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Application of FTA® Cards for detection and storage of avian influenza virus
2016
Jóźwiak, Michał | Wyrostek, Krzysztof | Domańska-Blicharz, Katarzyna | Olszewska-Tomczyk, Monika | Śmietanka, Krzysztof | Minta, Zenon
Introduction: The aim of the study was to test the utility of Flinders Technology Associates filter paper (FTA® Cards) for molecular detection and storage of avian influenza virus (AIV). Material and Methods: There were two strains of AIV used in the study: low pathogenicity H7N1 and high pathogenicity H5N1 subtypes. Detection of viral material was conducted using molecular RT-PCR and rRT- PCR method. Results: The infectivity of LPAIV/H7N1 and HPAIV/H5N1 was completely inactivated within 1 h and 24 h after adsorption to FTA® Cards at room temperature, respectively. Viruses stored on FTA® Cards had detection limit approximately 1 log₁₀ lower than live viruses. Viral RNA of both strains were detectable on the cards by rRT-PCR for a minimum of 150 d, irrespectively of storage temperatures (room temperature, -20ºC). RNA was also detected in all samples obtained from SPF chickens experimentally infected with HPAI/H5N1 on 3ʳᵈ and 4ᵗʰ day post-infection (p.i.). Conclusion: FTA® Cards enable safe and effective alternative transport of samples for molecular diagnosis of AIV.
Show more [+] Less [-]Development and application of a TaqMan-MGB real-time RT-PCR assay for the detection of porcine epidemic diarrhoea virus strains in China
2016
Hou, Yi-Xuan | Xie, Chun | Wang, Kang | Zhao, Yu-Ting | Xie, Yang-Yang | Shi, Hong-Yan | Chen, Jian-Fei | Feng, Li | Tong, Guang-Zhi | Hua, Xiu-Guo | Yuan, Cong-Li | Zhou, Yan-Jun | Yang, Zhi-Biao
Introduction: A real-time RT-PCR method for identification and quantification of porcine epidemic diarrhoea virus (PEDV) strains in China was developed.Material and Methods: Based on the conserved sequence of the PEDV nucleocapsid (N) gene, a primer pair and probe were designed to establish a TaqMan-MGB real-time RT-PCR assay for quantitative detection of the virus. The sequence was cloned into the pMD18-T vector and a series of diluted recombinant plasmids were used to generate a standard curve with an R2 value of 0.999.Results: The developed quantitative PCR assay detected viral titres as low as 0.1 TCID₅₀ with high specificity and no cross-reaction with other porcine viruses (PoRV, TGEV, PRRSV, or CSFV). The intra-batch and inter-batch coefficients of variation were both less than 1%, which indicated good reproducibility. Thirty clinical diarrhoea samples obtained from pigs in Shanghai and Fujian were analysed using this quantitative PCR assay. Out of these samples, 93.3% were found to be PEDV positive.Conclusion: This approach is suitable for clinical sample identification and pathogenesis studies.
Show more [+] Less [-]Investigation of human papillomaviruses (HPV), mouse mammary tumour virus (MMTV), Epstein–Barr virus (EBV), and human polyomavirus entities in canine mammary tumours
2016
Sonmez, Kivilcim | Altan, Eda | Yildirim, Funda | Arun, Seçkin Serdar | Turan, Nuri | Yılmaz, Hüseyin | Kuskucu, Mert Ahmet
Introduction: The aim of the study was to investigate the presence of human papillomaviruses (HPV), mouse mammary tumour virus (MMTV), Epstein-Barr virus (EBV), and human polyomavirus BK in canine mammary tumours (CMTs) and to correlate the results of histopathological classification with the results of virological examination. Material and Methods: Eighty CMTs and ten normal canine mammary gland samples were evaluated using histopathological methods and TaqMan real-time PCR analysis. Results: The results indicated that all mammary tumours and normal mammary tissue samples were negative for HPV16 and other HPV, EBV, human polyomavirus, and human mammary tumour virus strains. Conclusion: Further studies should be performed to investigate the existence of other strains of HPV, EBV, and human polyomavirus in CMTs.
Show more [+] Less [-]Selected aspects related to epidemiology, pathogenesis, immunity, and control of African swine fever
2016
Woźniakowski, Grzegorz | Frączyk, Magdalena | Niemczuk, Krzysztof | Pejsak, Zygmunt
African swine fever (ASF) is currently one of the most severe viral infections of domestic pigs, wild boars, and other hosts belonging to Suidae family. ASF is also considered as the most complex and devastating infectious and haemorrhagic disease of swine due to its severe socio-economic impact and transboundary character. ASF it is a notifiable disease and due to the lack of specific treatment and vaccine, the disease can be only limited by the administrative measures comprising wild boar hunting and stamping out of affected pigs. ASF occurred for the first time in Kenya in 1921 while in Europe (Portugal) the virus was detected at the end of the 1950s. In spite of successful eradication of this threat in a number of affected regions, the virus remains endemic in both feral and domestic pigs in Africa and Sardinia. The ‘new era’ of ASF started in 2007 after its re-introduction to Georgia. Following its intensive expansion, the virus spread to other Caucasian countries, including the territory of the Russian Federation. In 2014 the virus reached Ukraine, Belarus, and, consequently, European Union countries: Lithuania, Latvia, Estonia, and Poland. The occurrence of ASF in wild boars and pigs had a severe impact on both epidemiology and economy because of the national and international transport and trade consequences. Up to date, starting from the February 2014, eighty ASF cases in wild boar and three outbreaks in domestic pigs have been diagnosed. Taking into account the diverse rate of spread in Poland, this review aims to present and discuss the current state of knowledge on ASF including its epidemiology, pathology, transmission, and perspectives of control.
Show more [+] Less [-]Viral shedders in a herd vaccinated against infection with bovine viral diarrhoea virus (BVDV) without prior testing for the presence of persistently infected animals
2016
Polak, Mirosław P. | Antos, Aleksandra | Rola, Jerzy | Żmudziński, Jan F.
Introduction: Bovine viral diarrhoea (BVD), caused by the bovine viral diarrhoea virus (BVDV), is one of the most important diseases of cattle worldwide. The purpose of the study was to determine the BVDV infection status in a dairy herd vaccinated against BVD. Before vaccination started in 2008, there had been no prior identification or the removal of the possible source of infection (persistently infected animals). It was expected that vaccination itself would enable the elimination of viral shedders on a long term basis. Material and Methods: Serological screening for antibodies against BVDV with determination for antibodies titres, BVDV antigen, and the presence of the viral genome with phylogenetic analysis of positive samples in the herd were performed, despite the lack of any clinical problems indicating possible presence of BVDV infection. Results: 19 individuals persistently infected with BVDV were identified among calves and heifers but not in adult cattle. All virus shedders were antibody negative and the genotype of isolated virus was BVDV-1b, indicating a single source of infection. The vaccine used in the herd was composed of BVDV-1a strain. In each of the tested cowsheds, antibody titres against BVDV-1b were higher than against BVDV-1a (median values). Conclusion: Despite a long-lasting vaccination programme and relatively high sequence homology of vaccinal and field strains of BVDV (83.6%), it was not possible to avoid transplacental infections of foetuses and the birth of persistently infected calves from vaccinated heifers although the protection against clinical disease was accomplished.
Show more [+] Less [-]Efficacy of Fostera PRRS modified live virus vaccine against a Canadian heterologous virulent field strain of porcine reproductive and respiratory syndrome virus
2016
Savard, Christian | Alvarez, Fernando | Provost, Chantale | Chorfi, Younes | D'Allaire, Sylvie | Benoit-Biancamano, Maria-Odile | Gagnon, Carl A.
Vaccination is a useful option to control infection with porcine reproductive and respiratory syndrome virus (PRRSV), and several modified live-PRRSV vaccines have been developed. These vaccines have shown some efficacy in reducing the incidence and severity of clinical disease as well as the duration of viremia and virus shedding but have failed to provide sterilizing immunity. The efficacy of modified live-virus (MLV) vaccines is greater against a homologous strain compared with heterologous PRRSV strains. The objective of this study was to evaluate the efficacy of Fostera PRRS MLV vaccine in protecting against challenge with a heterologous field strain widely circulating in the swine herds of eastern Canada. Forty-six piglets were divided into 4 groups: nonvaccinated-nonchallenged; nonvaccinated-challenged; vaccinated-challenged; and vaccinated-nonchallenged. The animals were vaccinated at 23 d of age with Fostera PRRS and challenged 23 d later with a heterologous field strain of PRRSV (FMV12-1425619). Overall, the vaccine showed some beneficial effects in the challenged animals by reducing the severity of clinical signs and the viral load. A significant difference between nonvaccinated and vaccinated animals was detected for some parameters starting 11 to 13 d after challenge, which suggested that the cell-mediated immune response or other delayed responses could be more important than pre-existing PRRSV antibodies in vaccinated animals within the context of protection against heterologous strains.
Show more [+] Less [-]Safety and efficacy of a novel European vaccine for porcine reproductive and respiratory virus in bred gilts
2016
Piontkowski, Michael D. | Kroll, Jeremy | Orveillon, Francois-Xavier | Kraft, Christian | Coll, Teresa
Porcine reproductive and respiratory syndrome virus (PRRSV) can be devastating to commercial breeding operations. The objective of this study was to evaluate a novel European PRRSV vaccinal strain for safety and efficacy in bred gilts. In 2 experiments, 110 gilts were vaccinated intramuscularly and the vaccine was evaluated for safety and efficacy. Gilts in Experiment 1 were evaluated for local and systemic reactions and gilts in both experiments were observed for clinical signs of disease through farrow. In both experiments, piglet clinical observations, piglet average daily weight gain (ADWG), gilt serology [determined by enzyme-linked immunosorbent assay (ELISA)], gilt and piglet viremia [determined by quantitative real-time polymerase chain reaction (qPCR)], as well as piglet lung lesion scores and PRRS virus in lung tissue (qPCR) were determined. The vaccine was shown to be safe as there were no significant differences among groups in either experiment. Efficacy was established in Experiment 2 as both vaccinated groups were associated with desirable significant differences in percentage of gilts with abnormal clinical findings; gilt viral load post-challenge [day 125, day of farrowing (DOF), and DOF + 13]; percentages of alive, healthy live, weak live, and mummified piglets per litter at farrowing and weaning; percentage of piglets per gilt that were positive for viremia; percentage of piglets per gilt with clinical disease; and piglet viral load on DOF. It was concluded that a vaccine formulated from the PRRSV modified live virus (MLV) strain 94881 is a safe and effective method of protection against the detrimental effects of virulent PRRSV infection in breeding female pigs.
Show more [+] Less [-]Detection and phylogenetic analysis of bovine papillomavirus in cutaneous warts in cattle in Tamaulipas, Mexico
2016
Rojas-Anaya, Edith | Cantu-Covarrubias, Antonio | Álvarez, José Francisco Morales | Loza-Rubio, Elizabeth
Papillomas occur more frequently in cattle than other domestic animals. The causal agent of bovine papillomatosis is a virus that belongs to the family Papillomaviridae. In Tamaulipas, Mexico, the virus is considered a serious problem and has impeded the export of cattle to the United States, resulting in serious economic losses. Owing to the lack of information regarding the subtypes of papillomaviruses that infect cattle in Mexico, the aim of this study was to determine the subtypes in Tamaulipas. Fifty-two warts were analyzed with the use of polymerase chain reaction (PCR) involving primers that amplify the E7 gene of bovine papillomavirus (BPV). The PCR products were sequenced to differentiate the BPV-1 and BPV-2 subtypes. The sequencing quality was determined with the use of MEGA 6.0 software. Comparison of the Tamaulipas sequences with those of known BPV types by means of the MUSCLE algorithm showed that 53% of the former were BPV-1 and 47% were BPV-2. The distribution of the 2 subtypes in the cattle was homogeneous. This study demonstrated the presence of BPV-1 and BPV-2 in cattle from Tamaulipas and constitutes the first molecular characterization of papillomas in Mexico.
Show more [+] Less [-]In vitro evaluation of mitochondrial dysfunction and treatment with adeno-associated virus vector in fibroblasts from Doberman Pinschers with dilated cardiomyopathy and a pyruvate dehydrogenase kinase 4 mutation
2016
Sosa, Ivan | Estrada, Amara H. | Winter, Brandy D. | Erger, Kirsten E. | Conlon, Thomas J.
OBJECTIVE To compare mitochondrial oxygen consumption rate (OCR) of fibroblasts from Doberman Pinschers with and without dilated cardiomyopathy (DCM) and mutation of the gene for pyruvate dehydrogenase kinase isozyme 4 (PDK4) and to evaluate in vitro whether treatment with adeno-associated virus (AAV) vector (ie, gene therapy) would alter metabolic efficiency. ANIMALS 10 Doberman Pinschers screened for DCM and PDK4 mutation. PROCEDURES Fibroblasts were harvested from skin biopsy specimens obtained from Doberman Pinschers, and dogs were classified as without DCM or PDK4 mutation (n = 3) or with occult DCM and heterozygous (4) or homozygous (3) for PDK4 mutation. Fibroblasts were or were not treated with tyrosine mutant AAV type 2 vector containing PDK4 at multiplicities of infection of 1,000. Mitochondrial OCR was measured to evaluate mitochondrial metabolism. The OCR was compared among dog groups and between untreated and treated fibroblasts within groups. RESULTS Mean ± SD basal OCR of fibroblasts from heterozygous (74 ± 8 pmol of O2/min) and homozygous (58 ± 12 pmol of O2/min) dogs was significantly lower than that for dogs without PDK4 mutation (115 ± 9 pmol of O2/min). After AAV transduction, OCR did not increase significantly in any group (mutation-free group, 121 ± 26 pmol of O2/min; heterozygous group, 88 ± 6 pmol of O2/min; homozygous group, 59 ± 3 pmol of O2/min). CONCLUSIONS AND CLINICAL RELEVANCE Mitochondrial function was altered in skin fibroblasts of Doberman Pinschers with DCM and PDK4 mutation. Change in mitochondrial function after in vitro gene therapy at the multiplicities of infection used in this study was not significant.
Show more [+] Less [-]Farm-level prevalence and risk factors for detection of hepatitis E virus, porcine enteric calicivirus, and rotavirus in Canadian finisher pigs
2016
Wilhelm, Barbara | Leblanc, Danielle | Leger, David | Gow, Sheryl | Deckert, Anne | Pearl, David L. | Friendship, Robert | Raji, Andrijana | Houde, Alian | McEwen, Scott
Hepatitis E virus (HEV), norovirus (NoV), and rotavirus (RV) are all hypothesized to infect humans zoonotically via exposure through swine and pork. Our study objectives were to estimate Canadian farm-level prevalence of HEV, NoV [specifically porcine enteric calicivirus (PEC)], and RV in finisher pigs, and to study risk factors for farm level viral detection. Farms were recruited using the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) and FoodNet Canada on-farm sampling platforms. Six pooled groups of fecal samples were collected from participating farms, and a questionnaire capturing farm management and biosecurity practices was completed. Samples were assayed using validated real-time polymerase chain reaction (RT-PCR). We modeled predictors for farm level viral RNA detection using logistic and exact logistic regression. Seventy-two herds were sampled: 51 CIPARS herds (15 sampled twice) and 21 FoodNet Canada herds (one sampled twice). Hepatitis E virus was detected in 30/88 farms [34.1% (95% CI 25.0%, 44.5%)]; PEC in 18 [20.5% (95% CI: 13.4%, 30.0%)], and RV in 6 farms [6.8% (95% CI: 3.2%, 14.1%)]. Farm-level prevalence of viruses varied with province and sampling platform. Requiring shower-in and providing boots for visitors were significant predictors (P < 0.05) in single fixed effect mixed logistic regression analysis for detection of HEV and PEC, respectively. In contrast, all RV positive farms provided boots and coveralls, and 5 of 6 farms required shower-in. We hypothesized that these biosecurity measures delayed the mean age of RV infection, resulting in an association with RV detection in finishers. Obtaining feeder pigs from multiple sources was consistently associated with greater odds of detecting each virus.
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