[Ultrastructural characteristics of SARS associated virus in infected cells].
OBJECTIVE
Electron microscopical study of infected cells to identify the pathogenic agent of SARS.


METHODS
Vero E6 cells infected with lung autopsy samples or nasopharyngeal swabs from SARS patients of Beijing and Guangzhou were inoculated. The supernatant and cultured cells exhibiting identifiable cytopathic effect (CPE) were prepared for electron microscopic study.


RESULTS
Examination of CPE cells on thin-section revealed characteristic coronavirus particles within the cisternae of endoplasmic reticulum, Golgi apparatus, vesicles and extracellular space. They were mainly spherical or oval in shape, annular or dense, about 80 nm in diameter. Negative-stain electron microscopy identified coronavirus particles in culture supernatant, 80 - 120 nm in diameter, with club-shaped surface projections. Elongated, rod-, kidney- or other irregular shaped virons with the size of 100 - 200 nm by 60 - 90 nm were also found in the cultured cells infected with the lung samples from the Guangdong patients. Infectious virons entered cells by endocytosis or membrane fusion and released through a budding process.


CONCLUSIONS
These data indicate a novel coronavirus as the causative agent of SARS. Most viral particles showed typical characteristics of coronavirus. The potential role of special shape viruses is expected to be further investigated.
Wang
Cui-e
CE
Institute of Microbiology and Epidemiology, Beijing 100071, China. wangcuie1994@yahoo.com.cn
Li
Yu-chuan
YC
Wu
Xiao-hong
XH
Cao
Jun-tian
JT
Yan
Ge
G
Li
Jin-feng
JF
Si
Bing-yin
BY
Yu
Man
M
Qin
E-de
ED
Zhu
Qing-yu
QY
D000818:Animals; D002522:Chlorocebus aethiops; D006801:Humans; D008854:Microscopy, Electron; D045473:Severe acute respiratory syndrome-related coronavirus / Q000648:ultrastructure*; D045169:Severe Acute Respiratory Syndrome / Q000821:virology*; D014709:Vero Cells