[New subtype of coltivirus isolated from mosquitoes in the northeast part of China].

OBJECTIVE

The purpose of this study was to isolate new arbovirus from mosquitoes collected from the northeast part of China during the summer of 1996.

METHODS

The cell used for isolation were C6/36 and BHK-21 cells.

RESULTS

Two strains (NE97-12 and NE97-31) of coltivirus were isolated among 68 mosquito specimens. The viruses caused cytopathogenic effects on C6/36 cell, but not on BHK-21 cells. They were resistant to both 5-IDU and ether, but sensitive to pH3.0 and temperature at 56 degrees C for 30 minutes. IFA of new isolates with mouse ascitic fluid anti-coltivirus TRT2 strain showed positive reaction. Polyacrylamide gel electrophoresis (PAGE) of two isolates showed 12 segments of double-stranded(ds) RNA and PAGE profiles were 6-5-1, which were different from that of coltivirus TRT2 strain(6-6). There was no cross neutralization between new isolates and TRT2 strain by tissue culture cross-neutralization test.

CONCLUSION

The results indicated while new isolates were serologically related to TRT2 strain of coltivirus by IFA, the neutralization test suggests that it represents a distinct serotype. These new isolates isolated firstly from the northeast part of China belong to a new subtype of coltivirus.