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Takajo I.,University of MiyazakiMiyazaki | Sekizuka T.,Japan National Institute of Infectious Diseases | Fujita H.,Mahara Institute of Medical Acarology | Kawano A.,University of MiyazakiMiyazaki | And 10 more authors.
Emerging Infectious Diseases | Year: 2016

A 60-year-old woman experienced fever, headache, rash, and altered vision after returning to Japan from India. Testing detected elevated antibody titers to spotted fever group rickettsia; PCR on blood yielded positive results for the rickettsial outer membrane protein A gene. We isolated a unique rickettsial agent and performed a full-genome analysis. © 2016, Centers for Disease Control and Prevention (CDC). All rights reserved.


Andoh M.,Japan National Institute of Infectious Diseases | Andoh M.,Kagoshima University | Sakata A.,Japan National Institute of Infectious Diseases | Takano A.,Japan National Institute of Infectious Diseases | And 8 more authors.
PLoS ONE | Year: 2015

One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals, reptiles and amphibians also carry ticks that may harbor Rickettsia and Ehrlichia strains that are pathogenic to humans. Furthermore, reptiles and amphibians are exempt from quarantine in Japan, thus facilitating the entry of parasites and pathogens to the country through import. Accordingly, in the current study, we examined the presence of Rickettsia and Ehrlichia spp. genes in ticks associated with reptiles and amphibians originating from outside Japan. Ninety-three ticks representing nine tick species (genera Amblyomma and Hyalomma) were isolated from at least 28 animals spanning 10 species and originating from 12 countries (Ghana, Jordan, Madagascar, Panama, Russia, Sri Lanka, Sudan, Suriname, Tanzania, Togo, Uzbekistan, and Zambia). None of the nine tick species are indigenous in Japan. The genes encoding the common rickettsial 17-kDa antigen, citrate synthase (gltA), and outer membrane protein A (ompA) were positively detected in 45.2%(42/93), 40.9% (38/93), and 23.7% (22/93) of the ticks, respectively, by polymerase chain reaction (PCR). The genes encoding ehrlichial heat shock protein (groEL) and major outer membrane protein (omp-1) were PCR-positive in 7.5% (7/93) and 2.2% (2/93) of the ticks, respectively. The p44 gene, which encodes the Anaplasma outer membrane protein, was not detected. Phylogenetic analysis showed that several of the rickettsial and ehrlichial sequences isolated in this study were highly similar to human pathogen genes, including agents not previously detected in Japan. These data demonstrate the global transportation of pathogenic Rickettsia and Ehrlichia through reptile- And amphibian-associated ticks. These imported animals have potential to transfer pathogens into human life. These results highlight the need to control the international transportation of known and potential pathogens carried by ticks in reptiles, amphibians, and other animals, in order to improve national and international public health. © 2015 Andoh et al.


Yamauchi T.,Toyama Institute of Health | Sato M.,Rishiri Town Museum | Ito T.,Hokkaido Institute of Public Health | Fujita H.,Mahara Institute of Medical Acarology | And 5 more authors.
International Journal of Acarology | Year: 2013

Tick fauna and tick-borne pathogenic bacteria were surveyed on Rishiri Island, off the northwest coast of Hokkaido, Japan. We collected Ixodes pavlovskyi and Ixodes persulcatus from vegetation, Ixodes angustus from Myodes rex, and Ixodes tanuki from Mustela itatsi and Felis silvestris catus. Borrelia garinii, the cause of Lyme disease in Eurasia, and Rickettsia helvetica and Rickettsia tarasevichiae of the spotted fever group were detected from I. persulcatus. These results indicate a potential threat of Lyme disease and spotted fever group rickettsiosis on Rishiri Island. It is possible that an introduced species, Mu. itatsi, contributes to maintenance of the infectious diseases as a blood source for the ticks on the island. © 2013 Taylor & Francis.


Harasawa R.,The Iwate Research Center for Wildlife Diseases | Fujita H.,Mahara Institute of Medical Acarology | Kadosaka T.,Aichi Medical University | Ando S.,Japan National Institute of Infectious Diseases | Rikihisa Y.,Ohio State University
International Journal of Systematic and Evolutionary Microbiology | Year: 2015

Mycoplasma haemomuris is causative of infectious anaemia or splenomegaly in rodents. We examined the nucleotide sequences of the non-ribosomal genes, rnpB and dnaK, in strains of the species M. haemomuris detected in small field mice and black rats. rnpB nucleotide sequences in strains of the species M. haemomuris isolated from small field mice and black rats had only 89% sequence similarity, suggesting their separation into two distinct subgroups. dnaK had a nucleotide sequence similarity of 84% between the subgroups. These results support the classification of M. haemomuris into two genetically distinct subgroups. Here we propose the establishment of these subgroups as ‘Candidatus Mycoplasma haemomuris subsp. musculi’, detected in small field mice (Apodemus argenteus), and ‘Candidatus Mycoplasma haemomuris subsp. ratti’, detected in black rats (Rattus rattus). ©2015 IUMS.


Oda S.,Nihon University | Kabeya H.,Nihon University | Sato S.,Nihon University | Shimonagane A.,Nihon University | And 6 more authors.
Journal of Wildlife Diseases | Year: 2015

Yersinia enterocolitica was isolated from 15.7% (88/560) of wild rodents captured in 15 prefectures in Japan. Prevalences by rodent species were 18.0%(70/388) in Japanese field mice (Apodemus speciosus), 20% (14/71) in small Japanese field mice (Apodemus argenteus), and 11% (4/38) in gray red-backed vole (Myodes rufocanus bedfordiae), suggesting that these rodent species are important reservoirs of Y. enterocolitica. Although most of the isolates were identified as biotype 1A, the pathogenic bioserotype 1B/O:8 was detected in one of the A. speciosus and in three of the A. argenteus captured in Aomori Prefecture. It is suggested that Apodemus mice may be an important reservoir of Y. enterocolitica, and that there are foci of the pathogenic bioserotype 1B/O:8 in Aomori Prefecture, because human sporadic cases by the serotype have been reported in this prefecture. ©.Wildlife Disease Association 2015


Soon Kim K.,Nihon University | Inoue K.,Nihon University | Kabeya H.,Nihon University | Sato S.,Nihon University | And 9 more authors.
Journal of Wildlife Diseases | Year: 2016

We collected 641 small mammals belonging to 17 species of Rodentia and four species of Soricomorpha in Japan, Korea, Russia, Taiwan, and Thailand and investigated the prevalence and genetic diversity of Bartonella species. Apodemus (field mice) and Rattus (rats) were the most-common genera captured, making up 56.0% and 23.1% of the total specimens, respectively. Bartonellae were isolated from 54.6% of the collected animals, and the prevalence varied depending on the host species and the country of origin. The isolates were identified to the species level based on gltA and rpoB sequences. Although most Bartonella species were shared by more than two host species, the distribution patterns of Bartonella species clearly differed among the four most-common host genera: Apodemus, Rattus, Myodes (voles), and Suncus (shrews). The predominant Bartonella species were Bartonella grahamii in Apodemus, Bartonella tribocorum in Rattus, B. grahamii and Bartonella taylorii in Myodes, and an unclassified Bartonella sp. in Suncus. © Wildlife Disease Association 2016.


Andoh M.,Japan National Institute of Infectious Diseases | Ogasawara Y.,Japan National Institute of Infectious Diseases | Sakata A.,Japan National Institute of Infectious Diseases | Ito T.,Hokkaido Institute of Public Health | And 3 more authors.
Vector-Borne and Zoonotic Diseases | Year: 2014

Two rickettsial isolates, HM-1 and HM-2, were isolated from Haemaphysalis megaspinosa collected in Japan in 2006 and 2011, respectively. The isolates were analyzed by DNA sequences of the outer membrane protein A gene, the outer membrane protein B gene, the citrate synthase gene, the genus Rickettsia-specific outer membrane protein 17-kDa gene, the 16S ribosome RNA gene, and the PS120 protein gene ("geneD"). HM-1 was identified as Rickettsia tamurae. HM-2 matched most closely with 'Candidatus Rickettsia kotlanii' DNA, which has only been reported from H. concinna in Hungary. This is the first report of isolation in Japan of the agent genetically similar to 'Candidatus R. kotlanii,' which belongs phylogenetically to the spotted fever group Rickettsia. Our study shows the possibility that 'Candidatus R. kotlanii' can be carried by at least two tick species. Furthermore, because the Rickettsia sp. has been found two distant countries, Hungary and Japan, it has potential for wider distribution. © 2014, Mary Ann Liebert, Inc. 2014.


PubMed | Japan National Institute of Infectious Diseases, Mahara Institute of Medical Acarology, Ohio State University, The Iwate Research Center for Wildlife Diseases and Aichi Medical University
Type: Journal Article | Journal: International journal of systematic and evolutionary microbiology | Year: 2015

Mycoplasma haemomuris is causative of infectious anaemia or splenomegaly in rodents. We examined the nucleotide sequences of the non-ribosomal genes, rnpB and dnaK, in strains of the species M. haemomuris detected in small field mice and black rats. rnpB nucleotide sequences in strains of the species M. haemomuris isolated from small field mice and black rats had only 89 % sequence similarity, suggesting their separation into two distinct subgroups. dnaK had a nucleotide sequence similarity of 84 % between the subgroups. These results support the classification of M. haemomuris into two genetically distinct subgroups. Here we propose the establishment of these subgroups as Candidatus Mycoplasma haemomuris subsp. musculi, detected in small field mice (Apodemus argenteus), and Candidatus Mycoplasma haemomuris subsp. ratti, detected in black rats (Rattus rattus).


PubMed | 1 12 4 Sakamoto, Mahara Institute of Medical Acarology, Aichi University, Institute of Tropical Medicine and Nagasaki University
Type: | Journal: Scientific reports | Year: 2016

Ixodid ticks transmit several important viral pathogens. We isolated a new virus (Tofla virus: TFLV) from Heamaphysalis flava and Heamaphysalis formsensis in Japan. The full-genome sequences revealed that TFLV belonged to the genus Nairovirus, family Bunyaviridae. Phylogenetic analyses and neutralization tests suggested that TFLV is closely related to the Hazara virus and that it is classified into the Crimean-Congo hemorrhagic fever group. TFLV caused lethal infection in IFNAR KO mice. The TFLV-infected mice exhibited a gastrointestinal disorder, and positron emission tomography-computed tomography images showed a significant uptake of (18)F-fluorodeoxyglucose in the intestinal tract. TFLV was able to infect and propagate in cultured cells of African green monkey-derived Vero E6 cells and human-derived SK-N-SH, T98-G and HEK-293 cells. Although TFLV infections in humans and animals are currently unknown, our findings may provide clues to understand the potential infectivity and to develop of pre-emptive countermeasures against this new tick-borne Nairovirus.


PubMed | National Institute of Genetics, Tokyo Institute of Technology, 11 Health, Kyushu University and 7 more.
Type: | Journal: Genome biology and evolution | Year: 2017

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 R. 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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