title: Characterization of Pajaroellobacter abortibovis, the etiologic agent of epizootic bovine abortion.
abstract: Epizootic bovine abortion (EBA), first identified in the 1950s, is a major contributor of economic loss to western U.S. beef producers. The causative agent proved elusive for over fifty years until a novel Deltaproteobacteria was identified as the etiologic agent in 2005. The microbe, which has yet to be successfully cultured in vitro, has proven difficult to purify from necropsy tissues. Thus, phylogenetic characterization has been limited to analysis of the 16S ribosomal RNA (rRNA) gene (AF503916), which placed this bacterium in the order Myxococcales, suborder Sorangiineae, family Polyangiaceae and most closely related to Sorangium cellulosum. The focus of the current study was to further expand the morphologic characterization and taxonomic placement of this bacteria, named here as Pajaroellobacter abortibovis. Modified Gram staining, combined with transmission electron microscopy, provide strong evidence that the bacterium is gram negative. Flow cytometric analysis identified the presence of P. abortibovis in murine leukocytes. While attempts to sequence ten universally conserved protein-coding genes using previously published degenerative primers failed, redesigned primers based solely upon Deltaproteobacteria facilitated the partial sequencing of two genes; fusA (JQ173112) and pyrG (JQ173111). Primers designed in a similar fashion generated a partial sequence of the 23S rRNA gene (JQ173113) These sequences, combined with a revised 16S rRNA phylogenic analysis, support the placement of this bacteria as a unique genus separate from Sorangium.
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Roxann S
authors.initials: RS
authors.lastname: Brooks
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Myra T
authors.initials: MT
authors.lastname: Blanchard
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; California Animal Health and Food Safety Laboratory System, University of California, Davis, CA 95616, USA.
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Clothier
authors.affiliation: California Animal Health and Food Safety Laboratory System, University of California, Davis, CA 95616, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Fish
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; California Animal Health and Food Safety Laboratory System, University of California, Davis, CA 95616, USA.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Anderson
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. Electronic address: jlstott@ucdavis.edu.
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Stott
mesh_terms: D000034:Abortion, Veterinary / Q000382:microbiology*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D020564:Deltaproteobacteria / Q000235:genetics / Q000502:physiology*; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D051379:Mice; D016513:Mice, SCID; D010802:Phylogeny; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000662:veterinary; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S
keywords: Electron microscopy; Epizootic bovine abortion; Gram stain; Intracellular bacteria; Pajaroellobacter abortibovis; Phylogenetic analysis