Search Results (320)

Infectious diseases in swine demand affordable, broad-spectrum antiviral strategies, such as recombinant interferons (IFNs). However, commercial yeast expression platforms often present financial barriers through licensing royalties. To provide a cost-effective regional alternative, we evaluated the domestic, thermotolerant yeast Ogataea polymorpha OP39 for producing recombinant porcine IFNs. Recombinant OP39 strains carrying expression cassettes for types I (poIFN-α1), II (poIFN-γ), and III (poIFN-λ3) IFNs were constructed and evaluated for their recombinant protein production performance. Following initial screening, the highest-yielding candidate, poIFN-α1, was selected for bioprocess optimization in shake flasks and a 5 L fermenter. Results showed that OP39 successfully secreted all three IFN types with a relatively low level of hyperglycosylation. Batch fermentation scale-up of r-poIFN-α1 achieved a final protein concentration of 0.45 ± 0.10 mg/mL. Crucially, the OP39-produced r-poIFN-α1 exhibited antiviral efficacy in vitro against economically important porcine viruses including African Swine Fever Virus, Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus. Based on the proof-of-concept results in this study, the OP39 platform can be further developed into a viable, full freedom-to-operate system for local or regional biomanufacturing of biologically active veterinary therapeutics to support livestock health management. Full article

Porcine epidemic diarrhea virus (PEDV) variant strains lead to vaccine failures and significant economic losses in swine farming, highlighting the need for new natural small-molecule antiviral candidates. In this study, we screened a library of 45 small molecules using a cytopathic effect (CPE)-based cytoprotective assay. Saikosaponin B2 (SSB2), a triterpenoid saponin derived from Bupleuri Radix, emerged as the most promising candidate, boasting a selectivity index of 19.77, which surpasses that of most natural compounds. Dose–response tests confirmed SSB2’s concentration-dependent anti-PEDV activity, with an inhibitory plateau reached at concentrations above 60 μmol/L (μM). The 50 half-maximal effective concentration (EC₅₀) values differed between CPE reduction and viral titer readouts, a discrepancy commonly due to varying detection sensitivities. Mechanistic assays revealed that SSB2 does not possess direct virucidal properties; instead, its antiviral efficacy depends on sustained treatment to inhibit viral adsorption and internalization. Time-of-addition experiments further demonstrated that SSB2 effectively suppresses both early viral entry and mid-stage intracellular genome replication, without affecting viral release. Notably, post-infection treatment resulted in stronger inhibition compared to continuous administration, possibly due to disrupted cellular proliferation homeostasis from prolonged exposure. Additionally, SSB2 maintained strong inhibitory effects against prevalent G2a (JL-06) and G2b (JL-08) field variants, though its efficacy was reduced for both strains and slightly weaker against JL-08 than JL-06. Overall, this study systematically characterizes SSB2’s dual-stage anti-PEDV profile and its broad-spectrum activity against spike-mutant strains, supporting SSB2 as a promising herbal lead for developing veterinary antivirals targeting variant PEDV. Full article

Porcine epidemic diarrhea virus (PEDV) continues to cause devastating economic losses in the swine industry. However, the lack of species-specific in vitro models and reliance on costly animal models hinders development of effective interventions. We established a high-fidelity platform using porcine induced pluripotent stem cells (piPSCs; line VSMUi001-C) via a 28-day stepwise differentiation protocol. Successful lineage commitment was validated by OCT4 downregulation and robust FOXA2/SOX17 expression at day 5. By day 28, the piPSC-derived intestinal epithelial cells (piPSC-IECs) exhibited organized LGR5+ niches, MUC2+ goblet cells, and Villin+ enterocytes, mirroring native tissue architecture. Barrier functionality was confirmed by the continuous distribution of the tight junction protein zonula occludens-1 (ZO-1). Our results demonstrate that piPSC-IECs are permissive to PEDV and support productive infection, encompassing the complete viral life cycle from entry to release of infectious progeny. Productive replication was confirmed by direct immunodetection of viral antigen within inoculated cells. Viral challenge induced characteristic cytopathic effects and a specific pro-inflammatory elevation of tumor necrosis factor-alpha (TNF-α). Notably, infection fragmented ZO-1, providing a mechanistic explanation for the leaky gut phenotype observed in vivo. This platform serves as a robust system for investigating viral kinetics and host–pathogen interactions with high species-specific relevance. Full article

Autophagy is a highly conserved degradation and recycling process in eukaryotic cells that plays a critical role in maintaining cellular homeostasis and responding to external stress. During viral infection, autophagy exhibits a classic “double-edged sword” effect—it can act as a host defense mechanism by directly degrading viral components, but it can also be hijacked by viruses to promote their own replication. Porcine epidemic diarrhea virus (PEDV), an important enteric coronavirus that severely affects the global swine industry, engages in a complex and sophisticated interplay with the host autophagy system. This review systematically dissects the dual regulatory mechanisms of autophagy during PEDV infection and reveals two intertwined functional axes. On one hand, PEDV utilizes multiple viral proteins to cooperatively manipulate the autophagic pathway—inducing mitophagy to suppress innate immune responses, utilizing autophagic membranes to construct replication platforms, and blocking autophagic flux to evade degradation—thereby establishing a multi-level pro-viral network. On the other hand, host cells deploy a unified molecular axis of “ubiquitination–autophagy receptor–lysosome” by mobilizing a broad array of restriction factors to target and degrade viral proteins, forming a coordinated defense system. These two axes converge at the oxidative stress–endoplasmic reticulum stress–autophagy hub, where PEDV NSP1 and NSP2 synergistically inhibit the NRF2 antioxidant system to trigger this cascade, while host factors such as DDX6 and ACE2 finely regulate the process. Based on this mechanistic framework, we discuss the therapeutic implications of targeting autophagy for PEDV intervention, with particular emphasis on the development of selective autophagy modulators as potential antiviral agents. We also identify key knowledge gaps and propose future research directions to translate these mechanistic insights into clinical or field applications. This review synthesizes the peer-reviewed literature published between 2013 and 2026, identified through systematic searches of PubMed, Web of Science, and Scopus databases. Notably, the majority of mechanistic findings discussed are derived from in vitro cell culture models, and their translation to in vivo settings remains a significant challenge. Bridging this gap will require validation in physiologically relevant models, such as porcine intestinal organoids and controlled piglet challenge studies, to assess the efficacy and safety of autophagy-targeting interventions in the context of intestinal homeostasis and mucosal immunity. Full article

Porcine reproductive and respiratory syndrome (PRRS) represents a critical infectious disease caused by the PRRS virus (PRRSV), posing a substantial threat to the global swine industry. In China, there is currently an epidemic trend characterized by the coexistence of multiple evolving genotypes. Effective prevention and control measures are contingent upon the availability of rapid, precise, and sensitive pathogen detection technologies. Addressing the need for swift differentiation of the predominant circulating strains, including the classical strains (PRRSV-C), the highly pathogenic strains (PRRSV-HP), and NADC30-like strains (PRRSV-NA), this study focuses on the NSP2 region of each lineage. It establishes a triple TaqMan-qPCR method capable of simultaneously genotyping these three lineages. The method demonstrated no cross-reactivity with other viruses, including porcine parvovirus (PPV), porcine transmissible gastroenteritis virus (TGEV), porcine pseudorabies virus (PRV), classical swine fever virus (CFSV), African swine fever virus (ASFV), porcine epidemic diarrhea virus (PEDV), porcine rotavirus (RV), and porcine circovirus (PCV2), thereby fully affirming its specificity. The sensitivity analysis demonstrated that the limit of detection (LOD) for the NSP2 gene in each lineage was 1 copy/μL based on the purified plasmids. Both inter-group and intra-group coefficients of variation (CV) were less than 4%, indicating high reproducibility. Comparative studies with commercial kits revealed that the developed TaqMan-qPCR method exhibited 100% relative sensitivity and a relative conformity rate exceeding 98%, suggesting its potential as a viable alternative to commercial kits. Furthermore, the analysis of 1049 clinical samples using the qPCR method indicated that the PRRSV-NADC30-like strains are currently the predominant circulating strain in clinical settings in Hebei Province. In conclusion, this study developed a triple TaqMan-qPCR method capable of simultaneously identifying PRRSV-C, PRRSV-HP and PRRSV-NA, enabling rapid and accurate identification of the PRRSV genotypes prevalent in pig populations. This provides a robust technical tool for the development of targeted immunization and prevention strategies. Full article

Coronaviruses are responsible for numerous diseases causing substantial morbidity and mortality to both humans and animals. In particular, they have caused three significant outbreaks in humans including severe acute respiratory syndrome 1 (SARS-CoV-1), Middle East respiratory syndrome (MERS-CoV), and, most recently, the severe acute respiratory syndrome 2 (SARS-CoV-2) pandemic. Two relevant veterinary diseases are porcine transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV), which cause severe losses in the pork industry. While efficacious vaccines were developed in an unprecedented timeframe for COVID-19, vaccines have not been commercialized for other human coronaviruses and vaccines against animal coronaviruses have limited efficacy and logistical challenges in administration. There is a clear need for more efficacious vaccines with simpler methods of delivery and administration for both human and veterinary use. The production of subunit vaccines in plant systems holds great promise in addressing the current challenges and facilitate the preparation for future potential outbreaks and new viruses. This review will summarize the state of development of vaccines in plant systems including tobacco, rice, maize, and others. Full article

Porcine epidemic diarrhea virus (PEDV) G2c variants have recently emerged, posing significant challenges to swine health management. As a major coronavirus affecting the swine industry, PEDV exhibits extensive genetic variability, which has greatly complicated disease control. Current vaccines provide suboptimal protection under field conditions. Therefore, the isolation of recently circulating strains and the establishment of a robust reverse genetics system are critical for advancing the study of emerging variants and facilitating rational vaccine development. In this study, a PEDV field strain designated PEDV-BJ-2023 was isolated from diarrheic piglets in Guizhou, China. Phylogenetic analysis based on the complete genome and spike gene classified PEDV-BJ-2023 within the emerging G2c lineage. To facilitate functional studies, a full-length infectious cDNA clone was constructed using transformation-associated recombination cloning in yeast. Furthermore, an enhanced green fluorescent protein reporter virus was generated via CRISPR/Cas9-assisted homologous recombination by inserting an EGFP-2A cassette upstream of the nucleocapsid gene. The recombinant viruses displayed virion morphology and plaque characteristics similar to those of the parental wild-type PEDV-BJ-2023 strain, although the parental virus exhibited faster replication during the early stage of infection in vitro. In 5-day-old piglets, all three viruses caused severe diarrhea, weight loss, and intestinal lesions; however, recombinant viruses exhibited slightly reduced viral shedding and pathogenicity, with rPEDV-EGFP being the most attenuated. Notably, rPEDV-EGFP maintained stable EGFP expression over eight serial passages. This study establishes a reverse genetics platform for an emerging G2c PEDV strain and provides a stable fluorescent reporter virus, offering valuable tools for visualizing viral infection and investigating virus–host interactions. Full article

This study analyzed Porcine epidemic diarrhea virus (PEDV) spike protein sequences and structures in Thailand from 2008 to 2024 to provide predicted structural templates that could inform regional vaccine selection and planned exposure frameworks. Using an in-silico approach, the researchers reduced sequence redundancy via CD-HIT (v4.8.1), established evolutionary lineages with BEAST (v1.10.4), and reconstructed protein structures using SWISS-MODEL. Structural comparisons and clustering were performed using DALI Z-scores and DBSCAN (v1.2.2), while Discotope 3 (v3.0) and ElliPro mapped B-cell epitope landscapes against a G1 reference strain. The results revealed a major lineage shift from G2a to G2b strains around 2017, with the spike proteins categorized into 14 subtypes and 6 eigenvalue clusters. Notably, minor amino acid substitutions altered properties such as hydrophobicity without disrupting the core structure, and certain deletions caused minimal structural deviations, indicating that sequence data or predicted structures alone do not fully dictate viral virulence or immunogenicity. Furthermore, primitive TH2 strains shared evolutionary links with G1 or US-InDel strains despite their G2 classification, identifying Cluster 1 as a potential ancestral structural type. In conclusion, this updated analysis provides crucial baseline data to optimize regional PEDV preventative measures, though further rigorous structural investigations are needed to definitively link specific spike alterations to virulence and host immune response. Full article

Porcine epidemic diarrhea virus (PEDV) is a major enteric coronavirus that causes severe economic losses to the global swine industry. Current vaccines suffer from weak immunogenicity, insufficient mucosal immunity, and a short duration of protection. Nanoparticle delivery systems have emerged as a promising strategy for next-generation vaccine development. In the present study, we constructed an S1-Ferritin nanoparticle vaccine using the SpyTag-SpyCatcher modular conjugation system. The morphology, particle size, and uniformity of the nanoparticle vaccine were systematically characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). After two immunizations, the S-Ferritin nanoparticle vaccine elicited potent humoral and cellular immune responses in both mice and piglets. In piglets, at 2 weeks post booster vaccination, PEDV-specific serum IgG endpoint titers peaked at 1:2560, virus-neutralizing antibody titers reached 1:256 against the JS-2/2015 strain, and serum IFN-γ levels reached 274 pg/mL. All these immunological indicators were significantly higher than those observed in the PEDV-inactivated whole-virus vaccine group. Furthermore, challenge tests showed that the S1-Ferritin nanoparticle vaccine provided complete protection against PEDV infection and significantly reduced the severity of diarrhea and intestinal damage in piglets after challenge. These findings suggest that the S1-Ferritin nanoparticle vaccine constitutes a promising candidate against PEDV infection, though our study is only a preliminary step and subsequent field trials in pigs are still required. Full article

Porcine epidemic diarrhea virus (PEDV) causes severe enteric disease and high mortality in piglets, yet effective therapeutic options remain scarce. To identify novel antivirals, we evaluated the inhibitory potential and molecular mechanisms of four procyanidin subtypes (A1, A2, B1, and B2) in Vero cells. Our results indicate that procyanidins A1 and B1 possess superior anti-PEDV activity compared with their analogs, acting primarily through direct virucidal inactivation (p < 0.001) and by blocking viral adsorption (p < 0.001), internalization (p < 0.001), and replication (p < 0.05). The SI of procyanidin A1 and B1 in Vero cells are 22.4 and 10.8. At the cellular level, mitochondrial membrane dynamics proteins regulate mitophagy-related proteins. PEDV infection disrupts mitochondrial dynamics and hijacks the autophagic machinery, which is characterized by the upregulation of the fission protein DRP1 and the mitophagy regulator Parkin, concurrent with the decrease of p62 and the increase in LC3-II. Treatment with procyanidins A1 and B1 effectively counteracted these alterations, restoring p62 levels (p < 0.05), decreasing LC3-II levels (p < 0.001), reducing autolysosome formation, and reversing the aberrant upregulation of DRP1 (p < 0.001) and Parkin (p < 0.05) to maintain mitochondrial homeostasis. Molecular docking results suggested that the potential binding affinity between procyanidin A1 and the mitochondrial protein Parkin was significantly higher than that of other configurations. Structural analysis further indicated that the presence of an additional ether bond and the trans configuration of the terminal catechin unit in procyanidin A1 might be important factors contributing to its superior antiviral efficacy. These results suggest that procyanidins may inhibit PEDV by inactivating viral particles or blocking their adsorption and internalization to prevent viral entry, while simultaneously modulating host mitochondrial proteins to suppress the replication of viruses that have already entered the cells, thereby supporting the potential of procyanidins A1 and B1 as effective antiviral candidates. Full article

The protective effect of Compound terminalia chebula extract (HL) against colonic injury induced by Porcine epidemic diarrhea virus (PEDV) infection in neonatal piglets remains unclear. This study aimed to evaluate the mitigating effects of HL on PEDV-induced colonic injury and elucidate the underlying mechanisms. Eighteen 7-day-old Duroc × Landrace × Large White piglets (2.58 ± 0.05 kg) were randomly assigned to three groups (n = 6/group): CON (blank control), PEDV (infected), and HL + PEDV (HL-supplemented + infected). The 11-day trial included 3 days of acclimatization (days 0–3) and an 8-day experimental period (days 4–11). HL (10 mg/kg BW) was orally administered daily to the HL + PEDV group. On day 8, PEDV and HL + PEDV groups were challenged with 3 mL PEDV (3 × 10⁶ TCID₅₀/mL), while CON received Dulbecco’s Modified Eagle Medium (DMEM). All piglets were euthanized on day 11 for colonic tissue collection. Results indicated that PEDV infection induced colonic injury, manifested by a significant increase in crypt depth and disruption of intestinal homeostasis. This was evidenced by impaired barrier integrity (upregulation of matrix metalloproteinase-7 gene [MMP7] and matrix metalloproteinase 13 gene [MMP13], mucus disorganization (elevation of mucin 5AC gene [MUC5AC]), oxidative stress (reduced catalase [CAT] activity and increased malondialdehyde [MDA] levels in serum and colon), and inflammation (upregulation of regenerative islet-derived protein 3γ gene [REG3G], S100 calcium-binding protein A8/A9 gene [S100A8/A9], and interleukin-1β gene [IL-1β]). Additionally, PEDV impaired colonic ion transport by downregulating calcium channel genes (Transient Receptor Potential Cation Channel Subfamily V Member 6 gene [TRPV6], Transient Receptor Potential Cation Channel Subfamily M Member 6 gene [TRPM6]). Notably, HL supplementation effectively reversed these adverse effects. HL restored colonic morphology, increased CAT activity, reduced MDA accumulation, and suppressed inflammatory gene expression. Furthermore, HL modulated the expression of genes involved in water and ion transport upregulating Aquaporin 7 gene (AQP7), Chloride Channel Accessory 4 gene (CLCA4), Sodium-Hydrogen Exchanger 3 gene (NHE3), Transient Receptor Potential Vanilloid 6 (TRPV6), and Transient Receptor Potential Melastatin 6 gene (TRPM6) and significantly inhibited PEDV replication, as indicated by the downregulation of the transcription levels of PEDV membranegene (M), nucleocapsid gene (N), and spike gene (S). Taken together, HL alleviates PEDV-triggered colonic tissue damage in suckling piglets via improving colonic antioxidant capacity, mitigating inflammatory response, partially regulating intestinal barrier and ion/water transport-related genes, and downregulating the transcription of PEDV structural genes at molecular and histological levels. Full article

Porcine epidemic diarrhea virus (PEDV) continues to undergo genetic evolution and remains a major etiological agent of enteric disease in swine, causing significant economic losses worldwide. This study investigated the molecular epidemiology and genetic characteristics of PEDV circulating in Chongqing, China, between 2022 and 2024. A total of 296 diarrheic piglet samples collected from nine regions were screened using RT-qPCR, of which 48.31% (143/296) tested positive for PEDV. A subset of positive samples was subjected to S gene amplification and sequencing, yielding 15 complete sequences. Phylogenetic analysis revealed that all sequenced strains clustered within the G2c lineage and showed high nucleotide similarity (93.37–94.09%) to the classical CV777 strain. Recombination analysis indicated potential recombination events among field strains involving S-INDEL and G2b-like parental lineages, although these findings are based on a limited number of sequences. Sequence analysis identified multiple amino acid substitutions within the COE antigenic region, while other neutralizing epitopes (SS2, SS6, and 2C10) remained largely conserved. In addition, variation in predicted N-glycosylation sites was observed among some strains. Structural modelling suggested that these changes may influence spike protein conformation and antigenic properties; however, these interpretations are based on in silico analysis and require experimental validation. Overall, the findings indicate ongoing genetic evolution of PEDV in Chongqing and suggest circulation of G2c-associated variants in diarrheic piglets. However, given the limited and non-random nature of sequencing, these results may not fully represent the broader viral population. Continued large-scale molecular surveillance and functional studies are needed to better understand PEDV evolution and to support the development of improved control strategies and vaccines. Full article

Porcine epidemic diarrhea virus (PEDV) remains one of the most critical enteric coronaviruses affecting the global swine industry. PEDV causes severe diarrhea, dehydration, and high mortality in neonatal piglets. Despite the widespread use of commercial vaccines, persistent PEDV outbreaks worldwide indicate that current vaccination strategies provide suboptimal protection. Increasing evidence suggests that the limited effectiveness of current control strategies is primarily attributable to two interrelated factors: continuous antigenic variation among circulating PEDV strains and inadequate induction of maternal mucosal immunity. Unlike systemic viral infections, effective protection against PEDV in neonatal piglets predominantly depends on lactational immunity mediated by the gut–mammary gland–secretory IgA (sIgA) axis. However, most currently available vaccines predominantly induce systemic IgG responses and fail to effectively stimulate intestinal immune imprinting or sustain sIgA secretion in colostrum and milk. In this review, we summarize the mechanisms underlying PEDV evolution and maternal mucosal immunity, with particular emphasis on the gut–mammary gland–sIgA axis. We further discuss the recent advances in and limitations of current vaccine platforms and propose an integrated framework for broadly protective PEDV vaccines based on structural antigen optimization, mucosal-targeted immunization, and sIgA-oriented evaluation systems. This framework may provide new insights into the rational design of more effective maternal vaccines against PEDV and other enteric coronaviruses affecting pigs. Full article

Porcine epidemic diarrhea virus (PEDV) imposes substantial economic losses on the global swine industry owing to its high pathogenicity and transmissibility. Although arginine (Arg) is known to support the integrity of intestinal barrier, it is not clear whether Arg can alleviate intestinal injury induced by PEDV. A total of 32 healthy 7-day-old piglets were randomly assigned to four groups (Control, Arg, PEDV, PEDV + Arg; eight replicates per group). From day 5, piglets in the Arg and PEDV + Arg groups were orally administered Arg at 400 mg/kg body weight until day 11; then, PEDV (1 × 10^5.5 TCID₅₀) was given orally for two PEDV-infected groups. On day 14, all piglets were slaughtered to obtain blood and intestine samples for further analysis. The results showed that PEDV infection significantly reduced T-SOD and CAT activities in plasma and intestine while elevating MPO levels. Arg supplementation restored T-SOD (plasma, duodenum, ileum), CAT (plasma, ileum), and GSH-Px (jejunum, ileum) activities and reduced MDA (jejunum) content in PEDV-infected piglets. Hematological analysis showed Arg alleviated PEDV-induced increases in MCV and RDW-SD, and significantly elevated MCHC. The real-time quantitative PCR analysis demonstrated that Arg further enhanced PEDV structural genes (M, N, S) expression in the duodenum, ileum, and colon. Concurrently, Arg significantly up-regulated interferon-stimulated genes (MX1, OASL, ISG15, IFITM3) in the ileum, IRF7 in the duodenum and colon, and IFN-β in the ileum. Arg also down-regulated the pro-inflammatory cytokines IL-6 and CXCL2 and the antimicrobial peptide REG3G in the colon, while up-regulating the tissue repair gene MMP13 in the ileum. In conclusion, oral Arg exhibits a unique dual role: it promotes PEDV replication to a certain extent while significantly enhancing antioxidant capacity, strengthening intestinal antiviral immunity, and attenuating intestinal inflammation. These findings highlight Arg’s role in promoting disease tolerance and offer a novel perspective for nutritional intervention strategies against PEDV infection. Full article

Porcine circovirus type 2 (PCV2) is the primary causative agent of a spectrum of porcine circovirus-associated diseases (PCVDs) and remains a major threat to the global swine industry. In this study, ten monoclonal antibodies (mAbs) targeting the Cap protein of PCV2 were generated and characterized. One mAb, designated 4C4, which exhibited high reactivity, strong neutralizing activity, and superior blocking efficacy, was selected for horseradish peroxidase (HRP) labeling. After optimizing the reaction parameters, a blocking ELISA was developed for the detection of the anti-PCV2 antibody. Using receiver operating characteristic (ROC) curve analysis, a cutoff value of 40% was established to distinguish positive from negative serum samples. The sensitivity and specificity of this blocking ELISA method were 98.66% and 100%, respectively. No cross-reactivity was observed with serum antibodies against classical swine fever virus (CSFV), porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), porcine reproductive and respiratory syndrome virus (PRRSV), or pseudorabies virus (PRV). Intra-assay and inter-assay repeatability tests yielded coefficients of variation (CVs) all below 10%, confirming the assay’s excellent reproducibility. Simultaneous testing of 312 clinical porcine serum samples using the developed bELISA and a commercial indirect ELISA kit revealed an overall coincidence rate of 99.04%. In addition, the percentage inhibition (PI) in the bELISA was strongly correlated with serum anti-PCV2 neutralizing antibody titers. In conclusion, the blocking ELISA developed herein demonstrates high sensitivity, strong specificity, and good reproducibility, serving as a potentially effective tool for the detection of the anti-PCV2 antibody and epidemiological investigation. Full article