Genome organization and structural aspects of the SARS-related virus

Abstract

The first appearance of severe acute respiratory syndrome (SARS) occurred in Guangdong province in southern China with the earliest cases dating from November 16, 2002. By February 14, 2003 the WHO reported a total of 305 cases of acute respiratory syndrome of unknown etiology in Guangdong province (WHO WER 7/2003). At the time of writing this review, scientists in the Guangdong province of China believe that the SARS virus may have shifted to human hosts by at least five independent events, however sequence information to support this conclusion on these five isolates is still incomplete. The SARS virus was spread to Hong Kong by a physician from Guangdong when he traveled to Hong Kong and stayed at the Metropole Hotel on Feb 21. From there, world-wide dissemination of the virus to Vietnam, Singapore, Taiwan and Canada plus other locations occurred. The SARS agent was initially believed to be an influenza virus, possibly an avian influenza virus, parainfluenza virus (metapneumovirus) or a bacterium, Chlamydia pneumoniae However, by March 19, the WHO reported that these agents were unlikely to be the cause and hence suggested that a new agent was responsible. Within a few days four groups obtained evidence that a coronavirus-like agent might be the causative agent using PCR primers for known coronaviruses to amplify short fragments of DNA which were sequenced ([1–3]; R. Tellier, personal communication). In addition de Risi’s group at UCSF used a DNA microarraybased assay to detect viral sequences from samples cultured in Vero6 cells. These results were made available over the internet and have now appeared in print [4]. This group also recovered a ~ 1kb fragment of viral cDNA which was purified from contaminating cellular cDNAs by selecting the fragment on a DNA microarray and sent the DNA to the Washington University Genome Sequence Centre. The sequence was determined and the results indicated that it was most closely related to coronaviruses. Genome organization and structural aspects of the SARS-related virus