Molecular detection and characterization of spotted fever group rickettsiae in Taiwan.
Rickettsioses are emerging infectious diseases caused by rickettsiae in association with arthropods. We report the detection of spotted fever group rickettsiae (SFGR) in Taiwan using molecular methods. Phylogenetic analyses of the 17-kd protein and citrate synthase (gltA) genes showed that SFGR TwKM01 detected in Rhipicephalus haemaphysaloides ticks was most similar to Rickettsia rhipicephali. Three TwKM01 isolates were obtained from three individual R. haemaphysaloides ticks. Small, intracellular, coccobacillary bacteria were found in infected L929 cells using immunofluorescence antibody testing and transmission electron microscopy. Two other SFGRs, TwKM02 and TwKM03, identified in Leptotrombidium chigger mites, were closely related to R. australis and R. felis URRWXCal(2), respectively. The TwKM03 strain was also detected in Ixodes granulatus ticks and widely distributed in Hualien, Kinmen, and Lienchiang counties in Taiwan. The endonucleases MaeII and HhaI selected for restriction fragment length polymorphism analysis of the gltA and 17-kd polymerase chain reaction products, respectively, were useful for genotyping Rickettsia species TwKM01, TwKM02, TwKM03, and other SFGRs. Although their infectivity and pathogenicity for vertebrates are unknown, the finding of SFGRs raises the possibility that bacteria other than Orientia tsutsugamushi, Coxiella burnetii, and R. typhi may be involved in rickettsial diseases in Taiwan.
Tsui
Pei-Yi
PY
Institute of Preventive Medicine, Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan. pytsui@mail.ndmctsgh.edu.tw
Tsai
Kun-Hsien
KH
Weng
Ming-Hui
MH
Hung
Yao-Wen
YW
Liu
Yu-Tien
YT
Hu
Kuang-Yu
KY
Lien
Jih-Ching
JC
Lin
Pey-Ru
PR
Shaio
Men-Fang
MF
Wang
Hsi-Chieh
HC
Wang
Hsis-Chieh
HC
Ji
Dar-Der
DD
D000818:Animals; D018884:Ixodes / Q000382:microbiology; D010802:Phylogeny; D051381:Rats; D048494:Rhipicephalus / Q000382:microbiology; D012281:Rickettsia / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D012282:Rickettsia Infections / Q000382:microbiology*; D012377:Rodentia / Q000469:parasitology; D013624:Taiwan; D014324:Trombiculidae / Q000382:microbiology; D050994:Voltage-Dependent Anion Channels
D050994:Voltage-Dependent Anion Channels