高致病性猪生殖和呼吸系统综合征病毒的遗传进化和致病性变化
1State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
Virulence
|May 22, 2025
概括
高致病性猪生殖和呼吸系统综合征病毒 (HP-PRRSV) L8.7菌株,包括新型HP类变种,在全球普遍存在. 这项研究阐明了它们的进化,病原性和与疫苗的关系,有助于控制策略.
科学领域:
- 兽医病毒学 兽医病毒学
- 分子流行病学分子流行病学
- 病原体的进化 病原体的进化
背景情况:
- 高致病性猪生殖和呼吸系统综合征病毒 (HP-PRRSV)及其变种在中国和东南亚构成了重大威胁.
- 流行病学动态,基因组特征,疫苗菌株关系和HP-PRRSV L8.7菌株的致病性变化仍然不完全理解.
研究的目的:
- 系统地分析全球HP-PRRSV L8.7菌株的流行病学特征,基因组变异,进化趋势和病原性.
- 调查疫苗接种对中国HP-PRRSV演变的影响.
- 为了比较新型HP类PRRSV菌株与经典HP-PRRSV的致病性.
主要方法:
- 对2509个全球L8.7 ORF5序列的家族遗传学分析,将菌株分为7组 (L8.7.1-L8.7.7).
- 统计分析以确定不同L8.7群体的流行率和最近的趋势.
- 基因组分析以评估病毒表型.
- 进化速率分析和猪仔的病原性测试.
主要成果:
- L8.7菌株被分为7组,其中HP类PRRSV (L8.7.4-L8.7.7) 是最常见的,特别是近年来L8.7.5和L8.7.6.
- 大多数L8.7菌株 (72.15%) 呈现野生类型的表型.
- 在引入改性活病毒 (MLV) HP-PRRSV疫苗后,中国PRRSV菌株的进化速度显著下降.
- 与经典HP-PRRSV (HuN4) 相比,HP类PRRSV菌株在小猪中表现出较低的致病性,同时保持显著的毒性.
结论:
- 这项研究提供了HP-PRRSV L8.7菌株流行病学,演变和致病性的全面概述.
- 类似HP的PRRSV变种的出现和流行凸显了更新控制策略的必要性.
- 疫苗接种后的进化率降低表明MLV有效性,但由于新变种的毒性,持续监测至关重要.
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