[Isolation and identification of SARS virus in Guangdong province].

BACKGROUND:To isolate and identify pathogen of atypical pneumonia in Guangdong. METHODS:Pathogens were isolated from variety of samples collected from atypical pneumonia patient by using MDCK cells, and identified with serological and molecular methods. RESULTS:A novel coronavirus was isolated from patients with atypical pneumonia, from which an RNA fragment of 279 nt was amplified by nested RT-PCR. And sequence assay showed that only 39-65 percent of sequence of the virus was homogenous to known coronavirus, but almost 100% homogenous (with one base exception, 12a to t) to SARS-associated coronavirus isolated from patients outside Guangdong, such as in Beijing, Hong Kong, Taiwan, Germany, Italy and so on. Indirect immunofluorescence test showed a specific antigen-antibody reactivity between the coronavirus and convalescent-phase sera of SARS patients. CONCLUSION:The pathogen of the atypical pneumonia in Guangdong province was a novel type of coronavirus, which could be isolated by using MDCK cells.