Recently, the detection rate of PDCoV (Porcine Deltacoronavirus) in cases of nursing piglet diarrhea on pig farms across multiple regions of China has continued to rise. This emerging pathogen, with clinical symptoms highly similar to those of PEDV and TGEV, is often overlooked due to missed diagnosis, causing severe casualties in entire litters of nursing piglets. To help colleagues in farming and research systematically understand this pathogen and to provide reliable diagnostic raw materials, Qianxun Bio's content this issue systematically reviews the virological basis of PDCoV, while officially launching the PDCoV S protein new product expressed in CHO cells (eukaryotic).
I. What is Porcine Deltacoronavirus (PDCoV)?
Porcine deltacoronavirus (PDCoV) is a porcine enteric coronavirus of the genus Delta-coronavirus in the family Coronaviridae, and is a pathogen of the Class II animal disease as classified in China. Unlike the well-known PEDV (Alpha) and TGEV (Alpha), PDCoV is the first delta-coronavirus confirmed to infect humans, and has important public health significance.
1. Discovery History
2012: The University of Hong Kong first discovered PDCoV sequences in pig feces through metagenomics.
February 2014: Ohio, USA detected the virus in feces of diarrheal piglets and sows, and successfully isolated the strain for the first time, confirming its pathogenicity.
From 2014: Countries including South Korea, mainland China, Thailand and Canada successively reported PDCoV clinical cases.
2018: A study published in the US Proceedings of the National Academy of Sciences (PNAS) confirmed PDCoV's potential for cross-species transmission.
2021: Teams including the University of Florida and Marco Salemi reported in Nature independent PDCoV infection cases in plasma samples of children in Haiti; PDCoV became the first delta-coronavirus to break the alpha/beta infection restriction.
2. Etiological Characteristics
Virus classification: Nidovirales → Coronaviridae → genus Delta-coronavirus.
Genome: Single-stranded positive-sense RNA, about 25.4 kb in length, one of the smallest known coronavirus genomes.
Major structural proteins:
S protein (Spike): Responsible for recognizing host cell surface receptors (porcine aminopeptidase N, pAPN) and mediating membrane fusion; contains major neutralizing antibody epitopes, and is the core target for vaccine and diagnostic reagent development.
N protein (Nucleocapsid): Wraps the viral RNA and participates in viral replication; the most commonly used target gene for molecular detection (RT-PCR).
M protein (Membrane), E protein (Envelope): Participate in virion assembly and budding.
Morphology: Enveloped, pleomorphic virions about 60–180 nm in diameter, with typical crown-like spikes on the surface.
3. Clinical Symptoms
Susceptible animals: Pigs of all ages can be infected, but 5–15-day-old nursing piglets show the most severe symptoms, with mortality reaching 50%–100%.
Main manifestations: Acute watery diarrhea, vomiting, severe dehydration, emaciation; some cases accompanied by vomiting.
Pathological changes: Atrophy of small intestinal villi (especially jejunum and ileum) and vacuolization of intestinal epithelial cells, similar to lesions caused by PEDV and TGEV, difficult to distinguish by naked eye.
Adult pigs: Mostly covert infection or transient mild diarrhea, but can continue to shed virus, serving as an important source of infection on the farm.
4. Prevalence and Public Health Significance
PDCoV currently circulates in pig herds in North America and multiple Asian countries, and has the potential for cross-species transmission. Because its clinical symptoms are highly similar to those of PEDV and TGEV, it is difficult to identify based solely on clinical manifestations and requires laboratory testing (RT-PCR, ELISA, immunofluorescence) for confirmation. The 2021 Nature-reported cases of Haitian children infections further suggest the virus has potential zoonotic risk and should be regarded as an "important pathogen worthy of long-term monitoring."
II. Key Points for Clinical Differentiation of PDCoV, PEDV and TGEV
Clinically, all three cause severe diarrhea in nursing piglets. The conventional differentiation points are as follows:
PEDV: Alpha genus, spreads extremely fast, neonatal piglet mortality can reach 100%, currently many commercial vaccines available, relatively high herd antibody levels.
TGEV: Alpha genus, more common in winter and spring, adult pigs can also show obvious symptoms, prevalence has declined significantly in recent years.
PDCoV: Delta genus, relatively milder clinical course, but can still cause severe casualties in entire litters of nursing piglets; currently no commercial vaccine available, herds generally lack specific antibodies.
Tip: Clinical manifestations alone cannot accurately distinguish the three; it is recommended to simultaneously conduct PEDV / TGEV / PDCoV triple RT-PCR testing, combined with etiological and serological results for comprehensive judgment.
III. Qianxun Bio Launches PDCoV S Protein New Product
To support the R&D needs of PDCoV diagnostic reagents and vaccines, Qianxun Bio has independently developed the PDCoV S protein based on its mature CHO cell eukaryotic expression platform, and it is now officially available.
Three Major Product Advantages
Strong antigenicity: High immunogenicity, suitable for ELISA detection and colloidal gold strip development, with clear and sharp signals.
High specificity: No cross-reaction with common porcine enteric coronaviruses such as PEDV and TGEV; reliable and unambiguous results.
Eukaryotic expression: Expressed in CHO cells, with complete natural conformation and authentic glycosylation modification, maximizing the restoration of the natural structure of the viral protein, most suitable for neutralizing antibody detection and vaccine evaluation.
Major Application Directions
Coating antigen for ELISA test kits, used for PDCoV antibody monitoring and vaccine immunity evaluation.
Labeling/coating antigen for colloidal gold strips, used for on-site rapid screening.
Immunogen and screening antigen for monoclonal antibody preparation.
Key target for PDCoV vaccine development (subunit vaccine, mRNA vaccine design).
Neutralizing antibody detection and pathogenic mechanism research of PDCoV infection.
Quality Control Information
Expression system: CHO cell eukaryotic expression.
Identification method: SDS-PAGE electrophoresis identification, high purity, single band.
Storage conditions: Stored according to the conditions recommended in the batch COA.
IV. Ordering and Service Consultation
Qianxun Bio has long provided high-quality antigens, antibodies and mAb customization services for scientific research institutes, diagnostic reagent enterprises and vaccine manufacturers. If you need PDCoV S protein trial packs, technical materials or customization plans, please feel free to contact us:
Contact: Manager Yang Tel / WeChat: 190-2544-6380
"We are serious and professional in animal disease control!" — Qianxun Bio will continue to provide you with trustworthy raw materials and services.
Guangzhou Qianxun Biotechnology Co., Ltd. Address: Room 2117, No.12 Shuixi Fuye 2nd Street, Huangpu District, Guangzhou Tel / WeChat: 190-2544-6380 (same number on WeChat)