Experimental cross-infections with Ehrlichia phagocytophila and human granulocytic ehrlichia-like agent in cows and horses.
Abstract: Four cows and four horses were infected experimentally with Ehrlichia phagocytophila, the cause of tickborne fever in ruminants, and with human granulocytic ehrlichia-like agent, a recently discovered species that infects people, horses and dogs in the USA and Europe. They were infected in either order, 30 days apart, to investigate serological cross-reactivity within the Ephagocytophila genogroup. The course of infection was assessed by routine clinical, haematological, serological and polymerase chain reaction (PCR) examinations. Two of the cows infected with Ephagocytophila and two of the horses infected with granulocytic ehrlichia-like agent, developed characteristic signs of ehrlichiosis. When the same animals were infected with their heterologous ehrlichial isolate 30 days later, they did not develop clinical signs of disease. The infection of the other two cows with human granulocytic ehrlichia-like agent and the other two horses with Ephagocytophila, resulted in asymptomatic seroconversion. When the same animals were infected with their homologous ehrlichial isolate 30 days later, they remained asymptomatic and had normal haematological results and negative PCRS until the end of the monitoring period, 60 days after the first infection. In these animals, there was an increase in antibody titre after the second infection which was interpreted as a specific immune response, and as a reactivation of the immune response to the first infection.
Publication Date: 1999-10-09 PubMed ID: 10515618DOI: 10.1136/vr.145.11.311Google Scholar: Lookup
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- Comparative Study
- Journal Article
- Research Support
- Non-U.S. Gov't
- Animal Health
- Antibodies
- Clinical Examination
- Clinical Signs
- Diagnosis
- Disease Diagnosis
- Disease Treatment
- Ehrlichia
- Epidemiology
- Equine Health
- Experimental Methods
- Hematology
- Horses
- Immune Response
- Infectious Disease
- Polymerase Chain Reaction
- Serological Surveys
- Tick-Borne Diseases
- Veterinary Medicine
- Veterinary Research
Summary
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The research article is about an experimental study where cows and horses were infected with Ehrlichia phagocytophila, the cause of tickborne fever in ruminants, and with human granulocytic ehrlichia-like agent to investigate serological cross-reactivity within the Ephagocytophila genogroup.
Research Experiment Details
- The researchers carried out an experiment on four cows and four horses, infecting them with Ehrlichia phagocytophila, a bacterium commonly responsible for tickborne fever in ruminants, and a human granulocytic ehrlichia-like (HGE) agent, a relatively newly discovered species that is known to infect humans, horses, and dogs in the USA and Europe.
- The animals were infected by either one of the strains first, followed by the other one 30 days later. The aim of this approach was to investigate serological cross-reactivity – in essence, to see if exposure to one strain can trigger an immune response against the other – within the Ephagocytophila genogroup, a group of closely related bacteria.
Observations and Findings
- The course of infection was monitored through routine clinical checks, blood tests, serological studies to identify immune response, and PCR (Polymerase Chain Reaction) examinations to detect and measure the presence of the bacteria’s DNA in the animals’ bodies.
- Two of the cows infected with E. phagocytophila and two of the horses infected with HGE started to show characteristic signs of ehrlichiosis, a disease caused by these species of bacteria. However, when the same animals were later infected by the other bacterium (30 days after the first infection), they exhibited no new signs of disease.
- The other two cows and horses, who were initially infected with HGE and E. phagocytophila respectively, underwent a process known as asymptomatic seroconversion – their bodies produced an immune response, seen in the production of antibodies, though they showed no physical symptoms of disease. Again, when these animals were later infected by the other bacterium, they still showed no physical symptoms of disease, their blood test results remained normal, and PCRs were negative until the 60th day
- The second infection, however, still caused an increase in the antibody count in these second pair of animals, which the researchers interpret as an immune response specific to the second infection, as well as a reactivation of the immune response to the first infection.
Cite This Article
APA
Pusterla N, Pusterla JB, Braun U, Lutz H.
(1999).
Experimental cross-infections with Ehrlichia phagocytophila and human granulocytic ehrlichia-like agent in cows and horses.
Vet Rec, 145(11), 311-314.
https://doi.org/10.1136/vr.145.11.311 Publication
Researcher Affiliations
- Department of Veterinary Internal Medicine, University of Zurich, Switzerland.
MeSH Terms
- Animals
- Cattle
- Dogs
- Ehrlichia / pathogenicity
- Ehrlichiosis / blood
- Ehrlichiosis / immunology
- Female
- Horses
- Humans
- Male
- Polymerase Chain Reaction
- Species Specificity
Citations
This article has been cited 12 times.- Langenwalder DB, Schmidt S, Silaghi C, Skuballa J, Pantchev N, Matei IA, Mihalca AD, Gilli U, Zajkowska J, Ganter M, Hoffman T, Salaneck E, Petrovec M, von Loewenich FD. The absence of the drhm gene is not a marker for human-pathogenicity in European Anaplasma phagocytophilum strains.. Parasit Vectors 2020 May 7;13(1):238.
- Majazki J, Wüppenhorst N, Hartelt K, Birtles R, von Loewenich FD. Anaplasma phagocytophilum strains from voles and shrews exhibit specific ankA gene sequences.. BMC Vet Res 2013 Nov 28;9:235.
- Rejmanek D, Freycon P, Bradburd G, Dinstell J, Foley J. Unique strains of Anaplasma phagocytophilum segregate among diverse questing and non-questing Ixodes tick species in the western United States.. Ticks Tick Borne Dis 2013 Dec;4(6):482-7.
- Dyachenko V, Geiger C, Pantchev N, Majzoub M, Bell-Sakyi L, Krupka I, Straubinger RK. Isolation of canine Anaplasma phagocytophilum strains from clinical blood samples using the Ixodes ricinus cell line IRE/CTVM20.. Vet Microbiol 2013 Mar 23;162(2-4):980-986.
- Johns JL, Borjesson DL. Downregulation of CXCL12 signaling and altered hematopoietic stem and progenitor cell trafficking in a murine model of acute Anaplasma phagocytophilum infection.. Innate Immun 2012 Jun;18(3):418-28.
- Rejmanek D, Bradburd G, Foley J. Molecular characterization reveals distinct genospecies of Anaplasma phagocytophilum from diverse North American hosts.. J Med Microbiol 2012 Feb;61(Pt 2):204-212.
- Scharf W, Schauer S, Freyburger F, Petrovec M, Schaarschmidt-Kiener D, Liebisch G, Runge M, Ganter M, Kehl A, Dumler JS, Garcia-Perez AL, Jensen J, Fingerle V, Meli ML, Ensser A, Stuen S, von Loewenich FD. Distinct host species correlate with Anaplasma phagocytophilum ankA gene clusters.. J Clin Microbiol 2011 Mar;49(3):790-6.
- Johns JL, Macnamara KC, Walker NJ, Winslow GM, Borjesson DL. Infection with Anaplasma phagocytophilum induces multilineage alterations in hematopoietic progenitor cells and peripheral blood cells.. Infect Immun 2009 Sep;77(9):4070-80.
- Bown KJ, Lambin X, Ogden NH, Petrovec M, Shaw SE, Woldehiwet Z, Birtles RJ. High-resolution genetic fingerprinting of European strains of Anaplasma phagocytophilum by use of multilocus variable-number tandem-repeat analysis.. J Clin Microbiol 2007 Jun;45(6):1771-6.
- von Loewenich FD, Baumgarten BU, Schröppel K, Geissdörfer W, Röllinghoff M, Bogdan C. High diversity of ankA sequences of Anaplasma phagocytophilum among Ixodes ricinus ticks in Germany.. J Clin Microbiol 2003 Nov;41(11):5033-40.
- Dumler JS, Asanovich KM, Bakken JS. Analysis of genetic identity of North American Anaplasma phagocytophilum strains by pulsed-field gel electrophoresis.. J Clin Microbiol 2003 Jul;41(7):3392-4.
- Stuen S, Van De Pol I, Bergström K, Schouls LM. Identification of Anaplasma phagocytophila (formerly Ehrlichia phagocytophila) variants in blood from sheep in Norway.. J Clin Microbiol 2002 Sep;40(9):3192-7.
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