Control of multidrug-resistant planktonicAcinetobacter baumannii: biocidal efficacy study by atmospheric-pressure air plasma

Abstract

In this research, an atmospheric-pressure air plasma is used to inactivate the multidrug-resistant Acinetobacter baumannii in liquid. The efficacy of the air plasma on bacterial deactivation and the cytobiological variations after the plasma treatment are investigated. According to colony forming units, nearly all the bacteria (6-log) are inactivated after 10 min of air plasma treatment. However, 7% of the bacteria enter a viable but non-culturable state detected by the resazurin based assay during the same period of plasma exposure. Meanwhile, 86% of the bacteria lose their membrane integrity in the light of SYTO 9/PI staining assay. The morphological changes in the cells are examined by scanning electron microscopy and bacteria with morphological changes are rare after plasma exposure in the liquid. The concentrations of the long-living RS, such as H 2 O 2 , NO , 3 and O 3 , in liquid induced by plasma treatment are measured, and they increase with plasma treatment time. The changes of the intracellular ROS may be related to cell death, which may be attributed to oxidative stress and other damage effects induced by RS plasma generated in liquid. The rapid and effective bacteria inactivation may stem from the RS in the liquid generated by plasma and air plasmas may become a valuable therapy in the treatment of infected wounds.

Non-thermal Plasma Treatment of ESKAPE Pathogens: A Review

“…While the pure helium gas NTP was only less effective, the helium/air mixture gas NTP led to the full inactivation of A. baumannii (7 log decrease). A complete inactivation of A. baumannii was also reported by Ruan et al (2018) , who used the NTP in open air. A rapid decrease of the surviving bacteria was observed in 2 ml suspension of 10 6 CFU/ml concentration after 5 min of NTP exposure; a total inactivation occurred after 10 min.…”

Cold atmospheric plasma‑activated Ringer's solution inhibits the proliferation of osteosarcoma cells through the mitochondrial apoptosis pathway

“…The air plasma discharge electrode consists of six copper rods with a diameter of 1 mm. Other articles have reported similar types of configuration (24,25). In the present study, the six electrodes were driven by high voltage direct current (DC) without the requirement for any external gas supply.…”

In vitro antimicrobial effect and mechanism of action of plasma-activated liquid on planktonic Neisseria gonorrhoeae

“…An analysis of PAL revealed that its major components are ROS and reactive nitrogen species (RNS), which can effectively inactivate various bacteria [16]…”

“…The intracellular ROS concentration was evaluated using a ROS assay kit (Beyotime, China)[ 16 ]. After immersing the bacterial cells in PAL for 30 min, the bacterial suspension was mixed with diluted 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) solution and incubated for 20 min at 37°C in the dark.…”