Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: June 5, 2005
Publication Date: June 5, 2005
Citation: Nicholson, T.L., Brockmeier, S., Register, K.B. 2005. Expression profiling of bordetella bronchiseptica responses to temperature using a long-oligonucleotide microarray. American Society for Microbiology. D118, p. 218.
Bordetella species are gram negative bacteria responsible for respiratory infections in humans and in a variety of animals. Most known virulence factors in Bordetella are regulated by the BvgAS two-component signal transduction system in response to environmental cues. Bacteria grown in rich media at 37'C exhibit the virulent Bvg+ phase that is characterized by the expression of toxins, adhesions, and other virulence factors. Growth at or below 25'C induces modulation to the Bvg- phase, which is characterized by the absence of bvgAS and virulence gene expression, while specific genes such as those required for motility are expressed. To begin dissecting the hierarchical cascade of transcriptional activity within Bordetella, we focused on the effect of growth temperature. We hypothesized that different growth temperatures would result in large prominent shifts in transcription. Using the Bordetella bronchiseptica RB50 genome sequence, we designed an open reading frame (ORF)-specific DNA microarray in which each gene was represented by a long 70mer oligonucleotide. This microarray was then used to monitor the expression profiles of several B. bronchiseptica strains, along with their phase-locked derivatives, grown at 37'C and 23'C. This approach has allowed for the identification of many genes, and operons, whose expression is mediated by growth temperature. The results revealed an extensive transcriptional network and provide a framework for the understanding of basic regulatory mechanisms of gene expression in this pathogen.