Transcriptome analysis of quorum-sensing regulation and virulence factor expression inPseudomonas aeruginosa

The opportunistic pathogenPseudomonas aeruginosapossesses two well-studied quorum-sensing (QS) systems (lasandrhl) that are important in the production of virulence factors, antibiotic sensitivity, and biofilm development. High-density oligonucleotide microarrays were used to further characterize thelasQS system and to investigate the effect of environment (planktonic or biofilm mode of growth, absence or presence of oxygen) and nutritional conditions on detection of transcripts encoding QS-regulated virulence factors. Transcriptome results indicate that the QS system is far more complex than previously proposed. Interestingly, we found that many QS-regulated genes encoding virulence products were expressed in all conditions investigated.