Kamolsiripichaiporn Somjai, Subharat Supatsak, Udon Romphruke, Thongtha Panithan, Nuanualsuwan Suphachai
Regional Reference Laboratory for FMD in South East Asia, National Institute for Animal Health, Nakhon Ratchasima, Thailand.
Appl Environ Microbiol. 2007 Nov;73(22):7177-84. doi: 10.1128/AEM.00629-07. Epub 2007 Jul 27.
The heat resistance of foot-and-mouth disease virus (FMDV) strains isolated from outbreaks in Thailand was investigated in phosphate-buffered saline (PBS) at 50, 60, 70, 80, 90, and 100 degrees C. The first-order kinetic model fitted most of the observed linear inactivation curves. The ranges of decimal-reduction time (D value) of FMDV strains at 50, 60, 70, 80, 90, and 100 degrees C were 732 to 1,275 s, 16.37 to 42.00 s, 6.06 to 10.87 s, 2.84 to 5.99 s, 1.65 to 3.18 s, and 1.90 to 2.94 s, respectively. The heat resistances of FMDV strains at lower temperature (50 degrees C) were not serotype specific. The effective inactivating temperature is approximately 60 degrees C. Heat resistances of FMDV strains at 90 and 100 degrees C were not statistically different (P > 0.05), while the FMDV serotype O (OPN) appeared to be the most heat resistant at 60 to 80 degrees C. The other observed inactivation curves were linear with shoulder or tailing (biphasic curves). The shoulder effect was mostly observed at 90 and 100 degrees C, while the tailing effect was mostly observed at 50 to 80 degrees C. The adjusted D values in the case of shoulder and tailing effects did not affect the overall estimated heat resistance of these FMDV strains, so even unadjusted D values of deviant inactivation curves were legitimate. The z values of FMDV serotypes O, A, and Asia 1 were 21.78 to 23.26, 20.75 to 22.79, and 19.87 degrees C, respectively. The z values of FMDV strains studied were not statistically significantly different (P > 0.05). The results of this study indicated that the heat resistance in PBS of FMDV strains from Thailand was much less than had been reported for foreign epidemic FMDV strains.
研究了从泰国疫情中分离出的口蹄疫病毒(FMDV)毒株在50、60、70、80、90和100摄氏度的磷酸盐缓冲盐水(PBS)中的耐热性。一级动力学模型拟合了大部分观察到的线性失活曲线。FMDV毒株在50、60、70、80、90和100摄氏度下的十进制减少时间(D值)范围分别为732至1275秒、16.37至42.00秒、6.06至10.87秒、2.84至5.99秒、1.65至3.18秒和1.90至2.94秒。FMDV毒株在较低温度(50摄氏度)下的耐热性与血清型无关。有效灭活温度约为60摄氏度。FMDV毒株在90和100摄氏度下的耐热性无统计学差异(P>0.05),而FMDV O型(OPN)在60至80摄氏度下似乎是最耐热的。其他观察到的失活曲线呈带有肩部或拖尾的线性(双相曲线)。肩部效应大多在90和100摄氏度下观察到,而拖尾效应大多在50至80摄氏度下观察到。肩部和拖尾效应情况下的调整后D值不影响这些FMDV毒株的总体估计耐热性,因此即使是异常失活曲线的未调整D值也是合理的。FMDV O型、A型和亚洲1型的z值分别为21.78至23.26、20.75至22.79和19.87摄氏度。所研究的FMDV毒株的z值无统计学显著差异(P>0.05)。本研究结果表明,泰国FMDV毒株在PBS中的耐热性远低于国外流行FMDV毒株的报道。