New Ehrlichia Species Closely Related to Ehrlichia chaffeensis Isolated from Ixodes ovatus Ticks in Japan
| Autor: | Tadahiko Ito, Yuriko Watanabe, Shin Ichiro Shibata, Hiromi Fujita, Chiharu Suto, Yasuko Rikihisa, Makoto Kawahara |
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| Rok vydání: | 2000 |
| Předmět: |
Microbiology (medical)
Human monocytotropic ehrlichiosis Chlamydiology and Rickettsiology Molecular Sequence Data Ehrlichia Thymus Gland Mice Japan RNA Ribosomal 16S parasitic diseases Leukocytes medicine Animals Ehrlichia chaffeensis Amino Acid Sequence Lung Phylogeny Ehrlichia muris Mice Inbred BALB C Ixodes biology Macrophages Ehrlichiosis Genes rRNA Chaperonin 60 bacterial infections and mycoses biology.organism_classification medicine.disease Antibodies Bacterial Virology Microscopy Electron Ehrlichiaceae Rickettsiales Ixodidae |
| Zdroj: | Journal of Clinical Microbiology. 38:1331-1338 |
| ISSN: | 1098-660X 0095-1137 |
| DOI: | 10.1128/jcm.38.4.1331-1338.2000 |
| Popis: | Seven Ehrlichia strains (six HF strains and one Anan strain) that were obtained from laboratory mice by intraperitoneally inoculating homogenates of adult Ixodes ovatus collected in Japan were characterized. 16S rRNA sequences of all six HF strains were identical, and the sequences were 99.7, 98.2, and 97.7% identical to those of Anan strain, Ehrlichia chaffeensis (human monocytic ehrlichiosis agent), and E. muris , respectively. Partial GroEL amino acid sequencing also revealed that the six HF strains had identical sequences, which were 99.0, 98.5, and 97.3% identical to those of E. chaffeensis , the Anan strain, and E. canis , respectively. All HF strains were lethal to mice at higher dosages and intraperitoneal inoculation, whereas the Anan or E. muris strain induced only mild clinical signs. Light and electron microscopy of moribund mice inoculated with one of the HF strains revealed severe liver necrosis and the presence of numerous ehrlichial inclusions (morulae) in various organs. The study revealed that members of E. canis genogroup are naturally present in Ixodes ticks. HF strains that can cause severe illness in immunocompetent laboratory mice would be valuable in studying the pathogenesis and the roles of both cellular and humoral immune responses in ehrlichiosis caused by E. canis genogroup. |
| Databáze: | OpenAIRE |
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