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1.
Deer, Journal of the British Deer Society ; 20(2):21-24, 2021.
Article in English | CAB Abstracts | ID: covidwho-2169389
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.
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.

4.
Zhongguo Yufang Shouyi Xuebao / Chinese Journal of Preventive Veterinary Medicine ; 44(3):346-346, 2022.
Article in English, Chinese | CAB Abstracts | ID: covidwho-2034493

ABSTRACT

The new coronavirus (SARS-CoV-2) is raging around the world, infecting more than 460 million people and killing more than 6 million people, posing a serious threat to human health. Analyzing the pathogenic mechanism of the virus and discovering new drug targets are the keys to the development of antiviral drugs. Similar to the envelope proteins of many important viruses such as Ebola virus and Marburg virus, the spike (S) protein of SARS-CoV-2 relies on the cleavage and processing of cellular furin to mature during infection, and then make the virus infective, so furin is an important potential target for antiviral therapy. However, the regulation mechanism of furin enzyme activity in cells under physiological and infection conditions is not yet very clear.

5.
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.

6.
Wiener Tierarztliche Monatsschrift ; 109(Artikel 11), 2022.
Article in English | CAB Abstracts | ID: covidwho-2025202

ABSTRACT

We have evaluated the diagnostic performance of immunochromatographic point-of-care tests (POCT) for the detection of rotavirus, coronavirus, Escherichia (E.) coli F5, Cryptosporidium (C.) parvum, Clostridium (Cl.) perfringens and Giardia (G.) intestinalis in fresh and thawed faecal samples from calves aged up to six months with diarrhoea. We performed POCTs to detect rotavirus, coronavirus, E. coli F5, C. parvum, Cl. perfringens and G. intestinalis on fresh samples in a field study and re-evaluated the performance for C. parvum, Cl. perfringens and G. intestinalis using thawed samples. We calculated the performance based on the results of the reference methods, which were RT-qPCR for the detection of rota- and coronavirus and bacteriological culturing and PCR to detect E. coli F5 and Cl. perfringens a and ss2 toxins. C. parvum was detected by phase-contrast microscopy and G. intestinalis by immunofluorescence microscopy. We collected 177 faecal samples from diarrhoeic calves. We found good performance for the POCT targeting rotavirus (sensitivity (SE)=92.9%;specificity (SP)=95.6%) and C. parvum (SE=63.3%;SP=96.2%). For E. coli F5, the number of true positive samples (n=1) was too low to evaluate the performance. The POCT to detect coronavirus gave a poor performance (SE=3.3%;SP=96.6%) and the POCT to detect Cl. perfringens a moderate performance (SE=52.8%;SP=78.2%). G. intestinalis POCT showed a higher sensitivity to immunofluorescence microscopy in thawed than in fresh faecal samples (SE=43.9% versus SE=29.2%). There are substantial differences in diagnostic performance between the commercially available immunochromatographic POCTs. Still, POCT can make a valuable contribution to the diagnosis and prevention of calf diarrhoea.

7.
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.

8.
Summa, Animali da Compagnia ; 39(6):19-25, 2022.
Article in Italian | CAB Abstracts | ID: covidwho-1989439

ABSTRACT

Since the appearance of COVID-19 in humans, there have been numerous reports of dogs and cats being infected with SARSCoV- 2, with cats appearing to be particularly susceptible. The portal of entry of the virus into the body's cells is a membrane receptor called ACE2 (angiotensin converting enzyme 2) belonging to the renin-angiotensin-aldosterone system. The ACE2 receptor is expressed in airway epithelial cells, myocardium, venous and arterial endothelial cells, kidney, liver, oral cavity, intestine and also adipose tissue, explaining the diversity of clinical expression of the disease, with respiratory manifestations predominating. SARS-CoV-2 causes an imbalance in the renin-angiotensin- aldosterone system. In addition, the virus has a direct action combined with an immune reaction, that is sometimes intense, causing a cascade of lesions, mainly in the lungs but also in the heart. The clinical expression of SARS-CoV-2 infection remains rare in dogs and cats and mainly includes fever, depression, anorexia, digestive, respiratory or ocular disorders. As in humans, various cardiovascular clinical signs are less frequently seen. Several cases of myocarditis, correlated with a positive SARS-CoV-2 test (PCR or serology), have been identified in England and at least one in France. In the latter case, further investigation led to a strong suspicion of hypertrophic cardiomyopathy complicated by myocarditis. It is highly likely that obesity (with significant fat deposition in the pleural and pericardial spaces, tissues with high expression of the ACE2 receptor) may have favoured these complications. SARS-CoV-2 infection should therefore now be included in the differential diagnosis of agents causing myocarditis and pneumonia in both cats and dogs.

9.
Chinese Veterinary Science / Zhongguo Shouyi Kexue ; 50(6):671-678, 2020.
Article in Chinese | CAB Abstracts | ID: covidwho-1975502

ABSTRACT

In present study, in order to develop a new and effective porcine epidemic diarrhea virus (PEDV)vaccine, three B cell epitopes and the truncated S1 gene of PEDV spike protein were combined and inserted into the immunodominant region of the HBcAg. Then the constructed recombinant plasmid HBcAg-PE was transformed to E. coli BL21 (DE3) for expression. After purification and identification by Western-blot, the expressed recombinant proteins HBPE were injected into BALB/c mice as vaccine antigen with different doses through intramuscular injection and its immune effect were preliminary evaluated. The results showed that the recombinant proteins HBPE was expressed as precipitation form and it could reacted specifically with PEDV-positive serum after purification and renaturation. Besides, the RH could induce anti-PEDV specific antibodies and the related Thl and Th2 cytokines in mice. The above results indicate that the recombinant compound epitope antigen of PEDV was successfully constructed. and its immunogenicity as a new vaccine candidate was evaluated in the mice in this study. The results of this study provided a new idea for the development of PEDV genetic engineering vaccine in the future.

10.
Journal of Yangzhou University, Agricultural and Life Sciences Edition ; 42(6):48-53, 2021.
Article in English, Chinese | CAB Abstracts | ID: covidwho-1964809

ABSTRACT

As a member of the family Picornaviridae, porcine sapelovirus (PSV) is often infected with porcine epidemic diarrhea virus, teschovirus and so on. In recent years, PSV has been isolated from porcine in many provinces of China. It suggests that it is necessary to strengthen the research on PSV. In this study, according to the sequence of PSV HuN2 strain, VP1 gene was inserted into the pGEX-6 P-1 vector, and expressed the recombinant protein. BALB/c mice aged 6-8 weeks were immunized according to the standard procedure. After the third immunization, the mouse orbital blood was collected to identify the antibody level. The highly positive mouse spleen cells were selected for cell fusion. The positive hybridoma cells and two subclones were screened by IFA method, and then a PSV VP1 monoclonal antibody was obtained, named as 33-2 A. The results of IFA showed that PSV could be recognized by 33-2 A MAb, and specific green fluorescence appeared in the cytoplasm;The results of WB and IP showed that PSV infected porcine cell could specifically bind to 33-2 A, and there was a specific band at 32 ku. We also identified the B-cell antigen epitope of 33-2 A, it was at amino acids 40-46 of PSV VP1 protein, and the polypeptide sequence was 40PALTAAE46. The results showed that the monoclonal antibody can react with PSV VP1 protein. The epitope was analyzed with the PSV sequences uploaded in NCBI, 33-2 A antibody can react with most PSV strains and has a certain universal to PSV. This study laid a foundation for the study of the etiology and pathogenesis of PSV.

11.
Journal of Southwest Minzu University Natural Science Edition ; 48(2):135-141, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-1958497

ABSTRACT

Feline Astrovirus (FAstV), Feline Parvovirus(FPV) and Feline Enteric Coronavirus (FECoV) are important pathogens causing diarrhea in cats.In order to establish a molecular detection method which can differentiate the three pathogens in the same PCR system, an FAstV/FPV/FECoV triple PCR method was established with optimized primer concentrations and annealing temperature, and specificity, sensitivity and repeatability were tested. The results showed that the PCR method could only identify FAstV (320 bp), FPV (468 bp) and FECoV (664 bp) genes, while not other canine and feline related pathogens. The detection limits of FAstV, FPV and FECoV were 2x10~7 copy/L (7.1 pg/L),4.7x10~6 copy/L (2.4 pg/L) and 7x10~6 copy/L (5.1 pg/L) respectively. The established triple PCR method was used to detect 207 cat fecal samples collected in Chengdu from 2019 to 2020, including 141 diarrhea samples and 66 clinical health samples. The detection rates of FAstV, FPV and FECoV were 24.15% (50/207), 37.20% (77/207) and 15.46% (32/207) respectively, and the co-infection rates of FAstV/FPV, FPV/FECoV and FAstv/FECoV were 9.18%,6.28% and 6.28% respectively. In conclusion, the triple PCR method of FAstV/FPV/FECoV was successfully established, and could be applied for virus detection and epidemiological investigation.

12.
Revista de Salud Animal ; 43(3), 2021.
Article in Spanish | CAB Abstracts | ID: covidwho-1863877

ABSTRACT

Winter dysentery (WD) is a highly contagious disease characterized by gastrointestinal disorders in cattle. Bovine coronavirus (BCoV) has been recognized as the etiological agent of this syndrome. In Cuba, it appeared for the first time in adult cattle in 2004, and later between January 2008 and February 2009. In 2020, diarrheal outbreaks with clinical and epidemiological characteristics similar to WD occurred in units from Mayabeque province. Of eight stool samples collected, the presence of BCoV was confirmed in seven of them by reverse transcription assays coupled to endpoint polymerase chain reaction (RT-PCR), which confirmed 87.5% positivity. Virus was isolated in cell cultures and its characteristic cytopathic effect was observed on the fifth day after inoculation. The results of the present study confirmed that BCoV is the causative agent of diarrheas in the bovine herds studied, and confirmed the epizootic mode of presentation of this disease in them.

13.
Albeitar ; 249:4-7, 2021.
Article in Spanish | CAB Abstracts | ID: covidwho-1837126
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