This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Reubel, G. H.
Right arrow Articles by Madigan, J. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Reubel, G. H.
Right arrow Articles by Madigan, J. E.

 Previous Article  |  Next Article 

Journal of Clinical Microbiology, June 1998, p. 1501-1511, Vol. 36, No. 6
0095-1137/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Production and Characterization of Ehrlichia risticii, the Agent of Potomac Horse Fever, from Snails (Pleuroceridae: Juga spp.) in Aquarium Culture and Genetic Comparison to Equine Strains

Gerhard H. Reubel, Jeffrey E. Barlough, and John E. Madigan*

Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616

Received 17 December 1997/Accepted 24 February 1998

We report on the production and characterization of Ehrlichia risticii, the agent of Potomac horse fever (PHF), from snails (Pleuroceridae: Juga spp.) maintained in aquarium culture and compare it genetically to equine strains. Snails were collected from stream waters on a pasture in Siskiyou County, Calif., where PHF is enzootic and were maintained for several weeks in freshwater aquaria in the laboratory. Upon exposure to temperatures above 22°C the snails released trematode cercariae tentatively identified as virgulate cercariae. Fragments of three different genes (genes for 16S rRNA, the groESL heat shock operon, and the 51-kDa major antigen) were amplified from cercaria lysates by PCR and sequenced. Genetic information was also obtained from E. risticii strains from horses with PHF. The PCR positivity of snail secretions was associated with the presence of trematode cercariae. Sequence analysis of the three genes indicated that the source organism closely resembled E. risticii, and the sequences of all three genes were virtually identical to those of the genes of an equine E. risticii strain from a property near the snail collection site. Phylogenetic analyses of the three genes indicated the presence of geographical E. risticii strain clusters.

* Corresponding author. Mailing address: School of Veterinary Medicine, University of California, Davis, CA 95616. Phone: (530) 752-6513. Fax: (530) 752-0414. E-mail: jemadigan{at}ucdavis.edu.

Journal of Clinical Microbiology, June 1998, p. 1501-1511, Vol. 36, No. 6
0095-1137/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Rikihisa, Y., Zhang, C., Kanter, M., Cheng, Z., Ohashi, N., Fukuda, T. (2004). Analysis of p51, groESL, and the Major Antigen P51 in Various Species of Neorickettsia, an Obligatory Intracellular Bacterium That Infects Trematodes and Mammals. J. Clin. Microbiol. 42: 3823-3826 [Abstract] [Full Text]  
  • Mott, J., Muramatsu, Y., Seaton, E., Martin, C., Reed, S., Rikihisa, Y. (2002). Molecular Analysis of Neorickettsia risticii in Adult Aquatic Insects in Pennsylvania, in Horses Infected by Ingestion of Insects, and Isolated in Cell Culture. J. Clin. Microbiol. 40: 690-693 [Abstract] [Full Text]  
  • Kanter, M., Mott, J., Ohashi, N., Fried, B., Reed, S., Lin, Y. C., Rikihisa, Y. (2000). Analysis of 16S rRNA and 51-Kilodalton Antigen Gene and Transmission in Mice of Ehrlichia risticii in Virgulate Trematodes from Elimia livescens Snails in Ohio. J. Clin. Microbiol. 38: 3349-3358 [Abstract] [Full Text]  
  • Pusterla, N., Madigan, J. E., Chae, J.-S., DeRock, E., Johnson, E., Pusterla, J. B. (2000). Helminthic Transmission and Isolation of Ehrlichia risticii, the Causative Agent of Potomac Horse Fever, by Using Trematode Stages from Freshwater Stream Snails. J. Clin. Microbiol. 38: 1293-1297 [Abstract] [Full Text]  
  • Barlough, J. E., Reubel, G. H., Madigan, J. E., Vredevoe, L. K., Miller, P. E., Rikihisa, Y. (1998). Detection of Ehrlichia risticii, the Agent of Potomac Horse Fever, in Freshwater Stream Snails (Pleuroceridae: Juga spp.) from Northern California. Appl. Environ. Microbiol. 64: 2888-2893 [Abstract] [Full Text]  
  • Reubel, G. H., Kimsey, R. B., Barlough, J. E., Madigan, J. E. (1998). Experimental Transmission of Ehrlichia equi to Horses through Naturally Infected Ticks (Ixodes pacificus) from Northern California. J. Clin. Microbiol. 36: 2131-2134 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»