were detected in 95% of the faecal samples. The BCS was negatively correlated with the eggs per gram of faeces (EpG) (r = −0.156; p < 0.001) and the FAMACHA© score was slightly positively correlated with EpG (r = 0.196; p < 0.001). A small proportion of sheep (25%) shed the majority of eggs (47% to 84%). A moderate to good agreement for the parameters was found between the raters. In conclusion, the clinical parameters showed only weak correlations with faecal egg counts, and we confirmed that a minority of the flock is responsible for the majority of the pasture contamination with trichostrongylid eggs. Clinical raters should be trained before a study to increase the agreement between them.

18 June 2023 in International Journal for Parasitology: Drugs and Drug Resistance
Verified
Journal Article
Open access
BHBarbara Hinney
Barbara Hinney
SWSandra Wiedermann
Sandra Wiedermann
ABAntonio Bosco
Antonio Bosco
LRLaura Rinaldi
Laura Rinaldi
MHMartin Hofer
Martin Hofer
RSRalf Steinborn
Ralf Steinborn
Haemonchus contortus is the most pathogenic nematode in small ruminants and anthelmintic resistance (AR) hampers its efficient control. Early detection of AR status is required to reduce selection for AR and cannot be achieved using phenotypic tests. For benzimidazoles (BZs), the detection of AR-associated alleles characterised by single nucleotide polymorphisms (SNPs) in the isotype 1 β-tubulin gene allows early AR detection in strongyles. The F200Y, F167Y, E198A and E198L polymorphisms have been described in BZ-resistant populations with a clear variation in frequencies between regions. A novel digital PCR (dPCR) enables the detection of all of the above-described polymorphisms in H. contortus. Assays were validated using synthetic DNA fragments containing these SNPs. Then, larvae obtained and pooled at farm level from 26 Austrian and 10 Italian sheep farms were analysed. For all assays a detection limit of 15 copies/μl of resistance alleles and a high level of accuracy were demonstrated, allowing to detect allele frequencies of 1% in most samples. In Austrian samples, elevated frequencies of F200Y resistance alleles were detected on all farms. Polymorphisms in codon 167 and codon 198 were identified in H. contortus from Austria for the first time. In Italian samples, the frequency of resistance alleles was still comparatively low, but F200Y resistance alleles were traceable. In conclusion we developed for the first time dPCR assays that target all SNPs of relevance associated with BZ-resistance in H. contortus. Future research on AR development could benefit from an early onset of SNP-based surveillance that would include the developed assays for all SNPs of relevance. Improved surveillance in the long term will include other important, though less pathogenic, nematode genera in the analyses.

18 September 2023 in Research in Veterinary Science
Verified
Journal Article
Open access
Anja JoachimAnja Joachim
Anja Joachim
VAValerie Auersperg
Valerie Auersperg
JDJoel Drüe
Joel Drüe
SWSandra Wiedermann
Sandra Wiedermann
BHBarbara Hinney
Barbara Hinney
JSJoachim Spergser
Joachim Spergser
Due to their close associations with humans, dogs and cats can be important reservoirs for zoonotic pathogens. In the current study 200 fecal samples of dogs (n = 70 samples) and cats (n = 130 samples) from animal shelters in Carinthia, southern Austria, were examined for the presence of parasites (fecal flotation and larval migration assay) and selected bacteria. Overall, 17.1% of the canine and 38.5% of the feline samples were positive for parasites (p < 0.001), most commonly Giardia duodenalis (dogs and cats), including potentially zoonotic genotypes revealed by multilocus genotyping, and Toxocara cati (cats). Cryptosporidium (C. felis), Cystoisospora spp. (dogs and cats), hookworms (dog), Trichuris (dog) Capillaria hepatica (cats), taeniids (cat), and Aelurostrongylus abstrusus (cat) were also found. Zoonotic bacteria were detected in 10.5% of the samples, Salmonella enterica (dogs), Campylobacter jejuni (dogs and cats) and Yersinia enterocolitica (cat) and were significantly associated with parasite infections in cats but not in dogs. Samples that were positive for several pathogens were common; especially G. duodenalis and T. cati were frequently found in association with each other, other parasites or bacteria. The spectrum of detected pathogens is comparable to that of other dog and cat populations in central Europe. However, since animals from shelters are frequently rehomed, diagnostic measures, appropriate hygiene and therapy as well as training of shelter staff are recommended to prevent zoonotic transmission of enteropathogens to staff or new owners. The presence of heteroxenic parasites, i.e. Aelurostrongylus abstrusus and Taenia taeniaeformis, and spurious excretion of Ca. hepatica in cats, indicates that these animals preyed on intermediate hosts, and that biosafety measures in pet shelters need to be evaluated for their efficacy in the prevention of pathogen transmission.