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1.
Veterinary Ireland Journal ; 11(8):460-462, 2021.
Article in English | CAB Abstracts | ID: covidwho-2167975
2.
Journal of Southern Agriculture ; 53(8):2077-2087, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2201259

ABSTRACT

Object: To explore genetic evolution relationship of variant porcine epidemic diarrhea virus(PEDV)and antigenic differential sites among variant strain subtypes,so as to lay a foundation for the development of novel vaccines and diagnostic kits. Method: Three PEDV-positive porcine intestinal samples were inoculated on to confluent Vero cells to isolate PEDV. Virus identification was performed by indirect fluorescence assay(IFA), Western blotting,RT-PCR and whole genome sequencing and electron microscopic observation;virus titer was determined by TCID50and the in vitvo proliferation dynamin curve of the virus was drawn. The genome of the isolated strain was divided into 33 segments for RT-PCR amplification, and the SeqMan of Lasergene was used to splice sequences. Then the genetic evolution analysis was performed with MEGA 7.0, and the antigenicity analysis was performed with Jameson-Wolf algorithm in Protean. Result: Typical cytopathic effect appeared in one PEDV-positive porcine intestinal sample in Vero cells when it was blindly passaged to the 6thgeneration and the sample was designated as CH-HK-2021. IFA and Western blotting results showed that the strain CH-HK-2021 could react with PEDV N monoclonal antibody and expected reads were obtained through RT-PCR amplification, which demonstrated this virus was PEDV. Diameter of strain CH-HK-2021 was 80-120 nm and the surface of the virus particles were in spike-like shape, indicating it was coronavirus. The strain could be stably propagated in Vero cells, and it has been passaged to 100thgeneration. After 24 h of infecting the Vero cells, virus titer of strain CH-HK-2021 reached the highest,105.6TCID50/mL. The size whole genome of strain CH-HK-2021 not including poly(A)tail was 28034 bp, with a similarity of 96.0%-98.9% with nucleotide sequence of the PEDV reference strain and a similarity of 93.1%-99.0% with S-base nucleotide sequence of the reference strain. The strain had the highest similarity with nucleotide sequence of variant strain CH/JX/01(KX058031)and the lowest similarity with nucleotide sequence of classical strain AVCT12(LC053455). Strain CH-HK-2021 was a subtype of G2a and it is spreading in China. Strain G2a and variant strain G2b had 42 nucleotide differential sites in S gene and 6 antigenic differential sites;and main differential sites located in subunit S2.

3.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 51(11):1355-1360, 2021.
Article in Chinese | CAB Abstracts | ID: covidwho-2155897

ABSTRACT

To develop a real-time fluorescent quantitative PCR method for rapid, accurate, sensitive and quantitative detection of porcine epidemic diarrhea virus (PEDV), according to the highly conserved nucleotide sequence of S gene reported by GenBank, a pair of PEDV S gene specific primers were designed, and a fluorescent quantitative RT-PCR detection method using SYBR Green I as the dye was established. The clinical samples suspected of PEDV infection were tested and compared with the results of ordinary RT-PCR. The results showed that the established standard curve of the SYBR Green I fluorescence quantitative RT-PCR method had a good linear relationship. The linear correlation coefficient R2=1, its amplification efficiency E=2.03, and the melting curve was a sharp single peak. The amplification of transmissible gastroenteritis virus, porcine parvovirus, classical swine fever virus, porcine reproductive and respiratory syndrome virus, porcine deltacoronavirus and porcine rotavirus was negative and had strong specificity. The lowest detection concentration of 1 x 101 copies/L was 100 times more sensitive than that of the ordinary RT-PCR method. The coefficient of variation of intra- and inter-assay repeatability test were both less than 2%, with good repeatability and stability. Comparing the test results of 36 clinical samples, the total coincidence rate with ordinary RT-PCR was 88.89%. The results show that the established real-time fluorescent quantitative RT-PCR detection method has strong specificity, good reproducibility, and high sensitivity, which is of great significance for the rapid and quantitative detection of PEDV.

4.
Ptitsevodstvo ; 9:65-69, 2022.
Article in Russian | CAB Abstracts | ID: covidwho-2148190

ABSTRACT

The successful experiment in large-scale commercial conditions is described with new vaccination program for broiler parental flock involving vaccination at 130 days of age (at the transfer of pullets to poultry houses for adult broiler breeders) with 4-valent vaccine PROVAC 4 against chicken infectious bronchitis, Newcastle and Gumboro diseases, and reoviral infection, together with additional vaccination against rhinotracheitis. Control treatment was vaccinated according to a standard scheme previously used in the farm, with separate vaccines against the aforementioned diseases;certain vaccines contained several antigens of a single disease. It was found that productive performance in the parental flocks and in broilers from these flocks was similar and consistently high with both vaccination schemes;the antibody titers at different ages of parental flocks were also similar. However, the cost of the experimental vaccination scheme was lower by 16% as compared to the standard one;on 4 batches of parental flock (120,000 hens each) it saved over 1 mio. rubles to the farm. The conclusion was made that vaccine PROVAC 4 can provide prolonged and effective protection of broiler parental flock and its progeny against viral diseases at low financial expenses.

5.
Veterinary Times ; 52(30):6-8, 2022.
Article in English | CAB Abstracts | ID: covidwho-2147103
6.
World Aquaculture ; 52(3):52-54, 2021.
Article in English | CAB Abstracts | ID: covidwho-2124606

ABSTRACT

In this article the authors discussed how catfish producers in Mississippi, Arkansas, and Alabama were able to maintain and even increase their production despite of Covid-19 by adopting new intensive production systems and complementary technologies such as intensively aerated small ponds, use of hybrids, automated oxygen monitoring systems, and vaccinations.

7.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(1):10-19, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-2056573

ABSTRACT

The aim of this study is to establish an indirect ELISA technique for detecting the SIgA antibody against porcine epidemic diarrhea virus (PEDV) to evaluate its mucosal immunity. Firstly, the S1D gene (534-789 aa) of PEDV was cloned into the pET-28a(+) vector, and induced in Escherichia coli BL21 (DE3) by IPTG, the product of which was in the form of inclusion bodies. According to Western-blot, the target protein S1D with antigenic activity was 32 ku in molecular weight and could be well detected. Then, the S1D protein was denatured by 8 mol/L urea, purified and gradient as the coating antigen to establish an indirect ELISA for detecting the PEDV specific SIgA antibody in nasal or oral mucus by optimizing conditions. And the optimal antigen coating concentration of ELISA was 2 micro g mL, the working concentrations of nasal mucus was 1:1 and the optimal blocking solution was 50 g/L skimmed milk, while the working concentrations and optimal blocking solution were 1:2 and 30 g/L BSA in oral mucus, the working concentrations of the enzyme-labeled antibody was 1:2 000 in nasal and oral mucus. Finally, 84 samples of oral and nasal mucus from immunized pigs were detected by S1D of ELISA, and the coincidence rate could reach 95.2% compared with purified PEDV of ELISA. In conclusion, the indirect ELISA established in this study provided a quick, simple, sensitive, and specific method to detect PEDV specific SigA for evaluating the level of PEDV mucosal immunity.

8.
International Hatchery Practice ; 35(4):27-28, 2021.
Article in English | CAB Abstracts | ID: covidwho-2045268
9.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(11):1373-1378, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-2040499

ABSTRACT

In order to build a specific, sensitive and rapid detection method for PAstV3 detection, the PAstVB gene sequences in Genbank were used and the conserved region in ORFlb was selected to design specific primers and TaqMan probe. Clinical stool samples were collected and preliminary detected by this newly established real-time RT-PCR method after reaction systems and conditions optimization. This detection method established in this study has a good linear relationship with the standard curve, with R2 value up to 0.9971. The sensitivity is 100 times higher than conventional PCR method, The variation co-efficient of in-batch and inter-batch repeatability test is less than 2.0%, indicating good repeatability. The detection results of Clinical samples showed that the positive rate of this method is higher than conventional PCR method. The establishment of this method provides a rapid detection means for PAstV3 laboratory diagnosis and epidemiological investigation.

10.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(11):1341-1347, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-2040497

ABSTRACT

The recombinant expression plasmid pIRES-S1 was constructed according to the gene sequence of PEDV S1 in NCBI (GenBank:JQ517274). The plasmid pIRES-S1 was transfected into ST cells by electrotransfer. After G418 pressurization screening, western-blot detection and suspension domestication, a stable transduction cell pool expressing S1 protein was obtained. The results of Western-blot showed that S1 protein have good reactivity. An indirect ELISA was established by using S1 protein as coating antigen, and the ELISA was used to detect PEDV clinical serum and PEDV negative serum of imported breeder pigs. Take the serum neutralization test as the standard, the results showed that the sensitivity of the ELISA was 96.3% and the specificity was 97.7%.It was significantly consistent with the serum neutralization test (kappa value=0.882, P < 0.05). The ELISA was used to detect the tracking serum of PEDV back-feeding pigs. The results showed that it could accurately evaluate the growth and decline of PEDV Ig G antibody level in infected pigs. Our results suggested that the ELISA based on S1 protein established in this study has high sensitivity and specificity. It could be used to detect PEDV antibody in clinical serum samples and provide an effective basis for immune evaluation of PEDV in pigs.

11.
Acta Microbiologica Sinica ; 8:3152-3165, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2040441

ABSTRACT

Objective: To identify the key host protein that can regulate the replication of porcine epidemic diarrhea virus (PEDV).

12.
Journal of Camel Practice and Research ; 27(2):207-208, 2020.
Article in English | CAB Abstracts | ID: covidwho-2040330

ABSTRACT

MERS-CoV was isolated from nasal swabs for 10 days from an adult female camel which displayed clear nasal discharge from both nostrils. When MERS-CoV ELISA antibodies appeared in the camel's blood, the virus was no longer present in its nasal cavities.

13.
Veterinarski Glasnik ; 74(1):1-17, 2020.
Article in English | CAB Abstracts | ID: covidwho-2039613

ABSTRACT

Background. Coronaviruses (CoVs) have been recognized in veterinary virology for a long time and comprise a large group of RNA viruses responsible for enteric, respiratory, hepatic, and neurologic diseases in a variety of animal species and humans. These viruses are very adaptable considering their highly error-prone replication process and recombination ability, resulting in remarkable mutability and efficient expansion of their host range and tissue tropism. Scope and Approach. In the recent past, after the outbreaks caused by SARS-CoV in 2002 and MERS-CoV in 2012, CoVs became a research focus in the scientific community. Moreover, the ongoing SARS-CoV-2 pandemic raised more questions concerning the threats posed by these viruses. Several significant examples of coronaviruses jumping the species barrier and changing their tropism have been reported in the past, and novel viruses of both animals and humans have appeared as a consequence. This paper reviews some of the examples of CoV mutability and the most notable animal coronaviruses of veterinary relevance. Key Findings and Conclusions. There is still no proof that the novel virus SARS-CoV-2 can be transmitted to humans from domestic animals, and its recent cross-species jump is currently being intensively researched. Intensified and diverse human activities that lead to the disruption of ecosystems contribute to the increased risk of contact with animals that might represent virus reservoirs. The need for constant surveillance of CoVs and expanded studies of their virological traits, mutation mechanisms, diversity, prophylactic and therapeutic measures highlight the key role of both veterinarians and medical doctors in order to preserve the health of the human population.

14.
Zhongguo Yufang Shouyi Xuebao / Chinese Journal of Preventive Veterinary Medicine ; 44(1):108-108, 2022.
Article in English, Chinese | CAB Abstracts | ID: covidwho-2034138

ABSTRACT

Avian infectious bronchitis (IB) is one of the acute and highly contagious upper respiratory tract infectious diseases in poultry caused by the Infectious bronchitis virus (IBV), which significantly affects the health and development of world poultry farming industry. IBV RNA polymerase lacks a complete correctional function and is prone to gene mutation and RNA-RNA recombination during the replication process, resulting in the emergence of new serotypes, genotypes and mutant strains. The continuous generation of recombinant strains through homologous recombination between strains also complicates the prevention and control of IB. Therefore, monitoring the genetic evolutionary characteristics of circulating strains and evaluating the protective effect of commonly used vaccines against local circulating strains of IBV are the keys to preventing and controlling this disease.

15.
Slovensky Veterinarsky Casopis ; 45(2):72-74, 2020.
Article in Slovak | CAB Abstracts | ID: covidwho-2034129

ABSTRACT

This article describes the differences between the influenza pandemic and the Covid-19 pandemic and the immunological and virus-host cell characteristics of SARS-CoV-2.

16.
Zycie Weterynaryjne ; 96(1):42-49, 2021.
Article in Polish | CAB Abstracts | ID: covidwho-2034018

ABSTRACT

Poultry industry is dynamically developing worldwide, and the threat from infectious viral diseases also increases. One of them is an acute, highly contagious avian infectious bronchitis (IB), caused by infectious bronchitis virus (IBV), the coronavirus of the fowl. IBV is characterized by extensive variations in the surface spike protein gene. Those genetic variations lead to rapid changes in IBV serotypes that need to be constantly monitored to assess the epidemiological situation in the field. The aim of this article was to present current knowledge and recent epidemiology, based on IBV field strains circulation. Several serotypes can be simultaneously present in a region and as they cross-protect poorly, broiler chickens can be infected more than once within their short period of life. Careful, constant monitoring is necessary to respond fast in case of new genetic IBV variants development. Some of these strains have global range, while the prevalence of others is limited to some geographical areas. Thus, the understanding the IB epidemiology, virus spread and the occurrence of individual strains allows to use the optimal vaccination schedule to limit the disease and improve the poultry production. Finaily, a good recognition of the IB problem in Central and Eastern Europe on the example of Poland as the largest European poultry producer, can be a key factor in the quickest response to emerging new IBV variants. Some practical solutions may help to introduce the similar and effective procedures also in other regions of the world with high intensity of poultry production.

17.
Acta Microbiologica Sinica ; 7(23), 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2025659

ABSTRACT

Objective: The aim of this study is to screen an ideal adjuvant for an inactivated porcine deltacoronavirus(PDCoV) vaccine to induce mucosal immunity and reduce the side effect of the vaccine. We used different mucosal adjuvants to prepare the inactivated PDCoV vaccines. We then used mouse model to evaluate the humoral, cellular and mucosal immune responses induced by the inactivated vaccines via different immunization routes.

18.
Acta Veterinaria et Zootechnica Sinica ; 53(7):2260-2267, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2025546

ABSTRACT

The C-terminal domain (CTD) of porcine deltacoronavirus S1 subunit is the main region which induces the neutralizing antibody. S1-CTD was expressed by HEK-293T eukaryotic expression system and purified, and porcine ileal epithelium cells membrane proteins were extracted to investigate porcine host proteins that interact with it. Thirty-two suspected interacting host proteins were obtained by co-inmunprecipitation (Co-IP) and mass spectrometry. Eukaryotic expression plasmid of KIF1 binding protein (KIFBP) was constructed, and the interaction between KIFBP and S1-CTD was identified by Co-IP and laser confocal microscopy. All results proved that KIFBP interacted with S1-CTD and co-located in cytoplasm. Further research indicated that overexpression of KIFBP could effectively reduce the viral mRNA level and the viral titer in which the mRNA level decreased by about 70%, and the viral titer decreased by 101.6TCID50. In conclusion, a host protein KIFBP interacting with PDCoV S1-CTD was screened and identified in this study which provides a theoretical basis for understanding the pathogenesis of PDCoV.

19.
Acta Veterinaria et Zootechnica Sinica ; 53(6):2024-2028, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-2025545

ABSTRACT

This study aimed to analyze the proliferation characteristics of porcine deltacoronavirus (PDCoV) in suspension cultured porcine kidney cells LLC-PK1, so as to provide Candidate cell for large-scale production of PDCoV inactivated vaccine. LLC-PK1 cells were suspended by gradually decreasing serum method. PDCoV adaptive monoclonal cell lines were screened by limited dilution method. Indirect immunofluorescence method was used to identify the infectivity of PDCoV. The initial cell density, MOI, time of receiving virus collection and TPCK pancreatin concentration were screened to determine the best suspension culture conditions. The suspension cell strain LLC-PK1Sa which can proliferate PDCoV efficiently was screened out;PDCoV can specifically infect LLC-PK1 cells;PDCoV inoculated LLC-PK1Sa cells with a density of 2 x 106 cells.mL-1 according to the MOI of 10-3, When the final concentration of TPCK pancreatin reached 7.5 g.mL-1, the titer of virus solution harvested 48 h after inoculation was the highest. In this study, the efficient proliferation of PDCoV in LLC-PK1Sa suspension cells was realized for the first time, and the suspension culture conditions were preliminarily optimized, which could provide theoretical reference for large-scale production of PDCoV inactivated vaccine.

20.
XIV. Simpozij peradarski dani ; 11(14):64-70, 2022.
Article in English | CAB Abstracts | ID: covidwho-2011772

ABSTRACT

Proper control of infectious bronchitis, pursued through strict biosecurity and mass vaccination, is essential in intensive broiler production. Despite effective and routinely adopted, hatchery spray vaccination has been hypothesized to affect body temperature and wellbeing of day-old chicks. Recently, gel administration has been proposed as an alternative and proved feasible in experimental settings. In this study, IBV spray and gel vaccination were compared in field conditions. One hundred birds from the same hatch were vaccinated, half by spray and half by gel, with 793B and Mass vaccines. After vaccination, rectal temperature was measured and vaccine intake assessed. The two groups were raised for 35 days in separate pens, and swabs and blood samples were collected at multiple time points for lineage-specific molecular analyses and serology, respectively. Temperature was significantly lower in spray vaccinated chicks 10 minutes and an hour after administration. A similar trend in 793B titres was observed in both groups, while Mass-based vaccine was detected later but persisted longer in gel vaccinated chicks. No differences were observed in mean antibody titres. Compared to spray, gel administration appears equally effective and less impactful on body temperature, thus supporting its application for IBV vaccmatlon.

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