Characterization of Pajaroellobacter abortibovis, the etiologic agent of epizootic bovine abortion. Brooks RS(1), Blanchard MT(1), Clothier. J Vet Diagn Invest. May;14(3) Diagnosis of epizootic bovine abortion in Nevada and identification of the vector. Hall MR(1), Hanks D, Kvasnicka W. Kennedy PC, Casaro AP, Kimsey PB, Bon Durant RH, Bushnell RB, Mitchell GM. The development of the fetal lesions of epizootic bovine abortion (EBA) was.

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Histopathologic changes in bovine fetuses after repeated reintroduction of a spirochete-like agent into pregnant heifers: Two of the three healthy calves born from antibiotic-treated dams were euthanized immediately prior to consumption of colostrumand tissues were collected for PCR analysis.

GenBank accession numbers are shown. The heifers were exposed to the agent of EBA by i natural exposure fetuses were submitted by ranchersii tick feeding under experimental conditions, or iii inoculation with tissue homogenate derived from fetuses previously diagnosed as being EBA positive.

Necropsy tissues were collected using a sterile technique. In summary, this work demonstrates a aborhion relationship between a novel bacterium and EBA. Although these agents were detected in some of the DNA samples, the pattern for neither bacterium paralleled the epizootkc and histopathological diagnosis of EBA data not shown.

A specific PCR was subsequently developed to detect the presence of this bacterium in DNA extracted from fetal thymuses. Denaturing gradient gel electrophoresis: The novel bacterium described in this paper represents only the second member of the delta subdivision of the class Proteobacteria to be a mammalian pathogen the first was Lawsonia intracellularis [ 413 ], the bobine agent of porcine proliferative enteropathy. These lesions were similar to immune-mediated lesions that result from the deposition of toxic complexes in the tissues.

Diagnosis of epizootic bovine abortion in Nevada and identification of the vector.

Preliminary data demonstrated the EBA agent to be present abrotion 4 of 11 nymphs tested and 2 of 8 female ticks tested; The nucleic acid sequences were the same five were directly sequenced to confirm the identity of the PCR product as that identified in EBA fetal bovine tissues. A wpizootic of direct sequencing bp from 25 EBA-positive fetuses representing 16 field cases, four experimental tick transmissions, and five experimental tissue transmissions, the last using thymus homogenate derived from an EBA-positive fetus and Southern blotting of these amplicons was used to confirm PCR specificity.


A diagnosis of EBA was established on the basis of histopathology and elevated serum immunoglobulin G, as previously defined 910 The phylogenetic position of SerratiaButtiauxella and some other genera of the family Enterobacteriaceae. Characterization of Borrelia coriaceae antigens with monoclonal antibodies.

This article has been cited by other articles in PMC. These data imply boivne close association between this abortkon agent and the etiology of EBA. The present study employed an shPCR technique in an attempt to identify a bacterial agent present in fetal thymic tissues collected from EBA cases.

Furthermore, the PCR failed to amplify DNA extracted from pure cultures of a selection of bacterial pathogens typically encountered in veterinary medicine or even P.

Epizootic bovine abortion EBAfirst identified in the s, is a major contributor of economic loss to western U. The phylogenetic location of the putative EBA etiologic agent was surprising, since none of the closest relatives have been demonstrated to be mammalian pathogens. Instruments were subjected to bleach and heat treatment alcohol burn between collections of individual organs.

Histologic examination of fetal tissues, particularly the lymphoid organs, is required to confirm a diagnosis 9 Argasidae with the exposure of cattle to epizootic bovine abortion in California.

Epizootic bovine abortion characterized by foetal hepatopathy.

Carbon dioxide as an attractant for certain ticks Acarina: Tissue Presence of agent in fetus a: In contrast, the three challenge control fetuses aborttion dams did not receive antibiotics all presented with classic EBA-associated lesions, and their tissues were PCR positive.

Two different fetal bovine thymic pools containing tissue homogenates from two EBA-positive tester or three EBA-negative driver individual cases were prepared by phenol-chloroform extraction These primer regions showed the most variation compared with other bacterial sequences in multiple-nucleotide alignments.

In addition, with the development of a diagnostic PCR, efforts can be initiated to better define the ecology of EBA, including the identification of additional reservoirs of the bacterium and defining the association between the EBA agent and the tick vector. Although all bacterial culture attempts have been unsuccessful, this breakthrough provided sufficient direction to develop a molecular approach for the abodtion of the etiologic agent.


Similar approaches have been successfully used to identify microbial pathogens, including those responsible for cat scratch fever, Whipple’s disease, human ehrlichiosis, hepatitis C, and hantavirus pulmonary syndrome 5 Polymerase chain reaction for detection of Borrelia coriaceaeputative agent of epizootic bovine abortion.

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The recent development of a challenge system in which inoculation of EBA-diseased fetal thymus into pregnant 90 to days of gestation heifers could result in consistent and predictable transmission of the EBA agent has facilitated efforts to define the causative organism In the fetuses which were either aborted or carried to term after prolonged infection, acute necrotizing lesions were superimposed on the chronic proliferative fetuses. In the absence of a cultivable agent, it is proposed that these molecular data are sufficient evidence to classify this bacterium as the etiologic agent of EBA.

Experimentally induced immunity to chlamydial abortion of cattle.

Blanchard1 Brian M. Novel bacterium in phylum Bacteroidetes. The scale represents percent nucleotide substitutions per site. Acute vasculitis developed at the same time as the acute focal-necrotizing lesions.

Characterization of Pajaroellobacter abortibovis, the etiologic agent of epizootic bovine abortion.

In these experiments, an additional 13 clones were sequenced. Widespread inflammatory lesions with a vascular orientation are evident in most tissues. Nucleotide sequence accession numbers.

Open in a separate window. This study demonstrates a strong association between the presence of a novel deltaproteobacterium and the development of EBA. Gross lesions include mucosal and thymic epozootic, lymphadenopathy, splenomegaly, hepatomegaly, and ascites. Detection and identification of previously unrecognized microbial pathogens.

The early changes observed in the fetuses consisted of transformation and proliferation of lymphocytes and mononuclear phagocytes.