A trypanosome species isolated from naturally infectedHaemaphysalis hystricisticks in Kagoshima Prefecture, Japan

Abstract

SUMMARYCommon arthropod vectors for trypanosomes are flies, fleas and bugs. This study reports on an unknown trypanosome species isolated from naturally infectedHaemaphysalis hystricisticks, hereby, referred to asTrypanosomaKG1 isolate. The parasite has been successfully culturedin vitrowith L929 or HEK 293T cell line as feeder cells. This trypanosome cannot survivein vitrowithout feeder cells. Following experimental infections of ticks, the trypomastigote-like and the epimastigote-like forms of this trypanosome could be detected by Giemsa-stained smears of the midgut and salivary glands ofOrnithodoros moubataticks which were made to feed on a culturing medium containingTrypanosomaKG1 isolate through an artificial membrane.TrypanosomaKG1 isolate could also be detected from Giemsa-stained smears of the haemolymph up to 30 days post-inoculation into theO. moubatahaemocoel.TrypanosomaKG1 isolate cannot be propagated in laboratory animals including mice, rats, rabbits and sheep. A phylogenetic tree constructed with the 18S rRNA gene indicates thatTrypanosomaKG1 is a member of the stercorarian trypanosomes.