Immunological Analysis of Newly Isolated Strains of Rickettsia tsutsugamushi Using Monoclonal Antibodies

Sensitivity of Polymerase Chain Reaction Assay for Rickettsia tsutsugamushi in Patients' Blood Samples

“…In the present study, primers were selected from the region coding the 58-kDa protein, a common antigen (18), to assure hybridization among the heterologous strains of R. tsutsugamushi prevalent in Japan. The strains prevalent in Miyazaki Prefecture have been shown to be of a new type rickettsiae represented by the prototype strain hie and Hirano, which are antigenically different from the reference strains Gilliam, Karp, and Kato (7,20,23). The results showed that the primers could amplify genome DNA of five strains almost at the same level, suggesting the usefulness of the test in diagnosing patients infected with rickettsiae of unidentified type.…”

“…Although it can detect antibody in the early convalescent stage, measuring different antibody classes (IgG and IgM) (19), antibody reactivity usually does not reach a level high enough for diagnosis in the acute stage. In addition, the test is hampered by the multiple serotypes of R. tsutsugamushi resulting from antigenic diversity within the species (7,20,23).…”

Newly isolated strains of Rickettsia tsutsugamushi in Japan identified by using monoclonal antibodies to Karp, Gilliam, and Kato strains

“…In recent years, several investigators reported new isolates which were antigenically distinguished from standard strains (2,5,11). Kobayashi et al (4) reported newly isolated strains which were identified as the Gilliam-Kato type by using the IFA technique with MAbs to Karp, Gilliam, and Kato strains. It was surprising to see that three independent strains were isolated from four patients in such a small geographical area and that all isolates revealed antigenic differences from standard strains.…”