Transcriptional responses of K. pneumoniae, S. maltophilia, P.aeruginosa, and B. thailandensis exposed to lung surfactant

The interactions between Gram-negative respiratory pathogens and the host environment at the site of infection largely unknown. Pulmonary surfactant serves as an initial point of contact for inhaled bacteria entering the lung and is thought to contain molecular cues that aid colonization and pathogenesis. To gain insight into this ecological transition, we characterized the transcriptional responses of Pseudomonas aeruginosa PA14, Burkholderia thailandensis E264, Klebsiella pneumoniae MGH 78578, and Stenotrophomonas maltophilia K279A exposed to purified pulmonary surfactant (Survanta) through microarrays. This study provides novel insight into the interactions occurring between Gram-negative opportunistic pathogens and the host at an important infection site, and demonstrates the utility of purified lung surfactant preparations for dissecting host-lung pathogen interactions in vitro. The goal of this study was to compare the transcriptional responses of Pseudomonas aeruginosa PA14, Burkholderia thailandensis E264, Klebsiella pneumoniae MGH 78578, and Stenotrophomonas maltophilia K279A exposed to pulmonary surfactant using a custom affymetrix chip designed for their genomes. The goal of this study was to compare the transcriptional responses of Pseudomonas aeruginosa PA14, Burkholderia thailandensis E264, Klebsiella pneumoniae MGH 78578, and Stenotrophomonas maltophilia K279A exposed to pulmonary surfactant using a custom affymetrix chip designed for their genomes. Microarrays were performed with total RNA collected from two independent gene induction experiments, where each strain was cultured in MOPS minimal media in the presence and absence of Survanta (purified pulmonary surfactant). Total RNA collected from these experiments were then mixed together 1:1 (P. aeruginosa & B. thailandensis, or K. pneumoniae & S. maltophilia) prior to hybridization to custom Affymetrix microarray chips (PaKpSmBta521148F). The resulting eight chips were then processed via RMA using Affymetrix's Expression Console and Transcriptome Analysis Console.