|Ewalt, Darla - USDA, APHIS, NVSL|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 27, 2004
Publication Date: November 13, 2004
Citation: Bricker, B.J., Ewalt, D.R. 2004. Strain diversity identified by HOOF-print genetic typing of a large collection of b. abortus field isolates [abstract]. Technical Abstract: HOOF-Printing is a new technique for genotyping Brucella strains. It exploits the accelerated mutation rates observed in genomic regions containing large numbers of tandemly repeated DNA motifs. Previously we reported that the Brucella genome contains tandem repeats of the octamer, AGGGCAGT, in eight independent chromosomal loci distributed on both chromosomes. A PCR test was developed to categorize the number of repeat units at each locus based on the size of the amplified fragment. This report describes the genetic typing of a collection of 97 B. abortus field isolates. Among the 97 field isolates, 93 unique genotypes were identified. Among the individual loci, the array of alleles varied significantly, ranging from one allele for Locus-8 to 14 alleles for Locus-1. The allele frequencies among the eight loci were also variable. We looked for potential geographic clustering of alleles. The USA was divided into 5 regions and the alleles associated with each region were identified. No clustering of alleles was found. We conclude that HOOF-Print genotyping continues to look promising as an epidemiological tool from trace back.