Fang Ying, Brault Aaron C, Reisen William K
Center for Vectorborne Diseases and Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
Am J Trop Med Hyg. 2009 May;80(5):862-3.
During the monitoring of arbovirus seroprevalence in wild birds collected in California, we inadvertently made two isolates of western equine encephalomyelitis virus (WEEV) from California quail sera being tested by plaque reduction neutralization assay for antibodies against St Louis encephalitis (SLEV) and West Nile (WNV) viruses despite heating the sera at 56 degrees C for 30 minutes. These data prompted us to examine the thermostability of these viruses during heat treatment. The flaviviruses, SLEV and WNV, at titers up to 10(6) plaque-forming units (PFU), were readily inactivated by the standard protocol of heating at 56 degrees C for 30 minutes. In contrast, solutions containing 10(5) and 10(6) PFU of WEEV required 2 hours for complete inactivation. Occasional presence of live virus within sera could lead to false negatives using standard plaque reduction neutralization test protocols.
在监测加利福尼亚采集的野生鸟类的虫媒病毒血清流行率时，我们在对加利福尼亚鹌鹑血清进行针对圣路易斯脑炎（SLEV）和西尼罗河（WNV）病毒抗体的空斑减少中和试验时，尽管已将血清在56摄氏度加热30分钟，但仍意外地从血清中分离出两株西部马脑炎病毒（WEEV）。这些数据促使我们研究这些病毒在热处理过程中的热稳定性。黄病毒SLEV和WNV，滴度高达10⁶空斑形成单位（PFU），通过在56摄氏度加热30分钟的标准方案很容易被灭活。相比之下，含有10⁵和10⁶ PFU WEEV的溶液需要2小时才能完全灭活。血清中偶尔存在活病毒可能会导致使用标准空斑减少中和试验方案出现假阴性结果。
