Construction and validation of a first-generation Bordetella bronchiseptica long-oligonucleotide microarray by transcriptional profiling the Bvg regulon

Background: Bordetella bronchiseptica is a bacterial respiratory pathogen that infects a broad range of mammals, causing chronic and often subclinical infections. Gene expression in Bordetella is regulated by a two-component sensory transduction system, BvgAS, which controls the expression of a spectrum of phenotypic phases transitioning between a virulent (Bvg(+)) phase and a non-virulent (Bvg(-)) phase. Results: Based on the genomic sequence and using the freely available software ArrayOligoSelector, a long oligonucleotide B. bronchiseptica microarray was designed and assembled. This long-oligonucleotide microarray was subsequently tested and validated by comparing changes in the global expression profiles between B. bronchiseptica RB50 and its Bvg-phase-locked derivative, RB54. Data from this microarray analysis revealed 1,668 Bvg- regulated genes, which greatly expands the BvgAS regulon defined in previous reports. For previously reported Bvg- regulated transcripts, the gene expression data presented here is congruent with prior findings. Additionally, quantitative real-time PCR data provided an independent verification of the microarray expression values. Conclusion: The results presented here provide a comprehensive, genome-wide portrait of transcripts encompassing the BvgAS regulon, while also providing data validating the long-oligonucleotide microarray described here for studying gene expression in Bordetella bronchiseptica.