Department of Molecular Medicine, University of Padova, Padova, Italy.
Veneto Institute of Oncology IOV-IRCCS, Padova, Italy.
J Appl Microbiol. 2018 Aug;125(2):398-408. doi: 10.1111/jam.13780. Epub 2018 May 20.
The objective of this study was to determine the efficacy and mechanisms of inactivation of two clinically relevant ESKAPE bacteria namely Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus by atmospheric pressure cold plasma.
Plasma was generated between two brass grids by applying a radiofrequency electric field to a flow of helium. Intracellular generation of reactive species, alterations in cell membrane, and inactivation of bacteria in planktonic or biofilm growth were studied. Results were compared with commonly used antimicrobial drugs. Plasma exposure generated reactive oxygen and nitrogen species in bacteria, disrupted membrane integrity and reduced bacterial load. The efficacy in bacterial inactivation was comparable to antibiotics but exhibited a quicker killing rate. The antibacterial effect of plasma synergistically increased in association with antibiotics and did not diminish over repeated exposures, suggesting no development in bacterial resistance.
Through generation of reactive species, cold plasma altered cell membrane and effectively inactivated clinically important bacteria, both in suspension and in biofilms.
As cold plasma damages different targets in bacterial cells, it emerges as an effective strategy used alone or in combination with antimicrobial drugs to control microbial infections and prevent the selection of resistant bacterial strains.
本研究旨在确定常压冷等离子体对两种临床相关 ESKAPE 细菌（铜绿假单胞菌和耐甲氧西林金黄色葡萄球菌）的灭活效果及其机制。
通过向氦气流施加射频电场，在两个黄铜网格之间产生等离子体。研究了活性物质在细胞内的产生、细胞膜的改变以及浮游或生物膜生长中的细菌失活情况。将结果与常用的抗菌药物进行了比较。等离子体暴露会在细菌中产生活性氧和氮物质，破坏膜的完整性并减少细菌负荷。其在细菌灭活方面的效果与抗生素相当，但具有更快的杀菌速度。与抗生素联合使用时，等离子体的抗菌效果协同增强，并且在重复暴露时不会减弱，表明不会产生细菌耐药性。
通过产生活性物质，冷等离子体改变了细胞膜并有效灭活了悬浮液和生物膜中的临床重要细菌。
由于冷等离子体对细菌细胞中的不同靶标造成损伤，因此它作为一种单独使用或与抗菌药物联合使用的有效策略，可以用于控制微生物感染并防止耐药菌株的选择。
