Study On Infectious Model Of Cevet For SARS-COV Isolated From Human

Severe acute respiratory syndrome(SARS) outbroke firstly in Guang dong /which caused by a novel virus now known as SARS coronavirus(SARS-COV). Epidemiological data strongly suggest an animal origin for SARS-COV although the reservoir host is yet to be identified .The discovery of SAS-CoV-like virus in masked palm civets and the relationship of their genomic sequences with viruses isolated from humans raise the possibility that civets may play a key role in SARS-CoV transmission.At the same time, some scientist disputed the view.To test susceptibility of civet to SARS-CoV, Ten masked palm civets(Paguma larvata ) were divided into two groups(n=5 per group).Animal in group A and B were inoculated intracheally and intranasally(total virus 3 X 10~6TCID50) with isolate GZ01 or BJ01,respectively. Here we show that civet are susceptible to experimental infection with SARS-CoV and display clinical signs during the early stage of infection.From 24 to 48 hours p.i.,all animals became febrile,lethargic and less aggressive . Two civets in group A and one in group B developed diarrhea between 3-14 d.p.i. Conjunctivitis was observed for one animal in group A and two in group B.Virus was detected by RT-PCR in throat and rectal swabs from day 3-18p.i. and isolated on day 3 p.i. from animals in both groups,and on day 8p.i.from animals in group A..Detection frequency of virus in blood samples was very low,with only one animal in group A giving positive results for both virus isolation and RT-PCR for samples taken on days 3,8,and 13 p.i.In contrast,virus was readily detected in a variety of organs up to day 13 p.i.including lung,liver,kidney,*and heart. Virus was still detected by RT-PCR at the end of the experiment (35 d.p.i) in lymph nodes and spleen .Seroconversion was monitored on the day of euthanasia ,and neutralizing antibodies were detected in samples taken from 13d.p.i. onwards,with the antibody titers varying from 20 at 13d.p.i.to 80 at 34 or 35 d.p.i.