title: From the environment to the host: re-wiring of the transcriptome of Pseudomonas aeruginosa from 22°C to 37°C.
abstract: Pseudomonas aeruginosa is a highly versatile opportunistic pathogen capable of colonizing multiple ecological niches. This bacterium is responsible for a wide range of both acute and chronic infections in a variety of hosts. The success of this microorganism relies on its ability to adapt to environmental changes and re-program its regulatory and metabolic networks. The study of P. aeruginosa adaptation to temperature is crucial to understanding the pathogenesis upon infection of its mammalian host. We examined the effects of growth temperature on the transcriptome of the P. aeruginosa PAO1. Microarray analysis of PAO1 grown in Lysogeny broth at mid-exponential phase at 22°C and 37°C revealed that temperature changes are responsible for the differential transcriptional regulation of 6.4% of the genome. Major alterations were observed in bacterial metabolism, replication, and nutrient acquisition. Quorum-sensing and exoproteins secreted by type I, II, and III secretion systems, involved in the adaptation of P. aeruginosa to the mammalian host during infection, were up-regulated at 37°C compared to 22°C. Genes encoding arginine degradation enzymes were highly up-regulated at 22°C, together with the genes involved in the synthesis of pyoverdine. However, genes involved in pyochelin biosynthesis were up-regulated at 37°C. We observed that the changes in expression of P. aeruginosa siderophores correlated to an overall increase in Fe²⁺ extracellular concentration at 37°C and a peak in Fe³⁺ extracellular concentration at 22°C. This suggests a distinct change in iron acquisition strategies when the bacterium switches from the external environment to the host. Our work identifies global changes in bacterial metabolism and nutrient acquisition induced by growth at different temperatures. Overall, this study identifies factors that are regulated in genome-wide adaptation processes and discusses how this life-threatening pathogen responds to temperature.
authors.affiliation: Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America.
authors.forename: Mariette
authors.initials: M
authors.lastname: Barbier
authors.affiliation: Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America.
authors.forename: F Heath
authors.initials: FH
authors.lastname: Damron
authors.affiliation: Synthetic and Systems Biology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Piotr
authors.initials: P
authors.lastname: Bielecki
authors.affiliation: Systems and Synthetic Biology, Wageningen University, Wageningen, Netherlands.
authors.forename: María
authors.initials: M
authors.lastname: Suárez-Diez
authors.affiliation: Synthetic and Systems Biology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Jacek
authors.initials: J
authors.lastname: Puchałka
authors.affiliation: IUNICS, University of the Balearic Islands, Palma de Mallorca, Spain.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Albertí
authors.affiliation: Synthetic and Systems Biology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany ; Systems and Synthetic Biology, Wageningen University, Wageningen, Netherlands ; LifeGlimmer GmbH, Berlin, Germany.
authors.forename: Vitor Martins
authors.initials: VM
authors.lastname: Dos Santos
authors.affiliation: Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America ; Department of Pediatrics, and Center for Cystic Fibrosis Research, Emory University School of Medicine, Children's Healthcare of Atlanta, Inc., Atlanta, Georgia, United States of America.
authors.forename: Joanna B
authors.initials: JB
authors.lastname: Goldberg
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology*; D054884:Host-Pathogen Interactions; D046228:Microarray Analysis; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013696:Temperature; D059467:Transcriptome / Q000235:genetics*