NEW YORK (GenomeWeb News) - Scientists at the Virginia Bioinformatics Institute at Virginia Tech and collaborators have completed the genomic sequencing of the bacteria Brucella abortus strain S19.
Brucella abortus causes the disease brucellosis in cattle and can cause spontaneous abortions. Cows found to have the disease are usually killed. However, the S19 strain does not cause disease and is used as a vaccine to protect cattle against brucellosis.
Researchers are hoping that its genome may “hold the secret as to why other Brucella strains cause disease and trigger the abortion of developing embryos in livestock,” according to a VBI statement.
VBI collaborated with researchers at the National Animal Disease Center in Ames, Iowa, and Roche subsidiary 454 Life Sciences on the project. They used 454’s GS-FLX and GS-20 instruments to complete the sequencing. The results of their study are published in the current issue of PLoS One.
“Brucella is able to pass from animals to humans with relative ease and poses a significant public health burden for workers in the livestock industry,” said Bruno Sobral, who is VBI’s Executive and Scientific Director. He also called Brucella “a possible agent for agricultural, civilian and military bioterrorism.”
The researchers involved in the project discovered a group of 24 genes that are linked to virulence, which may help scientists understand why some Brucella strains cause disease.
By using both pyrosequencing and Sanger sequencing the researchers assembled 99.5 percent of the 3.2 Mb genome after one day of sequencing. The S19 genome is comprised of two circular chromosomes: one that is 2,122,487 bp long and the other 1,161,449 bp long. The average length of the sequence reads in this study were 110 base pairs, according to the paper.
"Further studies are underway to characterize the short list of protein differences that appear to be involved in cellular processes ranging from lipid transport and metabolism to transcription and protein transport,” said VBI’s Cyberinfrastructure Group Project Director Oswald Crasta, who is the corresponding author on the paper.
“We believe that this characterization will explain why strain S19 has been such a successful vaccine over the years and why infection with other strains leads to disease," Crasta added.
Funding for the S19 sequencing research came from VBI, and the Commonwealth Research Initiative, and the data analysis was funded in part through a grant from the National Science Foundation. The preparation and submission of genomic sequences to GenBank were funded by the National Institute of Allergy and Infectious Diseases.