No abstract available.
Rickettsia typhi* ; Rickettsia*

No abstract available.
Antibodies, Monoclonal* ; Rickettsia typhi* ; Rickettsia*

No abstract available.
Antibodies, Monoclonal* ; Rickettsia typhi* ; Rickettsia*

No abstract available.
Electrophoresis, Polyacrylamide Gel* ; Immunoblotting* ; Korea* ; Rickettsia typhi* ; Rickettsia*

OBJECTIVETo develop a quantitative real-time polymerase chain reaction (PCR) for detecting Rickettsia prowazekii.

METHODSPrimers and TaqMan-MGB probes designed based on ompB gene of R. prowazekii, were used to develop this method.

RESULTSFor the quantitative real-time PCR, the relationship between the values of threshold cycle (Ct) and the DNA copy number was linear (r = 0.999) and the sensitivity was about 100 times higher than that of the nested PCR for detecting the same DNA sample. The results of the genomic DNA samples of other rickettsial and bacterial agents detected by real-time PCR were all negative. DNAs extracted from blood samples of guinea pig infected with R. prowazekii were examined by real-time PCR and the positive results were obtained from some of these samples. However, the results of some samples in nested PCR assay were all negative.

CONCLUSIONThese results suggested that the real-time PCR was highly specific and sensitive for detection of R. prowazekii that was useful for the detection of tiny DNA of R. prowazekii in blood samples from patients suspected of having epidemic typhus.

DNA Primers ; DNA, Bacterial ; analysis ; Humans ; Polymerase Chain Reaction ; methods ; Rickettsia prowazekii ; genetics ; isolation & purification ; Sensitivity and Specificity ; Typhus, Epidemic Louse-Borne ; diagnosis

Murine typhus is an acute febrile illness caused by Rickettsia typhi. It is one of the four major acute febrile illnesses in Korea during autumn. To study a species-specific antigen of R. typhi, two clinical isolates (87-91 and 87-100) and two reference strains (VR-144 and VR-738) were analyzed by mouse antisera and monoclonal antibodies (MAbs). On SDS- polyacrylamide gel electrophoresis (PAGE), R. typhi showed major antigen bands of 135, 80, 75, 64, 47, 22, and 19 kDa and these bands differed with those of other species. On Western blot analysis, the MAbs reacting only with R. typhi could only detect 135 kDa protein. The 135 kDa protein appeared to be the species-specific antigen. Other MAbs showing cross-reactivity with R. prowazekii reacted with 135 kDa protein in fresh culture supernatant of R. typhi infected host cell. However, the cross-reacting antibody did also react with smaller protein bands, most of which seem to be degradation products of the 135 kDa protein since they increase in old protein stocks purified from R. typhi harvested from infected host cell. These suggest that 135 kDa protein is unstable and the R. typhi specific epitopes are located at the regions of 135 kDa protein that are removed when the protein is degraded. The 135 kDa protein or its specific and stable recombinant protein would serve an important target for the development of vaccine and specific diagnostic antigen.
Animals ; Antibodies, Monoclonal ; Blotting, Western ; Electrophoresis, Polyacrylamide Gel ; Epitopes ; Immune Sera ; Korea ; Mice ; Rickettsia typhi* ; Rickettsia* ; Typhus, Endemic Flea-Borne

The crystalline surface layer protein (SLP) and a 28-32 kDa antigen of Rickettsia typhi were known as strong immunogens. We previously reported a cloning and sequence analysis of the SLP gene of R. typhi (slpT) and showed that the open reading frame of this gene encodes both the SLP and a 32-kDa protein. Our study also showed that a 48-kDa protein reacted strongly with polyclonal antiserum of a patient with murine typhus. In this study, we produced three recombinant proteins (SLP, 32-kDa, and 48-kDa protein) in E. coli as fusion proteins with maltose binding proteins. The reactivity of these proteins with patients' sera was investigated.
Clone Cells* ; Cloning, Organism* ; Crystallins ; Humans ; Maltose-Binding Proteins ; Open Reading Frames ; Recombinant Proteins ; Rickettsia typhi* ; Rickettsia* ; Sequence Analysis ; Typhus, Endemic Flea-Borne

Coxiella burnetii is the etiological agent of Q fever, that may occur either acutely or the chronically. To understand the seroepidemiological patterns of C. burnetii infection in Korea, we examined a total of 3,178 sera from patients with acute febrile episodes by using indirect immunofluorescence assay (IFA) for detectable antibodies to C. burnetii and other eight rickettsial antigens. The IFA seropositivity>or=1:20 for C. burnetii phase II was 11.5% (368 out of 3,178 sera). The co-existence of antibodies to other rickettsial antigens was found in 216 out of the 368 positive sera. Thirty-seven point five percent (n=138) had antibodies to R. tsutsugamushi (cutoff>or=1:20), 16% (n=59) to Ehrlichia sennetsu, 14.9% (n=55) to Rickettsia typhi, 13.5% (n=50) to R. akari, 11.4% (n=42) to R. japonica, 8.9% (n=33) to R. prowazekii, 7.6% (n=28) to R. sibirica, and 6.7% (n=25) to R. conorii by IFA, respectively. These results are consistent with previous reports documenting diverse serum cross-reactivity in chronic Q fever. Therefore we excluded the samples that reacted to other rickettsial antigens at same or higher titers than to C. burnetii, resulting in the seropositive rate of 4.1%. The serological prevalence was 2% (n=64) when the conventional cut-off titer of 1:80 was used. Our results suggest that infections with C. burnetii are more prevalent than expected previously and should be differentially diagnosised for febrile illness occurring after exposure to ticks or other vectors.
Antibodies ; Coxiella burnetii* ; Coxiella* ; Diagnosis ; Fluorescent Antibody Technique, Indirect ; Humans ; Korea ; Neorickettsia sennetsu ; Prevalence ; Q Fever ; Rickettsia ; Rickettsia typhi ; Seroepidemiologic Studies* ; Ticks

No abstract available.
Orientia tsutsugamushi* ; Rickettsia* ; Ulsan*

No abstract available.
Korea* ; Orientia tsutsugamushi* ; Rickettsia*