Development of a Genetically Engineered Bivalent Vaccine against Porcine Epidemic Diarrhea Virus and Porcine Rotavirus

Core-shell Au@Ag NPs-based SERS-LFIA for the simultaneous quantitation of PEDV and PoRVA on site

Porcine epidemic diarrhea virus (PEDV) and porcine group A rotavirus (PoRVA) are predominant pathogens responsible for infectious diarrhea in porcine. Co-infections of PEDV and PoRVA have become a common situation in porcine farms in recent years, which increases the severity of the diarrhea disease and makes the accurate diagnosis more difficult. Rapid quantitation of PEDV and PoRVA is of great significance for the guarantee of disease control. In this study, a 4-mercaptobenzoic acid (MBA) modified core-shell Au@Ag nanoparticles (Au@MBA@Ag NPs) based lateral flow immunochromatography (LFIA) with dual-signal modes of visual observation and surface-enhanced Raman scattering (SERS) signal analysis was developed for the rapid and sensitive detection of PEDV and PoRVA. The established SERS-LFIA was capable of simultaneous quantitation of PEDV and PoRVA in porcine fecal samples within 20 min, with visual limits of detection (LODs) of 6.25 × 102 TCID50/mL and 7.42 × 102 copies/μL for PEDV and PoRVA, respectively. The LODs based on Raman signals were as low as 8.01 × 101 TCID50/mL and 3.19 × 102 copies/μL for PEDV and PoRVA, respectively, which were more than two orders of magnitude lower than the conventional colloidal gold (AuNPs) based colorimetric immunochromatography. Additionally, the SERS-LFIA exhibited no cross-reactivity with other prevalent pathogens and was highly repeatability, with a coefficient of variation (CV) of less than 15 %. When detecting clinical samples, the overall compliance of the SERS-LFIA with RT-PCR results was 93.3 %. Thus, the developed SERS-LFIA showed great potential for field applications on the rapid diagnosis of PEDV and PoRVA infection.

Traditional Chinese medicine as a promising choice for future control of PEDV

Porcine epidemic diarrhea virus (PEDV) is the major agent of the recent outbreaks of diarrhea in piglets, which has caused huge economic losses to the global swine industry. Since traditional vaccine strategies cannot provide complete protection for piglets, the development of safe, effective, and economical antiviral drugs is urgently needed. For many years, traditional Chinese medicines (TCMs) have been broadly applied for viral infectious diseases, exhibiting advantages such as abundant resources, lower toxicity, and minimal drug resistance. Many Chinese herbal monomers, single herbal extracts derived from these traditional drugs, and Chinese herbal recipes exhibit significant anti-PEDV effects in vitro and/or in vivo by targeting multiple sites and perspectives, including inhibition of the viral life cycle, anti-inflammation effects, enhancement of the host immune response, modulation of reactive oxygen species, and apoptosis. However, to date, no review has been published on the anti-PEDV effects of TCM. Therefore, this review summarizes the current control strategies for PEDV and systematically analyses the research progress of TCMs against PEDV. Furthermore, the future directions including the integration of nanotechnology and artificial intelligence with TCMs are also discussed. This review will provide a valuable reference for future studies on TCMs in antiviral research.

Rapid on-site diagnosis of PEDV and PoRV co-infection by gold magnetic nanoparticles-based SERS immunochromatography

Porcine epidemic diarrhea virus (PEDV) and porcine rotavirus (PoRV) are the two main pathogens causing porcine diarrhea, which are characterized by high morbidity and mortality. Most of the diagnostic methods available are limited to the laboratory or fail to highlight their advantages in terms of target species, detection time, sensitivity, and stability. To meet the demand for rapid on-site diagnosis of PEDV and PoRV co-infection, a surface-enhanced Raman scattering (SERS) immunochromatographic sensor based on gold magnetic nanoparticles (MNPs) was developed. The sensor is dual-mode, detecting on the basis of color signals by the naked eye and Raman signals. After a series of optimizations, the constructed sensor could perform simultaneous qualitative and quantitative detection of PEDV and PoRV in just 18 min, with visualized (color signals observed by the naked eye) limits of detection (LOD) of 3.13 × 102 TCID50/mL and 4.69 × 102 copies/μL, respectively. The LOD based on Raman signal analysis was as low as 4.63 × 101 TCID50/mL and 3.30 × 102 copies/μL for PEDV and PoRV, respectively. In addition, the sensor exhibited excellent specificity without cross-reactivity with common pathogens. The overall compliance rate with RT-PCR was 92.1 % (35/38) for 38 clinical samples. Therefore, the sensor is characterized by high sensitivity, specificity, reproducibility, and accuracy, making it suitable for the simultaneous rapid on-site detection of PEDV and PoRV.

Evolutionary characterization and pathogenicity of the highly virulent human-porcine reassortant G9P[23] porcine rotavirus HB05 strain in several Chinese provinces

Rotavirus A (RVA), a member of the Sedoreoviridae family, is significant intestinal pathogen that cause diarrhea in both piglets and humans. During of an outbreak that struck nursing piglets with diarrhea, a human-porcine reassortment rotavirus, named as RVA/Pig-wt/China/HB05/2023/G9P[23] (hereafter referred to as HB05), was identified. This specific strain was found to be prevalent in pig farms in several regions, including Hebei, Liaoning, Sichuan, Zhejiang and Henan, and caused significant economic losses from March to August 2023. To further explore the evolutionary diversity of HB05, a comprehensive analysis of all gene segments was conducted. The genome constellation was identified as G9-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1. Nucleotide sequence identity and phylogenetic analyses indicated that the NSP3 gene of HB05 is most closely related to the corresponding genes of Human strains, with the highest homology at 95.45% identity. The other genes (VP1-VP4, VP6-VP7, NSP1-NSP2, NSP4-NSP5) exhibited the closest relationship to porcine strains, with the highest homology ranging from 94.79 to 98.89% similarity. Therefore, it is likely that HB05 originated from genetic reassortment between porcine and human rotaviruses. The pathogenicity study performed on 3-day-old piglets revealed that severe diarrhea manifested 8 h post-infection after oral inoculation with the PoRV HB05 strain at a dose of 2 × 10^5.5 TCID50/mL per piglet. To our knowledge, this marks the first report of a prevalent and highly virulent human-porcine reassortment G9P[23] rotavirus A (RVA) strain identified in mainland China. This finding provides valuable insights into the evolutionary traits of the G9P[23] strain and suggests a possible risk of cross-species transmission.

Advances in porcine epidemic diarrhea virus research: genome, epidemiology, vaccines, and detection methods

Porcine epidemic diarrhea (PED) is a highly contagious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). The economic impact of PEDV on the global pig industry has been significant, resulting in considerable losses. This paper presents a review of the latest research progress on PEDV genome, molecular epidemiology, vaccine development, and molecular detection methods. It was determined that the genetic diversity of the PEDV spike (S) gene was closely associated with the epidemiological trend of PEDV. The prevalence of S gene variants of different genotypes exhibited variability across regions and pig populations. Epidemiological analyses have demonstrated that PEDV can be transmitted via multiple routes, including direct contact, airborne aerosol, and water source contamination. With regard to vaccine research, the available vaccines can be classified into several categories, including live-attenuated vaccines, inactivated vaccines, subunit vaccines, bacterial vector vaccines, viral vector vaccines, mRNA vaccines, etc. Each of these has distinctive characteristics in terms of immunogenicity, protection efficiency, and safety. Molecular detection methods, including PCR-based methods, isothermal amplification techniques, immunological assays, and biosensors, play an important role in the diagnosis and monitoring of PEDV. Furthermore, this paper examines the current developments in PEDV research and identifies the key areas of future investigation. The objective of this paper is to establish a theoretical foundation for the prevention and control strategies of PED, and to provide a point of reference for further research on the genomics, epidemiology, vaccine development and detection methods of PEDV.

Development and Validation of RAA-CRISPR/Cas12a-Based Assay for Detecting Porcine Rotavirus

Piglet diarrhea poses significant economic losses to the pig industry, posing a worldwide challenge that urgently needs to be addressed in pig breeding practices. Porcine rotavirus (PoRV) is an important viral diarrhea pathogen in piglets, with a high incidence rate and a tendency to cause growth retardation. To enhance the sensitivity and specificity of PoRV detection, we sequenced the NSP3 gene of G5 and G9 genotypes of rotavirus A (RVA), enabling simultaneous detection of the two serotypes. Subsequently, we developed a rapid PoRV detection method using a combination of recombinase-aided amplification (RAA) and CRISPR/Cas12a. In this method, Cas12a binds to RAA amplification products, guided by CRISPR-derived RNA (crRNA), which activates its cleavage activity and releases fluorescence by cutting FAM-BHQ-labeled single-stranded DNA (ssDNA). In the optimized reaction system, the recombinant plasmid PoRV can achieve a highly sensitive reaction within 30 min at 37 °C, with a detection limit as low as 2.43 copies/μL, which is ten times higher in sensitivity compared to the qPCR method. Results from specificity testing indicate that no cross-reactivity was observed between the RAA-CRISPR/Cas12a analysis of PoRV and other viral pathogens, including PoRV G3, PoRV G4, porcine epidemic diarrhea virus (PEDV), porcine epidemic diarrhea (PDCoV), and porcine reproductive and respiratory syndrome virus (PRRSV). In the clinical sample detection using the RAA-CRISPR/Cas12a method and qPCR, Cohen's Kappa value reached as high as 0.952. Furthermore, this approach eliminates the need for large-scale instrumentation, offering a visual result under an ultraviolet lamp through fluorescence signal output.

Tris stabilized AuNPs based lateral flow immunochromatography for the simultaneous detection of porcine epidemic diarrhea virus and rotavirus on-site

Porcine epidemic diarrhea virus (PEDV) and rotavirus has posed a significant threat to the pig industry annually across different nations, resulting in huge economic losses. The frequent co-infection of these two viruses in clinical settings complicates the process of differential diagnoses. Rapid and accurate detection of PEDV and rotavirus is in great demand for timely diarrhea disease prevention and control. In this study, tris stabilized AuNPs were prepared and a sensitive lateral flow immunoassay (LFIA) sensor was developed for the simultaneous and rapid detection of PEDV and rotavirus on site. After the system optimization, the established LFIA can simultaneously identify PEDV and rotavirus with limits of detection (LOD) of 1.25 × 103 TCID50 mL-1 and 3.13 × 102 pg mL-1, respectively. When applying for clinical samples, the LFIA show a concordance of 95 % and 100 % to reverse transcript polymerase chain reaction (RT-PCR) for PEDV and rotavirus respectively. Therefore, this LFIA can qualitatively detect PEDV and rotavirus in 18 min with high sensitivity and accuracy without any sophisticated equipment and operation, making it a promising candidate for the early diagnosis of PEDV or/and rotavirus diarrhea on site.

Isolation and identification of BRV G6P[1] strain in Heilongjiang province, Northeast China

Bovine rotavirus (BRV) is the main cause of acute gastroenteritis in calves, resulting in significant economic losses to the cattle industry worldwide. Additionally, BRV has multiple genotypes, which could enable cross-species transmission, thereby posing a significant risk to public health. However, there is a problem of multiple genotypes coexisting in BRV, and the cross-protection effect between different genotypes of rotavirus strains is not effective enough. Therefore, mastering clinical epidemic genotypes and using epidemic genotype strains for vaccine preparation is an effective means of preventing and controlling BRV. In this study, BRV strain DQ2020 in MA104 cells was identified by transmission electron microscopy (TEM), reverse transcription polymerase chain reaction (RT-PCR), and colloidal gold immunochromatographic test strips. The whole genome of BRV strain DQ2020 was sequenced and pathogenicity in suckling mice was assessed. The results showed that after 10 passages in MA104 cells, BRV strain DQ2020 induced cytopathic effects. Wheel-shaped virus particles (diameter, ~80 nm) were observed by TEM. A target band of 382 bp was detected by RT-PCR, a positive band was detected with the colloidal gold immunochromatographic test strips, and significant green fluorescence was observed by indirect immunofluorescence (IFA). The highest median tissue culture infectious dose of strain DQ2020 after 9 passages in MA104 cells was 10-4.81 viral particles/0.1 mL. Based on phylogenetic analysis of 11 gene fragments, the genotype of BRV strain DQ2020 was G6-P[1]-I2-R2-C2-M2-A11-N2-T6-E2-H3, confirming transmission of the G6-P[1] genotype in Chinese cattle herds. Further analysis showed that the isolated strain was a reassortant of bovine (VP7, VP6, NSP3, and NSP5), human (VP4, VP1, VP2, VP3, NSP2, and NSP4), and ovine (NSP1) rotaviruses. BRV strain DQ2020 caused damage to the intestinal villi of suckling mice and diarrhea, confirming pathogenicity. In summary, this study identified a reassortant strain of bovine, human, and ovine rotavirus that is pathogenic to lactating mice, and conducted whole genome sequence analysis, providing valuable insights for the genetic evolution of the virus and the development of vaccines.

The synergy of recombinant NSP4 and VP4 from porcine rotavirus elicited a strong mucosal response

Porcine rotavirus (PoRV) is one of the main pathogens causing diarrhea in piglets, and multiple genotypes coexist. However, an effective vaccine is currently lacking. Here, the potential adjuvant of nonstructural protein 4 (NSP4) and highly immunogenic structural protein VP4 prompted us to construct recombinant NSP486-175aa (NSP4*) and VP426-476aa (VP4*) proteins, combine them as immunogens to evaluate their efficacy. Results indicated that NSP4* enhanced systemic and local mucosal responses induced by VP4*. The VP4*-IgG, VP4*-IgA in feces and IgA-secreting cells in intestines induced by the co-immunization were significantly higher than those induced by VP4* alone. Co-immunization of NSP4* and VP4* also induced strong cellular immunity with significantly increased IFN-λ than the single VP4*. Summarily, the NSP4* as a synergistical antigen exerted limited effects on the PoRV NAbs elevation, but conferred strong VP4*-specific mucosal and cellular efficacy, which lays the foundation for the development of a more effective porcine rotavirus subunit vaccine.

Integrating network pharmacology with pharmacological research to elucidate the mechanism of modified Gegen Qinlian Decoction in treating porcine epidemic diarrhea

Porcine Epidemic Diarrhea Virus (PEDV) poses a significant threat to neonatal piglets, particularly due to the limited efficacy of existing vaccines and the scarcity of efficacious therapeutic drugs. Gegen Qinlian Decoction (GQD) has been employed for over two millennia in treating infectious diarrhea. Nonetheless, further scrutiny is required to improve the drug's efficacy and elucidate its underlying mechanisms of action. In this study, a modified GQD (MGQD) was developed and demonstrated its capacity to inhibit the replication of PEDV. Animal trials indicated that MGQD effectively alleviated pathological damage in immune tissues and modulated T-lymphocyte subsets. The integration of network analysis with UHPLC-MS/MS facilitated the identification of active ingredients within MGQD and elucidated the molecular mechanisms underlying its therapeutic effects against PEDV infections. In vitro studies revealed that MGQD significantly impeded PEDV proliferation in IPEC-J2 cells, promoting cellular growth via virucidal activity, inhibition of viral attachment, and disruption of viral biosynthesis. Furthermore, MGQD treatment led to increased expression levels of IFN-α, IFN-β, and IFN-λ3, while concurrently decreasing the expression of TNF-α, thereby enhancing resistance to PEDV infection in IPEC-J2 cells. In conclusion, our findings suggest that MGQD holds promise as a novel antiviral agent for the treatment of PEDV infections.

An isothermal nucleic acid amplification-based enzymatic recombinase amplification method for dual detection of porcine epidemic diarrhea virus and porcine rotavirus A

Viral diarrhea is the predominant digestive tract sickness in piglings, resulting in substantial profit losses in the porcine industry. Porcine rotavirus A (PoRVA) and porcine epidemic diarrhea virus (PEDV) are the main causes of grave gastroenteritis and massive dysentery, especially in piglets. PoRVA and PEDV have high transmissibility, exhibit similar clinical symptoms, and frequently co-occur. Therefore, to avoid financial losses, a quick, highly efficient, objective diagnostic test for the prevention and detection of these diseases is required. Enzymatic recombinase amplification (ERA) is a novel technology based on isothermal nucleic acid amplification. It demonstrates high sensitivity and excellent specificity, with a short processing time and easy operability, compared with other in vitro nucleic acid amplification technologies. In this study, a dual ERA method to detect and distinguish between PEDV and PoRVA nucleic acids was established. The method shows high sensitivity, as the detection limits were 101 copies/μL for both viruses. To test the usefulness of this method in clinical settings, we tested 64 swine clinical samples. Our results were 100% matched with those acquired using a commercially available kit. Therefore, we have successfully developed a dual diagnostic ERA nucleic acids method for detecting and distinguishing between PEDV and PoRVA.

Progress of research on coronaviruses and toroviruses in large domestic animals using reverse genetics systems

The generation of genetically engineered recombinant viruses from modified DNA/RNA is commonly referred to as reverse genetics, which allows the introduction of desired mutations into the viral genome. Reverse genetics systems (RGSs) are powerful tools for studying fundamental viral processes, mechanisms of infection, pathogenesis and vaccine development. However, establishing RGS for coronaviruses (CoVs) and toroviruses (ToVs), which have the largest genomes among vertebrate RNA viruses, is laborious and hampered by technical constraints. Hence, little research has focused on animal CoVs and ToVs using RGSs, especially in large domestic animals such as pigs and cattle. In the last decade, however, studies of porcine CoVs and bovine ToVs using RGSs have been reported. In addition, the coronavirus disease-2019 pandemic has prompted the development of new and simple CoV RGSs, which will accelerate RGS-based research on animal CoVs and ToVs. In this review, we summarise the general characteristics of CoVs and ToVs, the RGSs available for CoVs and ToVs and the progress made in the last decade in RGS-based research on porcine CoVs and bovine ToVs.

A Comprehensive Review of Our Understanding and Challenges of Viral Vaccines against Swine Pathogens

Pig farming has become a strategically significant and economically important industry across the globe. It is also a potentially vulnerable sector due to challenges posed by transboundary diseases in which viral infections are at the forefront. Among the porcine viral diseases, African swine fever, classical swine fever, foot and mouth disease, porcine reproductive and respiratory syndrome, pseudorabies, swine influenza, and transmissible gastroenteritis are some of the diseases that cause substantial economic losses in the pig industry. It is a well-established fact that vaccination is undoubtedly the most effective strategy to control viral infections in animals. From the period of Jenner and Pasteur to the recent new-generation technology era, the development of vaccines has contributed significantly to reducing the burden of viral infections on animals and humans. Inactivated and modified live viral vaccines provide partial protection against key pathogens. However, there is a need to improve these vaccines to address emerging infections more comprehensively and ensure their safety. The recent reports on new-generation vaccines against swine viruses like DNA, viral-vector-based replicon, chimeric, peptide, plant-made, virus-like particle, and nanoparticle-based vaccines are very encouraging. The current review gathers comprehensive information on the available vaccines and the future perspectives on porcine viral vaccines.

Developing Next-Generation Live Attenuated Vaccines for Porcine Epidemic Diarrhea Using Reverse Genetic Techniques

Porcine epidemic diarrhea virus (PEDV) is the etiology of porcine epidemic diarrhea (PED), a highly contagious digestive disease in pigs and especially in neonatal piglets, in which a mortality rate of up to 100% will be induced. Immunizing pregnant sows remains the most promising and effective strategy for protecting their neonatal offspring from PEDV. Although half a century has passed since its first report in Europe and several prophylactic vaccines (inactivated or live attenuated) have been developed, PED still poses a significant economic concern to the swine industry worldwide. Hence, there is an urgent need for novel vaccines in clinical practice, especially live attenuated vaccines (LAVs) that can induce a strong protective lactogenic immune response in pregnant sows. Reverse genetic techniques provide a robust tool for virological research from the function of viral proteins to the generation of rationally designed vaccines. In this review, after systematically summarizing the research progress on virulence-related viral proteins, we reviewed reverse genetics techniques for PEDV and their application in the development of PED LAVs. Then, we probed into the potential methods for generating safe, effective, and genetically stable PED LAV candidates, aiming to provide new ideas for the rational design of PED LAVs.

Recombinant bivalent subunit vaccine combining truncated VP4 from P[7] and P[23] induces protective immunity against prevalent porcine rotaviruses

Porcine rotaviruses (PoRVs) cause severe economic losses in the swine industry. P[7] and P[23] are the predominant genotypes circulating on farms, but no vaccine is yet available. Here, we developed a bivalent subunit PoRV vaccine using truncated versions (VP4*) of the VP4 proteins from P[7] and P[23]. The vaccination of mice with the bivalent subunit vaccine elicited more robust neutralizing antibodies (NAbs) and cellular immune responses than its components, even at high doses. The bivalent subunit vaccine and inactivated bivalent vaccine prepared from strains PoRVs G9P[7] and G9P[23] were used to examine their protective efficacy in sows and suckling piglets after passive immunization. The immunized sows showed significantly elevated NAbs in the serum and colostrum, and the suckling piglets acquired high levels of sIgA antibodies from the colostrum. Challenging subunit-vaccinated or inactivated-vaccinated piglets with homologous virulent strains did not induce diarrhea, except in one or two piglets, which had mild diarrhea. Immunization with the bivalent subunit vaccine and inactivated vaccine also alleviated the microscopic lesions in the intestinal tissues caused by the challenge with the corresponding homologous virulent strain. However, all the piglets in the challenged group displayed mild to watery diarrhea and high levels of viral shedding, whereas the feces and intestines of the piglets in the bivalent subunit vaccine and inactivated vaccine groups had lower viral loads. In summary, our data show for the first time that a bivalent subunit vaccine combining VP4*P[7] and VP4*P[23] effectively protects piglets against the diarrhea caused by homologous virulent strains.IMPORTANCEPoRVs are the main causes of diarrhea in piglets worldwide. The multisegmented genome of PoRVs allows the reassortment of VP4 and VP7 genes from different RV species and strains. The P[7] and P[23] are the predominant genotypes circulating in pig farms, but no vaccine is available at present in China. Subunit vaccines, as nonreplicating vaccines, are an option to cope with variable genotypes. Here, we have developed a bivalent subunit candidate vaccine based on a truncated VP4 protein, which induced robust humoral and cellular immune responses and protected piglets against challenge with homologous PoRV. It also appears to be safe. These data show that the truncated VP4-protein-based subunit vaccine is a promising candidate for the prevention of PoRV diarrhea.

Prevention and Control of Swine Enteric Coronaviruses in China: A Review of Vaccine Development and Application

Swine enteric coronaviruses (SECs) cause significant economic losses to the pig industry in China. Although many commercialized vaccines against transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV) are available, viruses are still widespread. The recent emergence of porcine deltacoronavirus (PDCoV) and swine acute diarrhea syndrome coronavirus (SADS-CoV), for which no vaccines are available, increases the disease burden. In this review, we first introduced the genomic organization and epidemiology of SECs in China. Then, we discussed the current vaccine development and application in China, aiming to provide suggestions for better prevention and control of SECs in China and other countries.

Reverse Genetics Systems for Emerging and Re-Emerging Swine Coronaviruses and Applications

Emerging and re-emerging swine coronaviruses (CoVs), including porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome-CoV (SADS-CoV), cause severe diarrhea in neonatal piglets, and CoV infection is associated with significant economic losses for the swine industry worldwide. Reverse genetics systems realize the manipulation of RNA virus genome and facilitate the development of new vaccines. Thus far, five reverse genetics approaches have been successfully applied to engineer the swine CoV genome: targeted RNA recombination, in vitro ligation, bacterial artificial chromosome-based ligation, vaccinia virus -based recombination, and yeast-based method. This review summarizes the advantages and limitations of these approaches; it also discusses the latest research progress in terms of their use for virus-related pathogenesis elucidation, vaccine candidate development, antiviral drug screening, and virus replication mechanism determination.

Establishment and Application of a Triplex Real-Time RT-PCR Assay for Differentiation of PEDV, PoRV, and PDCoV

Porcine viral diarrhea is very common in clinical practice and has caused huge losses to the pig industry. Porcine epidemic diarrhea virus (PEDV), porcine rotavirus (PoRV), and porcine deltacoronavirus (PDCoV) are important pathogens of porcine viral diarrhea. Co-infection situations among these three viruses in clinics are common, which increases the difficulty of differential diagnosis. Currently, polymerase chain reaction (PCR) is commonly used to detect pathogens. TaqMan real-time PCR is more sensitive than conventional PCR and has better specificity and accuracy. In this study, a triplex real-time RT-PCR assay based on TaqMan probes was developed for differential detection of PEDV, PoRV, and PDCoV. The triplex real-time RT-PCR assay developed in this study could not detect unrelated pathogens and showed satisfactory specificity, sensitivity, repeatability, and reproducibility with a limit of detection (LOD) of 6.0 × 10¹ copies/μL. Sixteen clinical samples were used to compare the results of the commercial RT-PCR kit and the triplex RT-PCR for PEDV, PoRV, and PDCoV detection, and the results were completely consistent. A total of 112 piglet diarrhea samples collected from Jiangsu province were next used to study the local prevalence of PEDV, PoRV, and PDCoV. The positive rates of PEDV, PoRV, and PDCoV detected by the triplex real-time RT-PCR were 51.79% (58/112), 59.82% (67/112), and 2.68% (3/112), respectively. The co-infections of PEDV and PoRV were frequent (26/112, 23.21%), followed by the co-infections of PDCoV and PoRV (2/112, 1.79%). This study established a useful tool for simultaneous differentiation of PEDV, PoRV, and PDCoV in practice and provided valuable information on the prevalence of these diarrhea viral pathogens in Jiangsu province.