title: Non-thermal Plasma Exposure Rapidly Attenuates Bacterial AHL-Dependent Quorum Sensing and Virulence.
abstract: The antimicrobial activity of atmospheric pressure non-thermal plasma has been exhaustively characterised, however elucidation of the interactions between biomolecules produced and utilised by bacteria and short plasma exposures are required for optimisation and clinical translation of cold plasma technology. This study characterizes the effects of non-thermal plasma exposure on acyl homoserine lactone (AHL)-dependent quorum sensing (QS). Plasma exposure of AHLs reduced the ability of such molecules to elicit a QS response in bacterial reporter strains in a dose-dependent manner. Short exposures (30-60 s) produce of a series of secondary compounds capable of eliciting a QS response, followed by the complete loss of AHL-dependent signalling following longer exposures. UPLC-MS analysis confirmed the time-dependent degradation of AHL molecules and their conversion into a series of by-products. FT-IR analysis of plasma-exposed AHLs highlighted the appearance of an OH group. In vivo assessment of the exposure of AHLs to plasma was examined using a standard in vivo model. Lettuce leaves injected with the rhlI/lasI mutant PAO-MW1 alongside plasma treated N-butyryl-homoserine lactone and n-(3-oxo-dodecanoyl)-homoserine lactone, exhibited marked attenuation of virulence. This study highlights the capacity of atmospheric pressure non-thermal plasma to modify and degrade AHL autoinducers thereby attenuating QS-dependent virulence in P. aeruginosa.
authors.affiliation: Biofilm Research Group, School of Pharmacy, Queen's University Belfast, BT9 7BL, UK.|Centre for Plasma Physics, School of Maths and Physics, Queen's University Belfast, BT7 1NN, UK.
authors.forename: Padrig B
authors.initials: PB
authors.lastname: Flynn
authors.affiliation: Biofilm Research Group, School of Pharmacy, Queen's University Belfast, BT9 7BL, UK.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Busetti
authors.affiliation: Advanced Asset Centre, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, UK.
authors.forename: Ewa
authors.initials: E
authors.lastname: Wielogorska
authors.affiliation: Advanced Asset Centre, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, UK.
authors.forename: Olivier P
authors.initials: OP
authors.lastname: Chevallier
authors.affiliation: Advanced Asset Centre, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, UK.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Elliott
authors.affiliation: Biofilm Research Group, School of Pharmacy, Queen's University Belfast, BT9 7BL, UK.
authors.forename: Garry
authors.initials: G
authors.lastname: Laverty
authors.affiliation: Biofilm Research Group, School of Pharmacy, Queen's University Belfast, BT9 7BL, UK.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Gorman
authors.affiliation: Centre for Plasma Physics, School of Maths and Physics, Queen's University Belfast, BT7 1NN, UK.
authors.forename: William G
authors.initials: WG
authors.lastname: Graham
authors.affiliation: Biofilm Research Group, School of Pharmacy, Queen's University Belfast, BT9 7BL, UK.
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Gilmore
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism*; D016960:Agrobacterium tumefaciens / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D001419:Bacteria / Q000235:genetics / Q000472:pathogenicity; D018407:Bacterial Physiological Phenomena / Q000187:drug effects*; D002861:Chromobacterium / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018545:Lactuca / Q000382:microbiology; D008163:Luminescent Measurements; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology; D058626:Plasma Gases / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D053038:Quorum Sensing / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D017550:Spectroscopy, Fourier Transform Infrared; D014774:Virulence / Q000187:drug effects* / Q000235:genetics / Q000502:physiology
chemical_list: D054742:Acyl-Butyrolactones; D058626:Plasma Gases