1 NUROP Congress Paper A Second Quorum Sensing Regulon in Burkholderia pseudomallei

Burkholderia pseudomallei, a Gram-negative soil bacterium, is the causative agent of melioidosis. Quorum sensing is a mechanism responsible for the regulated expression of virulence genes in many bacterial pathogens. The first quorum sensing regulon in B. pseudomallei, Ais/Air, was recently identified in our laboratory. The report describes the identification of a second quorum sensing regulon, RhlI/RhlR, in B. pseudomallei. By data mining of the recently completed B. pseudomallei K96243 genome sequence using homologous sequences from related bacteria, we have found several putative quorum sensing genes in B. pseudomallei. Gene-specific primers were designed to amplify the putative quorum sensing genes, rhlI and rhlR. The primers included BamHI restriction sites to facilitate the cloning of the PCR products into a broad host range mobilizable plasmid, pRK415. The PCR products were sequenced to obtain the nucleotide sequences of the rhlI and rhlR genes B. pseudomallei KHW, a clinical isolate. The translated amino acid sequences of the B. pseudomallei KHW RhlI and RhlR proteins show high homology to the RhlI and RhlR proteins, respectively, of the P. aeruginosa quorum sensing system