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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Infectious Bacterial Diseases Research » Research » Publications at this Location » Publication #158410
Title: COMPARATIVE GENOMICS OF BRUCELLOSIS MELITENSIS, B. SUIS, AND B. ABORTUS

Author
item Halling, Shirley
item GIBAS, C - VIRGINIA POLY TECH
item BOYLE, S - VIRGINIA POLY TECH

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 1/27/2004
Publication Date: 7/1/2004
Citation: Halling, S.M., Gibas, C., Boyle, S. 2004. Comparative genomics of brucellosis melitensis, b. suis, and b. abortus. Lopez-Goni,I., Moiyon,I., editors. In: Brucella: Molecular and Cellular Biology. England:Horizon Biosciences. p 85-102.

Interpretive Summary: Several genomes of the causative agents of brucellosis have been sequenced. A comparison of these genomes reveals that the differences are minor and few. Those differences in genomic sequences identify genes for study to determine their effect on virulence and host specificity as related to vaccine construction for wildlife.

Technical Abstract: The genomes of the classical Brucella species and their OIE biovars have two chromosomes with the exception of B. suis biovar 3 strain 686 which has a single chromosome. The larger chromosome has approximately 2.1 Mbp and has a bacterial origin of replication. The smaller chromosome has approximately 1.2 Mbp and has plasmid replication functions. There is a large inversion within the small chromosome of B. abortus biovars 1, 2, and 4. The genomes are highly similar with over 90% of the genome being more than 95% similar. There is a single large unique genetic island among the genomic sequences of B. melitensis, B. suis, and B. abortus. This island resides in the small genome of B. suis and encodes homologs of transfer functions and phage related genes. The major difference among the genomic sequences appears to be minor sequence variation selected during adaptation to different hosts. RT-PCR detects transcription of several unique genomic sequences. However, differences among the Brucella with regards to host preference, virulence and infectious cycle of the classical Brucella species are likely to be due to subtle variation in the conserved DNA and differential expression of conserved genes, rather than solely to unique genomic DNA fragments. Detailed comparative sequence analysis identifies common and unique regions and diverged regions in conserved genes, and suggests sequence targets to be used in a comparative approach to functional genomics experiments.