| Enterovirus 71(EV71) is member of Picornaradae Enterovirus genus. It is reported continually around the world since it was first isolated in 1969 in America. EV71 was distributing globally and has not locality. Prevalence with EV71 always occurred in summer and autumn, but infection may occurre all year. Human is its unique natural host. EV71 is usually transmitted through respiratory tract, alimentary tract by colse contact among people. EV71 infection is recessive, and aome cases may result in hand-foot-mouth disease (HFMD) and herpangina(HA) of children. It can cause central nervous system disease that remains severer sequelae or causes death because its neurotropic characteristic. Outbreak surveillance of EV71 infectionl has very important significance in pubic health, and it is emergency to develop HFMD vaccine, whereas there is not specific treatment for infection of EV71.EV71 can be categorized into three genotypes (A, B, C), and further sub-divided into more than ten subgenotypes. There is a relation in some degree between the genotypes of EV71 and isolating time and outbreak zone of virus, but is not positive connection with being resulted in clinic symptoms by infection with EV71. Epidemically C4 is the major lineage in Chinese Mainland since 1999.Replicative cycle of EV71 is about 12 hours. Replication of EV71 correlate with temperature, pH, host cell and multiformity of infection. It consist of adsorbing, exuviating, entry, RNA synthesis and replication, protein synthesis, particle assembly, release, etc. The virus are assembled to provirion with no infectious, but to mature viral paticle with infectious when VPO is splited to VP2 and VP4.The pathogenic processes of EV71 have three stages. In the early stage, EV71 replicate in the mucosa of pharynx, tonsil, and the intestinal lymphoid tissue. In the middle stage, EV71 result in viremia by entering blood circulation, and repilcate in reticuloendothelial cell. In the laster stage, EV71 result in HA and aseptic meningitis by attacking many organs and tissues such as the mucosa,the skin and the central nervous system.The objective of the study investigates the effect of proliferation kinetics of EV71 in Vero cell under different temperature. Three EV71 strains of Chinese epidemic types from different region was titrated by microtitrimetry, and growth curve of virus were drawed, and virus plaque forming assay was take under 32℃,35℃,37℃and 40℃. The virus which was collected from culturing under 32℃,35℃,37℃and 40℃was take the plaque forming assay under 37℃.The pathological effect was evaluated by intracerebral inoculation with the neonatal ICR mouse. The time that an equal number of Vero was complete pathologic under 37℃was the shortest. The infectious titer of progeny virus was the highest that an equal number of Vero was complete pathologic under 35℃. The infectious titer of progeny virus was the highest when the virus infected under 37℃after 24 hours. The proliferation rate was the highest when the virus infected under 37℃anterior 24 hours. It was higher under 35℃, and the lowest under 40℃. Because the exponential phase of virus proliferation was prolonged under 35℃,the virus proliferation under 35℃entered plateau phase when it acquired higher balance of proliferation than under 37℃. It was resulted that the virus titer was the highest under 35℃after the virus proliferation ertered the plateau phase.The virus plaque forming assay and the pathogenecity of virus were observed. The temperature dose not result in distinction of experimental consequence.
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