Veterinary Biosciences - Research Publications
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ItemNo Preview AvailableBayesian Validation of the Indirect Immunofluorescence Assay and Its Superiority to the Enzyme-Linked Immunosorbent Assay and the Complement Fixation Test for Detecting Antibodies against Coxiella burnetii in Goat Serum(AMER SOC MICROBIOLOGY, 2016-06)Although many studies have reported the indirect immunofluorescence assay (IFA) to be more sensitive in detection of antibodies to Coxiella burnetii than the complement fixation test (CFT), the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of the assay have not been previously established for use in ruminants. This study aimed to validate the IFA by describing the optimization, selection of cutoff titers, repeatability, and reliability as well as the DSe and DSp of the assay. Bayesian latent class analysis was used to estimate diagnostic specifications in comparison with the CFT and the enzyme-linked immunosorbent assay (ELISA). The optimal cutoff dilution for screening for IgG and IgM antibodies in goat serum using the IFA was estimated to be 1:160. The IFA had good repeatability (>96.9% for IgG, >78.0% for IgM), and there was almost perfect agreement (Cohen's kappa > 0.80 for IgG) between the readings reported by two technicians for samples tested for IgG antibodies. The IFA had a higher DSe (94.8%; 95% confidence interval [CI], 80.3, 99.6) for the detection of IgG antibodies against C. burnetii than the ELISA (70.1%; 95% CI, 52.7, 91.0) and the CFT (29.8%; 95% CI, 17.0, 44.8). All three tests were highly specific for goat IgG antibodies. The IFA also had a higher DSe (88.8%; 95% CI, 58.2, 99.5) for detection of IgM antibodies than the ELISA (71.7%; 95% CI, 46.3, 92.8). These results underscore the better suitability of the IFA than of the CFT and ELISA for detection of IgG and IgM antibodies in goat serum and possibly in serum from other ruminants.
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ItemEquine rhinitis A virus infection and cytokine expression in primary tracheobronchial epithelial cell culture(Elsevier BV, 2016-04)Primary bronchial cells and ex-vivo explants are commonly used as a model for respiratory viral infections and lung diseases in humans. Similarly, these systems can be used to mimic and study respiratory conditions in the horse. Therefore, equine tracheobronchial epithelial cells (TBEC) could be used to investigate viral respiratory infections and their immune/inflammatory responses in this species. The aims of the present study were to investigate the cytopathic characteristics of equine rhinitis A virus (ERAV) in primary TBECs and the gene expression of IFN-gamma, IFN-Beta, IL-4, and IL-8. TBECs were obtained from the lower trachea, carina and primary bronchi of five euthanized horses. After dissection, the tracheal mucosa was removed, washed and kept overnight on pronase. Twelve to eighteen hours later, the airway mucosa was scraped and cells were mechanically separated. TBECs were then washed, plated on collagen coated flasks/plates using modified DMEM F12 cell culture medium and allowed to propagate to confluency. In order to investigate the cytopathic characteristics, confluent TBEC monolayers were exposed to ERAV and observed daily for 5 consecutive days. Additionally, to investigate cytokine expression by qPCR, TBEC monolayers were exposed to either ERAV or equine influenza virus (EIV) and supernatant samples were collected at 0, 2, 4, 6, 8, 10, 12, 16, 20 and 24 hours post-infection. EIV was used as a comparison for cytokine expression. Interestingly, in this study ERAV infected TBECs developed syncytial cell formations and/or cell clumping commonly observed during other in-vitro viral infections, such as syncytial or herpesviruses. Contrary to our expectations, significant changes in the expression of interferons and IL-4 were not detectable by qPCR after exposure of TBECs to ERAV or EIV within 24 hours. However, up-regulation of IL-8 after exposure to these two viruses was identified from 2 up to 24 hours post-infection in a similar magnitude. IL-8 is consistently detected in respiratory secretions during viral infections in humans and has been shown to induce chemotaxis and phagocytosis of inflammatory cells in the airways. Therefore, changes in the expression of IL-8 indicate that this chemokine might play an important role during early infections, perhaps as a chemotactic factor and/or phagocytic inductor.
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ItemSynthesis, Characterization, and Biological Activity of Ferrocenyl Analogues of the Anthelmintic Drug Monepantel(AMER CHEMICAL SOC, 2016-10-10)There is major demand for the development of structurally new anti-infectives using innovative approaches to circumvent multidrug resistance in parasites. Herein, we describe the synthesis and characterization of ferrocenyl precursors and derivatives (2-8) of an anthelmintic drug, monepantel. All compounds were isolated as their racemates and characterized by 1H, 13C, and 19F NMR spectroscopy, mass spectrometry, and IR spectroscopy. The purity of individual compounds was confirmed by elemental microanalysis. The molecular structures of three of the organometallic compounds (5-7) were also established by X-ray crystallography. The biological activities of these compounds were then evaluated in vitro on various important eukaryotic parasites, including H. contortus, T. colubriformis, and D. immitis. The potencies against D. immitis (canine heartworm) of two compounds, a ferrocene-containing precursor (4) and the final ferrocene-based monepantel derivative (8), were shown to be moderate (EC50 = 3.70 μg/mL for 4 and 5.60 μg/mL for 8) and were comparable with those of the controls AAD85 (EC50 = 2.20 μg/mL) and a commercial drug, ivermectin (EC50 = 1.00-3.00 μg/mL). The assessment of the cytotoxicity using cancerous HeLa and noncancerous MRC-5 cell lines revealed that these compounds have moderate to low toxicities in mammalian cells, thereby showing selective activity on parasites.
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ItemCan New Digital Technologies Support Parasitolocy Teaching and Learning?(ELSEVIER SCI LTD, 2016-07)Traditionally, parasitology courses have mostly been taught face-to-face on campus, but now digital technologies offer opportunities for teaching and learning. Here, we give a perspective on how new technologies might be used through student-centred teaching approaches. First, a snapshot of recent trends in the higher education is provided; then, a brief account is given of how digital technologies [e.g., massive open online courses (MOOCs), flipped classroom (FC), games, quizzes, dedicated Facebook, and digital badges] might promote parasitology teaching and learning in digital learning environments. In our opinion, some of these digital technologies might be useful for competency-based, self-regulated, learner-centred teaching and learning in an online or blended teaching environment.
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ItemGenetic characterisation of Taenia multiceps cysts from ruminants in Greece(ELSEVIER, 2016-03)This study was designed to genetically characterise the larval stage (coenurus) of Taenia multiceps from ruminants in Greece, utilising DNA regions within the cytochrome c oxidase subunit 1 (partial cox1) and NADH dehydrogenase 1 (pnad1) mitochondrial (mt) genes, respectively. A molecular-phylogenetic approach was used to analyse the pcox1 and pnad1 amplicons derived from genomic DNA samples from individual cysts (n=105) from cattle (n=3), goats (n=5) and sheep (n=97). Results revealed five and six distinct electrophoretic profiles for pcox1 and pnad1, respectively, using single-strand conformation polymorphism. Direct sequencing of selected amplicons representing each of these profiles defined five haplotypes each for pcox1 and pnad1, among all 105 isolates. Phylogenetic analysis of individual sequence data for each locus, including a range of well-defined reference sequences, inferred that all isolates of T. multiceps cysts from ruminants in Greece clustered with previously published sequences from different continents. The present study provides a foundation for future large-scale studies on the epidemiology of T. multiceps in ruminants as well as dogs in Greece.
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ItemDiagnosis of human taeniasis(CSIRO PUBLISHING, 2016-03)Taenia solium, T. saginata and T. asiatica are taeniid tapeworms that cause taeniasis in humans and cysticercosis in intermediate host animals. T. solium can also cause cysticercosis in humans. A number of diagnostic methods have been developed to diagnose Taenia species that infect humans. This article is aimed at providing an overview of currently available diagnostic methods for human taeniasis.
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ItemNo Preview AvailableMolecular epidemiology of an outbreak of clinical mastitis in sheep caused by Mannheimia haemolytica(ELSEVIER SCIENCE BV, 2016-08-15)The aetiology and epidemiology of outbreaks of clinical mastitis in sheep under extensive pastoral conditions are incompletely understood. The objective of this study was to conduct a detailed investigation of a clinical mastitis outbreak that affected more than 10% of 230 at-risk ewes on a sheep and grain producing property in south east Australia during drought conditions in 2009. Milk samples were collected aseptically from all affected ewes and plated on sheep blood agar for bacterial identification. M. haemolytica was isolated from 80% of the samples that yielded cultivable microorganisms and thus was the main microorganism responsible for the outbreak. Analysis of the restriction endonuclease cleavage patterns of the isolates using pulsed field gel electrophoresis revealed some evidence of clonality, suggesting the possibility of horizontal transmission, but there was also considerable diversity between the clusters of closely related isolates. Multilocus sequence typing of the M. haemolytica isolates revealed most of the isolates belonged to ST1 with no association between the PFGE and MLST fingerprints of the isolates. Resistance to neomycin, streptomycin and sulphafurazole was detected in some of the isolates, but they were all susceptible to penicillin, ampicillin, ceftiofur, amoxycillin/clavulanic acid, ciprofloxacin, tetracycline, erythromycin and trimethoprim. This is the first published record of a comparison of the strains of M. haemolytica involved in a clinical mastitis outbreak in sheep and demonstrates the importance of this pathogen in sheep production systems, particularly during adverse climatic conditions and increased stocking rate.
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ItemEarly Decision Indicators for Foot-and-Mouth Disease Outbreaks in Non-Endemic Countries(Frontiers Media, 2016)This Research Topic presents valuable studies presenting different aspects and implementations of mathematical modeling for disease spread and control in the veterinary field.
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ItemThe antiepileptic medications carbamazepine and phenytoin inhibit native sodium currents in murine osteoblasts(WILEY, 2016-09)OBJECTIVE: Fracture risk is a serious comorbidity in epilepsy and may relate to the use of antiepileptic drugs (AEDs). Many AEDs inhibit ion channel function, and the expression of these channels in osteoblasts raises the question of whether altered bone signaling increases bone fragility. We aimed to confirm the expression of voltage-gated sodium (NaV ) channels in mouse osteoblasts, and to investigate the action of carbamazepine and phenytoin on NaV channels. METHODS: Immunocytochemistry was performed on primary calvarial osteoblasts extracted from neonatal C57BL/6J mice and additional RNA sequencing (RNASeq) was included to confirm expression of NaV . Whole-cell patch-clamp recordings were made to identify the native currents expressed and to assess the actions of carbamazepine (50 μm) or phenytoin (50 μm). RESULTS: NaV expression was demonstrated with immunocytochemistry, RNA sequencing, and functionally, with demonstration of robust tetrodotoxin-sensitive and voltage-activated inward currents. Application of carbamazepine or phenytoin resulted in significant inhibition of current amplitude for carbamazepine (31.6 ± 5.9%, n = 9; p < 0.001), and for phenytoin (35.5 ± 6.9%, n = 7; p < 0.001). SIGNIFICANCE: Mouse osteoblasts express NaV , and native NaV currents are blocked by carbamazepine and phenytoin, supporting our hypothesis that AEDs can directly influence osteoblast function and potentially affect bone strength.