Genetic Variation of SARS Coronavirus in Beijing Hospital

摘要

To characterize genetic variation of severe acute respi-ratory syndrome–associated coronavirus (SARS-CoV)transmitted in the Beijing area during the epidemic outbreakof 2003, we sequenced 29 full-length S genes of SARS-CoVfrom 20 hospitalized SARS patients on our unit, the Beijing302 Hospital. Viral RNA templates for the S-gene amplifica-tion were directly extracted from raw clinical samples,including plasma, throat swab, sputum, and stool, during thecourse of the epidemic in the Beijing area. We used a TA-cloning assay with direct analysis of nested reverse tran-scription–polymerase chain reaction products in sequence.One hundred thirteen sequence variations with nine recur-rent variant sites were identified in analyzed S-genesequences compared with the BJ01 strain of SARS-CoV.Among them, eight variant sites were, we think, the first doc-umented. Our findings demonstrate the coexistence of S-gene sequences with and without substitutions (comparedto BJ01) in samples analyzed from some patients