title: Gene and protein expression in response to different growth temperatures and oxygen availability in Burkholderia thailandensis.
abstract: Burkholderia thailandensis, although normally avirulent for mammals, can infect macrophages in vitro and has occasionally been reported to cause pneumonia in humans. It is therefore used as a model organism for the human pathogen B. pseudomallei, to which it is closely related phylogenetically. We characterized the B. thailandensis clinical isolate CDC2721121 (BtCDC272) at the genome level and studied its response to environmental cues associated with human host colonization, namely, temperature and oxygen limitation. Effects of the different growth conditions on BtCDC272 were studied through whole genome transcription studies and analysis of proteins associated with the bacterial cell surface. We found that growth at 37°C, compared to 28°C, negatively affected cell motility and flagella production through a mechanism involving regulation of the flagellin-encoding fliC gene at the mRNA stability level. Growth in oxygen-limiting conditions, in contrast, stimulated various processes linked to virulence, such as lipopolysaccharide production and expression of genes encoding protein secretion systems. Consistent with these observations, BtCDC272 grown in oxygen limitation was more resistant to phagocytosis and strongly induced the production of inflammatory cytokines from murine macrophages. Our results suggest that, while temperature sensing is important for regulation of B. thailandensis cell motility, oxygen limitation has a deeper impact on its physiology and constitutes a crucial environmental signal for the production of virulence factors.
authors.affiliation: Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy.
authors.forename: Clelia
authors.initials: C
authors.lastname: Peano
authors.affiliation: Department of Biosciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Chiaramonte
authors.affiliation: Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Motta
authors.affiliation: Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pietrelli
authors.affiliation: Humanitas Clinical and Research Center Institute, Rozzano, Milan, Italy.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Jaillon
authors.affiliation: Department of Biosciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Elio
authors.initials: E
authors.lastname: Rossi
authors.affiliation: Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Consolandi
authors.affiliation: College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom.
authors.forename: Olivia L
authors.initials: OL
authors.lastname: Champion
authors.affiliation: College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Michell
authors.affiliation: Department of Biosciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Freddi
authors.affiliation: Department of Chemistry, Università degli Studi di Milano, Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Falciola
authors.affiliation: Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Basilico
authors.affiliation: Humanitas Clinical and Research Center Institute, Rozzano, Milan, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Garlanda
authors.affiliation: Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Mauri
authors.affiliation: Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: De Bellis
authors.affiliation: Department of Biosciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Landini
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001704:Biopolymers / Q000378:metabolism; D019117:Burkholderia / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development* / Q000648:ultrastructure; D002450:Cell Communication / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D016680:Genome, Bacterial; D008070:Lipopolysaccharides / Q000378:metabolism; D051379:Mice; D022423:Myeloid Cells / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology*; D016612:Paraffin Embedding; D010587:Phagocytosis / Q000187:drug effects; D054813:Polyhydroxyalkanoates / Q000494:pharmacology; D000067996:RAW 264.7 Cells; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA; D017423:Sequence Analysis, RNA; D013696:Temperature; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D001704:Biopolymers; D008070:Lipopolysaccharides; D054813:Polyhydroxyalkanoates; D010100:Oxygen