Affiner votre recherche
Résultats 291-300 de 815
The main DNA viruses significantly affecting pig livestock Texte intégral
2020
Swine DNA viruses have developed unique mechanisms for evasion of the host immune system, infection and DNA replication, and finally, construction and release of new viral particles. This article reviews four classes of DNA viruses affecting swine: porcine circoviruses, African swine fever virus, porcine parvoviruses, and pseudorabies virus. Porcine circoviruses belonging to the Circoviridae family are small single-stranded DNA viruses causing different diseases in swine including poly-weaning multisystemic wasting syndrome, porcine dermatitis and nephropathy syndrome, and porcine respiratory disease complex. African swine fever virus, the only member of the Asfivirus genus in the Asfarviridae family, is a large double-stranded DNA virus and for its propensity to cause high mortality, it is currently considered the most dangerous virus in the pig industry. Porcine parvoviruses are small single-stranded DNA viruses belonging to the Parvoviridae family that cause reproductive failure in pregnant gilts. Pseudorabies virus, or suid herpesvirus 1, is a large double-stranded DNA virus belonging to the Herpesviridae family and Alphaherpesvirinae subfamily. Recent findings including general as well as genetic classification, virus structure, clinical syndromes and the host immune system responses and vaccine protection are described for all four swine DNA virus classes.
Afficher plus [+] Moins [-]Detection of myxoma virus in the classical form of myxomatosis using an AGID assay: statistical assessment of the assay’s diagnostic performance Texte intégral
2020
Kwit, Ewa | Osiński, Zbigniew | Lavazza, Antonio | Rzeżutka, Artur
The aim of the study was to estimate the diagnostic sensitivity (DSe) and specificity (DSp) of an agar gel immunodiffusion (AGID) assay for detection of myxoma virus (MYXV) in the classical form of myxomatosis and to compare its diagnostic performance to that of molecular methods (IAC-PCR, OIE PCR, and OIE real-time PCR). A panel of MYXV-positive samples of tissue homogenates with low (1 PCR unit – PCRU) and high (3,125 PCRU) virus levels and outbreak samples were used for method comparison studies. The validation parameters of the AGID assay were assessed using statistical methods. The AGID attained DSe of 0.65 (CI₉₅%: 0.53–0.76), DSp of 1.00 (CI₉₅%: 0.40–1.00), and accuracy of 0.67 (CI₉₅%: 0.55–0.76). The assay confirmed its diagnostic usefulness primarily for testing samples containing ≥3,125 PCRU of MYXV DNA. However, in the assaying of samples containing <3,125 PCRU of the virus there was a higher probability of getting false negative results, and only molecular methods showed a 100% sensitivity for samples with low (1 PCRU) virus concentration. The overall concordance of the results between AGID and IAC-PCR was fair (ĸ = 0.40). Full concordance of the results was observed for OIE PCR and OIE real-time PCR when control reference material was analysed. Findings from this study suggest that AGID can be used with some limitations as a screening tool for detection of MYXV infections.
Afficher plus [+] Moins [-]Characterisation of classical enterotoxins, virulence activity, and antibiotic susceptibility of Staphylococcus aureus isolated from Thai fermented pork sausages, clinical samples, and healthy carriers in northeastern Thailand Texte intégral
2020
Sankomkai, Wanwisa | Boonyanugomol, Wongwarut | Kraisriwattana, Kairin | Nutchanon, Julalak | Boonsam, Kraisorn | Kaewbutra, Sasalux | Wongboot, Warawan
Contamination by Staphylococcus aureus of food produced from animal sources may have diverse and multifactorial causes that depend on geographical distribution. The goal of this study was to isolate and characterise S. aureus strains from contaminated fermented pork sausage, which is a local food of northeastern Thailand. S. aureus strains were isolated from local pork sausage, and the presence of classical enterotoxins was determined by PCR and reversed passive latex agglutination. These results were compared with strains derived from hospitalised patients and healthy carriers. Additionally, production of extracellular enzymes and haemolysin, biofilm formation, and antibiotic susceptibility were assessed. S. aureus was identified in 36 sausage isolates (60%). The strains positive for staphylococcal enterotoxin A were more frequently found in isolates from sausage and healthy carriers than in those from patients. All tested S. aureus strains were positive for DNase, lipase, proteinase, haemolysin, and biofilm formation; notably, strains isolated from food and healthy carriers displayed similar values. Most isolates were resistant to penicillin and ampicillin, while none were to methicillin. Thai fermented pork sausages are associated with a high risk of staphylococcal food poisoning, which may be linked to contamination caused by carriers. Dissemination of knowledge regarding best practices in sanitation and hygiene is important in local communities.
Afficher plus [+] Moins [-]Non-antibiotic possibilities in prevention and treatment of calf diarrhoea Texte intégral
2020
Smulski, Sebastian | Turlewicz-Podbielska, Hanna | Wylandowska, Agata | Włodarek, Jan
Due to increasing bacterial antibiotic resistance and the consumers’ tendency to choose organic products, cattle farmers are interested in alternative methods of calf diarrhoea treatment. This is a major challenge for veterinarians. Few methods of non-antibiotic treatment that bring satisfactory results have been reported in the related literature so far. In this article, the authors compare different non-antibiotic methods of diarrhoea prevention and treatment in calves. Among the alternatives discussed are herbs, probiotics, prebiotics and synbiotics, lactoferrin, and bacteriophages. It was found that the best results could be achieved through the use of pro-, pre- and synbiotics. However, the authors would like to point out that with the expansion of knowledge about the practical use of broad-scale bacteriophages, they could be the best alternative to antibiotics.
Afficher plus [+] Moins [-]Cytotoxic and apoptotic effect of nanoclinoptilolite on canine osteosarcoma cell lines Texte intégral
2020
Ulutaş, Pınar Alkım | Kıral, Funda | Ulutaş, Bülent | Aşıcı, Gamze Sevri Ekren
Clinoptilolite has antiviral, antibacterial, anti-inflammatory, antidiabetic, and anticancer properties due to its biological activities. In various cancer cell culture studies, it has been reported effective against tumour cells and gave positive results in treatment of various tumours in dogs. No study was found on the effects of the nanoparticulate form, nanoclinoptilolite, on cancer cells. The aim of this study was to determine its cytotoxic and apoptotic effects in canine osteosarcoma (OSA) cell culture. Doses at 50% inhibitory concentration were determined by measuring the dose- and duration-dependent cytotoxicity of nanoclinoptilolite on canine D-17 osteosarcoma cells by methylthiazol tetrazolium (MTT) test for 24 h, 48 h, and 72 h. Murine caspase-3 and -7 activity and expression levels of the BAX and BCL2 genes were measured using RT-PCR to investigate the apoptotic effect. Nanoclinoptilolite decreased cell viability and induced caspase-3- and -7-mediated apoptosis in treated canine OSA cells. Furthermore, its application to canine OSA cells downregulated the expression of BCL2 and upregulated the expression of proapoptotic BAX. Clinoptilolite, which was previously demonstrated to have anticancer properties, decreased cell viability effectively and rapidly and increased the apoptotic cell ratio in a novel use in nanoparticle form, exhibiting this effect by increasing the BAX/BCL2 ratio.
Afficher plus [+] Moins [-]Efficacy of natural formulations in bovine mastitis pathology: alternative solution to antibiotic treatment Texte intégral
2020
Pașca, Claudia | Mărghitaș, Liviu Alexandru | Dezmirean, Daniel Severus | Matei, Ioana Adriana | Bonta, Victorița | Pașca, Ioan | Chirilă, Flore | Cîmpean, Adrian | Iosif Fiț, Nicodim
Bovine mastitis is an inflammatory disease of the udder that causes important economic losses in the animal breeding and dairy product industries. Nowadays, the conventional livestock antibiotic treatments are slowly being replaced by alternative treatments. In this context, the main aim of this study was to evaluate the efficacy of natural products in alternative treatment of bovine mastitis. Two natural formulations with previously suggested in vitro antimicrobial effect were tested in vivo on mastitic cows. Animals with a positive diagnosis for mastitis (n = 20) were divided into three treatment groups: two groups (n = 8) were administered formulations of propolis, alcoholic extracts of Brewers Gold and Perle hops, plum lichen, common mallow, marigold, absinthe wormwood, black poplar buds, lemon balm, and essential oils of oregano, lavender, and rosemary designated R4 and R7 (differing only in the latter being more concentrated) and one group (n = 4) a conventional antibiotic mixture. In vivo efficacy of treatments was evaluated by somatic cell and standard plate counts, the treatment being considered efficacious when both parameters were under the maximum limit. R7 was effective in the most cases, being therapeutically bactericidal in six out of eight cows, while R4 gave good results in three out of eight cows, and conventional antibiotics cured one out of four. These results suggest the possible therapeutic potential of these natural products in bovine mastitis.
Afficher plus [+] Moins [-]E-test determination of antifungal susceptibility of Candida species isolated from turkeys Texte intégral
2020
Sokół, Ireneusz | Tokarzewski, Stanisław | Bobrek, Kamila | Gaweł, Andrzej
Candida species are a natural component of the intestinal tract microflora, but in favourable conditions they can cause superficial, mucosal, or even systemic candidiasis. Poultry production might be a source of human drug-resistant yeast infections, including Candida spp. The limited data concerning the antifungal susceptibility of poultry Candida isolates prompted us to carry out research to determine the susceptibility of isolates from turkey intestinal tracts. The beak cavity, crop and cloaca were swabbed of 580 turkeys from 58 flocks in western Poland. The susceptibility tests were conducted using the E-test method with amphotericin B, fluconazole, itraconazole, and voriconazole on 52 isolates of C. albicans, C. catenulata, C. glabrata, C. palmioleophila, C. rugosa, C. krusei and C. lusitaniae. All isolates were susceptible to voriconazole. According to the MIC values obtained for amphotericin B and fluconazole, all Candida spp. isolates were classified as susceptible according to the described breakpoints except for C. krusei, which was the only isolate that was amphotericin B-, fluconazole- and itraconazole-resistant. The susceptibility to itraconazole varied: 11 of the Candida isolates were susceptible (21.1%), 29 were dose-dependently susceptible (55.8%), and 12 isolates were resistant (23.1%). There are few resistant strains of Candida in turkeys, and the drug resistance varies. When Candida passes from turkeys to humans, there is a wide range of antifungal treatment options.
Afficher plus [+] Moins [-]Effects of α-enolase gene silencing on reproductive-related hormone receptor expression and steroid hormone synthesis of primary granulosa cells from goose F1 follicles Texte intégral
2020
Ji, Hong | Niu, Chun-Yang | Zhang, Hong-Liang | Guo, Jing-Ru | Zhen, Li | Lian, Shuai | Yang, Chuang | Yang, Huan-Min | Wang, Jian-Fa
Enolases are enzymes in the glycolytic pathway, which catalyse the reversible conversion of D-2-phosphoglycerate into phosphoenol pyruvate in the second half of the pathway. In this research, the effects of α-enolase (ENO1) on steroid reproductive-related hormone receptor expression and on hormone synthesis of primary granulosa cells from goose F1 follicles were studied. Primary granulosa cells from the F1 follicles of eight healthy 8-month-old Zi geese were separated and cultured. An ENO1 interference expression vector was designed, constructed and transfected into primary cultured granulosa cells. The mRNA expression levels of follicle-stimulating hormone receptor (FSHR), luteinising hormone receptor (LHR), oestrogen receptor α (ER α), oestrogen receptor β (ER β), growth hormone receptor (GHR) and insulin-like growth factor binding protein-1 (IGFBP-1) in the cells were evaluated as were the secretion levels of oestradiol, activin, progesterone, testosterone, inhibin and follistatin in cell supernatant. α-enolase gene silencing reduced the expression of FSHR, LHR, ERα, ERβ, GHR, and IGFBP-1 mRNA, potentiated the secretion of oestrogen, progesterone, testosterone, and follistatin of granulosa cells, and hampered the production of activin and inhibin. ENO1 can regulate the reactivity of granulosa cells to reproductive hormones and regulate cell growth and development by adjusting their hormone secretion and reproductive hormone receptor expression. The study provided a better understanding of the functional action of ENO1 in the processes of goose ovary development and egg laying.
Afficher plus [+] Moins [-]Point-of-service diagnostic technology for detection of swine viral diseases Texte intégral
2020
Nannucci Lapo | Barattini Paolo | Bossis Ioannis | Woźniakowski Grzegorz | Balka Gyula | Pugliese Carolina
Point-of-service diagnostic technology for detection of swine viral diseases Texte intégral
2020
Nannucci Lapo | Barattini Paolo | Bossis Ioannis | Woźniakowski Grzegorz | Balka Gyula | Pugliese Carolina
A research project is underway aiming to develop a field diagnostic tool for six important viruses of the pig sector, namely: African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), porcine parvovirus (PPV), porcine circovirus (PCV2), and classical swine fever virus (CSFV).
Afficher plus [+] Moins [-]Point-of-service diagnostic technology for detection of swine viral diseases Texte intégral
2020
Nannucci, Lapo | Barattini, Paolo | Bossis, Ioannis | Woźniakowski, Grzegorz | Balka, Gyula | Pugliese, Carolina
A research project is underway aiming to develop a field diagnostic tool for six important viruses of the pig sector, namely: African swine fever virus (ASFV), porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), porcine parvovirus (PPV), porcine circovirus (PCV2), and classical swine fever virus (CSFV). To obtain a preliminary sounding of the interest in this type of instrument among its potential operators, a questionnaire was drawn up and submitted to three categories of stakeholders: farmers, veterinarians, and others (including scientific and technical staff working on animal farms). Four countries participated: Italy, Greece, Hungary, and Poland. In total, 83 replies were collected and analysed in a breakdown by stakeholder type and pertinence, where the areas were the importance of the main diseases within the different countries, diagnostic tool operational issues, and economic issues. The main end-users of this kind of instrument are expected to be private veterinarians and pig producers. The infectious agents seeming to be most interesting to diagnose with the instrument are PRRSV, SIV, PPV, and PCV2. The most decisive parameters which have been selected by the stakeholders are sensitivity, cost, simplicity, and time required to obtain results. The economic issue analysis showed that the majority of those who would prefer to buy rather than rent the device are willing to pay up to €3,000 for a diagnostic field tool.
Afficher plus [+] Moins [-]Cyclooxygenase-2 as a biomarker with diagnostic, therapeutic, prognostic, and predictive relevance in small animal oncology Texte intégral
2020
Szweda Marta | Rychlik Andrzej | Babińska Izabella | Pomianowski Andrzej
Cyclooxygenase-2 as a biomarker with diagnostic, therapeutic, prognostic, and predictive relevance in small animal oncology Texte intégral
2020
Szweda Marta | Rychlik Andrzej | Babińska Izabella | Pomianowski Andrzej
In canine and feline populations, the number of neoplasm cases continues to increase around the world. Attempts are being made in centres of research to identify new biomarkers that speed up and improve the quality of oncological diagnostics and therapy in human and animal tumour patients. Cyclooxygenase-2 (COX-2) is a promising biomarker with increasing relevance to human oncology, but as yet with less application in veterinary oncology. The expression of COX-2 increases significantly during pathological processes involving inflammation, pain or fever. It is also overexpressed in humans presenting various types of tumours and in selected types of tumours in animals, particularly in dogs. This article discusses the expression of COX-2 in canine and feline tumours, the importance of COX-2 as a biomarker with diagnostic, therapeutic, prognostic and predictive relevance in oncology, and the clinical significance of inhibiting COX-2 overexpression in tumours.
Afficher plus [+] Moins [-]Cyclooxygenase-2 as a biomarker with diagnostic, therapeutic, prognostic, and predictive relevance in small animal oncology Texte intégral
2020
Szweda, Marta | Rychlik, Andrzej | Babińska, Izabella | Pomianowski, Andrzej
In canine and feline populations, the number of neoplasm cases continues to increase around the world. Attempts are being made in centres of research to identify new biomarkers that speed up and improve the quality of oncological diagnostics and therapy in human and animal tumour patients. Cyclooxygenase-2 (COX-2) is a promising biomarker with increasing relevance to human oncology, but as yet with less application in veterinary oncology. The expression of COX-2 increases significantly during pathological processes involving inflammation, pain or fever. It is also overexpressed in humans presenting various types of tumours and in selected types of tumours in animals, particularly in dogs. This article discusses the expression of COX-2 in canine and feline tumours, the importance of COX-2 as a biomarker with diagnostic, therapeutic, prognostic and predictive relevance in oncology, and the clinical significance of inhibiting COX-2 overexpression in tumours.
Afficher plus [+] Moins [-]