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Home / Equine Research Bank / J Clin Microbiol / Production and characterization of Ehrlichia risticii, the a...
Journal of clinical microbiology1998; 36(6); 1501-1511; doi: 10.1128/JCM.36.6.1501-1511.1998

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.

Abstract: 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 degrees 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.
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Publication Date: 1998-06-10 PubMed ID: 9620368PubMed Central: PMC104868DOI: 10.1128/JCM.36.6.1501-1511.1998Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research article investigates the production and properties of Ehrlichia risticii, a bacterium causing Potomac horse fever, cultivated from snails in an aquarium setup and compares its genetic aspects to strains found within horses. The research suggests that snails may play a crucial role in carrying and spreading the disease-causing bacteria.

Snail Collection and Laboratory Conditions

  • The paper first discusses the collection of snails from stream waters in Siskiyou County, California, where Potomac horse fever is prevalent.
  • The snails were subsequently maintained for several weeks in freshwater aquaria in the laboratory.
  • When the temperature rose above 22 degrees Celsius, the snails started to release a specific type of trematode cercariae, which was tentatively identified as virgulate cercariae.

Gene Amplification and Sequencing

  • By using PCR (Polymerase Chain Reaction), fragments of three different genes (16S rRNA, the groESL heat shock operon, and the 51-kDa major antigen) were amplified from the cercaria lysates and sequenced.
  • Genetic information was also obtained from E. risticii strains taken from horses infected with Potomac horse fever.
  • The presence of the trematode cercariae was directly associated with the PCR positivity of snail secretions, demonstrating a link between the snails and the E. risticii bacteria.

Genetic Comparison and Phylogenetic Analysis

  • The sequence analysis of the three genes revealed that the source organism closely resembled E. risticii.
  • Tellingly, the sequences from all three genes were practically identical to those of an E. risticii strain found in a horse from a property near the snail collection site.
  • Phylogenetic analysis, the study of evolutionary relationships, of the three genes indicated geographical clusters of E. risticii strains, suggesting varying strains depending on the location.

The findings of this research paper provided key insights into the role of snails in carrying E. risticii, the agent of Potomac horse fever, and highlighted genetic similarities between E. risticii strains from snails and horses. This sheds light on potential new strategies for managing the spread of Potomac horse fever.

Cite This Article

APA
Reubel GH, Barlough JE, Madigan JE. (1998). 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. J Clin Microbiol, 36(6), 1501-1511. https://doi.org/10.1128/JCM.36.6.1501-1511.1998

Publication

Journal of clinical microbiology
ISSN: 0095-1137
NlmUniqueID: 7505564
Country: United States
Language: English
Volume: 36
Issue: 6
Pages: 1501-1511

Researcher Affiliations

Reubel, G H
  • Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA.
Barlough, J E
    Madigan, J E

      MeSH Terms

      • Amino Acid Sequence
      • Animals
      • Antigens, Bacterial / genetics
      • Aquaculture
      • Bacterial Proteins / genetics
      • Base Sequence
      • Chaperonins / genetics
      • Ehrlichia / genetics
      • Ehrlichia / growth & development
      • Ehrlichia / isolation & purification
      • Ehrlichiosis / transmission
      • Ehrlichiosis / veterinary
      • Genes, Bacterial
      • Horse Diseases / microbiology
      • Horse Diseases / transmission
      • Horses
      • Microscopy, Electron, Scanning
      • Molecular Sequence Data
      • Phylogeny
      • Polymerase Chain Reaction
      • RNA, Ribosomal, 16S / genetics
      • Sequence Alignment
      • Sequence Analysis, DNA
      • Snails / microbiology
      • Snails / parasitology
      • Trematoda / growth & development
      • Trematoda / microbiology
      • Trematoda / ultrastructure

      References

      This article includes 40 references
      1. Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ. Basic local alignment search tool.. J Mol Biol 1990 Oct 5;215(3):403-10.
        pubmed: 2231712doi: 10.1016/s0022-2836(05)80360-2google scholar: lookup
      2. Anderson BE, Dawson JE, Jones DC, Wilson KH. Ehrlichia chaffeensis, a new species associated with human ehrlichiosis.. J Clin Microbiol 1991 Dec;29(12):2838-42.
        pmc: PMC270443pubmed: 1757557doi: 10.1128/jcm.29.12.2838-2842.1991google scholar: lookup
      3. Barlough JE, Madigan JE, DeRock E, Bigornia L. Nested polymerase chain reaction for detection of Ehrlichia equi genomic DNA in horses and ticks (Ixodes pacificus).. Vet Parasitol 1996 Jun;63(3-4):319-29.
        pubmed: 8966998doi: 10.1016/0304-4017(95)00904-3google scholar: lookup
      4. Barlough JE, Reubel GH, Madigan JE, Vredevoe LK, Miller PE, Rikihisa Y. Detection of Ehrlichia risticii, the agent of Potomac horse fever, in freshwater stream snails (Pleuroceridae: Juga spp.) from northern California.. Appl Environ Microbiol 1998 Aug;64(8):2888-93.
        pmc: PMC106788pubmed: 9687446doi: 10.1128/aem.64.8.2888-2893.1998google scholar: lookup
      5. Barlough JE, Rikihisa Y, Madigan JE. Nested polymerase chain reaction for detection of Ehrlichia risticii genomic DNA in infected horses.. Vet Parasitol 1997 Mar;68(4):367-73.
        pubmed: 9106958doi: 10.1016/s0304-4017(96)01083-7google scholar: lookup
      6. Burch J B. North American freshwater snails. Hamburg, Mich: Malacological Publications; 1989.
      7. Chaichanasiriwithaya W, Rikihisa Y, Yamamoto S, Reed S, Crawford TB, Perryman LE, Palmer GH. Antigenic, morphologic, and molecular characterization of new Ehrlichia risticii isolates.. J Clin Microbiol 1994 Dec;32(12):3026-33.
        pmc: PMC264219pubmed: 7533780doi: 10.1128/jcm.32.12.3026-3033.1994google scholar: lookup
      8. Dillon R T. Karyotypic evolution in pleurocerid snails. II. Pleurocera, Goniobasis, and Juga. Malacologia 1991;33:339–344.
      9. Dumler JS, Bakken JS. Ehrlichial diseases of humans: emerging tick-borne infections.. Clin Infect Dis 1995 May;20(5):1102-10.
        pubmed: 7619983doi: 10.1093/clinids/20.5.1102google scholar: lookup
      10. Dutta SK, Shankarappa B, Mattingly-Napier BL. Molecular cloning and analysis of recombinant major antigens of Ehrlichia risticii.. Infect Immun 1991 Mar;59(3):1162-9.
        pmc: PMC258382pubmed: 1997417doi: 10.1128/iai.59.3.1162-1169.1991google scholar: lookup
      11. Dutta SK, Shankarappa B, Thaker SR, Mattingly-Napier BL. DNA restriction endonuclease cleavage pattern and protein antigen profile of Ehrlichia risticii.. Vet Microbiol 1990 Oct;25(1):29-38.
        pubmed: 2247934doi: 10.1016/0378-1135(90)90090-igoogle scholar: lookup
      12. Felsenstein J. PHYLIP—Phylogeny Inference Package. Cladistics 1989;5:164–166.
      13. FUKUDA T, SASAHARA T, KITAO T. [Studies on the causative agent of Hyuga fever. 10. The vector].. Nihon Densenbyo Gakkai Zasshi 1962 Sep;36:235-41.
        pubmed: 13960183
      14. Fukuda T, Yamamoto S. Neorickettsia-like organism isolated from metacercaria of a fluke, Stellantchasmus falcatus.. Jpn J Med Sci Biol 1981 Apr;34(2):103-7.
        pubmed: 7311106doi: 10.7883/yoken1952.34.103google scholar: lookup
      15. Hahn NE, Fletcher M, Rice RM, Kocan KM, Hansen JW, Hair JA, Barker RW, Perry BD. Attempted transmission of Ehrlichia risticii, causative agent of Potomac horse fever, by the ticks, Dermacentor variabilis, Rhipicephalus sanguineus, Ixodes scapularis and Amblyomma americanum.. Exp Appl Acarol 1990 Jan;8(1-2):41-50.
        pubmed: 2307070doi: 10.1007/bf01193380google scholar: lookup
      16. Holland CJ, Ristic M, Cole AI, Johnson P, Baker G, Goetz T. Isolation, experimental transmission, and characterization of causative agent of Potomac horse fever.. Science 1985 Feb 1;227(4686):522-4.
        pubmed: 3880925doi: 10.1126/science.3880925google scholar: lookup
      17. Kahler S. Transmission is unsolved mystery of equine monocytic ehrlichiosis.. J Am Vet Med Assoc 1989 Jun 15;194(12):1681-5, 1687.
        pubmed: 2753790
      18. Knowles R C, Anderson C W, Shipley W D, Whitlock R H, Perry B D. Acute equine diarrhea syndrome (AEDS): a preliminary report. Proc Am Assoc Eq Pract 1983;29:353–357.
      19. Madigan J E, Barlough J E, Rikihisa Y, Wen B, Miller P E, Sampson T J. Identification of an enzootic diarrhea (“Shasta River crud”) in northern California as Potomac horse fever. J Eq Vet Sci 1997;17:270–272.
      20. Madigan J E, Cohen M, Stabbe M T, True R G, Wohlford L A. Serologic evidence of Potomac horse fever (Ehrlichia risticii) in three California horses with enterocolitis and fever. Calif Vet 1987;41:8–10.
      21. Madigan JE, Rikihisa Y, Palmer JE, DeRock E, Mott J. Evidence for a high rate of false-positive results with the indirect fluorescent antibody test for Ehrlichia risticii antibody in horses.. J Am Vet Med Assoc 1995 Dec 1;207(11):1448-53.
        pubmed: 7493874
      22. Millemann RE, Knapp SE. Biology of Nanophyetus salmincola and "salmon poisoning" disease.. Adv Parasitol 1970;8:1-41.
        pubmed: 4934030
      23. Palmer JE. Prevention of Potomac horse fever.. Cornell Vet 1989 Jul;79(3):201-5.
        pubmed: 2666021
      24. Palmer JE. Potomac horse fever.. Vet Clin North Am Equine Pract 1993 Aug;9(2):399-410.
        pubmed: 8358652doi: 10.1016/s0749-0739(17)30406-6google scholar: lookup
      25. Perry BD, Rikihisa Y, Saunders GK. Intradermal transmission of Potomac horse fever.. Vet Rec 1985 Mar 2;116(9):246-7.
        pubmed: 4002597doi: 10.1136/vr.116.9.246google scholar: lookup
      26. Perry BD, Schmidtmann ET, Rice RM, Hansen JW, Fletcher M, Turner EC, Robl MG, Hahn NE. Epidemiology of Potomac horse fever: an investigation into the possible role of non-equine mammals.. Vet Rec 1989 Jul 22;125(4):83-6.
        pubmed: 2773237doi: 10.1136/vr.125.4.83google scholar: lookup
      27. Pretzman C, Ralph D, Stothard DR, Fuerst PA, Rikihisa Y. 16S rRNA gene sequence of Neorickettsia helminthoeca and its phylogenetic alignment with members of the genus Ehrlichia.. Int J Syst Bacteriol 1995 Apr;45(2):207-11.
        pubmed: 7537055doi: 10.1099/00207713-45-2-207google scholar: lookup
      28. Rikihisa Y. Cross-reacting antigens between Neorickettsia helminthoeca and Ehrlichia species, shown by immunofluorescence and Western immunoblotting.. J Clin Microbiol 1991 Sep;29(9):2024-9.
        pmc: PMC270252pubmed: 1774330doi: 10.1128/jcm.29.9.2024-2029.1991google scholar: lookup
      29. Rikihisa Y, Perry BD. Causative ehrlichial organisms in Potomac horse fever.. Infect Immun 1985 Sep;49(3):513-7.
        pmc: PMC261191pubmed: 4030092doi: 10.1128/iai.49.3.513-517.1985google scholar: lookup
      30. Rikihisa Y, Pretzman CI, Johnson GC, Reed SM, Yamamoto S, Andrews F. Clinical, histopathological, and immunological responses of ponies to Ehrlichia sennetsu and subsequent Ehrlichia risticii challenge.. Infect Immun 1988 Nov;56(11):2960-6.
        pmc: PMC259677pubmed: 3169993doi: 10.1128/iai.56.11.2960-2966.1988google scholar: lookup
      31. Sambrook J, Fritsch E F, Maniatis T. Molecular cloning: a laboratory manual. 2nd ed. Cold Spring Harbor, N.Y: Cold Spring Harbor Laboratory Press; 1989.
      32. Schell S C. How to know the trematodes. W. C. Dubuque, Iowa: Brown Company Publishers; 1970.
      33. Schmidtmann ET, Robl MG, Carroll JF. Attempted transmission of Ehrlichia risticii by field-captured Dermacentor variabilis (Acari: Ixodidae).. Am J Vet Res 1986 Nov;47(11):2393-5.
        pubmed: 3789501
      34. Stothard DR, Clark JB, Fuerst PA. Ancestral divergence of Rickettsia bellii from the spotted fever and typhus groups of Rickettsia and antiquity of the genus Rickettsia.. Int J Syst Bacteriol 1994 Oct;44(4):798-804.
        pubmed: 7981106doi: 10.1099/00207713-44-4-798google scholar: lookup
      35. Sumner JW, Nicholson WL, Massung RF. PCR amplification and comparison of nucleotide sequences from the groESL heat shock operon of Ehrlichia species.. J Clin Microbiol 1997 Aug;35(8):2087-92.
        pmc: PMC229908pubmed: 9230387doi: 10.1128/jcm.35.8.2087-2092.1997google scholar: lookup
      36. Thompson JD, Higgins DG, Gibson TJ. CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice.. Nucleic Acids Res 1994 Nov 11;22(22):4673-80.
        pmc: PMC308517pubmed: 7984417doi: 10.1093/nar/22.22.4673google scholar: lookup
      37. Vemulapalli R, Biswas B, Dutta SK. Pathogenic, immunologic, and molecular differences between two Ehrlichia risticii strains.. J Clin Microbiol 1995 Nov;33(11):2987-93.
        pmc: PMC228620pubmed: 8576359doi: 10.1128/jcm.33.11.2987-2993.1995google scholar: lookup
      38. Wen B, Rikihisa Y, Fuerst PA, Chaichanasiriwithaya W. Diversity of 16S rRNA genes of new Ehrlichia strains isolated from horses with clinical signs of Potomac horse fever.. Int J Syst Bacteriol 1995 Apr;45(2):315-8.
        pubmed: 7537065doi: 10.1099/00207713-45-2-315google scholar: lookup
      39. Wen B, Rikihisa Y, Yamamoto S, Kawabata N, Fuerst PA. Characterization of the SF agent, an Ehrlichia sp. isolated from the fluke Stellantchasmus falcatus, by 16S rRNA base sequence, serological, and morphological analyses.. Int J Syst Bacteriol 1996 Jan;46(1):149-54.
        pubmed: 8573488doi: 10.1099/00207713-46-1-149google scholar: lookup
      40. Wilson KH, Blitchington RB, Greene RC. Amplification of bacterial 16S ribosomal DNA with polymerase chain reaction.. J Clin Microbiol 1990 Sep;28(9):1942-6.
        pmc: PMC268083pubmed: 2095137doi: 10.1128/jcm.28.9.1942-1946.1990google scholar: lookup

      Citations

      This article has been cited 9 times.
      1. Xiong Q, Bekebrede H, Sharma P, Arroyo LG, Baird JD, Rikihisa Y. An Ecotype of Neorickettsia risticii Causing Potomac Horse Fever in Canada.. Appl Environ Microbiol 2016 Oct 1;82(19):6030-6.
        doi: 10.1128/AEM.01366-16pubmed: 27474720google scholar: lookup
      2. Greiman SE, Tkach VV, Vaughan JA. Transmission rates of the bacterial endosymbiont, Neorickettsia risticii, during the asexual reproduction phase of its digenean host, Plagiorchis elegans, within naturally infected lymnaeid snails.. Parasit Vectors 2013 Oct 22;6:303.
        doi: 10.1186/1756-3305-6-303pubmed: 24383453google scholar: lookup
      3. Baird JD, Arroyo LG. Historical aspects of Potomac horse fever in Ontario (1924-2010).. Can Vet J 2013 Jun;54(6):565-72.
        pubmed: 24155447
      4. Rikihisa Y, Zhang C, Kanter M, Cheng Z, Ohashi N, Fukuda T. 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 2004 Aug;42(8):3823-6.
        doi: 10.1128/JCM.42.8.3823-3826.2004pubmed: 15297539google scholar: lookup
      5. Mott J, Muramatsu Y, Seaton E, Martin C, Reed S, Rikihisa Y. 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 2002 Feb;40(2):690-3.
        doi: 10.1128/JCM.40.2.690-693.2002pubmed: 11825999google scholar: lookup
      6. Kanter M, Mott J, Ohashi N, Fried B, Reed S, Lin YC, Rikihisa Y. 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 2000 Sep;38(9):3349-58.
        doi: 10.1128/JCM.38.9.3349-3358.2000pubmed: 10970382google scholar: lookup
      7. Pusterla N, Madigan JE, Chae JS, DeRock E, Johnson E, Pusterla JB. 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 2000 Mar;38(3):1293-7.
        doi: 10.1128/JCM.38.3.1293-1297.2000pubmed: 10699046google scholar: lookup
      8. Barlough JE, Reubel GH, Madigan JE, Vredevoe LK, Miller PE, Rikihisa Y. Detection of Ehrlichia risticii, the agent of Potomac horse fever, in freshwater stream snails (Pleuroceridae: Juga spp.) from northern California.. Appl Environ Microbiol 1998 Aug;64(8):2888-93.
        doi: 10.1128/AEM.64.8.2888-2893.1998pubmed: 9687446google scholar: lookup
      9. Reubel GH, Kimsey RB, Barlough JE, Madigan JE. Experimental transmission of Ehrlichia equi to horses through naturally infected ticks (Ixodes pacificus) from Northern California.. J Clin Microbiol 1998 Jul;36(7):2131-4.
        doi: 10.1128/JCM.36.7.2131-2134.1998pubmed: 9650983google scholar: lookup
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