Affiliation:
1. Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, Dalian Minzu University, Dalian 116600, China
2. Liaoning Center for Animal Disease Control and Prevention, Shenyang 110164, China
3. School of Mechanical Engineering, Faculty of Mechanical Engineering, Materials and Energy, Dalian University of Technology, Dalian 116024, China
4. China Animal Disease Prevention Control Center, Beijing 100125, China
Abstract
Capripox viruses (CaPVs), including sheep pox virus (SPV), goat pox virus (GPV), and lumpy skin disease virus (LSDV), are the cause of sheep pox (SPP), goat pox (GTP), and lumpy skin disease (LSD) in cattle. These diseases are of great economic significance to farmers, as they are endemic on farms and are a major constraint to international trade in livestock and their products. Capripoxvirus (CaPV) infections produce similar symptoms in sheep and goats, and the three viruses cannot be distinguished serologically. In this study, we developed a real-time quantitative polymerase chain reaction (qPCR) method for identifying CaPV in goats, sheep, and cattle. Clinical samples were tested and verified. The developed assay was highly specific for target viruses, including GPVSPV and LSDV, which had no cross-reaction with other viruses causing similar clinical symptoms. An artificially synthesized positive control plasmid using the CaPV 32 gene inserted into the vector pMD19-T was used as a template, and the correlation coefficient of the linear regression curve (R2) was 0.9916, the estimated amplification efficiency (E) was 96.06%, and the sensitivity (limit of detection, LOD) was 3.80 copies per reaction. Using the clinical samples as a template, the limit of detection (LOD) was 4.91 × 10−5 ng per reaction (1.60 × 10−5–2.13 × 10−3 ng, 95% confidence interval (CI)), which means that this method was one of the most sensitive detection assays for CaPVs. A total of 85 clinical samples from CaPV-infected animals (goats, sheep, and cattle) and 50 clinical samples from healthy animals were used to test and compare the diagnostic results using the Synergy Brands (SYBR) Green-based PCR method recommended by the World Organization of Animal Health (WOAH). Both diagnostic sensitivity (DSe) (95.8–100%, 95% CI) and diagnostic specificity (DSp) (92.9–100%, 95% CI) results of the real-time quantitative PCR (qPCR) and SYBR Green PCR were 100%, and the kappa value (κ) was 1.0 (1-1, 95% CI). In summary, the assay established based on TaqMan probes was advantageous in high specificity, sensitivity, and general applicability and could be a competitive candidate tool for the diagnosis of CaPV in clinically suspected animals.
Funder
National Mutton Sheep Industry Technology System—Common Diseases Research and Diagnosis and Treatment, Beijing, China
Dalian high-level Talents Innovation Support Plan
Subject
Virology,Microbiology (medical),Microbiology
Reference35 articles.
1. Review: Capripoxvirus Diseases: Current Status and Opportunities for Control;Tuppurainen;Transbound. Emerg. Dis.,2015
2. Ennaji, M.M. (2020). Chapter 28—Capripoxvirus Diseases: Current Updates and Developed Strategies for Control, in Emerging and Reemerging Viral Pathogens, Academic Press.
3. Lumpy skin disease is expanding its geographic range: A challenge for Asian livestock management and food security;Azeem;Vet. J.,2022
4. Analysis of vaccine-like lumpy skin disease virus from flies near the western border of China;Wang;Transbound. Emerg. Dis.,2021
5. Ministry of Agriculture and Rural Affairs of People’s Republic of China (2020). Issues 1–12. Official Veterinary Bulletin.