Study of biologic attributes of Cuban dengue 2 virus after serial passage in primary dog kidney cells.
OBJECTIVE
The serial passage of dengue viruses in primary dog kidney (PDK) cells has resulted in selection of attenuated viruses. However, the molecular changes responsible for loss of virulence are not well characterized. This article describes the isolation and biologic attributes of one dengue 2 virulent strain as a first step to allow the study of determinants of virulence at the molecular level.


METHODS
A15 dengue 2 Cuban strain was isolated from the viremic plasma of a patient with uncomplicated dengue fever during the 1981 epidemic. This was then subjected to serial passage in PDK cells. Viruses resulting from several PDK passages were compared to the parent strain for plaque size and temperature sensitivity, neurovirulence in newborn mice, and cytopathogenic effects on LLC-MK(2) and C6/36-HT cell lines.


RESULTS
A15 dengue 2 Cuban strain was successfully propagated in PDK cells. Primary dog kidney 52 to 53 viruses exhibited several biologic attributes, such as small plaques, temperature sensitivity, reduced mouse neurovirulence, and cytopathic effect in permissive cell lines.


CONCLUSIONS
These results represent the first step to allow attenuation of this strain of dengue 2 virus.
Alvarez
M
M
Department of Virology, PAHO/WHO Collaborator Center for Viral Diseases, Tropical Medicine Institute of Havana, Cuba.
Guzmán
M G
MG
Pupo
M
M
Morier
L
L
Bravo
J
J
Rodriguez
R
R
D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling; D002478:Cells, Cultured; D003588:Cytopathogenic Effect, Viral; D003715:Dengue / Q000821:virology; D003716:Dengue Virus / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology; D004285:Dogs; D006801:Humans; D007668:Kidney / Q000382:microbiology* / Q000473:pathology; D007928:Lethal Dose 50; D051379:Mice; D012692:Serial Passage; D013696:Temperature; D014613:Vaccines, Attenuated; D010948:Viral Plaque Assay; D014765:Viral Vaccines; D014774:Virulence
D014613:Vaccines, Attenuated; D014765:Viral Vaccines