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Archives of Virology Nov 2022Porcine deltacoronavirus (PDCoV) is an enteric virus that was first identified in 2012. Although PDCoV has been detected worldwide, there is little information about its...
Porcine deltacoronavirus (PDCoV) is an enteric virus that was first identified in 2012. Although PDCoV has been detected worldwide, there is little information about its circulation in western China. In this study, fecal samples were collected from piglets with watery diarrhea in western China between 2015 and 2018 for the detection of PDCoV. The positive rate was 29.9%. A PDCoV strain (CHN/CQ/BN23/2016, BN23) was isolated and selected for further investigation. Phylogenetic analysis showed that this strain formed an individual cluster between the early Chinese lineage and the Chinese lineage. RDP4 and SimPlot analysis demonstrated that strain BN23 is a recombinant of Thailand/S5015L/2015 and CHN-AH-2004. The pathogenicity of BN23 was evaluated in 3-day-old piglets. Challenged piglets developed serious clinical signs and died at 3 days post-inoculation. Our data show that PDCoV is prevalent in western China and that strain BN23 is highly pathogenic to newborn piglets. Therefore, more attention should be paid to emerging PDCoV strains in western China.
Topics: Animals; China; Coronavirus Infections; Deltacoronavirus; Diarrhea; Genomics; Phylogeny; Swine; Swine Diseases; Virulence
PubMed: 36029354
DOI: 10.1007/s00705-022-05549-w -
Viruses Aug 2022Porcine deltacoronavirus (PDCoV) is an emerging enteropathogen which mainly causes diarrhea, dehydration and death in nursing piglets, threatening the global swine...
Porcine deltacoronavirus (PDCoV) is an emerging enteropathogen which mainly causes diarrhea, dehydration and death in nursing piglets, threatening the global swine industry. Moreover, it can infect multiple animal species and humans. Hence, reliable diagnostic assays are needed to better control this zoonotic pathogen. Here, a blocking ELISA was developed using a recombinant nucleocapsid (N) protein as the coating antigen paired with an N-specific monoclonal antibody (mAb) as the detection antibody. The percent inhibition (PI) of the ELISA was determined using 384 swine serum samples, with an indirect immunofluorescence assay (IFA) as the reference method. Through receiver operating characteristic analysis in conjunction with Youden's index, the optimal PI cut-off value was determined to be 51.65%, which corresponded to a diagnostic sensitivity of 98.79% and a diagnostic specificity of 100%. Of the 330 serum samples tested positive via IFA, 326 and 4 were tested positive and negative via the ELISA, respectively, while the 54 serum samples tested negative via IFA were all negative via the ELISA. The overall coincidence rate between the two assays was 98.96% (380/384). The ELISA exhibited good repeatability and did not cross-react with antisera against other swine pathogens. Overall, this is the first report on developing a blocking ELISA for PDCoV serodiagnosis.
Topics: Animals; Antibodies, Viral; Coronavirus Infections; Deltacoronavirus; Enzyme-Linked Immunosorbent Assay; Humans; Nucleocapsid Proteins; Swine; Swine Diseases
PubMed: 36016437
DOI: 10.3390/v14081815 -
Viruses Aug 2022Porcine deltacoronavirus (PDCoV) is a recently discovered enteropathogenic coronavirus and has caused significant economic impacts on the pork industry. Although studies...
Porcine deltacoronavirus (PDCoV) is a recently discovered enteropathogenic coronavirus and has caused significant economic impacts on the pork industry. Although studies have partly uncovered the molecular mechanism of PDCoV-host interaction, it requires further research. In this study, we explored the roles of Stromal Antigen 2 (STAG2) in PDCoV infection. We found that STAG2-deficient cells inhibited infection with vesicular stomatitis virus (VSV) and PDCoV, whereas restoration of STAG2 expression in STAG2-depleted (STAG2) IPEC-J2 cells line restored PDCoV infection, suggesting that STAG2 is involved in the PDCoV replication. Furthermore, we found that STAG2 deficiency results in robust interferon (IFN) expression. Subsequently, we found that STAG2 deficiency results in the activation of JAK-STAT signaling and the expression of IFN stimulated gene (ISG), which establish an antiviral state. Taken together, the depletion of STAG2 activates the JAK-STAT signaling and induces the expression of ISG, thereby inhibiting PDCoV replication. Our study provides new insights and potential therapeutic targets for unraveling the mechanism of PDCoV replication.
Topics: Animals; Antiviral Agents; Coronavirus; Coronavirus Infections; Deltacoronavirus; Interferons; Swine; Swine Diseases
PubMed: 36016405
DOI: 10.3390/v14081783 -
Pathogens (Basel, Switzerland) Aug 2022Porcine deltacoronavirus (PDCoV), belonging to family and genus , is a major enteric pathogen in swine. Accurate PDCoV diagnosis relying on laboratory testing and...
Porcine deltacoronavirus (PDCoV), belonging to family and genus , is a major enteric pathogen in swine. Accurate PDCoV diagnosis relying on laboratory testing and antibody detection is an important approach. This study evaluated the potential of the receptor-binding subunit of the PDCoV spike protein (S1), generated using a mammalian expression system, for specific antibody detection via indirect enzyme-linked immunosorbent assay (ELISA). Serum samples were collected at day post-inoculation (DPI) -7 to 42, from pigs ( = 83) experimentally inoculated with different porcine coronaviruses (PorCoV). The diagnostic sensitivity of the PDCoV S1-based ELISA was evaluated using serum samples ( = 72) from PDCoV-inoculated animals. The diagnostic specificity and potential cross-reactivity of the assay was evaluated on PorCoV-negative samples ( = 345) and samples collected from pigs experimentally inoculated with other PorCoVs ( = 472). The overall diagnostic performance, time of detection, and detection rate over time varied across different S/P cut-offs, estimated by Receiver Operating Characteristic (ROC) curve analysis. The higher detection rate in the PDCoV group was observed after DPI 21. An S/P cut-off of 0.25 provided 100% specificity with no serological cross-reactivity against other PorCoV. These results support the use of S1 protein-based ELISA for accurate detection of PDCoV infections, transference of maternal antibodies, or active surveillance.
PubMed: 36015031
DOI: 10.3390/pathogens11080910 -
Virulence Dec 2022Porcine deltacoronavirus (PDCoV) is an emerging enteropathogen causing severe diarrhoea, dehydration, and death in nursing piglets and enormous economic losses for the...
A nucleic acid detection assay combining reverse transcription recombinase-aided amplification with a lateral flow dipstick for the rapid visual detection of porcine deltacoronavirus.
Porcine deltacoronavirus (PDCoV) is an emerging enteropathogen causing severe diarrhoea, dehydration, and death in nursing piglets and enormous economic losses for the global swine industry. Furthermore, it can infect multiple animal species including humans. Therefore, a rapid, definitive diagnostic assay is required for the effective control of this zoonotic pathogen. To identify PDCoV, we developed a nucleic acid detection assay combining reverse transcription recombinase-aided amplification (RT-RAA) with a lateral flow dipstick (LFD) targeting the highly conserved genomic region in the gene. The RT-RAA-LFD assay exhibited good PDCoV detection reproducibility and repeatability and could be completed within 11 min. Ten minutes at 40 °C was required for nucleic acid amplification and 1 min at room temperature was needed for the visual LFD readout. The assay specifically detected PDCoV and did not cross-react with any other major swine pathogens. The 95% limit of detection (LOD) was 3.97 median tissue culture infectious dose PDCoV RNA per reaction. This performance was comparable to that of a reference TaqMan-based real-time RT-PCR (trRT-PCR) assay for PDCoV. Of 149 swine small intestine, rectal swab, and serum samples, 71 and 75 tested positive for PDCoV according to RT-RAA-LFD and trRT-PCR, respectively. The diagnostic coincidence rate for both assays was 97.32% (145/149) and the kappa value was 0.946 (p < 0.001). Overall, the RT-RAA-LFD assay is a user-friendly diagnostic tool that can rapidly and visually detect PDCoV.
Topics: Animals; Deltacoronavirus; Humans; Nucleic Acid Amplification Techniques; Nucleic Acids; Recombinases; Reproducibility of Results; Reverse Transcription; Sensitivity and Specificity; Swine
PubMed: 36005235
DOI: 10.1080/21505594.2022.2116157 -
Rapid detection of porcine circovirus type 2 by a red latex microsphere immunochromatographic strip.Applied Microbiology and Biotechnology Sep 2022To establish a rapid and specific antigen detection method for porcine circovirus type 2 (PCV2), monoclonal antibodies (mAbs) were produced against the PCV2 epidemic...
To establish a rapid and specific antigen detection method for porcine circovirus type 2 (PCV2), monoclonal antibodies (mAbs) were produced against the PCV2 epidemic strains and a red latex microsphere immunochromatographic strip was established. A total of eight anti-PCV2b and four anti-PCV2d mAbs were produced, and seven mAbs were confirmed to react with PCV2a, PCV2b, and PCV2d strains using an immunoperoxidase monolayer assay. The results of micro-neutralization tests showed that the mAbs 2C8, 9H4, 10G7, 7B9, and 7C7 had good neutralizing activity, whereas the neutralizing activity of the mAbs 4B3, 4C9, 6H9, and 7E2 was lower than 50%. Three mAbs, 4B3, 7C7, and 9H4, and PCV2 pAb were selected for the establishment of a red latex microsphere immunochromatographic strip, and the combination of mAb 7C7 labeled with red latex microspheres and mAb 9H4 exhibited the greatest detection ability. The immunochromatographic strip had minimum detection limits of 10 TCID/0.1 ml, 10 TCID/0.1 ml, and 10 TCID/0.1 ml for PCV2a/CL, PCV2b/MDJ, and PCV2d/LNHC, respectively. Furthermore, no cross-reactivity was found for African swine fever virus, classical swine fever virus, porcine respiratory and reproductive syndrome virus, porcine parvovirus, porcine pseudorabies virus, porcine circovirus type 1, transmissible gastroenteritis virus, porcine epidemic diarrhea virus, porcine rotavirus, or porcine deltacoronavirus using the immunochromatographic strip. Using PCR as a reference standard, the detection sensitivity, specificity, and overall coincidence rate of the immunochromatographic strip were 81.13%, 100%, and 90.00%. Additionally, the detection ability of the immunochromatographic strip was correlated with that of virus titration. The immunochromatographic strip was used to detect 183 clinical disease samples, and the average positive detection rate was 22.95%. In summary, this method has good sensitivity and specificity and is simple, convenient, and quick to operate. It has high application value for on-site diagnosis of PCV2 and virus quantification. KEY POINTS: • A red latex microsphere immunochromatographic strip for PCV2 detection was developed. • The method was not only simple to operate, but also takes less time. • The method had good sensitivity and specificity.
Topics: African Swine Fever Virus; Animals; Antibodies, Monoclonal; Circoviridae Infections; Circovirus; Latex; Microspheres; Swine; Swine Diseases
PubMed: 35945364
DOI: 10.1007/s00253-022-12074-y -
Journal of Virology Aug 2022Protein acetylation plays an important role during virus infection. Thus, it is not surprising that viruses always evolve elaborate mechanisms to regulate the functions...
Protein acetylation plays an important role during virus infection. Thus, it is not surprising that viruses always evolve elaborate mechanisms to regulate the functions of histone deacetylases (HDACs), the essential transcriptional and epigenetic regulators for deacetylation. Porcine deltacoronavirus (PDCoV), an emerging enteropathogenic coronavirus, causes severe diarrhea in suckling piglets and has the potential to infect humans. In this study, we found that PDCoV infection inhibited cellular HDAC activity. By screening the expressions of different HDAC subfamilies after PDCoV infection, we unexpectedly found that HDAC2 was cleaved. Ectopic expression of HDAC2 significantly inhibited PDCoV replication, while the reverse effects could be observed after treatment with an HDAC2 inhibitor (CAY10683) or the knockdown of HDAC2 expression by specific siRNA. Furthermore, we demonstrated that PDCoV-encoded nonstructural protein 5 (nsp5), a 3C-like protease, was responsible for HDAC2 cleavage through its protease activity. Detailed analyses showed that PDCoV nsp5 cleaved HDAC2 at glutamine 261 (Q261), and the cleaved fragments (amino acids 1 to 261 and 262 to 488) lost the ability to inhibit PDCoV replication. Interestingly, the Q261 cleavage site is highly conserved in HDAC2 homologs from other mammalian species, and the nsp5s encoded by seven tested mammalian coronaviruses also cleaved HDAC2, suggesting that cleaving HDAC2 may be a common strategy used by different mammalian coronaviruses to antagonize the antiviral role of HDAC2. As an emerging porcine enteropathogenic coronavirus that possesses the potential to infect humans, porcine deltacoronavirus (PDCoV) is receiving increasing attention. In this work, we found that PDCoV infection downregulated cellular histone deacetylase (HDAC) activity. Of particular interest, the viral 3C-like protease, encoded by the PDCoV nonstructural protein 5 (nsp5), cleaved HDAC2, and this cleavage could be observed in the context of PDCoV infection. Furthermore, the cleavage of HDAC2 appears to be a common strategy among mammalian coronaviruses, including the emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), to antagonize the antiviral role of HDAC2. To our knowledge, PDCoV nsp5 is the first identified viral protein that can cleave cellular HDAC2. Results from our study provide new targets to develop drugs combating coronavirus infection.
Topics: Animals; COVID-19; Deltacoronavirus; Histone Deacetylase 2; Humans; Mammals; Peptide Hydrolases; SARS-CoV-2; Swine; Swine Diseases
PubMed: 35916536
DOI: 10.1128/jvi.01027-22 -
Animals : An Open Access Journal From... Jul 2022African swine fever virus (ASFV) causes African swine fever (ASF), a devastating hemorrhagic disease of domestic pigs and wild boars. Currently, the MGF505R, EP402R...
The Development of a Multiplex Real-Time Quantitative PCR Assay for the Differential Detection of the Wild-Type Strain and the MGF505-2R, EP402R and I177L Gene-Deleted Strain of the African Swine Fever Virus.
African swine fever virus (ASFV) causes African swine fever (ASF), a devastating hemorrhagic disease of domestic pigs and wild boars. Currently, the MGF505R, EP402R (CD2v) and I177L gene-deleted ASFV strains were confirmed to be the ideal vaccine candidate strains. To develop an assay for differentiating the wild-type and gene-deleted ASFV strains, four pairs of specific primers and TaqMan probes targeting the ASFV B646L (p72), I177L, MGF505-2R and EP402R (CD2v) genes were designed. A multiplex real-time qPCR assay for the differential detection of the wild-type and gene-deleted ASFV strains was developed after optimizing the reaction conditions, including the annealing temperature, primer concentration and probe concentration. The results showed that the multiplex real-time qPCR assay can specifically test the ASFV B646L (p72), I177L, MGF505-2R and EP402R (CD2v) genes with a limit of detection (LOD) of 32.1 copies/μL for the B646L (p72) gene, and 3.21 copies/μL for the I177L, MGF505-2R and EP402R (CD2v) genes. However, the assay cannot test for the classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), porcine circovirus type 2 (PCV2), PCV3 and pseudorabies virus (PRV). The assay demonstrated good repeatability and reproducibility with coefficients of variation (CV) less than 1.56% for both the intra- and inter-assay. The assay was used to test 4239 clinical samples, and the results showed that 12.60% (534/4239) samples were positive for ASFV, of which 10 samples lacked the EP402R gene, 6 samples lacked the MGF505-2R gene and 14 samples lacked the EP402R and MGF505-2R genes. The results indicated that the multiplex real-time qPCR developed in this study can provide a rapid, sensitive and specific diagnostic tool for the differential detection of the ASFV B646L, I177L, MGF505-2R and EP402R genes.
PubMed: 35883301
DOI: 10.3390/ani12141754 -
Frontiers in Veterinary Science 2022Porcine deltacoronavirus (PDCoV) causes watery diarrhea, vomiting, and 30-40% mortality in newborn piglets. A simple, rapid, and sensitive method for PDCoV detection is...
Porcine deltacoronavirus (PDCoV) causes watery diarrhea, vomiting, and 30-40% mortality in newborn piglets. A simple, rapid, and sensitive method for PDCoV detection is valuable in its surveillance and control. Here, we developed a novel, cleaved probe-based reverse transcription loop-mediated isothermal amplification (CP-RT-LAMP) method for PDCoV detection. A cleaved probe with a ribonucleotide insertion that targeted the N gene of PDCoV was designed. During the reaction, the enzyme ribonuclease H2 is activated only when the cleaved probe is perfectly complementary to the template, leading to the hydrolytic release of a quencher moiety and signal output. This method can be easily used on a real-time fluorescence quantitative equipment or an on-site isothermal instrument combined with a smartphone. The specificity assay showed no cross-reactivity with other porcine enteric pathogens. This method had a detection limit of 25 copies/μL, suggesting comparable sensitivity with reverse transcription quantitative PCR (RT-qPCR). In detecting 100 clinical samples (48 fecal swab specimens and 52 intestinal specimens), the detection rate of the CP-RT-LAMP method (26%) was higher than that of RT-qPCR (17%). Thus, it is a highly specific and sensitive diagnostic method for PDCoV, with a great application potential for monitoring PDCoV in the laboratory or point-of-care testing in the field.
PubMed: 35812893
DOI: 10.3389/fvets.2022.896416 -
BMC Genomics Jul 2022Noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are pivotal regulators involved in the pathogenic mechanism of multiple...
BACKGROUND
Noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are pivotal regulators involved in the pathogenic mechanism of multiple coronaviruses. Porcine deltacoronavirus (PDCoV) has evolved multiple strategies to escape the innate immune response of host cells, but whether ncRNAs are involved in this process during PDCoV infection is still unknown.
RESULTS
In this study, the expression profiles of miRNAs, lncRNAs and mRNAs in IPEC-J2 cells infected with PDCoV at 0, 12 and 24 hours postinfection (hpi) were identified through small RNA and RNA sequencing. The differentially expressed miRNAs (DEmiRNAs), lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were screened from the comparison group of IPEC-J2 cells at 0 and 12 hpi as well as the comparison group of IPEC-J2 cells at 12 and 24 hpi. The target genes of these DEncRNAs were predicted. The bioinformatics analysis of the target genes revealed multiple significantly enriched functions and pathways. Among them, the genes that were associated with innate immunity were specifically screened. The expression of innate immunity-related ncRNAs and mRNAs was validated by RT-qPCR. Competing endogenous RNA (ceRNA) regulatory networks among innate immunity-related ncRNAs and their target mRNAs were established. Moreover, we found that the replication of PDCoV was significantly inhibited by two innate immunity-related miRNAs, ssc-miR-30c-3p and ssc-miR-374b-3p, in IPEC-J2 cells.
CONCLUSIONS
This study provides a data platform to conduct studies of the pathogenic mechanism of PDCoV from a new perspective and will be helpful for further elucidation of the functional role of ncRNAs involved in PDCoV escaping the innate immune response.
Topics: Animals; Immunity, Innate; MicroRNAs; RNA, Long Noncoding; RNA, Messenger; RNA, Untranslated; Swine
PubMed: 35787252
DOI: 10.1186/s12864-022-08722-2