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Ehrlichia chaffeensis, a new species associated with human ehrlichiosis
B E Anderson1, J E Dawson, D C Jones
1Division of Viral and Rickettsial Diseases, Centers for Disease Control, Atlanta, Georgia 30333.
Journal of Clinical Microbiology
|December 1, 1991
Summary
Researchers identified a new bacterial species causing human ehrlichiosis. Genetic analysis of 16S rRNA genes revealed it is most closely related to Ehrlichia canis.
Area of Science:
- Microbiology
- Genetics
- Infectious Diseases
Background:
- Human ehrlichiosis is an emerging infectious disease caused by Ehrlichia bacteria.
- Accurate identification and classification of Ehrlichia species are crucial for diagnosis and treatment.
Purpose of the Study:
- To genetically characterize the bacterial agent responsible for human ehrlichiosis.
- To compare the genetic sequence of the human ehrlichiosis agent with other Ehrlichia species.
Main Methods:
- Bacterial 16S rRNA genes were amplified from patient blood samples and an isolate using polymerase chain reaction (PCR).
- Amplified DNA fragments (amplimers) were cloned and sequenced.
- Sequences were compared to those of known Ehrlichia species, including Ehrlichia canis, E. equi, E. phagocytophila, E. sennetsu, and E. risticii.
Main Results:
- The 16S rRNA gene sequences from all human samples were identical.
- Sequence comparisons showed the human ehrlichiosis agent is a distinct species, 98.2% related to Ehrlichia canis.
- The agent is more distantly related to other examined Ehrlichia species.
Conclusions:
- The human ehrlichiosis agent represents a new Ehrlichia species.
- The proposed name for this new species is Ehrlichia chaffeensis sp. nov.
- The Arkansas strain is designated as the type strain for Ehrlichia chaffeensis.