Rapid and reliable single nucleotide polymorphism-based differentiation of Brucella live vaccine strains from field strains.

The reliable differentiation of live Brucella vaccine strains from field isolates is an important element in brucellosis control programs. We describe the design, validation, and implementation of a novel single nucleotide polymorphism (SNP)-based typing platform that offers a rapid, reliable, and robust tool to achieve this with improved diagnostic accuracy compared to existing molecular tests. Furthermore, the assays described are designed such that they supplement, and can be run as an intrinsic part of, a previously described assay identifying Brucella isolates to the species level (K.

"HOOF-Print" genotyping and haplotype inference discriminates among Brucella spp. isolates from a small spatial scale.

We demonstrate that the "HOOF-Print" assay provides high power to discriminate among Brucella isolates collected on a small spatial scale (within Portugal). Additionally, we illustrate how haplotype identification using non-random association among markers allows resolution of B. melitensis biovars (1 and 3).

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.

Parenteral vaccination of domestic pigs with Brucella abortus strain RB51.

Objective: To determine the immunogenicity and efficacy of Brucella abortus strain RB51 (SRB51) as a vaccine in domestic pigs.

Animals: Sixty-eight 6-week-old crossbred domestic pigs and twenty-four 4-month-old gilts.

Procedures: In experiment 1, pigs were vaccinated IM (n = 51) with 2 x 10(10) CFUs of SRB51 or sham inoculated (17).

HOOF prints: Brucella strain typing by PCR amplification of multilocus tandem-repeat polymorphisms.

A critical component of limiting bacterial disease outbreaks is the tracing of the infection to the index source, which can be facilitated by using a highly discriminating bacterial identification system that will reliably identify genetically related bacterial populations. For pathogenic bacteria with highly conserved genomes, such as the zoonotic pathogen Brucella, finding distinguishing markers or traits for strain identification is challenging. This chapter describes a relatively new procedure for identifying Brucella strains.

Evaluation of the HOOF-Print assay for typing Brucella abortus strains isolated from cattle in the United States: results with four performance criteria.

Background: A fundamental question that arises during epidemiological investigations of bacterial disease outbreaks is whether the outbreak strain is genetically related to a proposed index strain. Highly discriminating genetic markers for characterizing bacterial strains can help in clarifying the genetic relationships among strains. Under the auspices of the European Society of Clinical Microbiology and Infectious Diseases, the European Study Group for Epidemiological Markers (ESGEM) established guidelines for evaluating the performance of typing systems based of a number of criteria.

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.

Evaluation of the Brucella abortus species-specific polymerase chain reaction assay, an improved version of the Brucella AMOS polymerase chain reaction assay for cattle.

In a blind test, 344 samples representing 80 bacterial isolates were analyzed by the Brucella abortus species-specific polymerase chain reaction (BaSS PCR) assay for the identification and discrimination of B. abortus field strains (wild-type biovars 1, 2, and 4) from 1) B. abortus vaccine strains, 2) other Brucella species, and 3) non-Brucella bacteria.

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.

PCR as a diagnostic tool for brucellosis.

Numerous PCR-based assays have been developed for the identification of Brucella to improve diagnostic capabilities. Collectively, the repertoire of assays addresses several aspects of the diagnostic process. For some purposes, the simple identification of Brucella is adequate (e.