Continuous cell lines from embryonic tissues of ticks (Acari: Ixodidae).

Six new cell lines were established in continuous culture from embryonic tissues of ixodid ticks. Four were from Dermacentor variabilis and two from D. parumapertus. The cells are mostly fibroblastic and diploid. Mosquito-borne viruses (Chikungunya, O'nyong, yellow fever, and St. Louis encephalitis) as well as tick-borne ones (Langat, Powassan, Colorado tick fever, Kemerovo, and Sawgrass) replicated in certain of these cell lines, but a nonvector-borne flavivirus, Modoc, did not. An underscribed virus from D. occidentalis ticks, which could not be isolated in Vero cells or newborn mice, was readily isolated in the D. variabilis cell line.