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 an additional experiment, six heifers were challenged with aliquots of a single thymus tissue pool previously demonstrated to be capable of transmitting EBA EBA continues to be the primary diagnosed cause of abortion in beef cattle in California and is estimated to be responsible for the loss of 45, to 90, beef calves annually.
Furthermore, since this technique utilizes gene-specific primers directed toward the commonly sequenced 16S rRNA gene, phylogenetic comparisons with other bacteria were possible. Epizootic bovine abortion EBAfirst identified in the s, is a major contributor of economic loss to western U. Argasidae with the exposure of cattle to epizootic bovine abortion in California.
While attempts to sequence ten epiziotic conserved protein-coding genes using previously published degenerative primers failed, redesigned primers based solely upon Deltaproteobacteria facilitated the partial sequencing of two genes; fusA JQ and pyrG JQ 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.
Detection and identification of previously unrecognized microbial pathogens. 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. In addition, with the development of a diagnostic PCR, efforts can dpizootic 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.
Blanchard1 Brian M. In light of these data, this bacterium was epizoottic as a primary candidate for the putative agent of EBA. Springer-Verlag, New York, N. Thus, phylogenetic characterization has been limited to analysis of the 16S ribosomal RNA rRNA gene AFwhich placed this bacterium in the order Myxococcales, suborder Sorangiineae, family Polyangiaceae and most closely related to Sorangium cellulosum.
EBA-associated lesions are chronic, developing progressively fpizootic a period of 3 months or more. This study establishes the presence of EBA as a cause of late-term abortion in Nevada. Experimental transmission of epizootic bovine abortion foothill abortion.
Epizootic bovine abortion: histogenesis of the fetal lesions.
Fetuses from experimentally exposed heifers were obtained either by surgical removal following dam euthanasia captive bolt in the third trimester to days postchallenge or as dead, weak, or healthy calves following natural parturition. The majority of guidelines that have been suggested for sequence-based determination and incriminating of a presumptive microorganism in disease 5 have been satisfied.
In the abodtion which were either aborted or carried to term after prolonged infection, acute necrotizing lesions were superimposed on the chronic proliferative fetuses. Gross lesions include mucosal and thymic hemorrhages, lymphadenopathy, splenomegaly, hepatomegaly, and ascites.
Diagnosis of epizootic bovine abortion in Nevada and identification of the vector.
Histopathologic changes in bovine fetuses after repeated reintroduction of a spirochete-like agent into pregnant heifers: Phylogenetic identification and in situ detection of individual microbial cells without cultivation. Examination of aborted full-term bovine fetuses obtained from Epzootic ranches revealed gross abnormalities consistent with EBA enlarged lymph nodes, petechial hemorrhages of the oral mucosa and conjunctiva, ascites, and splenohepatomegalyand EBA was confirmed by histologic examination of fetal tissues.
The PCR developed in this study proved to epiziotic a useful tool, allowing the detection of the novel bacterium in DNA extracted from bovine tissues and ticks.
Vaccination against epizootic bovine chlamydial abortion. 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 causative agent of porcine proliferative enteropathy. These lesions were similar to immune-mediated lesions that result from the deposition of toxic complexes in the tissues.
The development of the fetal lesions of epizootic bovine abortion EBA was studied in a series of experiments and field cases of the disease.
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 bvoine Affected fetuses also have markedly elevated immunoglobulin levels, suggestive of a vigorous fetal immune response.
The histologic thymic changes were characteristic of EBA and included severe histocytic thymusitis with depletion of thymocytes, interlobular hemorrhage, and fibrinocellular exudation. Identification and sequencing of the groE operon and flanking genes of Lawsonia intracellularis: The bovins lives in tree and brush litter in deer and cattle beds, feeds rapidly in less than an hour under experimental conditionsand then departs the host. The unique fetal pathology of EBA has classically served as the only definitive basis of diagnosis 9 GenBank accession numbers are shown.
Characterization of Pajaroellobacter abortibovis, the etiologic agent of epizootic bovine abortion.
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.
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 Sequence-based identification of microbial pathogens: Nucleotide sequence accession numbers.
Characterization of Borrelia coriaceae antigens with monoclonal antibodies. Initial results using the small panel of nine bovine tissues see above showed complete concordance with the EBA status of the animals. 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.
Polymerase chain reaction for detection of Borrelia coriaceaeputative agent of epizootic bovine abortion. Published by Elsevier B.