Gas plasma sterilization of microorganisms and mechanisms of action

Abstract

Abstract. the use of true gas plasmas for the inactivation of microorganisms is an area of dynamic research. many types of gases are used as a source of plasma, and different plasma production methods have been applied. the antimicrobial mechanisms of oxygen-based gas plasmas may be due to an etching effect on microbial structures, particularly bacterial endospores resulting in shrinkage. By contrast, the definite mechanisms of actions of other gas plasma sources, such as n 2 , He, Ne, Ar and Xe gases, have not been clearly defined and indeed may be distinct. the speculated mechanisms of these gas plasmas involve the direct attack of metastable (excited molecular), UV and/or VUV to microbial structures, specifically the inner membrane and dna in the core of bacterial endospores. according to this speculation, sterilized spore figures would remain unchanged. However, these mechanisms remain to be clarified. Future perspectives on the use of gas plasma for sterilization are of interest, as it is possible that appropriate sterility assurance levels can be obtained in parallel with material and functional compatibility. Traditional sterilization methods are often limited in these requirements. therefore, gas plasma sterilization may prove to be an appropriate alternative sterilization procedure.

Inactivation of Bacterial Spore, Endotoxin, Lipid A, Normal Prion and Abnormal Prion by Exposures to Several Sorts of Gases Plasma

“…Different types of discharge have been used, and the results summarized Montie et al, 2000Laroussi 2002, 2005Gaunt et al, 2006Moreau et al, 2008Shintani et al, 2010 However, the conditions and geometry vary to a large extent, which makes the comparison of the results difficult. Moreover, determining the main processes leading to the sterilization of bacterial spores is more difficult than with low-pressure discharges, due to the presence of additional obstacles.…”

“…Endotoxins are extremely resistant to temperature and are not removed by conventional sterilization procedures such as autoclave sterilization or -ray or e-beam sterilization. A few papers have been published on the effect of gas plasma exposure on endotoxins to cause more than a 5 log reduction during 30 min exposure to nitrogen gas plasma Shintani et al, 2007, Shintani et al 2010Shintani, 2012Sakudo et al, 2013 . In general a 3-log reduction is required by the authorities and GMP good manufacturing practice and, according published papers by Shintani et al in 2007 andShintani in 2012, dur-ing 10 min at 28-45 operation, a 3-log reduction was completed in Figure 2, which is a significant achievement.…”

“…Non-equilibrium gas plasma sterilization studies have been carried out to show that many types of pathogens can be inactivated Lerouge et al, 2001Moisan et al, 2001Rossi et al, 2006Shintani et al, 2007Shintani et al, 2010Shintani, 2012 and the mechanism and inactivation factors of gas plasma sterilization against microorganisms or biomolecules have been extensively studied. According to our recent studies, the major factors causing sterilization by nitrogen gas plasma exposure were not well clarified and defined.…”

Study of Sterilization and Disinfection in Room Air by Using Atmospheric Microplasma

“…Active species are easily generated by non-thermal plasma and therefore used as a sterilization or inactivation tool for bacteria or bacteriophage [5][6][7][8][9][10][11]. It is expected to be alternatives to the other simple plasma techniques to purify indoor air.…”

A reference protocol for comparing the biocidal properties of gas plasma generating devices

“…Interest in the use of non-thermal, atmospheric pressure gas plasmas for inactivating micro-organisms has grown rapidly in recent years [1,2,3]. The majority of such applications are related to food [4,5,6] and medicine [7,8,9] but are by no means restricted solely to these.…”