title: Growth, motility and resistance to oxidative stress of the melioidosis pathogen Burkholderia pseudomallei are enhanced by epinephrine.
abstract: Burkholderia pseudomallei causes melioidosis, a severe invasive disease endemic in South-East Asia and Northern Australia. Bacterial pathogens of several genera have been reported to be able to sense and respond to the stress-related catecholamine hormone epinephrine. Here, we report that epinephrine induces growth of B. pseudomallei in minimal serum-rich medium and heat-inactivated whole human serum and enhances bacterial motility, transcription of flagellar genes and flagellin synthesis. The effect of epinephrine on motility, but not bacterial growth, could be partially reversed by the alpha-adrenergic receptor antagonist phentolamine. Epinephrine also altered the transcription of iron-regulated genes encoding superoxide dismutase (sodB) and the malleobactin receptor (fmtA). Consistent with induction of sodB expression, epinephrine-treated B. pseudomallei exhibited increased resistance to superoxide. Epinephrine treatment did not stimulate Type III secretion via the virulence-associated Bsa apparatus or the ability of B. pseudomallei to invade epithelial cells in culture. This study provides the first evidence that epinephrine, a hormone released from the host under stress and upon therapy, can affect B. pseudomallei virulence-associated properties.
authors.affiliation: Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Narin
authors.initials: N
authors.lastname: Intarak
authors.forename: Veerachat
authors.initials: V
authors.lastname: Muangsombut
authors.forename: Paiboon
authors.initials: P
authors.lastname: Vattanaviboon
authors.forename: Mark P
authors.initials: MP
authors.lastname: Stevens
authors.forename: Sunee
authors.initials: S
authors.lastname: Korbsrisate
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis; D016957:Burkholderia pseudomallei / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry; D004837:Epinephrine / Q000378:metabolism*; D005407:Flagella / Q000187:drug effects; D005408:Flagellin / Q000096:biosynthesis; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D008124:Locomotion / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects; D014774:Virulence / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D005408:Flagellin; C087504:SodB protein, Bacteria; D013482:Superoxide Dismutase; D004837:Epinephrine
keywords: Burkholderia pseudomallei; epinephrine; growth; iron; motility; oxidative stress