Genotype identification of Orientia tsutsugamushi isolated from Nan Peng Lie Islands in China.

Objective: To identify genotype of eight strains of Orientia tsutsugamushi (O. tsutsugamushi) isolated from Nan Peng Lie Islands in China and establish tsutsugamushi disease nature foci for this region.
Methods: The nested polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used. Three primers were selected from the DNA sequence of the gene encoding type-specific 56-kDa protein of the Karp strain. The positive products were digested by Hine II and Pst I, meanwhile profiles specific to each strain were analyzed.
Results: Three genotypes of O. tsutsugamushi including Karp, Kato and a new strain existed on Nan Peng Lie Islands.
Conclusion: Nan Peng Lie Islands is tsutsugamushi disease nature foci.