ISOLATION OF A NEW ORIENTIA-TSUTSUGAMUSHI SEROTYPE

Orientia tsutsugamushi, the etiological agent of scrub typhus, is an a ntigenically diverse organism and many serologically distinct strains have been identified. The 56 kDa protein of O. tsutsugamushi, a major protein in the outer membrane, has been thought to be responsible for this antigenic variability. A strain of O. tsutsugamushi isolated in K orea cross-reacted with both Gilliam strain-specific and Karp strain-s pecific monoclonal antibodies. When its 56 kDa protein gene was cloned and analyzed, its sequence showed variation especially between 1,200 and 1,250 bp, showing that this isolate is a new O. tsutsugamushi stra in.