我们研究了冷大气压等离子体(CAP)的功效,由一个二维数组生成的集成,同轴,微空心,介质阻挡放电等离子体,在不锈钢上对抗肠道沙门氏菌血清型海德堡(SH),生菜,鸡胸肉。SH在干燥的不锈钢表面上暴露于CAP具有较低的杀菌效力;暴露10分钟后,只有2.5log10菌落形成单位(CFU)被灭活。另一方面,仅3分钟后,水分的存在就导致了~6.5log10CFU的净化。尽管生菜和鸡胸肉样品在暴露10分钟后未达到完全净化,SH计数减少了4.5和3.7log10CFU,分别。在掺入细菌和暴露于血浆之前,用牛血清白蛋白包被时,在钢表面观察到杀菌作用的部分抑制,这表明鸡肉的蛋白质性质可能是导致CAP对鸡肌肉功效降低的部分原因。最初的细菌负荷也被发现影响抗SH功效;在高(~6.5logCFUs)和低(~3.5CFUs)的初始计数,在不锈钢和生菜上完全去污所需的时间从3到0.5分钟和>10到1分钟减少,分别。然而,灭活动力学分析显示,初始污染负荷对细菌灭活率的影响无统计学意义。这与两种细菌负荷都在可能影响杀灭率的多层阈值下的其他发现一致。
We studied the efficacy of cold atmospheric-pressure plasma (CAP), generated by a two-dimensional array of integrated, coaxial, microhollow, dielectric barrier discharge plasma, against Salmonella enterica serovar Heidelberg (SH) on stainless steel, romaine lettuce, and chicken breast. Exposure of SH to CAP on a dry stainless steel surface had low bactericidal efficacy; only 2.5 log10 colony-forming units (CFUs) were inactivated after 10 min of exposure. On the other hand, the presence of moisture led to decontamination of ∼6.5 log10 CFUs after only 3 min. Although complete decontamination was not achieved on lettuce and chicken breast samples after 10 min of exposure, SH counts were reduced by ∼4.5 and 3.7 log10 CFUs, respectively. A partial suppression of bactericidal effects was observed on steel surfaces when it was coated with bovine serum albumin before spiking with bacteria and exposure to plasma, indicating that the proteinaceous nature of chicken meat may be partially responsible for lower efficacy of CAP on chicken muscles. The initial bacterial load was also found to affect the anti-SH efficacy; at high (∼6.5 log CFUs) and low (∼3.5 CFUs) initial counts, the time required for complete decontamination on stainless steel and lettuce decreased from 3 to 0.5 min and >10 to 1 min, respectively. However, the analysis of inactivation kinetics showed that effects of initial loads of contamination on the rate of bacterial inactivation were not statistically significant. This is consistent with other findings for conditions where both bacterial loads were under the multilayering threshold that might have affected the rate of killing.