Assay for and replication of Karshi (mammalian tick-borne flavivirus group) virus in mice.
Little is known about the replication of Karshi virus, a member of the mammalian tick-borne flavivirus group, in its rodent hosts. Therefore, we developed a quantitative real-time RT-PCR assay and measured the amount of viral RNA in selected tissues of infected Swiss Webster mice. Two-day-old mice were highly susceptible, with 100% fatality 9 to 12 days after infection, whereas infection in 9-day-old mice was less virulent, with death occurring only rarely. In nearly all cases, mice inoculated when 2 days old contained similar numbers of viral genome equivalents from blood and liver samples from any given mouse, with titers declining after day 7. In contrast, the amount of viral RNA in the brain began to rise rapidly 4 days after exposure, peaked at about 6 days after virus exposure (titer of > 10(13) genome equivalents/g), and remained at that level until euthanasia or death. Viral profiles were similar in needle-inoculated or tick-exposed mice.
Turell
Michael J
MJ
Virology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland 21702-5011, USA. Michael.turell@amedd.army.mil
Whitehouse
Chris A
CA
Butler
Ashley
A
Baldwin
Carson
C
Hottel
Hannah
H
Mores
Christopher N
CN
D000818:Animals; D000833:Animals, Suckling; D001733:Bites and Stings; D004669:Encephalitis Viruses, Tick-Borne / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D004675:Encephalitis, Tick-Borne / Q000662:veterinary* / Q000821:virology; D007279:Injections, Subcutaneous; D051379:Mice; D026861:Ornithodoros / Q000821:virology; D012367:RNA, Viral / Q000032:analysis; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012376:Rodent Diseases / Q000821:virology*; D013997:Time Factors; D017361:Viral Nonstructural Proteins / Q000235:genetics; D014779:Virus Replication
C096041:NS5 protein, flavivirus; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins