Skip directly to local search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Volume 7, Number 3—June 2001

Letter

Proper Nomenclature for the HGE Agent

Suggested citation for this article

Read original article, http://wwwnc.cdc.gov/eid/article/6/5/00-0502_article.htm

To the Editor: In their recent article, "Antigenic variations in Vector-borne pathogens," Barbour and Restrepo discuss the outer membrane protein components of Anaplasma marginale and related bacteria (1). Citing a reference by Zhi et al. (2), they state that Ehrlichia granulocytophila is the agent of human granulocytic ehrlichiosis (HGE).

The use of new names and combinations not widely recognized for genera and species lends increasing confusion to a group of bacteria already in taxonomic disarray. Several other species names have been suggested for the HGE agent since the initial description of the clinical illness caused by this agent and the in vitro technique used to isolate the agent in blood samples (3,4). Both E. phagocytophila and E. equi are genetically nearly identical to the HGE agent, and the three are probably conspecific. Thus, most scientists in the field today would support use of the name Ehrlichia phagocytophila to describe these bacteria.

Recent phylogenetic analyses show that E. phagocytophila strains align into a clade that includes Anaplasma marginale, the historical precedent in this grouping. Such phylogenetic analyses, which are also supported by comparative antigenic and biological studies, have resulted in a proposal for reclassification of several Ehrlichia spp., including E. phagocytophila, into the genus Anaplasma (5). Until a cogent reclassification based on objective criteria is firmly accepted, the creation and use of new scientific name combinations for a single bacterium yield clinical and laboratory confusion and should be avoided.

Johan S. Bakken* and J. Stephen Dumler†
Author affiliations: *St. Mary's Duluth Clinic, Duluth, Minnesota, USA; †Johns Hopkins Medical Institutions, Baltimore, Maryland, USA

References

  1. Barbour AG, Restrepo BI. Antigenic variations in vector-borne pathogens. Emerg Infect Dis. 2000;6:44957. DOIPubMed
  2. Zhi N, Ohashi N, Rikihisa Y. Multiple p44 genes encoding major outer membrane proteins are expressed in the human granulocytic ehrlichiosis agent. J Biol Chem. 1999;274:1782836. DOIPubMed
  3. Bakken JS, Dumler JS, Chen S-M, Eckman MR, VanEtta LL, Walker DH. Human granulocytic ehrlichiosis in the upper midwest United States: A new species emerging? JAMA. 1994;272:2128. DOIPubMed
  4. Goodman JL, Nelson C, Vitale B, Madigan JE, Dumler JS, Munderloh UG. Direct cultivation of the causative agent of human granulocytic ehrlichiosis. N Engl J Med. 1996;334:20915. DOIPubMed
  5. Dumler JS, Rihihisa Y, Dasch GA, Barbet AF, Palmer GH, Ray SC. Proposal for taxonomic reorganization of the order Rickettsiales, family Rickettsiaceae, and tribe Ehrlichieae. [abstract 75]. In: Program and Abstracts of the 15th Sesqui-Annual Meeting of the American Society for Rickettsiology; April 30-May 5, 2000; Captiva Island, Florida. American Society for Rickettsiology;2000.

Suggested Citation for this article: Bakken JS, Dumler JS. Proper Nomenclature for the HGE Agent [letter].Emerg Infect Dis [serial on the Internet]. 2001, Jun [date cited]. http://dx.doi.org/10.3201/eid0703.017333

DOI: 10.3201/eid0703.017333

Related Links

Top of Page

Table of Contents – Volume 7, Number 3—June 2001

Comments to the EID Editors

Please contact the EID Editors via our Contact Form.

 

Past Issues

Select a Past Issue:

Art in Science - Selections from Emerging Infectious Diseases
Now available for order



CDC 24/7 – Saving Lives, Protecting People, Saving Money. Learn More About How CDC Works For You…

USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30333, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO