Potential applications of nonthermal plasmas against biofilm-associated micro-organisms in vitro

Abstract

Summary Biofilms as complex microbial communities attached to surfaces pose several challenges in different sectors, ranging from food and healthcare to desalination and power generation. The biofilm mode of growth allows microorganisms to survive in hostile environments and biofilm cells exhibit distinct physiology and behaviour in comparison with their planktonic counterparts. They are ubiquitous, resilient and difficult to eradicate due to their resistant phenotype. Several chemical‐based cleaning and disinfection regimens are conventionally used against biofilm‐dwelling micro‐organisms in vitro. Although such approaches are generally considered to be effective, they may contribute to the dissemination of antimicrobial resistance and environmental pollution. Consequently, advanced green technologies for biofilm control are constantly emerging. Disinfection using nonthermal plasmas (NTPs) is one of the novel strategies having a great potential for control of biofilms of a broad spectrum of micro‐organisms. This review discusses several aspects related to the inactivation of biofilm‐associated bacteria and fungi by different types of NTPs under in vitro conditions. A brief introduction summarizes prevailing methods in biofilm inactivation, followed by introduction to gas discharge plasmas, active plasma species and their inactivating mechanism. Subsequently, significance and aspects of NTP inactivation of biofilm‐associated bacteria, especially those of medical importance, including opportunistic pathogens, oral pathogenic bacteria, foodborne pathogens and implant bacteria, are discussed. The remainder of the review discusses majorly about the synergistic effect of NTPs and their activity against biofilm‐associated fungi, especially Candida species.

Cold Plasma for Effective Fungal and Mycotoxin Control in Foods: Mechanisms, Inactivation Effects, and Applications

“…The key reason underlying the attractiveness of cold plasma technology is that it enables rapid decontamination at ambient temperature and pressure conditions, without causing significant perceivable changes in food quality or incurring huge costs when using ambient air as the working gas. The range of micro‐organisms that have been shown to be inactivated using cold plasmas include Gram positive as well as Gram negative bacteria (Laroussi, ; Sysolyatina et al., ), biofilm forming bacteria (Puligundla & Mok, ), bacterial spores (Patil et al., ), yeast and fungi (Ishikawa et al., ), prions (Julák, Janoušková, Scholtz, & Holada, ), and viruses (Puligundla & Mok, ). The decontamination of foods and biomaterials using cold plasma technology has been reviewed by several authors (Misra, Schlüter, & Cullen, ; Misra, Tiwari, Raghavarao, & Cullen, ; Surowsky, Schlüter, & Knorr, ).…”

Effects on cell viability, growth and morphology ofC. albicansSC5314 biofilms after kINPen®09 plasma treatment

“…However, both used a different plasma source and a generally different experimental setup. It’s well known, that the biofilm thickness, the microorganism, treatment conditions and the used gas, play a predominant role in microbial inactivation (48).…”

Medical applications of nonthermal atmospheric pressure plasma in dermatology

“…Therefore, novel alternatives that improve chronic wound care are strongly needed. CAP can effectively inactivate broad‐spectrum infectious microorganisms within minutes through various mechanisms, without causing allergic skin reactions or resistance to plasma damage . It has been proposed that bacterial inactivation occurs by producing the following: a viable but nonculturable (VBNC) state; peroxidative damage of lipids, proteins, and DNA; programmed cell death in bacteria; direct mechanical cell lysis due to electrostatic pressure .…”