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Hiromi Fujita - One of the best experts on this subject based on the ideXlab platform.
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Genomic Features of Rickettsia heilongjiangensis Revealed by Intraspecies Comparison and Detailed Comparison With Rickettsia Japonica
Frontiers in microbiology, 2019Co-Authors: Kentaro Kasama, Hiromi Fujita, Seigo Yamamoto, Shuji Ando, Tadasuke Ooka, Yasuhiro Gotoh, Yoshitoshi Ogura, Tetsuya HayashiAbstract:Rickettsia heilongjiangensis is the causative agent of Far-Eastern spotted fever (FESF). In Japan, a human case of FESF was identified in Sendai in Miyagi Prefecture in 2008, and R. heilongjiangensis bacteria were isolated from Haemaphysalis concinna ticks collected in the suspected geographic area of infection. Although the intraspecies genome diversity of Rickettsiae has been poorly investigated, our recent analysis revealed extremely low genomic diversity of R. Japonica, the agent of Japanese spotted fever, which is a close relative of R. heilongjiangensis. In this study, to investigate the genomic diversity of R. heilongjiangensis and understand the genetic relationship between Japanese and Chinese strains, we sequenced three strains isolated in Sendai and one strain isolated in Inner Mongolia, China, and performed genomic comparisons between these strains and strain 054, the type strain isolated in Heilongjiang Province, China. Although the three Japanese strains were isolated in 2008, 2009, and 2012, their genome sequences were identical, indicating that H. concinna ticks carrying a single R. heilongjiangensis clone have colonized Sendai, Japan. Among the five R. heilongjiangensis strains, only 81 SNPs and 13 insertion/deletion sites were identified, despite the significant differences in these isolates both geographically and temporally. A significant portion of the 81 SNPs (15/81) were found to be recombinogenic. These results indicate low genomic diversity of R. heilongjiangensis, as observed in R. Japonica. We further performed a detailed genomic comparison of R. heilongjiangensis and R. Japonica to accurately define conserved and species-specific genes. This analysis revealed that although notable variations were found in the genomic loci encoding RelA/SpoT family proteins and tandem repeats in major surface proteins, there was only a small difference in the gene repertoire between the two species, suggesting that SNPs and small InDels are responsible for the functional or physiological differences between the two species, if present. Through this analysis, several species-specific genomic regions that can serve as ideal PCR targets for distinguishing R. heilongjiangensis and R. Japonica were also identified.
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Rickettsia Japonica Infection after Land Leech Bite, Japan
Emerging infectious diseases, 2019Co-Authors: Eiichiro Sando, Hiromi Fujita, Motoi Suzuki, Mitsuya Katayama, Masakatsu Taira, Koya AriyoshiAbstract:We report a case of Rickettsia Japonica infection in an 81-year-old man in central Japan. The patient had fever, rash, and an eschar but no evidence of a tick bite. His symptoms began 8 days after a land leech bite. The land leech is a potential vector of R. Japonica.
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Case Report: Concurrent Sympatric Scrub Typhus and Japanese Spotted Fever in Japan.
The American journal of tropical medicine and hygiene, 2018Co-Authors: Eiichiro Sando, Hiromi Fujita, Masakatsu Taira, Daniel H. Paris, Yuka Oshikawa, Atsushi Tanaka, Shungo Katoh, Tomoko Ogawa, Makito Yaegashi, Koya AriyoshiAbstract:Scrub typhus and Japanese spotted fever-both Rickettsial diseases-are endemic and notifiable in Japan and may cause a fatal outcome without prompt treatment. Here we present the first case of a concurrent sympatric infection of both diseases with grade II evidence. A 67-year-old woman, after a single event of potential exposure to the pathogens, presented with a 12-day history of fever, pharyngeal pain, papulo-erythematous rash, and pronounced fatigue. Her erythematous rash was distributed on her trunk and extremities, palms, and soles and eventually progressed to purpura. Fever persisted until doxycycline was administered on day 12. A significant > 4-fold increase in immunoglobulin G and immunoglobulin M titers against multiple serotypes of Orientia tsutsugamushi and Rickettsia Japonica were revealed by indirect immunoperoxidase assays. These clinical and serological data, even in the absence of molecular or isolation evidence, provided grade II evidence that this was a concurrent infection of sympatric scrub typhus and Japanese spotted fever.
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Serological Cross-Reactivity among Orientia tsutsugamushi Serotypes but Not with Rickettsia Japonica in Japan
Tropical medicine and infectious disease, 2018Co-Authors: Eiichiro Sando, Koya Ariyoshi, Hiromi FujitaAbstract:The Rickettsial diseases Japanese spotted fever (JSF) and scrub typhus (ST) are caused by Rickettsia Japonica and Orientia tsutsugamushi, respectively. The diseases share clinical symptoms, such as fever, rash, and eschar. However, there are no systematical investigations of the serological cross-reactivity between R. Japonica and O. tsutsugamushi. Also, the serological cross-reactivity among O. tsutsugamushi serotypes is still unclear. We analyzed 1406 cases tested by indirect immunoperoxidase assay using seven Rickettsial antigens—one R. Japonica and six O. tsutsugamushi serotypes—between 2003 and 2016 at two reference centers in Japan. Of these, 167 JSF and 190 ST cases were serologically diagnosed. None of the ST cases had a significant increase in IgM titers against R. Japonica. Six JSF cases showed IgG titers of ≥40 against O. tsutsugamushi, but no IgG titer showed a significant elevation in the convalescent phase sample. We observed a substantial degree of cross-reactivity between O. tsutsugamushi serotypes. Cross-reactivity was significant among Karp, Hirano/Kuroki, and Kato types and between Gilliam and Irie/Kawasaki types in IgM, while the Shimokoshi type was less cross-reactive than the others. In conclusion, there is no serological cross-reaction between R. Japonica and O. tsutsugamushi. The cross-reactivity among O.tsutsugamushi varies depending on serotypes.
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Evaluation of Diagnostic Assay for Rickettsioses Using Duplex Real-Time PCR in Multiple Laboratories in Japan.
Japanese journal of infectious diseases, 2018Co-Authors: Fumihiko Kawamori, Hiromi Fujita, Seigo Yamamoto, Asaka Ikegaya, Y. Shimazu, Hiroko Sato, Naota Monma, Hiroshi Morita, Yukiko Tamaki, Naoya TakamotoAbstract:Tsutsugamushi disease and Japanese spotted fever are representative rickettsioses in Japan, and are caused by infection with Orientia tsutsugamushi and Rickettsia Japonica, respectively. For molecular-based diagnosis, conventional PCR assays, which independently amplify respective Rickettsial DNA, are usually used; however, this approach is time-consuming. Here, we describe a new duplex real-time PCR assay for the simultaneous detection of O. tsutsugamushi and spotted fever group Rickettsiae, and its evaluation using several PCR conditions in 6 public health laboratories. The detection limit of the assay was estimated to be 102 copies and the sensitivity was almost identical to that of 3 conventional PCR methods. A total of 317 febrile patients were selected as clinically suspected or confirmed cases of rickettsioses. The detection efficiency of this assay for O. tsutsugamushi from blood or skin (eschar) specimens appeared to be almost the same as that of the conventional PCR method, even when performed in different laboratories, whereas the efficiency for spotted fever group Rickettsiae tended to be higher than that of the 2 traditional double PCR assays. Our duplex real-time PCR is thus a powerful tool for the rapid diagnosis of rickettsioses, especially at the acute stage of infection.
Tsuneo Uchiyama - One of the best experts on this subject based on the ideXlab platform.
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Restriction of the growth of a nonpathogenic spotted fever group Rickettsia.
FEMS immunology and medical microbiology, 2012Co-Authors: Tsuneo Uchiyama, Mahomi Kishi, Motohiko OgawaAbstract:The growth kinetics of pathogenic and nonpathogenic Rickettsiae were compared to elucidate the mechanism responsible for the pathogenicity of Rickettsiae. Vero and HeLa cells derived from mammals were inoculated with a nonpathogenic species of spotted fever group Rickettsia, Rickettsia montanensis , before being infected with the pathogenic species Rickettsia Japonica . The mammalian cells became persistently infected with R. montanensis and produced low levels of Rickettsiae. On the other hand, superinfection of the R. montanensis -infected cells with R. Japonica resulted in increased yields of R. montanensis accompanied by R. Japonica growth. Both Rickettsiae also grew well in the R. Japonica -infected cells subjected to superinfection with R. montanensis . Western blotting with an antibody to the autophagy-related protein LC3B found that autophagy was induced in the cells infected with R. montanensis alone. On the contrary, autophagy was restricted in the cells that were co-infected with R. Japonica . Electron microscopy of the cells infected with R. montanensis alone demonstrated Rickettsia particles being digested in intracytoplasmic vacuoles. Conversely, many freely growing Rickettsiae were detected in the co-infected cells.
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The major outer membrane protein rOmpB of spotted fever group Rickettsiae functions in the Rickettsial adherence to and invasion of Vero cells
Microbes and infection, 2006Co-Authors: Tsuneo Uchiyama, Hiroaki Kawano, Yoshito KusuharaAbstract:The role of one of the major outer membrane proteins, rOmpB, of spotted fever group Rickettsiae was examined. Antibodies generated against native rOmpB inhibited plaque formation by Rickettsia Japonica in Vero cells when applied at the time of inoculation of the Rickettsiae. However, antibodies to heat-denatured rOmpB did not. Moreover, the soluble recombinant rOmpB also inhibited plaque formation to some extent. Thus it seems that rOmpB functions at least in the adherence of Rickettsiae to host cells. To obtain direct evidence of its function in the adherence to and invasion of Vero cells, we generated Escherichia coli transformed by the vector pET-22b(+) inserted with the ompB open reading frame of R. Japonica. The recombinant bacteria expressed a 165-kDa protein consistent with the precursor of rOmpB. The protein reacted with monoclonal antibodies to heat-labile epitopes of rOmpB. Immunofluorescence of the recombinant bacteria demonstrated surface expression of the protein. It was shown by light microscopy and transmission and scanning electron microscopy that the bacteria adhered to and invaded Vero cells. Thus, although the recombinant precursor rOmpB was not processed on the outer membrane of E. coli, it functions during these steps. The manner of entry was similar to that of Rickettsiae although at a slower rate.
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Adherence to and Invasion of Vero Cells by Recombinant Escherichia coli Expressing the Outer Membrane Protein rOmpB of Rickettsia Japonica
Annals of the New York Academy of Sciences, 2003Co-Authors: Tsuneo UchiyamaAbstract:Abstract: Recombinant Escherichia coli expressing the outer membrane protein rOmpB of Rickettsiae on the surface were generated. The DNA corresponding to the open reading frame of the ompB gene of a spotted fever group Rickettsia, Rickettsia Japonica, was amplified by polymerase chain reaction. The amplified fragment was inserted between the Sal I and the Xho I sites of the expression vector pET-22b(+). E. coli BL21(DE3) was transformed by the constructed plasmid. The recombinant bacteria expressed a recombinant protein with a molecular size of 165 kilodaltons on the surface. The size was consistent with that of the precursor of rOmpB. The protein was reactive with monoclonal antibodies to heat-labile epitopes of the rOmpB. This result suggested a rather native conformation of the recombinant protein. Immunofluorescence of the recombinant bacteria demonstrated the surface expression of the protein. The recombinant bacteria acquired properties to enter Vero cells. The morphological change was observed by means of transmission electron microscopy and scanning electron microscopy. Adherence triggered the generation of abundant microvilli and membrane ruffling for the cells to engulf the bacteria The manner of entry of the recombinant bacteria was similar to that of Rickettsiae. Thus it is suggested that the rOmpB plays an important role in the adherence to and invasion of host cells by Rickettsiae. Moreover, since even the recombinant rOmpB precursor protein expressed on the surface of the bacteria promotes adherence and invasion, the conformation of the functional domain may be similar to that of the processed mature rOmpB.
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Phenotypic and genotypic homogeneity of the strains of Rickettsia Japonica isolated from patients with Oriental spotted fever.
Microbiology and immunology, 1999Co-Authors: Tsuneo UchiyamaAbstract:Nine pathogenic strains of Rickettsia Japonica isolated from patients with Oriental spotted fever were compared phenotypically and genotypically. Constitution and antigenicity of the proteins demonstrated to be the same among strains. Polymerase chain reaction (PCR) amplification of the two major outer membrane protein genes (ompA and ompB) and an intracellular spotted fever group-common antigen protein gene (rps120) produced the same sizes of products for all strains. Restriction fragment length polymorphism of the PCR products showed the same pattern among strains with each endonuclease. Thus, these strains belong to a single type, the same as the type strain YH (=ATCC VR-1363).
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Sequence analysis of the gene encoding the major outer membrane protein rOmp B of Rickettsia Japonica.
Microbiology and immunology, 1999Co-Authors: Tsuneo UchiyamaAbstract:The complete nucleotide sequence of the gene encoding rOmp B (ompB), one of the two major outer membrane antigen proteins, of Rickettsia Japonica was determined and compared to those of the other spotted fever group and typhus group Rickettsiae. Open reading frame of the ompB gene of R. Japonica consisted of 4,968 nucleotides coding for a putative precursor protein with 1,656 amino acids (aa) in which the N-terminal 1,363 aa and the C-terminal 293 aa encode 135-kilodalton rOmp B and 32-kilodalton β-peptide, respectively. Putative promoter and terminator sequences for transcription were present in the upstream region of the ATG start codon and downstream of the TAA stop codon. Overall sequences of the ompB genes were well conserved beyond the group, especially in the β-peptide regions.
Seigo Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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Genomic Features of Rickettsia heilongjiangensis Revealed by Intraspecies Comparison and Detailed Comparison With Rickettsia Japonica
Frontiers in microbiology, 2019Co-Authors: Kentaro Kasama, Hiromi Fujita, Seigo Yamamoto, Shuji Ando, Tadasuke Ooka, Yasuhiro Gotoh, Yoshitoshi Ogura, Tetsuya HayashiAbstract:Rickettsia heilongjiangensis is the causative agent of Far-Eastern spotted fever (FESF). In Japan, a human case of FESF was identified in Sendai in Miyagi Prefecture in 2008, and R. heilongjiangensis bacteria were isolated from Haemaphysalis concinna ticks collected in the suspected geographic area of infection. Although the intraspecies genome diversity of Rickettsiae has been poorly investigated, our recent analysis revealed extremely low genomic diversity of R. Japonica, the agent of Japanese spotted fever, which is a close relative of R. heilongjiangensis. In this study, to investigate the genomic diversity of R. heilongjiangensis and understand the genetic relationship between Japanese and Chinese strains, we sequenced three strains isolated in Sendai and one strain isolated in Inner Mongolia, China, and performed genomic comparisons between these strains and strain 054, the type strain isolated in Heilongjiang Province, China. Although the three Japanese strains were isolated in 2008, 2009, and 2012, their genome sequences were identical, indicating that H. concinna ticks carrying a single R. heilongjiangensis clone have colonized Sendai, Japan. Among the five R. heilongjiangensis strains, only 81 SNPs and 13 insertion/deletion sites were identified, despite the significant differences in these isolates both geographically and temporally. A significant portion of the 81 SNPs (15/81) were found to be recombinogenic. These results indicate low genomic diversity of R. heilongjiangensis, as observed in R. Japonica. We further performed a detailed genomic comparison of R. heilongjiangensis and R. Japonica to accurately define conserved and species-specific genes. This analysis revealed that although notable variations were found in the genomic loci encoding RelA/SpoT family proteins and tandem repeats in major surface proteins, there was only a small difference in the gene repertoire between the two species, suggesting that SNPs and small InDels are responsible for the functional or physiological differences between the two species, if present. Through this analysis, several species-specific genomic regions that can serve as ideal PCR targets for distinguishing R. heilongjiangensis and R. Japonica were also identified.
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Evaluation of Diagnostic Assay for Rickettsioses Using Duplex Real-Time PCR in Multiple Laboratories in Japan.
Japanese journal of infectious diseases, 2018Co-Authors: Fumihiko Kawamori, Hiromi Fujita, Seigo Yamamoto, Asaka Ikegaya, Y. Shimazu, Hiroko Sato, Naota Monma, Hiroshi Morita, Yukiko Tamaki, Naoya TakamotoAbstract:Tsutsugamushi disease and Japanese spotted fever are representative rickettsioses in Japan, and are caused by infection with Orientia tsutsugamushi and Rickettsia Japonica, respectively. For molecular-based diagnosis, conventional PCR assays, which independently amplify respective Rickettsial DNA, are usually used; however, this approach is time-consuming. Here, we describe a new duplex real-time PCR assay for the simultaneous detection of O. tsutsugamushi and spotted fever group Rickettsiae, and its evaluation using several PCR conditions in 6 public health laboratories. The detection limit of the assay was estimated to be 102 copies and the sensitivity was almost identical to that of 3 conventional PCR methods. A total of 317 febrile patients were selected as clinically suspected or confirmed cases of rickettsioses. The detection efficiency of this assay for O. tsutsugamushi from blood or skin (eschar) specimens appeared to be almost the same as that of the conventional PCR method, even when performed in different laboratories, whereas the efficiency for spotted fever group Rickettsiae tended to be higher than that of the 2 traditional double PCR assays. Our duplex real-time PCR is thus a powerful tool for the rapid diagnosis of rickettsioses, especially at the acute stage of infection.
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Extremely Low Genomic Diversity of Rickettsia Japonica Distributed in Japan.
Genome biology and evolution, 2017Co-Authors: Arzuba Akter, Hiromi Fujita, Seigo Yamamoto, Masakatsu Taira, Tadasuke Ooka, Yasuhiro Gotoh, Fumio Terasoma, Kouji Kida, Fumiko Nakadouzono, Mutsuyo GokudenAbstract:Rickettsiae are obligate intracellular bacteria that have small genomes as a result of reductive evolution. Many Rickettsia species of the spotted fever group (SFG) cause tick-borne diseases known as "spotted fevers". The life cycle of SFG Rickettsiae is closely associated with that of the tick, which is generally thought to act as a bacterial vector and reservoir that maintains the bacterium through transstadial and transovarial transmission. Each SFG member is thought to have adapted to a specific tick species, thus restricting the bacterial distribution to a relatively limited geographic region. These unique features of SFG Rickettsiae allow investigation of how the genomes of such biologically and ecologically specialized bacteria evolve after genome reduction and the types of population structures that are generated. Here, we performed a nationwide, high-resolution phylogenetic analysis of Rickettsia Japonica, an etiological agent of Japanese spotted fever that is distributed in Japan and Korea. The comparison of complete or nearly complete sequences obtained from 31 R. Japonica strains isolated from various sources in Japan over the past 30 years demonstrated an extremely low level of genomic diversity. In particular, only 34 single nucleotide polymorphisms were identified among the 27 strains of the major lineage containing all clinical isolates and tick isolates from the three tick species. Our data provide novel insights into the biology and genome evolution of R. Japonica, including the possibilities of recent clonal expansion and a long generation time in nature due to the long dormant phase associated with tick life cycles.
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Author affi liations: National Institute of Infectious Diseases, Tokyo,
2013Co-Authors: Nozomu Hanaoka, Hiromi Fujita, Seigo Yamamoto, Hiroki Kawabata, Motohiko Ogawa, Minenosuke Matsutani, Akiko Sakata, Yoshinao Azuma, Mutsunori Shirai, Ichiro KuraneAbstract:We developed a specifi c and rapid detection system for Rickettsia Japonica and R. heilongjiangensis, the causative agents of spotted fever, using a TaqMan minor groove binder probe for a particular open reading frame (ORF) identifi ed by the R. Japonica genome project. The target ORF was present only in R. Japonica–related strains. Rickettsia, a genus that includes the causative agents for spotted fever rickettsioses and typhus fever, comprises obligate intracellular bacteria (1). The first case of Japanese spotted fever (JSF), caused by R. Japonica (2), was reported in 1984 in Japan (3). According to the national surveillance system in Japa
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Diagnostic Assay for Rickettsia Japonica
Emerging infectious diseases, 2009Co-Authors: Nozomu Hanaoka, Hiromi Fujita, Seigo Yamamoto, Ai Takano, Hiroki Kawabata, Motohiko Ogawa, Minenosuke Matsutani, Akiko Sakata, Yoshinao Azuma, Haruo WatanabeAbstract:Rickettsia, a genus that includes the causative agents for spotted fever rickettsioses and typhus fever, comprises obligate intracellular bacteria (1). The first case of Japanese spotted fever (JSF), caused by R. Japonica (2), was reported in 1984 in Japan (3). According to the national surveillance system in Japan (http://idsc.nih.go.jp/idwr/ybata/report-Ea.html), JSF cases, including sporadic cases resulting in death, have been gradually increasing. Rapid diagnosis of Rickettsial infections is important because rickettsioses can be cured when appropriate antimicrobial drug treatment is given during the early clinical stages of the disease. Furthermore, development of a rapid and specific diagnostic system for R. Japonica is now a matter of increasing urgency (4) because JSF has also been reported in several other countries in Asia (1).
Takahiro Uchida - One of the best experts on this subject based on the ideXlab platform.
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Demonstration of a Heat-Stable 120-Kilodalton Protein of Rickettsia Japonica as a Spotted Fever Group-Common Antigen
Microbiology and immunology, 1996Co-Authors: Tsuneo Uchiyama, Licheng Zhao, Takahiro UchidaAbstract:Genomic libraries of Rickettsia Japonica were cloned into an expression vector λgt11. A clone expressing a protein reactive with antiserum against 120-kilodalton (kDa) proteins, a mixture of heat-modifiable and heat-stable polypeptides, was selected and designated as λRj120-1. The expressed protein has a molecular mass of 180 kDa. Western immunoblotting demonstrated that the expressed protein was a fusion protein with β-galactosidase. The antiserum against 120-kDa proteins was absorbed by the induced lysogen, resulting in the removal of reactivity to the heat-stable 120-kDa polypeptide. The antiserum against the expressed protein reacted with heat-stable 120- to 130-kDa polypeptides of spotted fever group (SFG) Rickettsiae in addition to R. Japonica. The findings indicated that the protein expressed from the cloned gene of R. Japonica possessed the antigenicity group-common to SFG Rickettsiae. Primers designed from the gene coding for R. conorii heat-stable 120-kDa protein (Schuenke, K.W., and Walker, D.H., Infect. Immun. 62: 904-909, 1994) and λgt11 lacZ gene amplified the λRj120-1 DNA by the polymerase chain reaction (PCR). Analysis of restriction fragment length polymorphism (RFLP) of the PCR-amplified products revealed that the cloned DNA corresponds to a portion of the gene coding for the heat-stable 120-kDa protein of R. conorii with 2,519 nucleotides beginning at nucleotide 190 of the open reading frame. RFLP demonstrated that the cloned gene was highly homologous to the corresponding gene of R. conorii.
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Cross-reactivity of Rickettsia Japonica and Rickettsia typhi demonstrated by immunofluorescence and Western immunoblotting
Microbiology and immunology, 1995Co-Authors: Tsuneo Uchiyama, Licheng Zhao, Yansheng Yan, Takahiro UchidaAbstract:Cross-reactivity between Rickettsia Japonica and R. typhi was observed by immunofluorescence tests using sera from patients with Oriental spotted fever (OSF), from whom the causative agent was isolated and identified as R. Japonica. Western immunoblotting with these sera revealed that only the 120-kilodalton surface polypeptide, i.e., Rickettsial outer membrane protein (rOmp) B, has a common antigenicity with the 105-kilodalton surface polypeptide of R. typhi. In some cases, antibodies specifically reactive with R. typhi were detected in acute-phase sera followed by a significant rise in titers, possibly because of an anamnestic response to a previous infection with an R. typhi-like agent; the sera retained reactivity to R. typhi even after absorption by a homologous strain. A lipopolysaccharide (LPS)-like antigen of R. typhi was found to be reactive with some sera of OSF patients. The ladder bands on Western immunoblot of Rickettsial organisms were confirmed to be polysaccharide in nature, which was demonstrated by comparing them with the pattern of silver-stained gel of proteinase K-treated Rickettsial specimens after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
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Detection of Rickettsia Japonica in Haemaphysalis longicornis ticks by restriction fragment length polymorphism of PCR product.
Journal of clinical microbiology, 1995Co-Authors: Takahiro Uchida, Yansheng Yan, S. KitaokaAbstract:PCR was applied to the detection of Rickettsia Japonica, the causative agent of Oriental spotted fever (OSF), in ticks collected at two sites of the Muroto area on Shikoku Island, a major area in Japan where OSF is endemic. Primer pair Rr190.70p and Rr190.602n of the R. rickettsii 190-kDa antigen gene sequence of Regnery and others (R.L. Regnery, C.L. Spruill, and B.D. Plikaytis, J. Bacteriol. 173:1576-1589, 1991) primed the DNA extracted from Haemaphysalis longicornis ticks but not those extracted from Haemaphysalis formosensis, Haemaphysalis flava, Haemaphysalis hystricis, or Amblyomma testudinarium ticks. Digestion of the amplification product with the restriction endonucleases PstI and AluI produced the restriction fragment length polymorphism pattern specific to R. Japonica. The HindIII and MspI digests gave restriction fragment length polymorphism patterns identical to those of the PCR product from R. Japonica DNA. Hemolymph preparations of H. longicornis ticks were demonstrated to contain rod-shaped organisms that were detected by immunofluorescence with the monoclonal antibody specific to R. Japonica species. The primer pair did not amplify the DNA of a laboratory colony of H. longicornis ticks originally collected at an area where OSF is not endemic. Our results provided evidence that H. longicornis ticks might be an arthropod reservoir for R. Japonica and a vector of OSF.
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Serosurvey for spotted fever group Rickettsial infection in vertebrates in Shimane Prefecture
Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases, 1995Co-Authors: Ken Hoshina, Asao Itagaki, Hiroshi Itogawa, Manabu Gomyoda, Takahiro UchidaAbstract:We carried out a survey for the prevalence of antibodies to the spotted fever group (SFG) Rickettsia in vertebrates such as dogs, cattle, deer, and mice in Shimane Prefecture. Rickettsia Japonica was employed as antigen in indirect immunofluorescence (IF) tests. The experiment for natural infections using decoy animals was performed in the field of the endemic area. 1. Among 115 street dogs, 18.3% possessed the antibodies against SFG Rickettsia, while all of the 8 hunting dogs had the antibodies. 2. Among 234 cattle tested, 17.9% possessed the antibodies. IF titers were 1:40 to 1:160 (mean 1:68). 3. Among 69 wild deer, 92.7% possessed the antibodies ranging between 1:40 and 1:640, which showed the highest IF titers (mean 1:89) among those of the examined vertebrates. 4. The incidence of the antibodies in Apodemus speciosus, Apodemus argenteus and Eothenomys smithi smithi mice were 16.5, 4.3 and 0%, respectively. The incidence of the antibodies against SFG Rickettsia in mice captured in the endemic area was significantly higher (22.8%) than that in non-endemicarea (10.4%). Difference in the incidence of antibody-positive mice was also observed within the endemic area. Therefore, we concluded that the infection of mice was restricted to a limited area. 5. No significant rise in IF titers was observed in decoy animals that had been infested with ticks in the endemic area.
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Analysis of Major Surface Polypeptides of Rickettsia Japonica
Microbiology and immunology, 1994Co-Authors: Tsuneo Uchiyama, Takahiro Uchida, David H. WalkerAbstract:Major surface polypeptides of Rickettsia Japonica migrated to the position of 120, 135, and 145 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, when the organisms were solubilized at room temperature. Two major bands at the position of 135 and 185 kDa were seen, when the organisms were solubilized by heating before electrophoresis. Heat-denaturation of the 120- and 145-kDa polypeptides in excised gel bands changed their mobility and caused them to migrate to 135- and 185-kDa positions, respectively. Two polypeptides at the 120-kDa position were demonstrated: one is a major heat-modifiable polypeptide and the other a minor heat-stable. Peptide mapping was performed to determine the identity between native and denatured polypeptides.
Nobuhiro Takada - One of the best experts on this subject based on the ideXlab platform.
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DISPATCHES Human Rickettsia heilongjiangensis Infection, Japan
2013Co-Authors: Shuji Ando, Hiromi Fujita, Akiko Sakata, Masahiro Kurosawa, Katsurou Sakai, Masao Sekine, Masanori Katsumi, Wakana Saitou, Yasuhiro Yano, Nobuhiro TakadaAbstract:A case of Rickettsia heilongjiangensis infection in Japan was identifi ed in a 35-year-old man who had rash, fever, and eschars. Serum contained R. heilongjiangensis antibodies, and eschars contained R. heilongjiangensis DNA. R. heilongjiangensis was also isolated from ticks in the suspected geographic area of infection. Spotted fever group (SFG) rickettsiosis is the most prevalent arthropod-borne infectious disease in Japan (1). Before publication of a 1984 report about Japanese spotted fever (JSF) caused by Rickettsia Japonica, scrub typhus caused by Orientia tsutsugamushi had been known as the sole rickettsiosis in Japan (1). Although many SFG Rickettsia species (R. Japonica, R. helvetica, R. tamurae, R. asiatica, and other related Rickettsia spp.) were known, only R. Japonica had been isolated or detected by PCR from Japanese SFG rickettsiosis patients (1–3). R. Japonica was found in Dermacentor taiwanensis, Haemaphysalis cornigera, H. fl ava, H. formonensis, H. hystricis, H. longicornis, and Ixodes ovatus ticks, and R. helvetica in H
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High incidence of rickettsiosis correlated to prevalence of Rickettsia Japonica among Haemaphysalis longicornis tick.
The Journal of veterinary medical science, 2010Co-Authors: Kenji Tabara, Hiromi Fujita, Hiroki Kawabata, Satoru Arai, Asao Itagaki, Takeo Yamauchi, Takashi Katayama, Nobuhiro TakadaAbstract:Endemic spotted fever group rickettsiosis was reported in Shimane Prefecture, Japan. From an analysis of 14 clinical cases found in the endemic area, the infectious agent of spotted fever group rickettsiosis was identified as Rickettsia Japonica. In this study, we also found that Rickettsia Japonica was highly infected with the vector tick, Haemaphysalis longicornis, in the endemic area. These findings suggest that the high incidence of rickettsiosis in Shimane Prefecture can be explained by the high prevalence of Rickettsia Japonica among Haemaphysalis longicornis ticks.
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Spotted fever group Rickettsia sp. closely related to Rickettsia Japonica, Thailand.
Emerging infectious diseases, 2009Co-Authors: Nobuhiro Takada, Hiromi Fujita, Shuji Ando, Ai Takano, Hiroki Kawabata, Akiko Sakata, Udom ChaithongAbstract:Suggested citation for this article: Takada N, Fujita H, Kawabata H, Ando S, Sakata A, Takano A, et al. Spotted fever group Rickettsia sp. closely related to R. Japonica, Thailand [letter]. Emerg Infect Dis [serial on the Internet]. 2009 Apr [date cited]. Available from http://www.cdc.gov/EID/content/15/4/610.htm
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genetic identification of Rickettsiae isolated from ticks in japan
Journal of Clinical Microbiology, 2002Co-Authors: Hiromi Fujita, Nobuhiro TakadaAbstract:Following the description in Japan of Japanese spotted fever, caused by Rickettsia Japonica, a search for the vector of this disease led to the isolation of several Rickettsiae from various tick species. Sixty-three Rickettsial isolates were obtained from six different tick species, and six type strains were described by PCR and monoclonal antibody testing. We identified these six strains by amplification and sequencing of the genes encoding 16S rRNA and citrate synthase. We confirmed that the isolates from Dermacentor taiwanensis and Haemaphysalis flava ticks were R. Japonica isolates. In Ixodes ovatus, Ixodes persulcatus, and Ixodes monospinosus, we identified a Rickettsia identical or closely related to Rickettsia helvetica, a species that is pathogenic for humans and that to date has only been found in Europe. Finally, we identified a new genotype of unknown pathogenicity, genotype AT, that was isolated from Amblyomma testudinarium ticks and that is closely related to a Slovakian genotype obtained from Ixodes ricinus ticks.
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Fulminant Japanese Spotted Fever Associated with Hypercytokinemia
Journal of clinical microbiology, 2001Co-Authors: Hiromichi Iwasaki, Nobuhiro Takada, Hiromi Fujita, Fumihiko Mahara, Takanori UedaAbstract:We report a patient with Japanese spotted fever caused by Rickettsia Japonica who developed shock associated with hypercytokinemia. Elevated levels of cytokines (macrophage colony-stimulating factor, interleukin 1 beta, interleukin 10, and gamma interferon) decreased rapidly after a combination treatment using an antibiotic (minocycline hydrochloride [MINO]) and methylprednisolone; however, tumor necrosis factor alpha levels were increased. The patient's fever relapsed and was resolved only after the addition of ciprofloxacin hydrochloride. The administration of new quinolones alone may be another useful form of treatment to eradicate R. Japonica even if the symptoms of hypercytokinemia appear to improve with the administration of MINO and methylprednisolone.
