Effect of pasteurization and evaporation on foot-and-mouth disease virus in whole milk from infected cows.

The effects of pasteurization and evaporation on foot-and-mouth disease virus in whole milk from infected cows obtained one day postinoculation were studied. Virus survived the heating of milk at high temperature-short time pasteurization at 75 degrees C for 15-17 seconds. In addition, virus from infected milk survived heating at 80 degrees C for the same time. Infective virus also survived in the pasteurized milk after evaporation at 65 degrees C to 50% of the original volume. The bovine udder was found to be highly susceptible to foot-and-mouth disease virus replication. Seven log10 plaque-forming units/ml of virus were recovered in whole milk 24 hours postinoculation, and decreasing titers were recovered for as long as seven days postinoculation.     

Electron microscopy demonstration of fibrillar structures in the foot-and-mouth disease virus]

Purified FMD virus was heat treated and then examined by electron microscopy with the negative contrast technique. Fibrils of varying length and thickness were present; they were not present after ribonuclease treatment. They were similar to the fibrils described for other picornaviruses. Viral RNA was the essential component of these artificially arranged fibrils, which were composed of threads about 10 A wide, separated from one another by a gap of about 10 A.     

口蹄疫病毒RT-LAMP检测方法的建立

为了建立检测口蹄疫的快速实用分子生物学技术,本研究借助新兴的环介导等温扩增技术,建立了一种灵敏、特异、快速的分子生物学检测方法-体外等温扩增检测方法。设计了6条针对FMDV3D基因的8个位点的特异性引物,建立了一套从核酸抽提到检测仅需要75min的快速检测技术。所建立的检测方法灵敏,与实时荧光RT-PCR灵敏度相当;且具有特异性,对其他水泡性疾病痛原体检测均为阴性;而且简单,不需要复杂的仪器,常规水浴锅在63．5℃即可进行,肉眼可直接观察检测结果。该方法是适合基层和现场检测而无需送至中心实验室的快速灵敏实用的分子生物学检测方法。