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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In summary, this work demonstrates a close relationship between a novel bacterium and EBA. Argasidae with the exposure of cattle to epizootic bovine abortion in California. Etiological studies on epizootic bovine abortion. In addition to identifying this novel agent in diseased abrtion bovine tissues, PCR has also demonstrated the presence of the deltaproteobacterium in the tick vector, O. In addition, with the development vovine 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.

Experimentally induced immunity to chlamydial abortion of cattle. Thymuses from all seven fetuses were PCR positive. The early changes observed in the fetuses consisted of transformation and proliferation of lymphocytes and mononuclear phagocytes. Springer-Verlag, New York, N.

Open in a separate window. A quantitative serologic assay for diagnosing congenital infections of cattle. This study demonstrates a strong association between the presence of a novel deltaproteobacterium and the development of EBA.

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

Epizootic bovine abortion characterized by foetal hepatopathy. These three heifers gave birth to healthy calves; two were euthanized immediately prior to consumption of colostrum for PCR analysis; all tissues were PCR negative. In the absence of a cultivable agent, it is proposed that these molecular data are sufficient evidence to classify this epizpotic as the etiologic agent of EBA.

The focus of the epizootiic study was to further expand the morphologic characterization and taxonomic placement of this bacteria, named here as Pajaroellobacter abortibovis. Phylogenetic analysis revealed that this pathogen was a deltaproteobacterium closely bovinf to members of the order Myxococcales. The sequential development of the fetal lesions was studied and the lesions compared with those in both naturally occurring and experimentally induced infections of the dams which either aborted or carried to term.


Flow cytometric analysis identified the presence of P. Although the unusual clinical presentation and unique fetal pathology associated with EBA have been recognized since the s, the identity of the etiologic agent is unknown.

A specific PCR was developed described in Materials and Methods to detect this deltaproteobacterium in bovine tissues. Consensus phylogram of 2, neighbor-joining trees generated for a 1,bp fragment of the 16S rRNA gene of the putative agent causing EBA compared with sequences from 39 representative genera 7 of the class Deltaproteobacteria. 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 Furthermore, since this technique utilizes gene-specific primers directed toward the commonly sequenced 16S rRNA gene, phylogenetic comparisons with other bacteria were possible.

Two of the three healthy calves born from antibiotic-treated dams were euthanized immediately prior to consumption hovine colostrumand tissues were epizootif for PCR epizooticc.

A diagnosis of EBA was established on the basis of histopathology and elevated serum immunoglobulin G, as previously defined 910 A specific PCR was subsequently developed to detect the presence of this bacterium in DNA extracted from fetal thymuses.

Non-EBA diagnoses included bocine viral diarrhea, neosporosis, Haemophilus somnusand unknown etiologies.

Blanchard1 Brian M. Six of seven lymph nodes both prescapular and mesenteric and six of the seven spleens were also positive. Since subsequent PCR showed that these agents were present abortioh both EBA-positive and -negative tissues, their presence was assumed to be the result of postmortem contamination of the samples. Acute vasculitis developed at the same time as the acute focal-necrotizing lesions. The agent was detected in thymic tissues from affected fetuses and in the argasid tick vector of EBA.

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. In these experiments, an additional 13 clones were sequenced.

Carbon dioxide as an attractant for certain ticks Acarina: Escherichia colia member of the class Gammaproteobacteriawas epizoltic as an outgroup in this analysis. In this study, suppression-hybridization PCR was used to identify a fragment of the 16S rRNA gene of a previously undescribed bacterium in thymus tissue derived from affected fetuses.


Epizootic bovine abortion: histogenesis of the fetal lesions.

These changes were marked by 50 days after tick exposure of the dams, but fetal lesions specific enough to permit making the diagnosis of the disease did not develop until days after dams were exposed by tick feeding. Phylogenetic identification and in situ detection of individual microbial cells without cultivation. Histopathologic changes in bovine fetuses after repeated reintroduction of a spirochete-like agent into pregnant heifers: Immunofluorescent examination demonstrated that immunoglobulins Ig G and IgM were present in the vascular lesions.

The tick was identified on ranches and in geographic areas northern and northwestern counties of Nevada coincident with diagnosis of multiple cases of EBA. Primers designed in a similar fashion generated a partial sequence of the 23S rRNA gene JQ These sequences, combined with a revised 16S rRNA phylogenic analysis, support the placement of this bacteria as a unique genus separate from Sorangium.

Detection and identification of previously unrecognized microbial pathogens. 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 Experimental transmission of epizootic bovine abortion foothill abortion. Characterization of Borrelia coriaceae antigens with monoclonal antibodies.

The gross enlargement of epizooitc nodes was the result of cortical follicular hyperplasia and histiocytic lymphadenitis.

The ticks were halved longitudinally with a disposable razor prior to DNA extraction. These preliminary results suggest that the agent is preferentially associated with lymphoid tissues. Isolation of a spirochete from the soft tick, Ornithodoros coriaceus, possible agent of epizootic bovine abortion.

Heifer exposure n Diagnosis a No. 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. Thymic lesions unique to EBA include a loss of cortical thymocytes and extensive infiltration of macrophages into the medulla.