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1.
  • Beech, Jason P., et al. (author)
  • The separation and identification of parasite eggs from horse feces
  • 2019
  • In: 23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2019. - 9781733419000 ; , s. 602-603
  • Conference paper (peer-reviewed)abstract
    • Freely grazing horses are at risk of infection by parasites such as Parascaris equorum (roundworm), Strongylus spp. (large bloodworms), Cyathostomes (small bloodworms), and Anoplochephala perfoliata (tapeworms). Mixed infections are common and diagnosis is based on demonstrations of eggs in feces followed by identification of larvae after fecal culture. Drug resistance is a growing problem, not least because treatments tend to be cheaper than diagnosis and “just in case” treatments common. There is a need for improved methods that are easy to use, rapid and cheap. Furthermore, a successful approach may find use with other livestock such as ruminants and pigs.
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2.
  • Carlsson, Gunnar, et al. (author)
  • Development and evaluation of gene expression biomarkers for chemical pollution in common frog (Rana temporaria) tadpoles
  • 2018
  • In: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 25, s. 33131-33139
  • Journal article (peer-reviewed)abstract
    • Pollutants have been proposed as one factor in the worldwide declines of amphibian species and populations. Applying gene expression analysis of liver RNA in tadpoles would be a possible approach for biomarker measurements to increase knowledge of ecological health in amphibian populations. The major aim of this study was to explore the relevance of applying gene expression analyses of cytochrome p450 (cyp1a), metallothionein (mt), and vitellogenin (vtg) in Rana temporaria tadpoles. Therefore, tadpoles were exposed for 1week to -naphthoflavone (BNF), cadmium chloride (CdCl2), and ethinylestradiol (EE2). Primers were developed for RT-qPCR to analyze gene expression in livers. The result showed that the methods for gene expression analyses of cyp1a, mt, and vtg as well as the reference gene -actin (bact) were successful not only in R. temporaria but also in another amphibian, Rana arvalis. The gene expression of cyp1a was induced by BNF and the gene expression of mt was induced by CdCl2 but no significant induction was recorded in vtg expression after exposure to EE2. Gene expressions varied throughout the tadpole metamorphosis development, in particular for vtg. Overall, the use of gene expression of cyp1a and mt as biomarkers in wild tadpoles seems promising while the use of vtg seems less relevant due to high natural variation and low background expression. The study shows that variations in gene expressions between tadpoles of different genetic origin are important to consider when evaluating the data. The present study has thus increased the background knowledge about gene expression applicability as biomarker for tadpoles.
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3.
  • Christianson, Monica (author)
  • What's behind sexual risk taking? : exploring the experiences of chlamydia-positive, HIV-positive, and HIV-tested young women and men in Sweden
  • 2006
  • Doctoral thesis (other academic/artistic)abstract
    • The overall aim was to explore the experiences of sexual risk taking among Chlamydia Trachomatis positive (CT+), HIV positive (HIV+), and HIV tested young women and men. The specific aims were to explore, from a gender perspective, the course of events, the norms, considerations and emotions involved in sexual risk taking in CT+, explore the perception of sexual risk taking in HIV+ youth, and their understanding of why they caught HIV and look at how the Law of Communicable Diseases Act impacts their sexuality. Moreover, to investigate why young adults test for HIV, how they construct the HIV risk, and what implications testing has for them.42 informants between 17-24 years of age were recruited from a youth clinic in Umeå and from three infection clinics for HIV patients in Sweden.In depth interviews and focus group interviews were tape-recorded, transcribed verbatim and analyzed according to a Grounded Theory approach.The finding revealed that behind sexual risk taking, there was a drive to go steady, where lust and trust guided if sex would take place. In one-night stands women were expected to be less forward compared with men. We found an uneven responsibility concerning condom use where men expected women to be "condom promoters". By catching CT, women experienced guilt, while men felt content through knowing "the source of contamination".Among the HIV+ youth, socio-cultural factors such as; lack of adult supervision, naivité, love, alcohol, drugs, the macho ideal and cultures of silence blinded the informants to the risks and made them vulnerable. By grouping narratives according to degree of consensus in sexual encounters, this demonstrated that sexual risks happened in a context of gendered power relations where the informants had varied agency. The Law of Communicable Diseases Act implied both support and burden for these HIV+ youth. A lot of responsibility was put on them and to be able to handle the infromation duty they tried to switch off lust, switch off the disease, or balance lust and obedience.Among the HIV tested youth, HIV was seen a distant threat. Many had event-driven reasons for testing for HIV; multiple partners being one. Risk zones, like bars were perceived to be a milieu that often was expected to include one-night stands. Responsibility for testing was a gendered issue; "natural" for women, while men rather escaped from responsibility and had a testing resistance. Receiving a "green card" confirmed healthiness and provided relief, and made the informants felt "clean". They could restart with new ambitious, including reconsidering risk.The findings can be used in public health and in health care sectors that work with young people. We present suggestions on how to decrease the spread of STIs:To implement how men could play an equal part in sexual and reproductive health.Promote general CT screening for men.Liberal HIV testing among both young women and men.Promote safer sex behaviour from the uninfected youth, especially focusing on men??.Consider the role of gender and social background in the context of risky behaviours.Give lots of positive rewards concerning HIV disclosure to diminish the risk for HIV transmission.
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4.
  • Dencker, Lennart, et al. (author)
  • Position Paper : EUFEPS Network on Veterinary Medicines Initiative: An interdisciplinary forum to support Veterinary Pharmacology and promote the development of new pharmaceuticals for Animal Health
  • 2016
  • In: European Journal of Pharmaceutical Sciences. - 0928-0987 .- 1879-0720. ; 91, s. I-VII
  • Journal article (peer-reviewed)abstract
    • Veterinary medicines account for a substantial portion of the production, sale, and consumption of medicines in Europe, and probably world-wide. This calls our attention to the fact that only healthy farm animals can ensure safe and sufficient livestock products to meet the growing demand for animal protein. Human and veterinary medicine share many common features - expressed and symbolised by the "One Health Concept". This concept forms the logical basis for the maintenance of healthy livestock by the control of zoonoses and foodborne diseases, the prevention of poor sanitary conditions, and the reduction of microbial and parasitic threats, including resistance to antibiotics and anti-parasitic drugs. Achieving these aims will require international cooperation and interdisciplinary action. A new initiative of the European Federation for Pharmaceutical Sciences (EUFEPS) - the Network on Veterinary Medicines - has the potential to manage and overcome these challenges. A number of EUFEPS expertise networks have already been established, and some will be instrumental in supporting the activities of the Network on Veterinary Medicines, e.g., the European Network on PharmacoGenomics Research and Implementation (EPRIN), as well as the Network on Bioavailability and Biopharmaceutics, and the envisioned Network on Systems Pharmacology. Notably, the EUFEPS Networks on Safety Sciences, on Environment and Pharmaceuticals and on NanoMedicine as well as on Regulatory Science, represent promising partners. New technologies are being introduced to veterinary medicine for the treatment of numerous and frequently species-specific conditions. Scientific input from different areas is required to evaluate the potential benefitrisk profiles of these novel products, drug delivery techniques, and medical attention for animals as a whole. Drug treatment of food-producing animals inevitably affects consumer safety and public health, as any administration of medicines to animals may result in the presence of drug residues in edible tissues or products such as milk, eggs, and honey. The many questions surrounding the risks to human health and to the environment posed by exposure to veterinary drug residues cause great concern among health authorities as well as the public. In particular, the shared use of many classes of antimicrobials in both veterinary and human medicine, the emergence and spread of resistant microbes from animals or animal-derived products to humans, and the presence of contaminated manure in the environment are all provoking deep concern throughout the world. The Network on Veterinary Medicines initiative sees itself as broadly positioned. Among its most important goals are contributing to legislative issues in veterinary medicine and to the development of new pharmaceuticals for animal health, including novel drug delivery systems. Efforts to support the academic teaching and training of veterinary professionals and formulators for veterinary drug delivery are also considered imperative objectives of the network. The pursuit of these tasks will depend on interdisciplinary cooperation among experts from pharmaceutical and veterinary sciences, concentrating on issues where scientists from academia, industry and regulatory agencies can collaborate. National and international healthcare bodies, as well as organisations dedicated to the endorsement of teaching and training of scientists in pharmaceutical and veterinary sciences, are also key partners. Major objectives of the network include the following: strengthening academic research to promote the emergence of new concepts, principles and mechanisms of action to develop innovative new veterinary medicinal products, supporting the education and training of future healthcare professionals in veterinary practice, pharmacy and industrial research, including continuing professional development, and supporting Veterinary Universities. Further efforts of the Network will encourage the European Commission to initiate calls for research in the area of veterinary medicines, such as Horizon 2020. Once these calls are in place, the formation of strong consortia to apply for funding (IMI, EU-funding) is projected. The success of the Network depends on the engagement and expertise of cooperating specialists. It will benefit from the experience and means of other EUFEPS networks.
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5.
  • Drevin, Jennifer, et al. (author)
  • Adverse childhood experiences influence development of pain during pregnancy.
  • 2015
  • In: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 94:8, s. 840-846
  • Journal article (peer-reviewed)abstract
    • OBJECTIVE: To investigate the association between adverse childhood experiences (ACE) and pain with onset during pregnancy.DESIGN: Cross-sectional study.SETTING: Eighteen antenatal clinics in southern Mid-Sweden.SAMPLE: Of 293 women invited to participate, 232 (79%) women agreed to participate in early pregnancy and were assessed in late pregnancy.METHODS: Questionnaires were distributed in early and late pregnancy. The questionnaires sought information on socio-demography, ACE, pain location by pain drawing and pain intensity by visual analogue scales. Distribution of pain was coded in 41 predetermined areas.MAIN OUTCOME MEASURES: Pain in third trimester with onset during present pregnancy: intensity, location and number of pain locations.RESULTS: In late pregnancy, 62% of the women reported any ACE and 72% reported any pain location with onset during the present pregnancy. Among women reporting any ACE the median pain intensity was higher compared with women without such an experience (p = 0.01). The accumulated ACE displayed a positive association with the number of reported pain locations in late pregnancy (rs  = 0.19, p = 0.02). This association remained significant after adjusting for background factors in multiple regression analysis (p = 0.01). When ACE was dichotomized the prevalence of pain did not differ between women with and without ACE. The subgroup of women reporting physical abuse as a child reported a higher prevalence of sacral and pelvic pain (p = 0.0003 and p = 0.02, respectively).CONCLUSIONS: Adverse childhood experiences were associated with higher pain intensities and larger pain distributions in late pregnancy, which are risk factors for transition to chronic pain postpartum.
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6.
  • Dube, Faruk, et al. (author)
  • Gene co-expression network analysis reveal core responsive genes in Parascaris univalens tissues following ivermectin exposure
  • 2024
  • In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 19:2
  • Journal article (peer-reviewed)abstract
    • Anthelmintic resistance in equine parasite Parascaris univalens, compromises ivermectin (IVM) effectiveness and necessitates an in-depth understanding of its resistance mechanisms. Most research, primarily focused on holistic gene expression analyses, may overlook vital tissue-specific responses and often limit the scope of novel genes. This study leveraged gene co-expression network analysis to elucidate tissue-specific transcriptional responses and to identify core genes implicated in the IVM response in P. univalens. Adult worms (n = 28) were exposed to 10−11 M and 10−9 M IVM in vitro for 24 hours. RNA-sequencing examined transcriptional changes in the anterior end and intestine. Differential expression analysis revealed pronounced tissue differences, with the intestine exhibiting substantially more IVM-induced transcriptional activity. Gene co-expression network analysis identified seven modules significantly associated with the response to IVM. Within these, 219 core genes were detected, largely expressed in the intestinal tissue and spanning diverse biological processes with unspecific patterns. After 10−11 M IVM, intestinal tissue core genes showed transcriptional suppression, cell cycle inhibition, and ribosomal alterations. Interestingly, genes PgR028_g047 (sorb-1), PgB01_g200 (gmap-1) and PgR046_g017 (col-37 & col-102) switched from downregulation at 10−11 M to upregulation at 10−9 M IVM. The 10−9 M concentration induced expression of cuticle and membrane integrity core genes in the intestinal tissue. No clear core gene patterns were visible in the anterior end after 10−11 M IVM. However, after 10−9 M IVM, the anterior end mostly displayed downregulation, indicating disrupted transcriptional regulation. One interesting finding was the non-modular calcium-signaling gene, PgR047_g066 (gegf-1), which uniquely connected 71 genes across four modules. These genes were enriched for transmembrane signaling activity, suggesting that PgR047_g066 (gegf-1) could have a key signaling role. By unveiling tissue-specific expression patterns and highlighting biological processes through unbiased core gene detection, this study reveals intricate IVM responses in P. univalens. These findings suggest alternative drug uptake of IVM and can guide functional validations to further IVM resistance mechanism understanding.
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7.
  • Dube, Faruk, et al. (author)
  • Ivermectin-induced gene expression changes in adult Parascaris univalens and Caenorhabditis elegans : a comparative approach to study anthelminthic metabolism and resistance in vitro
  • 2022
  • In: Parasites & Vectors. - : Springer Nature. - 1756-3305. ; 15:1
  • Journal article (peer-reviewed)abstract
    • Background: The nematode Parascaris univalens is one of the most prevalent parasitic pathogens infecting horses but anthelmintic resistance undermines treatment approaches. The molecular mechanisms underlying drug activity and resistance remain poorly understood in this parasite since experimental in vitro models are lacking. The aim of this study was to evaluate the use of Caenorhabditis elegans as a model for P. univalens drug metabolism/resistance studies by a comparative gene expression approach after in vitro exposure to the anthelmintic drug ivermectin (IVM).Methods: Twelve adult P. univalens worms in groups of three were exposed to ivermectin (IVM, 10(-13) M, 10(-11) M, 10(-9 )M) or left unexposed for 24 h at 37 degrees C, and total RNA, extracted from the anterior end of the worms, was sequenced using Illumina NovaSeq. Differentially expressed genes (DEGs) involved in metabolism, transportation, or gene expression with annotated Caemorhabditis elegans orthologues were identified as candidate genes to be involved in IVM metabolism/resistance. Similarly, groups of 300 adult C. elegans worms were exposed to IVM (10(-9) M, 10(-8) M and 10(-7) M) or left unexposed for 4 h at 20 degrees C. Quantitative RT-PCR of RNA extracted from the C. elegans worm pools was used to compare against the expression of selected P. univalens candidate genes after drug treatment.Results: After IVM exposure, 1085 DEGs were found in adult P. univalens worms but the relative gene expression changes were small and large variabilities were found between different worms. Fifteen of the DEGs were chosen for further characterization in C. elegans after comparative bioinformatics analyses. Candidate genes, including the putative drug target Igc-37, responded to IVM in P. univalens, but marginal to no responses were observed in C. elegans despite dose-dependent behavioral effects observed in C. elegans after IVM exposure. Thus, the overlap in IVM-induced gene expression in this small set of genes was minor in adult worms of the two nematode species.Conclusion: This is the first time to our knowledge that a comparative gene expression approach has evaluated C. elegans as a model to understand IVM metabolism/resistance in P. univalens. Genes in P. univalens adults that responded to IVM treatment were identified. However, identifying conserved genes in P. univalens and C. elegans involved in IVM metabolism/resistance by comparing gene expression of candidate genes proved challenging. The approach appears promising but was limited by the number of genes studied (n = 15). Future studies comparing a larger number of genes between the two species may result in identification of additional candidate genes involved in drug metabolism and/or resistance.
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8.
  • Dube, Faruk, et al. (author)
  • Transcriptomics of ivermectin response in Caenorhabditis elegans : Integrating abamectin quantitative trait loci and comparison to the Ivermectin-exposed DA1316 strain
  • 2023
  • In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 18:5
  • Journal article (peer-reviewed)abstract
    • Parasitic nematodes pose a significant threat to human and animal health, as well as cause economic losses in the agricultural sector. The use of anthelmintic drugs, such as Ivermectin (IVM), to control these parasites has led to widespread drug resistance. Identifying genetic markers of resistance in parasitic nematodes can be challenging, but the free-living nematode Caenorhabditis elegans provides a suitable model. In this study, we aimed to analyze the transcriptomes of adult C. elegans worms of the N2 strain exposed to the anthelmintic drug Ivermectin (IVM), and compare them to those of the resistant strain DA1316 and the recently identified Abamectin Quantitative Trait Loci (QTL) on chromosome V. We exposed pools of 300 adult N2 worms to IVM (10(-7) and 10(-8) M) for 4 hours at 20 degrees C, extracted total RNA and sequenced it on the Illumina NovaSeq6000 platform. Differentially expressed genes (DEGs) were determined using an in-house pipeline. The DEGs were compared to genes from a previous microarray study on IVM-resistant C. elegans and Abamectin-QTL. Our results revealed 615 DEGs (183 up-regulated and 432 down-regulated genes) from diverse gene families in the N2 C. elegans strain. Of these DEGs, 31 overlapped with genes from IVM-exposed adult worms of the DA1316 strain. We identified 19 genes, including the folate transporter (folt-2) and the transmembrane transporter (T22F3.11), which exhibited an opposite expression in N2 and the DA1316 strain and were deemed potential candidates. Additionally, we compiled a list of potential candidates for further research including T-type calcium channel (cca-1), potassium chloride cotransporter (kcc-2), as well as other genes such as glutamate-gated channel (glc-1) that mapped to the Abamectin-QTL.
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9.
  • Halvarsson, Peter, et al. (author)
  • The complete ITS2 barcoding region for Strongylus vulgaris and Strongylus edentatus
  • 2023
  • In: Veterinary Research Communications. - : Springer Science and Business Media LLC. - 0165-7380 .- 1573-7446. ; 47, s. 1767-1771
  • Journal article (peer-reviewed)abstract
    • Gastrointestinal nematode parasites are of major concern for horses, where Strongylus vulgaris is considered the most pathogenic among the Strongylus species. Diagnosis of S. vulgaris infections can be determined with next generation sequencing techniques, which are inherently dependent on reference sequences. The best marker for parasitic nematodes is internal transcribed spacer 2 (ITS2) and we provide the first complete ITS2 sequences from five morphologically identified S. vulgaris and additional sequences from two S. edentatus. These sequences have high similarity to already published partial sequences and amplicon sequence variants (ASV) based on next generation sequencing (NGS). The ITS2 sequences from S. vulgaris matched available partial ITS2 sequences and the full ASVs, whereas the S. edentatus sequence matched another complete sequence. We also compare Sanger sequencing and NGS methods and conclude that the ITS2 variation is better represented with NGS methods. Based on this, we recommend that further sequencing of morphologically identified specimens of various species should be performed with NGS cover the intraspecific variation in the ITS2.
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10.
  • Hedberg Alm, Ylva, et al. (author)
  • Clinical features and treatment response to differentiate idiopathic peritonitis from non-strangulating intestinal infarction of the pelvic flexure associated with Strongylus vulgaris infection in the horse
  • 2022
  • In: BMC Veterinary Research. - : Springer Science and Business Media LLC. - 1746-6148. ; 18
  • Journal article (peer-reviewed)abstract
    • Background Peritonitis in horses secondary to non-strangulating infarction (NSII) has a guarded prognosis, even after intestinal resection. In contrast, horses with idiopathic peritonitis respond well to medical treatment. Affected horses in both cases often show signs of both colic and systemic inflammation, but early diagnosis is crucial for optimal treatment and an accurate prognosis. One cause of NSII is thrombus formation secondary to Strongylus vulgaris larval migration. There has been a documented increase in S. vulgaris prevalence in Sweden since the implementation of selective anthelmintic treatment in 2007, which subsequently could result in a rise in NSII cases. In a retrospective clinical study, medical records from cases diagnosed with NSII of the pelvic flexure or idiopathic peritonitis from three equine referral hospitals in Sweden during 2017-2020 were reviewed. Information including demographic data, relevant medical history, and clinical- and laboratory parameters were obtained from patient records. To facilitate the differentiation between cases of idiopathic peritonitis and cases with confirmed NSII of the pelvic flexure, the aim of the study was to compare clinical and laboratory parameters, clinical progression and initial response to antimicrobial treatment. A secondary aim was to compare survival-rates. Results Horses with NSII (n = 20) were significantly more likely to present during the winter months with a poorer response to medical treatment within 48 h. Cases of idiopathic peritonitis (n = 107) had a 100% survival rate with medical treatment, although one case required surgical correction of a colon displacement. In comparison, all confirmed NSII cases were non-responsive to antimicrobial treatment, with a survival rate to discharge of 50% after colon resection. Specific rectal findings and peripheral blood neutropenia were strongly associated with NSII. Conclusions In Sweden, idiopathic peritonitis cases still predominate over S. vulgaris associated NSII cases and have an excellent survival rate with antimicrobial treatment. However, horses presenting with septic peritonitis during the winter months with a palpable rectal mass and displaying fever and colic signs beyond 48 h of medical treatment are likely to suffer from NSII of the pelvic flexure and should be considered for abdominal surgery.
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11.
  • Hedberg Alm, Ylva, et al. (author)
  • Demonstration of reduced efficacy against cyathostomins without change in species composition after pyrantel embonate treatment in Swedish equine establishments
  • 2023
  • In: International Journal for Parasitology: Drugs and Drug Resistance. - 2211-3207. ; 23, s. 78-86
  • Journal article (peer-reviewed)abstract
    • Consisting of approximately 50 different species, the cyathostomin parasites are ubiquitous in grazing horses. Coinfection with several species is common, and large burdens can cause the fatal disease of larval cyathostominosis. Due to intense anthelmintic drug use, cyathostomin resistance has developed to all available anthelmintic drug groups. Resistance to the anthelmintic drug pyrantel (PYR) has been documented in over 90% of studies published over the past two decades. In Sweden, a study performed in the early 2000s only confirmed resistance in 4.5% of farms. Further, prescription-only administration of equine anthelmintic drugs was enforced in Sweden in 2007. However, it is unknown if this conservative drug use has maintained PYR efficacy in cyathostomins. The aim of the present study was to investigate the effect of PYR on cyathostomin infection in Sweden using fecal egg count reduction tests (FECRTs). Further, the effect of PYR treatment on cyathostomin species composition was studied using metabarcoding. Sixteen farms with at least six horses excreting a minimum of 100 eggs per gram feces were included. Using the current World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines, PYR resistance was demonstrated in nine of farms, with seven farms showing full susceptibility. Farms with low biosecurity measures had significantly lower efficacy of PYR treatment. The most common cyathostomin species were Cylicocyclus nassatus, Cyathostomum catinatum, Cylicostephanus longibursatus, Cys. calicatus, Cys. goldi, Cys. minutus, Coronocyclus coronatus and Cya. pateratum, accounting for 97% of all sequence reads prior to treatment. Of these, Cyc. nassatus and Cya. catinatum had the highest occurrence, accounting for 68% of all sequence reads prior to PYR treatment. Treatment did not significantly affect the species composition. The results highlight the importance of drug efficacy testing when using PYR to treat cyathostomin infection, even when selective anthelmintic treatment and thus low treatment intensity, is used on the farm.
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12.
  • Hedberg Alm, Ylva, et al. (author)
  • Evaluation of Strategies to Reduce Equine Strongyle Infective Larvae on Pasture and Study of Larval Migration and Overwintering in a Nordic Climate
  • 2022
  • In: Animals. - : MDPI AG. - 2076-2615. ; 12
  • Journal article (peer-reviewed)abstract
    • Simple Summary All grazing horses are exposed to parasites that when ingested have the potential to cause disease. Drugs designed to kill parasites in horses have been used extensively since the 1960s, but this intensive use has led to the development of drug resistance, emphasising the need for more sustainable methods to lessen parasite burdens. The efficacy and suitability of pasture-management methods aiming to reduce the level of parasitic larvae in the herbage are, however, dependent on the prevailing weather conditions. The aim of the present study was therefore to generate data on the effect of regular faecal removal and harrowing of the pasture on reducing the number of parasites in herbage in a Nordic climate. Furthermore, the ability of parasite larvae to migrate from faeces to the herbage and to survive the winter season in Sweden's cold temperate climate was investigated. Twice-weekly faecal removal significantly reduced the number of larvae on the pasture, whereas harrowing on a single occasion in the summer under dry weather conditions did not. Parasite larvae migrated as far as 150 cm from faecal pats and were able to survive one winter season, with two years of rest from grazing horses required to achieve parasite-free pasture. Horses, as grazing animals, are inadvertently exposed to intestinal parasites that, if not controlled, may cause disease. However, the indiscriminate use of anthelmintic drugs has led to drug resistance, highlighting the need for pasture-management practices to reduce the level of parasitic exposure and lessen reliance on drugs. The efficacy of such methods depends both on the epidemiology of the parasites and the prevailing weather conditions. The aim of the study was to investigate the effect of faecal removal and harrowing on reducing the number of parasite larvae in herbage. Moreover, the migratory and survival ability of strongyle larvae in a Nordic climate was studied. Faeces from horses naturally infected with strongyle nematodes were used to contaminate pastures and grass samples were collected to harvest larvae. Twice-weekly faecal removal significantly reduced larval yields, whereas harrowing on a single occasion under dry weather conditions in the summer did not. Strongyle larvae were able to migrate 150 cm from the faecal pats, but most larvae were found within 50 cm. Both Cyathostominae and S. vulgaris survived the winter months with larvae harvested up to 17-18 months after faecal placement. Resting of pastures for one year greatly reduced the parasite level, but two years of rest were required for parasite-free pasture.
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13.
  • Hedberg Alm, Ylva, et al. (author)
  • Parasite Occurrence and Parasite Management in Swedish Horses Presenting with Gastrointestinal Disease-A Case-Control Study
  • 2020
  • In: Animals. - : MDPI AG. - 2076-2615. ; 10
  • Journal article (peer-reviewed)abstract
    • Simple Summary Abdominal pain, colic, is a common clinical sign in horses, sometimes reflecting life-threatening disease. One cause of colic is parasitic infection of the gut. Various drugs, anthelmintics, can be used to reduce or eliminate such parasites. However, frequent use has led to problems of drug resistance, whereby many countries now allow anthelmintics to be used on a prescription-only basis. In Sweden, this has led to a concern that parasitic-related colic in horses is increasing. This study aimed to investigate whether horses with colic differed in parasitological status compared to horses without colic. A secondary aim was to collect information regarding current parasite control measures used by horse owners. Exposure to S. vulgaris, a parasite with the potential to cause life-threatening disease, appeared high as determined by the presence of antibodies in the blood. Horses with inflammation in the abdominal cavity had higher antibody levels than other causes of colic. Despite new legislation, 29% of owners did not use fecal analyses for parasites and the use of extended methods to diagnose specific parasites was low. Also, owners rarely used alternative methods to reduce the pasture parasite burden. The study suggests a need for education in the use of both fecal analyses and pasture management.Abstract All grazing horses are exposed to intestinal parasites, which have the potential to cause gastrointestinal disease. In Sweden, there is a concern about an increase in parasite-related equine gastrointestinal disease, in particular Strongylus vulgaris, since the implementation of prescription-only anthelmintics approximately 10 years ago. In a prospective case-control study, parasitological status, using fecal analyses for strongyle egg counts, the presence of Anoplocephala perfoliata eggs and S. vulgaris Polymerase chain reaction (PCR) as well as serology for S. vulgaris, were compared between horses presenting with or without gastrointestinal disease at a University hospital during a one-year period. Information regarding anthelmintic routines and pasture management was gathered with an owner-filled questionnaire. Although the prevalence of S. vulgaris PCR was 5.5%, 62% of horses were positive in the enzyme-linked immunosorbent assay (ELISA) test and horses with peritonitis showed higher antibody levels for S. vulgaris, as compared to other diagnoses or controls. Overall, 36% of the horse owners used only fecal egg counts (FEC), 32% used FEC combined with specific diagnostics for S. vulgaris or A. perfoliata, and 29% dewormed routinely without prior parasite diagnostics. Effective management methods to reduce the parasitic burden on pastures were rare and considering exposure to S. vulgaris appears high; the study indicates a need for education in specific fecal diagnostics and pasture management.
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14.
  • Hellman, Stina, et al. (author)
  • Cytokine responses to various larval stages of equine strongyles and modulatory effects of the adjuvant G3 in vitro
  • 2020
  • In: Parasite Immunology. - : Wiley. - 0141-9838 .- 1365-3024. ; 43
  • Journal article (peer-reviewed)abstract
    • Aims To generate different larval stages ofStrongylus vulgarisand to study cytokine responses in cultures of eqPBMC exposed to defined larval stages ofS. vulgarisand cyathostomins with the aim to understand the early immune reaction to these parasites. Methods and results EqPBMC were exposed toS. vulgarislarvae (L3, exsheated L3 and L4) and cyathostomin L3 and analysed for cytokine gene expression. Procedures for decontamination, culturing and attenuation of larvae were established. Transcription of IL-4, IL-5 and IL-13 was induced by bothS. vulgarisand cyathostomin L3. Moulting ofS. vulgarisfrom L3 to L4 stage was accompanied by a shift to high expression of IL-5 and IL-9 (exsheated L3 and L4) and IFN-gamma (L4 only). In parallel, the adjuvant G3 modified the cytokine profile induced by both parasites by reducing the expression of IL-4, IL-5 and IL-10 while concomitantly enhancing the expression of IFN-gamma. Conclusion The L4 stage ofS. vulgarisgenerated a cytokine profile different from that induced by the earlier L3 stage ofS. vulgarisand cyathostomins. This diversity depending on the life cycle stage will have implications for the choice of antigen and adjuvant in future vaccine design.
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15.
  • Hellman, Stina, et al. (author)
  • Equine enteroid-derived monolayers recapitulate key features of parasitic intestinal nematode infection
  • 2024
  • In: Veterinary research (Print). - : Springer Nature. - 0928-4249 .- 1297-9716. ; 55:1
  • Journal article (peer-reviewed)abstract
    • Stem cell-derived organoid cultures have emerged as attractive experimental models for infection biology research regarding various types of gastro-intestinal pathogens and host species. However, the large size of infectious nematode larvae and the closed structure of 3-dimensional organoids often hinder studies of the natural route of infection. To enable easy administration to the apical surface of the epithelium, organoids from the equine small intestine, i.e. enteroids, were used in the present study to establish epithelial monolayer cultures. These monolayers were functionally tested by stimulation with IL-4 and IL-13, and/or exposure to infectious stage larvae of the equine nematodes Parascaris univalens, cyathostominae and/or Strongylus vulgaris. Effects were recorded using transcriptional analysis combined with histochemistry, immunofluorescence-, live-cell- and scanning electron microscopy. These analyses revealed heterogeneous monolayers containing both immature and differentiated cells including tuft cells and mucus-producing goblet cells. Stimulation with IL-4/IL-13 increased tuft- and goblet cell differentiation as demonstrated by the expression of DCLK1 and MUC2. In these cytokine-primed monolayers, the expression of MUC2 was further promoted by co-culture with P. univalens. Moreover, live-cell imaging revealed morphological alterations of the epithelial cells following exposure to larvae even in the absence of cytokine stimulation. Thus, the present work describes the design, characterization and usability of an experimental model representing the equine nematode-infected small intestinal epithelium. The presence of tuft cells and goblet cells whose mucus production is affected by Th2 cytokines and/or the presence of larvae opens up for mechanistic studies of the physical interactions between nematodes and the equine intestinal mucosa.
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16.
  • Höglund, Johan, et al. (author)
  • Real-time PCR detection for quantification of infection levels with Ostertagia ostertagi and Cooperia oncophora in cattle faeces
  • 2013
  • In: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 197, s. 251-257
  • Journal article (peer-reviewed)abstract
    • A quantitative real-time polymerase chain reaction (qPCR) based on hydrolysis (TaqMan (R)) probes is described for robust and sensitive detection of the infection levels with eggs and third stage larvae (L3) of Cooperia oncophora and Ostertagia ostertagi isolated from cattle faeces. The current microscopic method for identification of strongyle nematodes in cattle faeces is labour-intensive where reliable species determination also requires trained expertise, which is increasingly lacking. The goal of this study was to develop a sustainable non-labour intensive diagnostic qPCR assay to detect and determine the levels of infection with the two most common gastro-intestinal nematodes (GIN) in cattle faeces targeting the second internal transcribed spacer of nuclear ribosomal DNA (ITS2) region (rDNA). According to our results, this procedure allows to reliably detect the relative proportions of eggs and L3 for each of the two species. This assay produced consistent results when mixtures with known numbers of L3 of both species were tested, although it was also demonstrated that the calculated copy numbers of ITS2 between single L3 sometimes varied very much. In addition, a positive correlation (r(2) = 0.23) between the proportion of eggs and L3 in different paired samples collect in the field was observed for both species. Thus, for the first time a qPCR assay is reported, which can discriminate between the two most important cattle nematode parasites in temperate regions. This is of major importance to the livestock sector as it can be used with great precision to demonstrate strategic treatment efficacy that is important for the detection of anthelmintic resistance (AR). (C) 2013 Elsevier B.V. All rights reserved.
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17.
  • Lood, Christian, et al. (author)
  • Platelet-derived S100A8/A9 and cardiovascular disease in systemic lupus erythematosus.
  • 2016
  • In: Arthritis & Rheumatology. - : Wiley. - 2326-5205 .- 2326-5191.
  • Journal article (peer-reviewed)abstract
    • S100A8/A9, a pro-inflammatory and pro-thrombotic protein complex, is increased in several diseases and high levels predispose to cardiovascular disease (CVD). Recently, platelet S100A8/A9 synthesis was described in mouse and humans in relation to CVD. However, the role of platelet S100A8/A9 in systemic lupus erythematosus (SLE), a disease with markedly increased cardiovascular morbidity, as well as the exact platelet distribution of the S100A8/A9 proteins has not been investigated.
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18.
  • Lood, Christian, et al. (author)
  • Protein synthesis of the pro-inflammatory S100A8/A9 complex in plasmacytoid dendritic cells and cell surface S100A8/A9 on leukocyte subpopulations in systemic lupus erythematosus
  • 2011
  • In: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 13:2
  • Journal article (peer-reviewed)abstract
    • Introduction: Systemic lupus erythematosus (SLE) is an autoimmune disease with chronic or episodic inflammation in many different organ systems, activation of leukocytes and production of pro-inflammatory cytokines. The heterodimer of the cytosolic calcium-binding proteins S100A8 and S100A9 (S100A8/A9) is secreted by activated polymorphonuclear neutrophils (PMNs) and monocytes and serves as a serum marker for several inflammatory diseases. Furthermore, S100A8 and S100A9 have many pro-inflammatory properties such as binding to Toll-like receptor 4 (TLR4). In this study we investigated if aberrant cell surface S100A8/A9 could be seen in SLE and if plasmacytoid dendritic cells (pDCs) could synthesize S100A8/A9. Methods: Flow cytometry, confocal microscopy and real-time PCR of flow cytometry-sorted cells were used to measure cell surface S100A8/A9, intracellular S100A8/A9 and mRNA levels of S100A8 and S100A9, respectively. Results: Cell surface S100A8/A9 was detected on all leukocyte subpopulations investigated except for T cells. By confocal microscopy, real-time PCR and stimulation assays, we could demonstrate that pDCs, monocytes and PMNs could synthesize S100A8/A9. Furthermore, pDC cell surface S100A8/A9 was higher in patients with active disease as compared to patients with inactive disease. Upon immune complex stimulation, pDCs up-regulated the cell surface S100A8/A9. SLE patients had also increased serum levels of S100A8/A9. Conclusions: Patients with SLE had increased cell surface S100A8/A9, which could be important in amplification and persistence of inflammation. Importantly, pDCs were able to synthesize S100A8/A9 proteins and up-regulate the cell surface expression upon immune complex-stimulation. Thus, S100A8/A9 may be a potent target for treatment of inflammatory diseases such as SLE.
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19.
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20.
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21.
  • Löfgren, Maria, et al. (author)
  • Expression of xenobiotic metabolising enzymes in lungs of horses with or without histological evidence of lower airway inflammation
  • 2021
  • In: Veterinary Medicine and Science. - : Wiley. - 2053-1095. ; 7, s. 16-24
  • Journal article (peer-reviewed)abstract
    • Mild, moderate and severe equine asthma is a problem for equine welfare. The aetiology of the disease is not known in detail but is likely multi-factorial. One important factor may be inhaled dust which carries harmful substances which may be bioactivated and thus can lead to local inflammation in the airways. The aim of this study was to investigate gene expression and protein localisation of cytochrome P450 (CYP) enzymes, superoxide dismutase and glutathione-S-transferases (GST) involved in bioactivation and detoxification of harmful substances in lungs of horses with or without histological evidence of lower airway inflammation. Significantly lower gene expression of CYP2A13 and GSTM1 was observed in lungs from horses with histological evidence of lower airway inflammation compared with horses without. A higher expression, although not significant, was found for CYP1A1 in horses with histological evidence of lower airway inflammation. There were no differences in gene expression of GSTP1 and SOD3. The proteins were localised in the respiratory epithelium which is of relevance as a defence to local exposure of inhaled harmful substances. In conclusion, our study reports differential gene expression of enzymes involved in bioactivation and detoxification of foreign substances in the lungs of horses with histological evidence of lower airway inflammation compared with horses without.
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22.
  • Martin, Frida, et al. (author)
  • Constitutive and differential expression of transport protein genes in Parascaris univalens larvae and adult tissues after in vitro exposure to anthelmintic drugs
  • 2021
  • In: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 298
  • Journal article (peer-reviewed)abstract
    • The equine roundworm Parascaris univalens has developed resistance to the three anthelmintic substances most commonly used in horses. The mechanisms responsible for resistance are believed to be multi-genic, and transport proteins such as the P-glycopmtein (Pgp) family have been suggested to be involved in resistance in several parasites including P. univlaens. To facilitate further research into the mechanisms behind drug metabolism and resistance development in P. univalens we aimed to develop an in vitro model based on larvae. We developed a fast and easy protocol for hatching P. univalens larvae for in vitro studies, resulting in a hatching rate of 92 %. The expression of transport protein genes pgp-2, pgp-9, pgp-11.1, pgp-16.1 and major facilitator superfamily (MFS) genes PgR006_g137 and PgR015_g078 were studied in hatched larvae exposed to the anthelmintic drugs ivermecin (IVM) 10(-9) M, pyrantel citrate (PYR) 10(-6) M and thiabendazole (TBZ) 10(-5) M for 24 h. In comparison, the expression of these transport protein genes was studied in the anterior end and intestinal tissues of adult worms in vitro exposed to IVM, TBZ and PYR, at the same concentrations as larvae, for 3 h, 10 h and 24 h. Larval exposure to sub-lethal doses of IVM for 24 h did not affect the expression levels of any of the investigated genes, however larvae exposed to PYR and TBZ for 24 h showed significantly increased expression of pgp-9. In vitro drug exposure of adult worms did not result in any significant increases in expression of transport protein genes. Comparisons of constitutive expression between larvae and adult worm tissues showed that pgp-9, pgp11.1, pgp-16.1 and MFS gene PgR015_g078 were expressed at lower levels in larvae than in adult tissues, while pgp-2 and MFS gene PgR006_g137 had similar expression levels in larvae and adult worms. All investigated transport protein genes were expressed at higher rates in the intestine than in the anterior end of adult worms, except pgp-11.1 where the expression was similar between the two tissues. This high constitutive expression in the intestine suggests that this is an important site for xenobiotic efflux in P. univalens. Despite the fact that the results of this study show differences in expression of transport protein genes between larvae and adult tissues, we believe that the larval assay system described here will be an important tool for further research into the molecular mechanisms behind anthelmintic resistance development and for other in vitro studies.
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23.
  • Martin, Frida, et al. (author)
  • Exploring the beta-tubulin gene family in a benzimidazole-resistant Parascaris univalens population
  • 2021
  • In: International Journal for Parasitology: Drugs and Drug Resistance. - : Elsevier BV. - 2211-3207. ; 17, s. 84-91
  • Journal article (peer-reviewed)abstract
    • Benzimidazole (BZ) drugs are frequently used to treat infections with the equine ascarid Parascaris univalens due to increasing resistance to macrocyclic lactones and pyrantel. Benzimidazole resistance is rare in ascarids in contrast to strongyle parasites where this resistance is widespread. In strongyles, single nucleotide polymorphisms (SNPs) at codons 167, 198 and 200 in a 13-tubulin gene have been correlated to BZ resistance, but little is known about the 13-tubulin genes and their possible involvement in BZ resistance in P. univalens and other ascarids. Previously two 13-tubulin genes have been identified in P. univalens. In this study, we present five additional 13-tubulin genes as well as the phylogenetic relationship of all seven genes to 13-tubulins of other clade III and V nematodes. In addition, the efficacy of fenbendazole for treatment of P. univalens on a Swedish stud farm was studied in 2019 and 2020 using faecal egg count reduction test. Reductions varied from 73% to 88%, indicating the presence of a resistant P. univalens population on the farm. The emergence of BZ resistance emphasizes the need for development of molecular markers for rapid and more sensitive detection of resistant populations. We therefore investigated whether possible SNPs at positions 167, 198 or 200 in any of the 13-tubulin genes could be used to distinguish between resistant and susceptible P. univalens populations. Amplicon sequencing covering the mutation sites 167, 198 and 200 in all seven 13-tubulin genes revealed an absence of SNPs in both resistant and susceptible populations, suggesting that the mechanism behind BZ resistance in ascarids is different from that in strongyle nematodes and the search for a molecular marker for BZ resistance in P. univalens needs to continue.
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24.
  • Martin, Frida, et al. (author)
  • First Report of Resistance to Ivermectin in Parascaris univalens in Iceland
  • 2021
  • In: Journal of Parasitology. - : American Society of Parasitologists. - 0022-3395 .- 1937-2345. ; 107, s. 16-22
  • Journal article (peer-reviewed)abstract
    • Horses in Iceland have been isolated for more than 1,000 yr but still harbor a similar range of gastrointestinal parasites as do horses across the world. The long isolation of the horses and their parasites presumably means that no resistance genes have been introduced into the Parascaris spp. population. It is therefore of particular interest to investigate the efficacy of ivermectin on Parascaris spp. infecting Icelandic foals. Potential treatment failure of ivermectin in Iceland will add substantial new information on how resistance can arise independently. This study aimed to determine the efficacy of subcutaneous injection of ivermectin for the treatment of Parascaris spp. infection in foals and to identify the Parascaris species present in the west and north of Iceland. A fecal egg count reduction (FECR) test (FECRT) was performed on 50 foals from 8 farms, including an untreated control group of 6 foals, from September to November 2019. The foals were between 3 and 5 mo of age at the start of the study and had not previously been treated with anthelmintic drugs. Each foal was treated subcutaneously with off-label use of Ivomec (R) injection 10 mg/ml or Noromectin (R) 1% at a dose of 0.2 mg/kg. The FECR for each farm was calculated in 2 ways, by the eggCounts package in R and by the Presidente formula (FECRT). Both calculation methods resulted in efficacy levels between 0% and 80.78%, indicating ivermectin resistance on all farms. We also confirmed, by karyotyping, that the species of equine ascarid present in the west and north of Iceland is Parascaris univalens. This study provides evidence for treatment failure of ivermectin against P. univalens infection in foals. Since Icelandic horses have been isolated on the island for more than 1,000 yr, this implies that resistance alleles have developed independently in the Icelandic Parascaris population. The actual clinical impact of ivermectin resistance is unknown but another drug of choice should be considered to treat Parascaris infection in foals in Iceland.
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25.
  • Martin, Frida, et al. (author)
  • Resistance to pyrantel embonate and efficacy of fenbendazole in Parascaris univalens on Swedish stud farms
  • 2018
  • In: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 264, s. 69-73
  • Journal article (peer-reviewed)abstract
    • The aims of this study were to determine the species of Parascaris present in foals in Sweden and to establish whether anthelmintic resistance to pyrantel and fenbendazole is present on Swedish stud farms. Ascarid eggs collected from different regions in Sweden were karyotyped and were all identified as Parascaris univalens, characterized by one chromosomal pair. Faecal egg count reduction tests were performed on a total of 142 foals on 9 farms between September 2016 and May 2017. Healthy foals with at least 150 eggs per gram faeces (EPG) were included in the study and treated with oral pastes of pyrantel embonate or fenbendazole according to manufacturer instructions. The efficacy of the drugs was calculated by a Bayesian model using the R package "eggCounts". In accordance with the American Association of Equine Practitioners, parasites were classified as resistant to pyrantel if the reduction in EPG was <= 85% and to fenbendazole if the observed efficacy was <= 90%. Four of eleven groups treated with pyrantel had an observed efficacy of <= 85%, and as many as 43% of the foals treated with pyrantel excreted eggs 10-16 days after treatment. In contrast, one of the six groups treated with fenbendazole had an observed efficacy of s <= 90%, and only 6% of all foals were excreting eggs 10-16 days after treatment. Since resistance to ivermectin has earlier been shown to be widespread in Parascaris spp. in Sweden it is likely that multiresistant populations are present on Swedish stud farms. This is the first study showing the existence of pyrantel-resistant Parascaris spp. in Europe, and the first ever study where anthelmintic resistance has been shown in P. univalens.
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26.
  • Martis, Mihaela-Maria, et al. (author)
  • RNA-Seqde novo assembly and differential transcriptome analysis of the nematode Ascaridia galli in relation to in vivo exposure to flubendazole
  • 2017
  • In: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:11
  • Journal article (peer-reviewed)abstract
    • The nematode Ascaridia galli (order Ascaridida) is an economically important intestinal parasite responsible for increased food consumption, reduced performance and elevated mortality in commercial poultry production. This roundworm is an emerging problem in several European countries on farms with laying hens, as a consequence of the recent European Union (EU) ban on conventional battery cages. As infection is associated with slow development of low levels of acquired protective immunity, parasite control relies on repeated use of dewormers (anthelmintics). Benzimidazoles (BZ) are currently the only anthelmintic registered in the EU for use in controlling A. galli and there is an obvious risk of overuse of one drug class, selecting for resistance. Thus we developed a reference transcriptome of A. galli to investigate the response in gene expression before and after exposure to the BZ drug flubendazole (FLBZ). Transcriptional variations between treated and untreated A. galli showed that transcripts annotated as mitochondrial glutamate dehydrogenase and cytochrome P450 were significantly down-regulated in treated worms, whereas transcripts homologous to heat shock proteins (HSP), catalase, phosphofructokinase, and a multidrug resistance Pglycoprotein (PGP1) were significantly up-regulated in treated worms. Investigation of candidate transcripts responsible for anthelmintic resistance in livestock nematodes led to identification of several tubulins, including six new isoforms of beta-tubulin, and several ligandgated ionotropic receptors and ABC-transporters. We discovered several transcripts associated with drug binding and processing genes, but further characterisation using a larger set of worms exposed to BZs in functional assays is required to determine how these are involved in drug binding and metabolism.
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27.
  • Mochel, J. P., et al. (author)
  • Network on veterinary medicines initiated by the European Federation For Pharmaceutical Sciences
  • 2018
  • In: Journal of Veterinary Pharmacology and Therapeutics. - : WILEY. - 0140-7783 .- 1365-2885. ; 41:3, s. 378-383
  • Journal article (peer-reviewed)abstract
    • The European Federation for Pharmaceutical Sciences (EUFEPS) was founded 25 years ago by more than 20 national pharmaceutical societies and faculty members. As a pan-European organization, it brings together pharmaceutical societies as well as academic, industrial and regulatory scientists engaged in drug research and development, drug regulation and education of professionals working in these fields. EUFEPS represents pharmaceutical sciences in Europe and is recognized as such by both the European Commission and the European Medicines Agency. EUFEPS cooperates with the European Federation of Pharmaceutical Industries and other European organizations and maintains global connections with agencies such as the US Food and Drug Administration and the American Association of Pharmaceutical Scientists. EUFEPS has established specified networks forming the basis of its activities. The creation of a Network on Veterinary Medicines is prompted by the manifold problems resulting from the use of veterinary drugs and its inherent interconnections with human medicine, environmental and public health. A long-term goal of this initiative was to expand the spectrum of available therapeutics for use in animals, including the development of innovative delivery systems.
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28.
  • Tarbiat, Behdad, et al. (author)
  • Comparison between anthelmintic treatment strategies against Ascaridia galli in commercial laying hens
  • 2016
  • In: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 226, s. 109-115
  • Journal article (peer-reviewed)abstract
    • The efficacy of a sustainable deworming strategy based on targeted treatments (TT) against Ascaridia galli was investigated for the first time in laying hen flocks on a Swedish commercial farm. Three experimental protocols with different levels of treatment, e.g. targeted treatment (TT), conventional treatment (CT) and untreated (UT), were tested in randomly allocated flocks of two different bird hybrids. Every second week faecal egg counts (FECs) were determined from pooled faecal materials collected on trays (20 x 27 cm) placed for a maximum of 12 h on the litter belts. In the TT, anthelmintic administration (fenbendazole, 1 mg/kg body weight for 5 days) started at 22 weeks post placement (wpp) and was repeated twice when the pooled FECs surpassed the assigned threshold of 200 egg per gram faeces (EPG). The CT flocks were treated once at 27 wpp using the same anthelmintic. Hens in the UT were not dewormed and served as controls. Additionally, FECs on cloacal contents, worm fecundity and worm burdens were determined at 19, 35 and 45 wpp. None of the flocks became infected until after 16 wpp. The cumulative pooled FECs at the end of the study were significantly (p < 0.01) lower in the TT compared to both CT and UT. Although repeated treatment in the TT protocol did not affect the fecundity, a worm density-dependent increase in fecundity was observed. Cloacal FECs and the number of adult A. galli in TT at 35 and 45 wpp were significantly lower compared to other flocks. This study provides evidence that the TT strategy is better in terms of lower worm burden and decreased cumulative environmental parasite egg numbers compared to CT strategy. The TT strategy should be considered as an alternative to the CT strategy with regard to A. galli control in commercial laying hens. (C) 2016 Elsevier B.V. All rights reserved.
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29.
  • Tarbiat, Behdad, et al. (author)
  • Effect of a targeted treatment strategy against Ascaridia galli on egg production, egg quality and bird health in a laying hen farm
  • 2020
  • In: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 286
  • Journal article (peer-reviewed)abstract
    • Worm control is an important aspect of the successful management of the egg production industry. Of particular concern is Ascaridia galli, which at high parasite loads affect health and production in layers. Application of a targeted treatment strategy (TT) to control A. galli has shown promise. The purpose of this study was to explore the effect of such a strategy on welfare indicators and production performance of layers. Six flocks (F1-6) on a commercial farm were allocated to three treatment groups. Flocks Fl and F4 were treated (TT) with fenbendazole at 22, 27 and 36 weeks post-placement (WPP). Flocks F2 and F5 were treated at 27 WPP (conventional treatment, CT) and hens in flocks F3 and F6 served as untreated (UT) control groups. At 19, 35 and 45 WPP twenty-five hens plus thirty eggs per flock were randomly selected. Hens were weighed and their plumage conditions (PC) were assessed. The eggs were subjected to various external and interior quality analyses. Production data such as number of eggs/hen/week, egg mass and feed conversion ratio (FCR) were calculated from raw data obtained from all flocks on a weekly basis. The number of eggs/hen/week, egg mass and FCR were higher (P < 0.05) in the TT flocks and hens had better PC both at 35 and 45 WPP compared with other flocks. No differences in body weight and physical egg quality were observed between groups except for egg shell strength which was higher (P < 0.05) in the CT flocks. These data suggest that better production performance and plumage, which suggests improved health, can be achieved through the application of a TT strategy. The insights gained from this research should help to justify the extra cost and labor associated with the TT strategy.
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30.
  • Tarbiat, Behdad, et al. (author)
  • Evaluation of benzimidazole resistance status in Ascaridia galli
  • 2017
  • In: Parasitology. - 0031-1820 .- 1469-8161. ; 144, s. 1338-1345
  • Journal article (peer-reviewed)abstract
    • Susceptability of Ascaridia galli to benzimidazole (BZ) was investigated using faecal egg count reduction test (FECRT), in ovo larval development test (LDT) and genetic markers (mutations at codons 167, 198 and 200 of beta-tubulin gene). Six flocks (F1-F6) of a commercial laying hen farm with different number of exposure to BZ were recruited. The FECR was calculated by analyzing individual faeces (F1, F2, F4 and F5) before and 10 days after treatment. The LDT was performed on parasite eggs from pooled samples from F1 to F6 and LC50 and LC99 were calculated. DNA was extracted from 120 worms and sequenced for beta-tubulin gene. In all flocks, the FECRs were above 95% (lower CI above 90%). No significant difference was observed (p > 0.05) among obtained LC50 (F1/F4 and F2/F5 vs F3/F6) in the LDT. However, LC50 and LC99 were higher than suggested values for declaration of resistance in other nematode species. No variation was observed in codon positions involved in BZ resistance. Overall, our results indicated lack of evidence of resistance to BZ in A. galli. More research is needed to confirm these results and to further optimize the existing tools for detection and monitoring of anthelmintic resistance in A. galli.
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31.
  • Tarbiat, Behdad, et al. (author)
  • The efficacy of flubendazole against different developmental stages of the poultry roundworm Ascaridia galli in laying hens
  • 2016
  • In: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 218, s. 66-72
  • Journal article (peer-reviewed)abstract
    • Infection with the poultry roundworm Ascaridia galli has increased in European countries due to the ban on battery cages. This study was conducted in two commercial laying hen flocks (F1 & F2) on different farms in central Sweden. The aims were to (1) investigate the efficacy of flubendazole (FLBZ, 1.43 mg/kg administered in drinking water for 7 days) against adult and larval stages including histotrophic larvae of A. galli, and (2) determine how long it took before the flocks were reinfected after deworming. Accordingly, 180 randomly selected hens were sacrificed before drug administration (bd), on day 3 and 7 during drug administration (dd), and on a weekly basis for up to five weeks post drug administration (pd). Intestinal contents and cloacal materials of each hen plus pooled faecal samples from manure belts were investigated to assess the worm burden and the parasite egg per gram faeces (epg). Additionally, drinking water, and serum and gastrointestinal digesta content samples obtained from ten treated animals were analyzed by HPLC to measure FLBZ and its reduced (R-FLBZ) and hydrolyzed (H-FLBZ) metabolites. No parasite eggs were observed in cloacal samples on day 21 and 28 pd on F1 and on day 21 pd on F2. The epg in manure decreased by 65% and 88% on day 3 dd and by 99% and 97% on day 35 pd on F1 and F2 respectively. Mean FLBZ concentrations quantified in duodenal contents ranged between 0.50 and 0.79 mu g/g. Although, no histotrophic larvae were found dd, they reappeared one week pd (7 +/- 7 F1, 0.5 +/- 0.5 F2). Adult worms were found in both flocks before drug administration (44 +/- 20 F1, 35 +/- 25 F2), on day 3 dd (4 +/- 3 F1, 2 +/- 2 F2), and then not until day 35 (0.2 +/- 0.6) on Fl and day 28 (0.4 +/- 0.9) pd on F2. Thus, the only period in which no A. galli were found was on day 7 dd. Although FLBZ was highly efficient our results indicate that the birds were reinfected already within one week pd. (C) 2016 Elsevier B.V. All rights reserved.
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32.
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33.
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34.
  • Tyden, Eva, et al. (author)
  • Deep amplicon sequencing of preselected isolates of Parascaris equorum in beta-tubulin codons associated with benzimidazole resistance in other nematodes
  • 2014
  • In: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 7, s. 410-
  • Journal article (peer-reviewed)abstract
    • Background: The development of anthelmintic resistance (AR) to macrocyclic lactones in the equine roundworm Parascaris equorum has resulted in benzimidazoles now being the most widely used substance to control Parascaris infections. However, over-reliance on one drug class is a risk factor for the development of AR. Consequently, benzimidazole resistance is widespread in several veterinary parasites, where it is associated with single nucleotide polymorphisms (SNPs) in drug targets encoded by the beta-tubulin genes. The importance of these SNPs varies between different parasitic nematodes, but it has been hypothesised that they occur, at low allele frequencies, even in unselected populations. This study investigated whether these SNPs exist in the P. equorum population and tested the hypothesis that BZ resistance can develop from pre-existing SNPs in codons 167, 198 and 200 of the beta-tubulin isotype 1 and 2 genes, reported to be associated with AR in strongylids. The efficacy of the oral paste formula fenbendazole on 11 farms in Sweden was also assessed. Methods: Two isotype-specific primer pairs were designed, one on either side of the codon 167 and one on either side of codons 198 and 200. A pool of 100 000 larvae was sequenced using deep amplicon sequencing by Illumina HiSeq. Faecal egg count reduction test was used to assess the efficacy of fenbendazole. Results: No SNPs were observed in codons 167, 198 or 200 of the beta-tubulin isotype 1 or 2 genes of P. equorum, even though 100 000 larvae were sequenced. Faecal egg count reduction testing of fenbendazole showed that this anthelmintic was still 100% effective, meaning that the likelihood of finding high allele frequency of SNPs associated with benzimidazoles resistance in P. equorum was low. Unexpectedly, the allele frequencies observed in single worms were comparable to those in pooled samples. Conclusions: We concluded that fenbendazole does not exert selection pressure on the beta-tubulin genes of isotypes 1 and 2 in P. equorum. The fact that no pre-existing SNPs were found in codons 167, 198 and 200 in P. equorum also illustrates the difficulties in generalising about AR mechanisms between different taxonomic groups of nematodes.
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35.
  • Tyden, Eva, et al. (author)
  • Differential expression of beta-tubulin isotypes in different life stages of Parascaris spp after exposure to thiabendazole
  • 2016
  • In: Molecular and Biochemical Parasitology. - : Elsevier BV. - 0166-6851 .- 1872-9428. ; 205, s. 22-28
  • Journal article (peer-reviewed)abstract
    • Anthelmintic resistance (AR) to macrocyclic lactones (ML) has been described in Parascaris of horses world-wide. In contrast, benzimidazoles (BZ) are still effective, although reduced efficacy to this drug class was recently reported. The mode of action of BZ is binding to beta-tubulin, which prevents polymerisation of microtubules. In this study, beta-tubulin gene expression of isotypes 1 and 2 was investigated at seven time points (0, 6, 24, 72, 96 and 120h) during embryogenesis and in adult worms. In addition, an in ovo larval developmental test was developed to study beta-tubulin gene expression of both isotypes in parasacaris eggs after exposure to different concentrations of thiabendazole (TBZ) for five days at 25 degrees C. A strong pattern of differential expression of beta-tubulin and isotype 1 was observed in all stages, while isotype 2 expression was mainly found at an early phase of the embryogenesis. For isotype 1, a 5-fold increase was observed during the first 48 h, but gene expression gradually decreased after 72, 96 and 120 h. Isotype 2 was only expressed during the first 24 h, followed by a 130-fold decrease at (time points) 72, 96 and 120 h. The in ovo larval developmental test, in which we exposed initially unembryonated eggs to increased concentrations of TBZ, did affect isotype I gene expression but not isotype 2. This assumes that each isotype has specific functions in different life stages. This is in agreement with the 'multi-tubulin' hypothesis, which states that different tubulin isotypes are required for specialised microtubule functions. Isotype I is the most likely drug target for BZs, as isotype 2 was only expressed at very low levels later in development. Increasing concentrations of TBZ altered beta-tubulin isotype 1 gene expression after exposure of the eggs for five days, but this was not seen for isotype 2. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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36.
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37.
  • Tyden, Eva, et al. (author)
  • Differential gene expression of CYP3A isoforms in equine liver and intestines
  • 2012
  • In: Journal of Veterinary Pharmacology and Therapeutics. - : Wiley. - 0140-7783 .- 1365-2885. ; 35, s. 588-595
  • Journal article (peer-reviewed)abstract
    • Tyden, E., Lofgren, M., Pegolo, S., Capolongo, F., Tjalve, H., Larsson, P. Differential gene expression of CYP3A isoforms in equine liver and intestines. J. vet. Pharmacol. Therap. 35, 588595. Recently, seven CYP3A isoforms CYP3A89, CYP3A93, CYP3A94, CYP3A95, CYP3A96, CYP3A97 and CYP129 have been isolated from the horse genome. In this study, we have examined the hepatic and intestinal gene expression of these CYP3A isoforms using TaqMan probes. We have also studied the enzyme activity using luciferin-isopropyl acetal (LIPA) as a substrate. The results show a differential gene expression of the CYP3A isoforms in the liver and intestines in horses. In the liver, CYP3A89, CYP3A94, CYP3A96 and CYP3A97 were highly expressed, while in the intestine there were only two dominating isoforms, CYP3A93 and CYP3A96. The isoform CYP3A129 was not detected in the liver or the intestine, although this gene consists of a complete set of exons and should therefore code for a functional protein. It is possible that this gene is expressed in tissues other than the liver and intestines. In the intestine, both CYP3A96 and CYP3A93 showed the highest gene expression in the duodenum and the proximal parts of the jejunum. This correlated with a high protein expression in these tissues. Studies of the enzyme activity showed the same Km for the LIPA substrate in the liver and the intestine, while the maximum velocity (Vmax) in the liver was higher than in the intestine. Our finding of a differential gene expression of the CYP3A isoforms in the liver and the intestines contributes to a better understanding of drug metabolism in horses.
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38.
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39.
  • Tyden, Eva, et al. (author)
  • Expression and localization of BCRP, MRP1 and MRP2 in intestines, liver and kidney in horse
  • 2010
  • In: Journal of Veterinary Pharmacology and Therapeutics. - : Wiley. - 0140-7783 .- 1365-2885. ; 33, s. 332-340
  • Journal article (peer-reviewed)abstract
    • The gene and protein expression and the cellular localization of the ABC transport proteins breast cancer resistance protein (BCRP), multidrug resistance-associated protein 1 (MRP1) and multidrug resistance-associated protein 2 (MRP2) have been examined in the intestines, liver and kidney in horse. High gene and protein expression of BCRP and MRP2 were found in the small intestines, with cellular localization in the apical membranes of the enterocytes. In the liver, MRP2 was present in the bile canalicular membranes of the hepatocytes, whereas BCRP was localized in the cytoplasm of hepatocytes in the peripheral parts of the liver lobuli. In the kidney both BCRP and MRP2 were predominantly present in the distal tubuli and in the loops of Henle. In most tissues, the gene and protein expression of MRP1 were much lower than for BCRP and MRP2. Immunostaining of MRP1 was detectable only in the intestines and with localization in the cytoplasm of enterocytes in the caecum and colon and in the cells of serous acini of Brunner's glands in the duodenum and the upper jejunum. The latter cells were also stained for BCRP, but not for MRP2. Many drugs used in horse are substrates for one or more of the ABC transport proteins. These transporters may therefore have important functions for oral bioavailability, distribution and excretion of substrate compounds in horse.
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40.
  • Tyden, Eva, et al. (author)
  • Gene and protein expression and cellular localisation of cytochrome P450 enzymes of the 1A, 2A, 2C, 2D and 2E subfamilies in equine intestine and liver
  • 2014
  • In: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 56
  • Journal article (peer-reviewed)abstract
    • Among the cytochrome P450 enzymes (CYP), families 1-3 constitute almost half of total CYPs in mammals and play a central role in metabolism of a wide range of pharmaceuticals. This study investigated gene and protein expression and cellular localisation of CYP1A, CYP2A, CYP2C, CYP2D and CYP2E in equine intestine and liver. Real-time polymerase chain reaction (RT-PCR) was used to analyse gene expression, western blot to examine protein expression and immunohistochemical analyses to investigate cellular localisation.Results: CYP1A and CYP2C were the CYPs with the highest gene expression in the intestine and also showed considerable gene expression in the liver. CYP2E and CYP2A showed the highest gene expression in the liver. CYP2E showed moderate intestinal gene expression, whereas that of CYP2A was very low or undetectable. For CYP2D, rather low gene expression levels were found in both intestine and the liver. In the intestine, CYP gene expression levels, except for CYP2E, exhibited patterns resembling those of the proteins, indicating that intestinal protein expression of these CYPs is regulated at the transcriptional level. For CYP2E, the results showed that the intestinal gene expression did not correlate to any visible protein expression, indicating that intestinal protein expression of this CYP is regulated at the post-transcriptional level. Immunostaining of intestine tissue samples showed preferential CYP staining in enterocytes at the tips of intestinal villi in the small intestine. In the liver, all CYPs showed preferential localisation in the centrilobular hepatocytes.Conclusions: Overall, different gene expression profiles were displayed by the CYPs examined in equine intestine and liver. The CYPs present in the intestine may act in concert with those in the liver to affect the oral bioavailability and therapeutic efficiency of substrate drugs. In addition, they may play a role in first-pass metabolism of feed constituents and of herbal supplements used in equine practice.
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41.
  • Tyden, Eva, et al. (author)
  • Gene expression of ABC transporters in Cooperia oncophora after field and laboratory selection with macrocyclic lactones
  • 2014
  • In: Molecular and Biochemical Parasitology. - : Elsevier BV. - 0166-6851 .- 1872-9428. ; 198, s. 66-70
  • Journal article (peer-reviewed)abstract
    • The most widespread helminth parasites of grazing cattle in northern Europe are the gastrointestinal nematodes Ostertagia ostertagi and Cooperia oncophora. Heavy reliance on the use of macrocyclic lactone (ML) in cattle has led to world-wide emergence of resistance to this drug class in C. oncophora. There is evidence that members of the ATP-binding cassette (ABC) transporter family, such as P-glycoproteins (P-gp) and multidrug-resistant proteins (MRP), play a role in resistance to ML In this study gene expression of Con-pgp9, Con-pgp11, Con-pgp12, Con-pgp16 and Con-mrp1 was examined in two isolates of C oncophora sharing the same genetic background but exposed to ML differently. For isolate one (Laboratory-selected), adult worms were recovered before and after treatment with ML in vivo. For isolate two (Field-selected), adult worms were collected from tracer animals that had never received anthelmintics themselves. One group grazed together with untreated animals and one group grazed with animals that received suppressive prophylactic treatment with ML at monthly intervals for up to two consecutive grazing seasons. Real-time PCR data demonstrated differences in gene expression after ML selection, with the highest constitutive expression levels for Con-pgp16 and Con-mrp1. Remarkably, the same pattern of increasing expression levels of the ABC transport genes was observed in both Laboratory- and Field-selected isolates, despite the Field-selected isolate not being directly exposed to ML The higher expression levels of ABC transporters observed in the Field-selected isolate was thus not a response to direct exposure to ML, but rather appeared to reflect a genetic characteristic inherited from worms in the previous generation which had survived exposure to ML in the co-grazing treated animals. (C) 2015 Elsevier B.V. All rights reserved.
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42.
  • Tyden, Eva, et al. (author)
  • Health Risks of Growing Horses Related 6 to Exercise and Parasite Control
  • 2023
  • In: Feeding and Management of Foals and Growing Horses. - 9783031352706 ; , s. 97-123
  • Book chapter (peer-reviewed)abstract
    • In this chapter, health issues related to exercise and parasite control in growing horses are discussed. Concerning problems associated with bone health, the importance of exercise is highlighted, and many of the problems can be avoided by providing a balanced diet and ensuring that the skeletal system is trained properly. Proper nutrition is vital for a healthy skeleton only if the sufficient and right type of exercise is accompanying it. The best opportunity to make the skeleton strong is to provide it with proper stimuli through exercise when a horse is young and growing. Due to their high susceptibility to parasitic disease, anthelmintic treatment in growing horses is advisable without prior diagnostics. For example, any move to a new group, e.g. after weaning, should be performed only after anthelmintic treatment. In foals and young horses, in addition to strategic anthelmintic treatment, management practices aiming to reduce parasite burdens on pastures are especially prudent. Faecal removal twice weekly has been shown to be more effective than anthelmintic treatment. It is advisable to practice faecal removal from any paddocks in use, as long as temperatures are above freezing.
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43.
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44.
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45.
  • Tyden, Eva, et al. (author)
  • P-glycoprotein in intestines, liver, kidney and lymphocytes in horse
  • 2009
  • In: Journal of Veterinary Pharmacology and Therapeutics. - : Wiley. - 0140-7783 .- 1365-2885. ; 32, s. 167-176
  • Journal article (peer-reviewed)abstract
    • P-glycoprotein (P-gp) is an important drug transporter, which is expressed in a variety of cells, such as the intestinal enterocytes, the hepatocytes, the renal tubular cells and the intestinal and peripheral blood lymphocytes. We have studied the localization and the gene and protein expression of P-gp in these cells in horse. In addition we have compared the protein sequence of P-gp in horse with the protein sequences of P-gp in several other species. Real time RT-PCR and Western blot showed gene and protein expression of horse P-gp in all parts of the intestines, but there was no strict correlation between these parameters. Immunohistochemistry showed localization of P-gp in the apical cell membranes of the enterocytes and, in addition, staining was observed in the intestinal intraepithelial and lamina propria lymphocytes. Peripheral blood lymphocytes also stained for P-gp, and gene and protein expression of P-gp were observed in these cells. There was a high gene and protein expression of P-gp in the liver, with P-gp-immunoreactivity in the bile canalicular membranes of the hepatocytes. Gene and protein expression of P-gp were found in the kidney with localization of the protein in different parts of the nephrons. Protein sequence alignment showed that horse P-gp has two amino acid insertions at the N-terminal region of the protein, which are not present in several other species examined. One of these is a 99 amino acid long sequence inserted at amino acid positions 23-121 from the N-terminal. The other is a six amino acid long sequence present at the amino acid positions 140-145 from the N-terminal. The results of the present study indicate that P-gp has an important function for oral bioavailability, distribution and excretion of substrate compounds in horse.
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46.
  • Tyden, Eva, et al. (author)
  • Population genetics of Parascaris equorum based on DNA fingerprinting
  • 2013
  • In: Infection, Genetics and Evolution. - : Elsevier BV. - 1567-1348 .- 1567-7257. ; 13, s. 236-241
  • Journal article (peer-reviewed)abstract
    • The large roundworm of horses, Parascaris equorum is considered ubiquitous in breeding operations, and is regarded as a most important helminth pathogen of foals. Over the past decade, this parasite has been reported increasingly resistant to anthelmintic drugs worldwide. This paper reports analysis of the population genetic structure of P. equorum. Adult parasites (n = 194) collected from Sweden, Norway, Iceland, Germany, Brazil and the USA were investigated by amplified restriction fragment length polymorphism (AFLP) analysis. The genetic variation was low (Hj =0.12-0.4), for the global population of worms. This was accompanied by a weak degree of population structure (Fst = 0.2), low gene flow (Nm = 1.0) and low mutation rate (4 Nm = 0.07). Thus, the low genetic diversity is probably a result of a low mutation rate in DNA, although the gene flow (due to global movement of horses) is large enough to allow the spread of novel mutations. Surprisingly, isolates from Icelandic horses were not found to be different from other isolates, in spite of the fact that these have been isolated for thousands of years. The study indicates that the global P. equorum population is essentially homogenous, and continents do not appear to be strong barriers for the population structure of this species. Consequently, the potential spread of rare anthelmintic resistance genes may be rapid in a homogenous population.
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47.
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48.
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49.
  • Tyden, Eva, et al. (author)
  • Sequencing of the beta-tubulin genes in the ascarid nematodes Parascaris equorum and Ascaridia galli
  • 2013
  • In: Molecular and Biochemical Parasitology. - : Elsevier BV. - 0166-6851 .- 1872-9428. ; 190, s. 38-43
  • Journal article (peer-reviewed)abstract
    • Benzimidazoles (BZ) are used to control infections of the equine roundworm Parascaris equorum and the poultry roundworm Ascaridia gall. There are still no reports of anthelmintic resistance (AR) to BZ in these two nematodes, although AR to BZ is widespread in several other veterinary parasites. Several single nucleotide polymorphisms (SNP) in the beta-tubulin genes have been associated with BZ-resistance. In the present study we have sequenced beta-tubulin genes: isotype 1 and isotype 2 of P. equorum and isotype 1 of A. galli. Phylogenetic analysis of all currently known isotypes showed that the Nematoda has more diversity among the beta-tubulin genes than the Vertebrata. In addition, this diversity is arranged in a more complex pattern of isotypes. Phylogenetically, the A. galli sequence and one of the P. equorum sequences clustered with the known Ascaridoidea isotype 1 sequences, while the other P. equorum sequence did not cluster with any other beta-tubulin sequences. We therefore conclude that this is a previously unreported isotype 2. The beta-tubulin gene sequences were used to develop a PCR for genotyping SNP in codons 167, 198 and 200. No SNP was observed despite sequencing 95 and 100 individual adult worms of P. equorum and A. galli, respectively. Given the diversity of isotype patterns among nematodes, it is likely that associations of genetic data with BZ-resistance cannot be generalised from one taxonomic group to another. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.
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50.
  • Tyden, Eva, et al. (author)
  • The genes of all seven CYP3A isoenzymes identified in the equine genome are expressed in the airways of horses
  • 2013
  • In: Journal of Veterinary Pharmacology and Therapeutics. - : Wiley. - 0140-7783 .- 1365-2885. ; 36, s. 370-375
  • Journal article (peer-reviewed)abstract
    • In the present study, we examined the gene expression of cytochrome P450 3A (CYP3A) isoenzymes in the tracheal and bronchial mucosa and in the lung of equines using TaqMan probes. The results show that all seven CYP3A isoforms identified in the equine genome, that is, CYP3A89, CYP3A93, CYP3A94, CYP3A95, CYP3A96, CYP3A97 and CYP3A129, are expressed in the airways of the investigated horses. Though in previous studies, CYP3A129 was found to be absent in equine intestinal mucosa and liver, this CYP3A isoform is expressed in the airways of horses. The gene expression of the CYP3A isoenzymes varied considerably between the individual horses studied. However, in most of the horses CYP3A89, CYP3A93, CYP3A96, CYP3A97 and CYP3A129 were expressed to a high extent, while CYP3A94 and CYP3A95 were expressed to a low extent in the different parts of the airways. The CYP3A isoenzymes present in the airways may play a role in the metabolic degradation of inhaled xenobiotics. In some instances, the metabolism may, however, result in bioactivation of the xenobiotics and subsequent tissue injury.
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