Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
Zycie Weterynaryjne ; 96(6):403-407, 2021.
Article in Polish | CAB Abstracts | ID: covidwho-2073616

ABSTRACT

Coronaviruses (CoV), exhibit high mutation rates and strong tendency to recombine. These properties enable them to easy overcome the host species barrier and adapt to new hosts. It is currently known that six CoV are able to infect pigs. Four of them, belong to the genus Alphacoronavirus - transmissible gastroenteritis coronavirus (TEGV), porcine respiratory coronavirus (PRCV), porcine epidemic diarrhea virus (PEDV) and swine acute diarrhea syndrome coronavirus (SADS-CoV). One of them belongs to the genus Betacoronavirus - porcine hemagglutinating encephalomyelitis virus, PHEV, and the last one, to the genus Deltacoronavirus (PDCoV). PHEV was one of the first identified swine CoVs and is still widespread, causing subclinical infections in pigs in several countries. PRCV, a spike deletion mutant of TGEV, is considered as non-pathogenic. Since vaccines are available only for some porcine CoVs, prevention should focus mainly on a high level of biosecurity. In view of the diversity of CoVs and the potential risk factors associated with zoonotic emergence, updating the knowledge concerning this area is essential.

2.
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.

3.
International Hatchery Practice ; 35(4):27-28, 2021.
Article in English | CAB Abstracts | ID: covidwho-2045268
4.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(12):1500-1508, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-2040500

ABSTRACT

Based on the M gene sequence of TGEV and PEDV and VP2 gene sequence of PoRV, the optimal reaction system and amplification procedure were established by optimizing primer, probe concentration and annealing temperature, and the Quantitative PCR method of TaqMan probes for three viruses is successfully established. On this basis, after further optimization of conditions, a triple real-time fluorescent quantitative PCR method for detecting TGEV, PEDV, and PoRV was established. The detection sensitivity of this method for TGEV, PEDV, and PoRV were 2.49 copies/ L, 4.36 copies/ L, and 4.96 copies/ L respectively. The maximum value of CV in repeated trials detected by TGEV, PEDV and PoRV were 2.5%, 3.8%, 4.3%, and the maximum value of CV in repeated trials between groups were 3.7%, 3.4%, 3.2%, which are no more than 5%.indicating that the established method has good reproducibility. Using this method to detect PRV, PCV1, and PRRSV virus samples, there is no cross-reaction, indicating that the method is specific. Using the established method to detect 40 clinical diseases, the samples were tested, and the positive rates of TGEV, PEDV, and PoRV were 5%, 30%, and 12.5%respectively. The mixed infection rate of TGEV and PEDV was 2.5%, the mixed infection rate of PEDV and PoRV was 5%. The results of the multiple fluorescence quantitative PCR method are consistent with those of the detection of a single fluorescent RT-PCR method, indicating that the established method has good clinical application value.

5.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(11):1421-1427, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-2040498

ABSTRACT

Recently, the variation and isolation of porcine epidemic diarrhea Virus (PEDV) has been a focus of industry research. Whether porcine aminopeptidase (pAPN) is a functional receptor of PEDV infection is still controversial. Therefore, this article aims to review the latest progress on pAPN as a receptor of PEDV and its role during infection, to clarify whether pAPN is a functional receptor and to provide a reference for isolation and subsequent study of PEDV.

6.
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.

7.
Journal of South China Agricultural University ; 41(5):27-35, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-2040361

ABSTRACT

Objective: To prepare monoclonal antibodies against porcine epidemic diarrhea virus (PEDV) N protein, and develop an indirect immuno-fluorescence assay method used for detecting PEDV. Method: The expressed recombinantly PEDV N protein was used as an immunogen and 8-week-old female BALB/c mice were immunized. Then their spleen cells with high antibody titer were isolated and fused with SP2/0 cells. The hybridoma cell lines secreting monoclonal antibodies against PEDV N protein were screened. In Vero cells infected with PEDV, monoclonal antibody of anti-PEDV N protein was used as the primary antibody and FITC-goat-anti-mouse IgG was used as the secondary antibody to develop indirect immuno-fluorescence assay method used for detecting PEDV. Result: The prepared hybridoma cell lines could stably secrete anti-PEDV N protein antibodies, ELISA antibody titer in cell supernatant was above 1:3 200, and in mouse ascites above 1:1 000 000. While monoclonal antibodies were applied in established indirect immuno-fluorescence assay, the optimal conditions were that cells were fixed with 80% () acetone at -20 degrees C for 30 min;The primary antibody was diluted 1 000 times by PBS buffer solution and incubated at 4 degrees C overnight;The secondary antibody was diluted 100 times by PBS buffer solution and incubated at 37 degrees C for 1 h. Transmissible gastroenteritis virus (TGEV), classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine reproductive virus (PRV), porcine enteric a corone virus (PEAV), porcine rotavirus (PoRV) and PEDV were detected by established indirect immuno-fluorescence assay method, only PEDV showed positive, all the else viruses showed negative.

8.
Revista de Politica Agricola ; 31(1):105-122, 2022.
Article in Portuguese | CAB Abstracts | ID: covidwho-2034170

ABSTRACT

The relationship between international trade and animal health is particularly important in the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS) of the World Trade Organization - WTO. Supported by the World Organization for Animal Health (OIE), SPS measures are scientifically justified and play an important role in placing epidemiology at the center of decisions related to health and animal trade. The objective of this study was to discuss the interactions between the international meat trade and the epidemiology of zoonotic diseases of viral origin, in a debate on how the current Covid-19 pandemic could change the consumer behavior related to health and hygiene issues, and how the meat sector was affected by SPS measures, highlighting the relevance of Brazil in this context.

9.
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.

10.
Bangladesh Journal of Veterinary Medicine ; 20(1):17-24, 2022.
Article in English | CAB Abstracts | ID: covidwho-2026591

ABSTRACT

Background: Poultry and livestock are a leading sub-sector of agriculture, playing an important role to fulfill the protein requirements of the human diet and contributing to the national economy in Bangladesh. This sub-sector is often vulnerable due to frequent outbreaks of diseases in animals and unrest situations worldwide that hamper earning a profit up to the expected mark. Due to pandemic COVID-19, the Bangladesh government was bound to announce a countrywide lockdown and periodical restriction of movement in March 2020 to minimize the spread of the infection. This study aimed to evaluate the impact of COVID-19 on poultry and livestock health.

11.
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.

12.
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.

13.
Archives of Razi Institute ; 77(5):1611-1619, 2022.
Article in English | CAB Abstracts | ID: covidwho-2002783

ABSTRACT

Infectious bronchitis (IB) disease, avian Infectious Bronchitis disease in one of the major cause of respiratory problems and economic loss in poultry industry, even in developed countries with good biosecurity practice. Since the first isolation of the virus in 1931, a lot of serotypes and genotypes of the virus have been reported around the world. The GI-1 lineage, including Massachusetts (Mass) serotype viruses, is one of the most widely spread types worldwide. Moreover, the GI-23 lineage with a growing incidence rate was reported approximately 20 years ago in the Middle East, with no or little homologues vaccine use. The genotype was previously restricted to the Middle East;now, there is evidence that it has spread to European countries, raising concerns regarding potential outbreaks. In the present study, our attempt was to phylogenetically analyze the S1 gene of six isolates from Massachusetts and variant 2 genotypes, which were isolated from broiler and broiler breeder flocks in Iran. The variant 2 viruses were compared to other reported variant 2 viruses from neighboring countries and they had more than 98% identity with the latest reported Iranian variant 2. In addition, Three Mass type viruses were similar to vaccine strains which may be shows continuous circulation of vaccine viruses in the field. This event can cause increasing the risk of their mutation or even reversion to virulence after several passages in natural host, furthermore circulating viruses may recombinant with virulent field viruses and cause emergence of new variants. Considering the variable nature of IB viruses in which few changes lead to important differences, continuous epidemiological surveillance along with clinical studies of new isolates, are crucial to a better understanding of their pathogenicity and subsequent disease control.

14.
Sarhad Journal of Agriculture ; 38(2):480-488, 2022.
Article in English | CAB Abstracts | ID: covidwho-2002723

ABSTRACT

Broiler population is one of the most important segments of livestock due to its significant contribution in white meat production. Infectious disease outbreaks adversely influence the production potential and consequently cause economic losses. Epidemiological data regarding magnitude of these disease outbreaks is of fundamental importance for planning of a comprehensive control strategy. With retrospective design, this study was conducted from January 2013 through December 2017 in order to assess the disease burden on broilers reared in different open type poultry houses. Out of total 658 commercial farms with capacity of 4221800 broilers, across Chakwal, a representative sample of 70 farms with capacity of 448000 broilers was randomly selected for collection and analysis of disease data. Five years' data of these randomly selected farms revealed highest (44.64%) crude morbidity during monsoon season followed by 23.92%, 22.12% and 17.49% for winter, spring and post-monsoon seasons respectively. The highest (14.90%) prevalence was recorded for new castle disease followed by infectious bursal disease (11.79%), pullorum disease (11.17%), colibacillosis (8.71%), infectious bronchitis (7.87%), inclusion body hepatitis (7.79%), chronic respiratory disease (7.67%), necrotic enteritis (6.48%), coccidiosis (6.09%), mycotoxicosis (5.43%), fowl cholera (4.74%), infectious coryza (4.41%), fowl typhoid (4.22%), omphalitis (3.71%) and hydropericardium syndrome (0.05%). Maximum share in crude morbidity was contributed by bacterial diseases with highest proportional morbidity of 48.68% followed by viral (40.32%), parasitic (5.80%) and fungal (5.20%) diseases. This epidemiological data represents true picture of study population and is a valuable tool for planning of prevention strategy and research priorities.

15.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(7):825-832, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-1994655

ABSTRACT

In order to establish a method for rapid differential identification of Senecavirus A (SVA) and en-cephalomyocarditis virus (EMCV), two pairs of corresponding specific primers were designed based on the highly conserved 3D genes of SVA and EMCV. And two different fluorescent labeled TaqMan probes were used to establish a dual TaqMan real-time PCR method for simultaneous detection of these two viruses, and we also optimize the reaction conditions. The results showed that the minimum detection of the method was 760 copies/ micro L and 98 copies/ micro L for SVA and EMCV. respectively, and it can specifically detect SVA and EMCV, and there was no cross reaction with CSFV, PRRSV and PEDV. The established standard curves showed good linear relationship. Repeated experimental group and inter-group coefficient of variation were less than 5%. The results indicated that the dual-quantitative PCR established in this study has the advantages of convenience, rapidity, good specificity. high sensitivity and good repeatability .and can be used for simultaneous detection of SVA and EMCV.

16.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(9):1147-1158, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-1994654

ABSTRACT

To understand the genetic diversity of porcine deltacoronavirus(PDCo V) in Guangxi Province, clinical diarrhea samples were collected from suspected piglets in Guangxi Province from2017 to 2019, detected by RT-PCR for PDCoV, and the positive samples were used for amplification and sequence of S, M, N genes. Finally, 16 S, M and N gene sequences of PDCoV were obtained. Homology analysis showed that the S, M, N gene nucleotide identity among Guangxi strains were 95.8% -99.9%, 95.9%-100% and 97.9%-99.9%, respectively. The nucleotide identity of S, M and N genes among Guangxi strains and other reference strains were 95.1%-100%, 95.0%-100%and 96.3%-99.9%, respectively. Sequence alignment showed that S1 protein existed amino acid mutations and insertions, and there were some variations among different epidemic strains. Phylogenetic trees based on S, M and N genes obtained similar topological diagram and all strains could be divided into Group I, Group II and GroupIII, of which Group I came from USA, Japan and Korea, Group II came from China, and Group III came from China, Vietnam, Laos and Thailand. Most strains from Guangxi Province distributed in Group II, individual strain distributed in Group III and some strains formed a single small branch. The evolutionary rates of S, M and N genes of Guangxi strains and other reference strains were 2.57 x 10-4, 2.07 x 10-4, 1.70 x 10-4 substitutions/site/year, respectively, showing that the evolutionary rate of S gene was the fastest. The results indicated that the S, M, N genes of PDCo V strains from Guangxi Province had some variations and existed genetic diversity.

17.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(5):537-544, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-1994651

ABSTRACT

Long noncoding RNA (lncRNA) is a type of non-coding RNA molecule longer than 200 nt, which plays vital roles in biological events. Our previous results demonstrated that the host's lncRNA expression profile was significantly changed after porcine epidemic diarrhea virus (PEDV) infection. In this study, one of the lncRNAs, lncRNA9606, was selected to investigate its impact on PEDV replication. First, the kinetics of lncRNA9606 expression in IPEC-J2 cells were examined at different time points after PEDV infection. The results confirmed that PEDV infection significantly upregulated the expression of lncRNA9606. The lncRNA9606 expression levels in different cells or tissues were evaluated and the results showed that the amount of lncRNA9606 in Peyer's patches and peripheral blood mononuclear cells were significantly higher than that in small intestinal epithelial cell lines. It was mainly localized in the nucleus. Further investigations indicated that over expression of lncRNA in LLC-PK1 cells significantly inhibited PEDV replication. In conclusion, lncRNA9606 can suppress the PEDV replication in LLC-PK1 cells.

18.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(5):556-562, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-1994650

ABSTRACT

In order to establish an efficient, sensitive and specific semi-nest RT-PCR method for the detection of Transmissible gastroenteritis virus (TGEV), three specific primers were designed according to the N gene published by GenBank, the reaction system was established and optimized, and specificity and sensitivity were detected. The results showed that the method could successfully amplify the bands of 483 bp and 338 bp, and had good specificity to TGEV, there is no cross reaction with PEDV, PRov, PBov and PDCov, and the lowest sensitivity was 1.86 x 10-1 pg/L. The semi-nest RT-PCR shown the positive rate was 36% in 50 samples of pig diarrhea, which was higher than that of common RT-PCR, and then the positive samples coincidence rate was 100%. This semi-nest RT-PCR method has high sensitivity and specificity, and can accurately diagnose TGEV infection, which provides an effective method for clinical detection and epidemiological investigation of TGEV.

19.
Acta Veterinaria et Zootechnica Sinica ; 53(5):1536-1543, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-1994512

ABSTRACT

This study aims to investigate the protective effect of infected piglets which were immunized with different dose of inactivated porcine epidemic diarrhea virus (PEDV) vaccines. The number of infective virus particles and total virus particles of PEDV with different concentrations were determined, and the mice were immunized with different concentration vaccine prepared as antigen, respectively. The humoral and cellular immune production were determined by ELISA antibody detection method, neutralization test and ELISPOT method. Vaccine with appropriate antigen content was selected to immunize piglets, then the antibody was determined. The relationship between concentrated vaccine and protective effect was studied by challenge experiment. The results showed that, when the antigen dose was equal or greater than 8x106 pfu.mL-1, the inactive vaccine could effectively stimulate mice to produce humoral and cellular immunity. The piglets immunized with 2 mL inactivated PEDV vaccine containing 8x106 pfu.mL-1 antigen could resist diarrhea and continuous viral shedding caused by PEDV challenge. Compared with the total number of virus particles, the number of infectious virus particles was significantly correlated with antibody production (r=0.998 1), and neutralization titer was significantly correlated with piglet protection (r=0.974 7). PEDV inactivated vaccine can provide good immune protection, in which the number of infectious virus particles is the key factor to improve the antibody level. Antibody titer, as an index of humoral immunity, is an important reference for judging immune protection.

20.
Veterinary Ireland Journal ; 10(9):493-495, 2020.
Article in English | CAB Abstracts | ID: covidwho-1989503
SELECTION OF CITATIONS
SEARCH DETAIL