Non-thermal Plasma Treatment of ESKAPE Pathogens: A Review.

Vladimír Scholtz,Ramya Premanath,Jaroslav Julák,Petra Kašparová,Iddya Karunasagar,Eva Vaňková

doi:10.3389/fmicb.2021.737635

Abstract

The acronym ESKAPE refers to a group of bacteria consisting of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. They are important in human medicine as pathogens that show increasing resistance to commonly used antibiotics; thus, the search for new effective bactericidal agents is still topical. One of the possible alternatives is the use of non-thermal plasma (NTP), a partially ionized gas with the energy stored particularly in the free electrons, which has antimicrobial and anti-biofilm effects. Its mechanism of action includes the formation of pores in the bacterial membranes; therefore, resistance toward it is not developed. This paper focuses on the current overview of literature describing the use of NTP as a new promising tool against ESKAPE bacteria, both in planktonic and biofilm forms. Thus, it points to the fact that NTP treatment can be used for the decontamination of different types of liquids, medical materials, and devices or even surfaces used in various industries. In summary, the use of diverse experimental setups leads to very different efficiencies in inactivation. However, Gram-positive bacteria appear less susceptible compared to Gram-negative ones, in general.

Highlights

The misuse and overuse of antibiotics over the past four decades have created exceptional selective pressure toward the emergence of resistant microorganisms and bestowed the ideal environment for the spread and selection of resistance determinants
Thermal plasma consists of free electrons and ions that are of the same high temperature of several thousand of kelvins, and it is in a local thermodynamic equilibrium state
This review demonstrates the importance of non-thermal plasma (NTP) as an effective antimicrobial tool for the inactivation of prominent pathogens of the ESKAPE group

Summary

Introduction

The misuse and overuse of antibiotics over the past four decades have created exceptional selective pressure toward the emergence of resistant microorganisms and bestowed the ideal environment for the spread and selection of resistance determinants. NTP treatment was comparably effective to CHX for bacteria inactivation in infected root canals after 5 and 15 min exposures (both agents with 6 log decreases in CFU/ml). The total inactivation of 107 CFU/ml of E. faecalis, S. aureus, A. baumannii, and P. aeruginosa in both planktonic and biofilm forms was observed after 15 min of application.

Results

Conclusion