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Home / Equine Research Bank / Infect Immun / Causative ehrlichial organisms in Potomac horse fever.
Infection and immunity1985; 49(3); 513-517; doi: 10.1128/iai.49.3.513-517.1985

Causative ehrlichial organisms in Potomac horse fever.

Abstract: An ehrlichia was consistently isolated from the peripheral blood leukocyte fraction of ponies that had been experimentally infected with Potomac horse fever by whole blood transfusion from naturally infected horses. The organism was propagated in a human histiocyte cell line for 3 to 5 weeks and then inoculated intravenously or intradermally into healthy adult ponies. Clinical signs of Potomac horse fever, which varied in the degree of severity, occurred 9 to 14 days post-inoculation in all of the ponies. One pony died 20 days post-inoculation. The ehrlichial organism was reisolated in the human histiocyte cell line from the blood leukocyte fraction of all of the experimental ponies on each day that samples were examined (days 9, 10, 11, 19, and 39). These organisms were identical to those originally detected in the wall of the intestine of ponies with clinically diagnosed Potomac horse fever when compared by light and electron microscopy and an immunofluorescence labeling technique. The immunofluorescent antibody titer became positive in a pony at 20 days postinjection. These results indicate that the ehrlichial organisms is the causative agent of Potomac horse fever.
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Publication Date: 1985-09-01 PubMed ID: 4030092PubMed Central: PMC261191DOI: 10.1128/iai.49.3.513-517.1985Google Scholar: Lookup
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  • Non-U.S. Gov't

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.

The study established that an organism known as Ehrlichia is responsible for causing Potomac Horse Fever. It was repeatedly isolated from the blood of ponies infected with the disease, and successfully induced the same symptoms in healthy ponies when injected.

Experimental Procedure and Findings

  • The research entailed isolating Ehrlichia from the blood of ponies that were subjects of an experimental infection, a process done via a whole blood transfusion from naturally infected horses.
  • The isolated Ehrlichia was cultivated in a human histiocyte cell line for around 3 to 5 weeks.
  • After propagation, it was injected directly into the blood (intravenously) or skin (intradermally) of healthy ponies.
  • As a result, all ponies manifested clinical signs of Potomac horse fever, although the severity of symptoms ranged. This disease incubation period was between 9 to 14 days post-injection. One of the ponies succumbed to the disease on the 20th day.

Reisolation and Identification Process

  • Following the ponies’ succumbing to the Potomac horse fever induced by the Ehrlichia, the researchers reisolated the organism from the subjects’ blood.
  • This reisolation was carried out on various days during the experiment, specifically on the 9th, 10th, 11th, 19th and 39th days.
  • The examination under light and electron microscopes, and an immunofluorescence labeling technique aided in comparing these organisms.
  • Comparatively, the Ehrlichia organism initially found in ponies diagnosed with Potomac horse fever matched those reisolated from the experimental subjects.
  • A particular pony developed a positive immunofluorescent antibody titer (a blood test that measures the amount of antibodies in the blood) on the 20th day post-injection.

Conclusion

  • The findings conclusively indicate that the Ehrlichia organism is responsible for Potomac horse fever.
  • The researchers successfully demonstrated the disease’s pathogenic route by infecting the ponies, isolating the causative organism, growing it in a laboratory setting, and reintroducing it into healthy subjects, thereby replicating the disease process.

Cite This Article

APA
Rikihisa Y, Perry BD. (1985). Causative ehrlichial organisms in Potomac horse fever. Infect Immun, 49(3), 513-517. https://doi.org/10.1128/iai.49.3.513-517.1985

Publication

Infection and immunity
ISSN: 0019-9567
NlmUniqueID: 0246127
Country: United States
Language: English
Volume: 49
Issue: 3
Pages: 513-517

Researcher Affiliations

Rikihisa, Y
    Perry, B D

      MeSH Terms

      • Animals
      • Ehrlichia / isolation & purification
      • Female
      • Fever / microbiology
      • Fever / veterinary
      • Horse Diseases / microbiology
      • Horses
      • Male
      • Rickettsiaceae / isolation & purification
      • Rickettsiaceae Infections / microbiology
      • Rickettsiaceae Infections / veterinary

      References

      This article includes 3 references
      1. Rikihisa Y, Perry BD, Cordes DO. Ultrastructural study of ehrlichial organisms in the large colons of ponies infected with Potomac horse fever.. Infect Immun 1985 Sep;49(3):505-12.
        pubmed: 4030091doi: 10.1128/iai.49.3.505-512.1985google scholar: lookup
      2. 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
      3. Sundström C, Nilsson K. Establishment and characterization of a human histiocytic lymphoma cell line (U-937).. Int J Cancer 1976 May 15;17(5):565-77.
        pubmed: 178611doi: 10.1002/ijc.2910170504google scholar: lookup

      Citations

      This article has been cited 35 times.
      1. Budachetri K, Lin M, Yan Q, Chien RC, Hostnik LD, Haanen G, Leclère M, Waybright W, Baird JD, Arroyo LG, Rikihisa Y. Real-Time PCR Differential Detection of Neorickettsia findlayensis and N. risticii in Cases of Potomac Horse Fever.. J Clin Microbiol 2022 Jul 20;60(7):e0025022.
        doi: 10.1128/jcm.00250-22pubmed: 35695520google scholar: lookup
      2. Teymournejad O, Lin M, Bekebrede H, Kamr A, Toribio RE, Arroyo LG, Baird JD, Rikihisa Y. Isolation and Molecular Analysis of a Novel Neorickettsia Species That Causes Potomac Horse Fever.. mBio 2020 Feb 25;11(1).
        doi: 10.1128/mBio.03429-19pubmed: 32098825google scholar: lookup
      3. Tan Y, Zhang Z, Zheng C, Wintergerst KA, Keller BB, Cai L. Mechanisms of diabetic cardiomyopathy and potential therapeutic strategies: preclinical and clinical evidence.. Nat Rev Cardiol 2020 Sep;17(9):585-607.
        doi: 10.1038/s41569-020-0339-2pubmed: 32080423google scholar: lookup
      4. Lawrence SA, Poulin R. Detection of the bacterial endosymbiont Neorickettsia in a New Zealand digenean.. Parasitol Res 2016 Nov;115(11):4275-4279.
        doi: 10.1007/s00436-016-5208-xpubmed: 27461113google scholar: lookup
      5. Greiman SE, Rikihisa Y, Cain J, Vaughan JA, Tkach VV. Germs within Worms: Localization of Neorickettsia sp. within Life Cycle Stages of the Digenean Plagiorchis elegans.. Appl Environ Microbiol 2016 Apr;82(8):2356-2362.
        doi: 10.1128/AEM.04098-15pubmed: 26873314google scholar: lookup
      6. Greiman SE, Tkach VV, Pulis E, Fayton TJ, Curran SS. Large scale screening of digeneans for Neorickettsia endosymbionts using real-time PCR reveals new Neorickettsia genotypes, host associations and geographic records.. PLoS One 2014;9(6):e98453.
        doi: 10.1371/journal.pone.0098453pubmed: 24911315google scholar: lookup
      7. 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
      8. Lin M, Zhang C, Gibson K, Rikihisa Y. Analysis of complete genome sequence of Neorickettsia risticii: causative agent of Potomac horse fever.. Nucleic Acids Res 2009 Oct;37(18):6076-91.
        doi: 10.1093/nar/gkp642pubmed: 19661282google scholar: lookup
      9. 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
      10. 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
      11. Reubel GH, Barlough JE, Madigan JE. 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 1998 Jun;36(6):1501-11.
        doi: 10.1128/JCM.36.6.1501-1511.1998pubmed: 9620368google scholar: lookup
      12. Dutta SK, Vemulapalli R, Biswas B. Association of deficiency in antibody response to vaccine and heterogeneity of Ehrlichia risticii strains with Potomac horse fever vaccine failure in horses.. J Clin Microbiol 1998 Feb;36(2):506-12.
        doi: 10.1128/JCM.36.2.506-512.1998pubmed: 9466767google scholar: lookup
      13. Mott J, Rikihisa Y, Zhang Y, Reed SM, Yu CY. Comparison of PCR and culture to the indirect fluorescent-antibody test for diagnosis of Potomac horse fever.. J Clin Microbiol 1997 Sep;35(9):2215-9.
        doi: 10.1128/jcm.35.9.2215-2219.1997pubmed: 9276390google scholar: lookup
      14. 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.
        doi: 10.1128/jcm.33.11.2987-2993.1995pubmed: 8576359google scholar: lookup
      15. Brouqui P, Birg ML, Raoult D. Cytopathic effect, plaque formation, and lysis of Ehrlichia chaffeensis grown on continuous cell lines.. Infect Immun 1994 Feb;62(2):405-11.
        doi: 10.1128/iai.62.2.405-411.1994pubmed: 8300201google scholar: lookup
      16. Messick JB, Rikihisa Y. Inhibition of binding, entry, or intracellular proliferation of Ehrlichia risticii in P388D1 cells by anti-E. risticii serum, immunoglobulin G, or Fab fragment.. Infect Immun 1994 Aug;62(8):3156-61.
        doi: 10.1128/iai.62.8.3156-3161.1994pubmed: 8039884google scholar: lookup
      17. Chen SM, Popov VL, Feng HM, Wen J, Walker DH. Cultivation of Ehrlichia chaffeensis in mouse embryo, Vero, BGM, and L929 cells and study of Ehrlichia-induced cytopathic effect and plaque formation.. Infect Immun 1995 Feb;63(2):647-55.
        doi: 10.1128/iai.63.2.647-655.1995pubmed: 7822034google scholar: lookup
      18. Biswas B, Vemulapalli R, Dutta SK. Detection of Ehrlichia risticii from feces of infected horses by immunomagnetic separation and PCR.. J Clin Microbiol 1994 Sep;32(9):2147-51.
        doi: 10.1128/jcm.32.9.2147-2151.1994pubmed: 7814538google scholar: lookup
      19. 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.
        doi: 10.1128/jcm.32.12.3026-3033.1994pubmed: 7533780google scholar: lookup
      20. Rikihisa Y, Perry BD, Cordes DO. Ultrastructural study of ehrlichial organisms in the large colons of ponies infected with Potomac horse fever.. Infect Immun 1985 Sep;49(3):505-12.
        doi: 10.1128/iai.49.3.505-512.1985pubmed: 4030091google scholar: lookup
      21. Pretzman CI, Rikihisa Y, Ralph D, Gordon JC, Bech-Nielsen S. Enzyme-linked immunosorbent assay for Potomac horse fever disease.. J Clin Microbiol 1987 Jan;25(1):31-6.
        doi: 10.1128/jcm.25.1.31-36.1987pubmed: 3539995google scholar: lookup
      22. Rikihisa Y, Johnson GC, Burger CJ. Reduced immune responsiveness and lymphoid depletion in mice infected with Ehrlichia risticii.. Infect Immun 1987 Sep;55(9):2215-22.
        doi: 10.1128/iai.55.9.2215-2222.1987pubmed: 3497879google scholar: lookup
      23. Wells MY, Rikihisa Y. Lack of lysosomal fusion with phagosomes containing Ehrlichia risticii in P388D1 cells: abrogation of inhibition with oxytetracycline.. Infect Immun 1988 Dec;56(12):3209-15.
        doi: 10.1128/iai.56.12.3209-3215.1988pubmed: 3182078google scholar: lookup
      24. 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.
        doi: 10.1128/iai.56.11.2960-2966.1988pubmed: 3169993google scholar: lookup
      25. Rikihisa Y, Jiang BM. In vitro susceptibilities of Ehrlichia risticii to eight antibiotics.. Antimicrob Agents Chemother 1988 Jul;32(7):986-91.
        doi: 10.1128/AAC.32.7.986pubmed: 3142345google scholar: lookup
      26. Dutta SK, Mattingly BL, Shankarappa B. Antibody response to Ehrlichia risticii and antibody reactivity to the component antigens in horses with induced Potomac horse fever.. Infect Immun 1989 Oct;57(10):2959-62.
        doi: 10.1128/iai.57.10.2959-2962.1989pubmed: 2777369google scholar: lookup
      27. 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.
        doi: 10.1007/BF01193380pubmed: 2307070google scholar: lookup
      28. Thaker SR, Dutta SK, Adhya SL, Mattingly-Napier BL. Molecular cloning of Ehrlichia risticii and development of a gene probe for the diagnosis of Potomac horse fever.. J Clin Microbiol 1990 Sep;28(9):1963-7.
        doi: 10.1128/jcm.28.9.1963-1967.1990pubmed: 2229378google scholar: lookup
      29. Kaylor PS, Crawford TB, McElwain TF, Palmer GH. Passive transfer of antibody to Ehrlichia risticii protects mice from ehrlichiosis.. Infect Immun 1991 Jun;59(6):2058-62.
        doi: 10.1128/iai.59.6.2058-2062.1991pubmed: 2037365google scholar: lookup
      30. 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.
        doi: 10.1128/iai.59.3.1162-1169.1991pubmed: 1997417google scholar: lookup
      31. Biswas B, Mukherjee D, Mattingly-Napier BL, Dutta SK. Diagnostic application of polymerase chain reaction for detection of Ehrlichia risticii in equine monocytic ehrlichiosis (Potomac horse fever).. J Clin Microbiol 1991 Oct;29(10):2228-33.
        doi: 10.1128/jcm.29.10.2228-2233.1991pubmed: 1939575google scholar: lookup
      32. Park J, Rikihisa Y. Inhibition of Ehrlichia risticii infection in murine peritoneal macrophages by gamma interferon, a calcium ionophore, and concanavalin A.. Infect Immun 1991 Oct;59(10):3418-23.
        doi: 10.1128/iai.59.10.3418-3423.1991pubmed: 1910000google scholar: lookup
      33. Rikihisa Y. The tribe Ehrlichieae and ehrlichial diseases.. Clin Microbiol Rev 1991 Jul;4(3):286-308.
        doi: 10.1128/CMR.4.3.286pubmed: 1889044google scholar: lookup
      34. Rikihisa Y, Stills H, Zimmerman G. Isolation and continuous culture of Neorickettsia helminthoeca in a macrophage cell line.. J Clin Microbiol 1991 Sep;29(9):1928-33.
        doi: 10.1128/jcm.29.9.1928-1933.1991pubmed: 1774317google scholar: lookup
      35. Shankarappa B, Dutta SK, Mattingly-Napier B. Identification of the protective 44-kilodalton recombinant antigen of Ehrlichia risticii.. Infect Immun 1992 Feb;60(2):612-7.
        doi: 10.1128/iai.60.2.612-617.1992pubmed: 1730496google scholar: lookup
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