title: Inactivation of Acanthamoeba spp. and Other Ocular Pathogens by Application of Cold Atmospheric Gas Plasma.
abstract: Currently there are estimated to be approximately 3.7 million contact lens wearers in the United Kingdom and 39.2 million in North America. Contact lens wear is a major risk factor for developing an infection of the cornea known as keratitis due to poor lens hygiene practices. While there is an international standard for testing disinfection methods against bacteria and fungi (ISO 14729), no such guidelines exist for the protozoan Acanthamoeba, which causes a potentially blinding keratitis most commonly seen in contact lens wearers, and as a result, many commercially available disinfecting solutions show incomplete disinfection after 6 and 24 h of exposure. Challenge test assays based on international standard ISO 14729 were used to determine the antimicrobial activity of cold atmospheric gas plasma (CAP) against Pseudomonas aeruginosa, Candida albicans, and trophozoites and cysts of Acanthamoeba polyphaga and Acanthamoeba castellanii P. aeruginosa and C. albicans were completely inactivated in 0.5 min and 2 min, respectively, and trophozoites of A. polyphaga and A. castellanii were completely inactivated in 1 min and 2 min, respectively. Furthermore, for the highly resistant cyst stage of both species, complete inactivation was achieved after 4 min of exposure to CAP. This study demonstrates that the CAP technology is highly effective against bacterial, fungal, and protozoan pathogens. The further development of this technology has enormous potential, as this approach is able to deliver the complete inactivation of ocular pathogens in minutes, in contrast to commercial multipurpose disinfecting solutions that require a minimum of 6 h.
authors.affiliation: University of Wolverhampton, School of Biomedical Science, Wolverhampton, United Kingdom w.heaselgrave@wlv.ac.uk mkong@odu.edu.
authors.forename: Wayne
authors.initials: W
authors.lastname: Heaselgrave
authors.affiliation: University of Loughborough, Department of Chemical Engineering, Loughborough, Leicestershire, United Kingdom.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Shama
authors.affiliation: University of Leicester, Department of Infection, Immunity and Inflammation, Leicester, United Kingdom.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Andrew
authors.affiliation: Old Dominion University, Frank Reidy Center for Bioelectrics, Norfolk, Virginia, USA w.heaselgrave@wlv.ac.uk mkong@odu.edu.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kong
mesh_terms: D000048:Acanthamoeba / Q000187:drug effects* / Q000502:physiology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001274:Atmospheric Pressure; D002176:Candida albicans / Q000187:drug effects* / Q000502:physiology; D050296:Microbial Viability / Q000187:drug effects*; D058626:Plasma Gases / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology
chemical_list: D000890:Anti-Infective Agents; D058626:Plasma Gases