Comparison of effectiveness of whole viral,N and N199 proteins by ELISA for the rapid diagnosis of severe acute respiratory syndrome coronavirus

摘要

＜正＞ Background Although severe acute respiratory syndrome（SARS）has been controlled,the subsequently emergingsporadic cases in 2004 emphasize the necessity of developing a rapid diagnostic method,which would be of great help inclinical diagosis and also wild host screening.This study aims to establish an effective and rapid serological tool for thediagnosis of SARS-CoV by comparison among whole viral,N and N199 proteins by ELISA.Methods SARS-CoV N and N199（a truncated nucleocapsid gene）genes were cloned,expressed,identified byWestern blotting,and applied in screening of human and swine samples.Sera of SARS convalescent-phase patients,normal human sera,sera of patients with other respiratory diseases,and swine sera were screened by ELISA,with wholeSARS-CoV F69,N and N199 proteins as antigens.Results The sensitivity and specificity of N and N199 proteins in human sera diagnosis were approximate（P=0.743）,which was higher than whole viral protein but the difference was not significant（P=0.234）.The N199 protein proved to bemore specific in swine sera screening than whole viral and N protein（P＜0.001）.Conclusion N199 protein is feasible in both clinical diagnosis and SARS-CoV reservoir screening.