Evaluation of PCR-based assay for diagnosis of spotted fever group rickettsiosis in human serum samples.
A nested PCR assay was developed for the detection of spotted fever group (SFG) rickettsiae in serum samples. The assay was based on specific primers derived from the rickettsial outer membrane protein B gene (rompB) of Rickettsia conorii. An SFG rickettsia-specific signal is obtained from R. akari, R. japonica, R. sibirica, and R. conorii. Other bacterial species tested did not generate any signal, attesting to the specificity of the assay. As few as seven copies of the rompB gene of R. conorii could be detected in 200 microl of serum sample. The assay was evaluated with a panel of sera obtained from patients with acute-phase febrile disease tested by immunofluorescent antibody assay (IFA). The SFG rickettsia-specific DNA fragment was detected in 71 out of 100 sera, which were proven to have immunoglobulin M antibodies against SFG rickettsial antigen by IFA. The results were further confirmed by restriction fragment length polymorphism and sequencing analysis of the DNA fragments. The results indicated that this PCR assay is suitable for the diagnosis of spotted fever group rickettsiosis in Korea.
Choi
Yeon-Joo
YJ
Department of Microbiology, College of Medicine, Konkuk University, Choongu-shi, Choongbuk 380-701, Republic of Korea.
Lee
Seung-Hyun
SH
Park
Kyung-Hee
KH
Koh
Young-Sang
YS
Lee
Keun-Hwa
KH
Baik
Hyung-Suk
HS
Choi
Myung-Sik
MS
Kim
Ik-Sang
IS
Jang
Won-Jong
WJ
D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000097:blood* / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000097:blood* / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D012150:Polymorphism, Restriction Fragment Length; D012281:Rickettsia / Q000145:classification / Q000235:genetics*; D012282:Rickettsia Infections / Q000175:diagnosis* / Q000378:metabolism
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; C073150:rOmp B protein, Rickettsia