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Title: Atmospheric pressure, non thermal plasmas for the control of pathogens associated with hospital acquired infections
Author: Alshraiedeh, Nid'a Hamdan
ISNI:       0000 0004 5917 4339
Awarding Body: Queen's University Belfast
Current Institution: Queen's University Belfast
Date of Award: 2015
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Full text unavailable from EThOS. Thesis embargoed until 01 Jul 2020
The globally increasing risk of acquiring hospital-acquired infections (HAIs) has attracted much attention in recent years. In this study, an in-house designed kilohertz (kHz)-driven atmospheric pressure non-thermal plasma (APNTP) jet has been investigated for its potential application as a new and promising alternative decontamination and sterilization method for several potential clinical applications. APNTP has been shown to exert a significant antibiofilm activity against wide range of clinical Pseudomonas aeruginosa isolates. Phenotypic and genotypic factors mediate an elevated tolerance of Pseudomonas aeruginosa biofilms to APNTP, evident in observed variation in susceptibility profiles between mucoid and nonmucoid isolates following plasma exposure. In addition, APNTP significantly inactivated several biofilm forming persister Pseudomonas aeruginosa strains. APNTP has also shown to have marked antibiofilm activity against Burkholderia cenocepacia biofilms. This variability in sensitivity was correlated with biofilm biomass as well as catalase activity in each case. Isolates with greater biofilm biomass and higher catalase activity exhibited significantly enhanced tolerance to plasma exposure. A preliminary study was conducted to assess the potential of APNTP as adjuvant therapy with other conventional antimicrobial agents that frequently used for control of Pseudomonas aeruginosa infection, and whose activity are known to be attenuated in the presence of biofilm matrix components. Pre-exposure of a 48 hour biofilm to APNTP increased the sensitivity of Pseudomonas aeruginosa biofilm to the tested antimicrobial agents. Finally, Non-thermal plasma has a significant virucidal activity against MS2 bacteriophages which are frequently used as a surrogate for human Noroviruses. More than seven log10 reductions were achieved in nine minutes exposure to 0.75% oxygen/He APNTP. Virucidal activity was affected by percentage oxygen concentration in the helium (He) carrier gas where activity increased with increasing oxygen concentration up to 0.75% indicating a role for reactive oxygen species (ROS) in viral inactivation
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available