Effect of polymyxin B and environmental conditions on isolation of Brucella species and the vaccine strain RB51.

Brucella are resistant to polymyxin B (PB), but their relative susceptibility to PB and its derivative, colistin (COL) has not been rigorously or systematically studied. Comparative susceptibility of Brucella reference strains, vaccine strain RB51, and Brucella isolates from marine mammals to these two cationic peptides were determined by Etest. Vast differences among Brucella species were found in susceptibility to both PB and COL.

Defensin susceptibility and colonization in the mouse model of AJ100, a polymyxin B-resistant, Brucella abortus RB51 isolate.

Intracellular pathogens selected for increased susceptibility to polycations are commonly attenuated, yet the effect of decreased susceptibility to polycations on pathogenicity has not been researched. The polymyxin-resistant mutant Brucella abortus AJ100 was characterized by comparing its susceptibility to the polycationic antibiotic polymyxin B, defensins, and lactoferricin, and its colonization and clearance in the mouse model to the parent strain RB51. MIC (minimum inhibitory concentration) values determined by Etest for AJ100 and RB51 were 1.

Diagnostic characterization of a feral swine herd enzootically infected with Brucella.

Eighty feral swine were trapped from a herd that had been documented to be seropositive for Brucella and which had been used for Brucella abortus RB51 vaccine trials on a 7,100-hectare tract of land in South Carolina. The animals were euthanized and complete necropsies were performed. Samples were taken for histopathology, Brucella culture, and Brucella serology.

Intrinsic and selected resistance to antibiotics binding the ribosome: analyses of Brucella 23S rrn, L4, L22, EF-Tu1, EF-Tu2, efflux and phylogenetic implications.

Background: Brucella spp. are highly similar, having identical 16S RNA. However, they have important phenotypic differences such as differential susceptibility to antibiotics binding the ribosome.

Molecular targets for rapid identification of Brucella spp.

Background: Brucella is an intracellular pathogen capable of infecting animals and humans. There are six recognized species of Brucella that differ in their host preference. The genomes of the three Brucella species have been recently sequenced.

Completion of the genome sequence of Brucella abortus and comparison to the highly similar genomes of Brucella melitensis and Brucella suis.

Brucellosis is a worldwide disease of humans and livestock that is caused by a number of very closely related classical Brucella species in the alpha-2 subdivision of the Proteobacteria. We report the complete genome sequence of Brucella abortus field isolate 9-941 and compare it to those of Brucella suis 1330 and Brucella melitensis 16 M. The genomes of these Brucella species are strikingly similar, with nearly identical genetic content and gene organization.

Brucella 'HOOF-Prints': strain typing by multi-locus analysis of variable number tandem repeats (VNTRs).

Background: Currently, there are very few tools available for subtyping Brucella isolates for epidemiological trace-back. Subtyping is difficult because of the genetic homogeneity within the genus. Sequencing of the genomes from three Brucella species has facilitated the search for DNA sequence variability.

Paradigm shifts in vaccine development: lessons learned about antigenicity, pathogenicity and virulence of Brucellae.

As part of a program to support the USDA Animal Plant Health Inspection Service Bovine Brucellosis Eradication Program, the Brucellosis Research Unit of the National Animal Disease Center (NADC) sought to develop a bovine brucellosis vaccine that would allow vaccinated animals to be distinguished from virulent field infected animals. In order to meet that goal, several avenues of research were undertaken to construct and test candidate vaccines, including Brucella abortus RB51. In early vaccine development studies, a subunit preparation obtained by extracting B.

The Brucella suis genome reveals fundamental similarities between animal and plant pathogens and symbionts.

The 3.31-Mb genome sequence of the intracellular pathogen and potential bioterrorism agent, Brucella suis, was determined. Comparison of B.

Evidence for lateral transfer to Brucellae: characterization of a locus with a Tn-like element (Tn2020).

A genomic locus was discovered within Brucella abortus that contains a novel transposon-like element designated Tn2020. Tn2020 is bounded by a copy of an insertion sequence designated IS2020 and a truncated imperfect copy of IS2020 (tIS2020A). The truncated copy is immediately adjacent to a second copy of IS2020.