Department of Infectious Diseases and Veterinary Public Health Faculty of Animal Science and Veterinary Medicine, Nonglam University HCMC, Thu Duc District, Ho Chi Minh City, Viet Nam; Han-Viet Veterinary Diagnosis Laboratory, Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Viet Nam.
Han-Viet Veterinary Diagnosis Laboratory, Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Viet Nam.
Virology. 2022 Jun;571:39-45. doi: 10.1016/j.virol.2022.04.002. Epub 2022 Apr 16.
Classical swine fever (CSF) is a highly contagious, devastating, and transboundary viral disease that afflicts swine industries worldwide. Immunization with vaccines is one of the most effective strategies for controlling this disease. However, shifts in the antigenicity and pathogenicity of novel evolving viral strains have the potential to evade vaccination. In this study, 352 samples from swines exhibiting fever, hemorrhages, lethargy, and diarrhea in different pig farms located in 9 provinces of Vietnam were collected. CSFV was identified even within farms that had been vaccinated against CSFV. Several farms had swine which had been co-infection with CSFV and other pathogens. Copies of the E2 gene of 21 samples were isolated, cloned, sequenced, analyzed, and compared with copies of E2 in four vaccine strains. We identified a total of 42 amino acid substitutions in this glycoprotein, including 11 positions that affect the antigenic properties of E2 and 7 positions that are associated with neutralizing epitopes. The E2 glycoprotein of CSFV strains circulating in Vietnam and vaccine strains differ in their antigenicity. These findings provide deep insights into the molecular characteristics, genetic diversity, pathogenicity, antigenicity, and evolution of CSFV strains in Vietnam. Understanding the pathogenicity, antigenicity, and evolution of circulating CSFV strains will provide avenues for developing new vaccines and efficient approaches to control this disease.
古典猪瘟（CSF）是一种高度传染性、毁灭性的跨边界病毒病，影响全球的养猪业。疫苗免疫是控制该病的最有效策略之一。然而，新型变异病毒株的抗原性和致病性的变化有可能逃避疫苗接种。本研究收集了来自越南 9 个省不同养猪场出现发热、出血、嗜睡和腹泻症状的 352 个猪样本。即使在接种过 CSF 疫苗的农场中也发现了 CSF。一些农场的猪同时感染了 CSF 和其他病原体。从 21 个样本中分离、克隆、测序、分析并比较了 E2 基因的副本，并与 4 个疫苗株中的 E2 副本进行了比较。在这种糖蛋白中总共鉴定出 42 个氨基酸取代，包括影响 E2 抗原性的 11 个位置和与中和表位相关的 7 个位置。在越南流行的 CSF 毒株和疫苗株的 E2 糖蛋白在抗原性上存在差异。这些发现深入了解了越南 CSF 毒株的分子特征、遗传多样性、致病性、抗原性和进化。了解循环 CSF 毒株的致病性、抗原性和进化将为开发新疫苗和控制该病提供途径。
