Patange Apurva, O'Byrne Conor, Boehm Daniela, Cullen P J, Keener Kevin, Bourke Paula
School of Food Science and Environmental Health, Technological University Dublin, Dublin, Ireland.
Bacterial Stress Response Group, School of Natural Sciences, National University of Ireland, Galway, Galway, Ireland.
Front Microbiol. 2019 Dec 11;10:2841. doi: 10.3389/fmicb.2019.02841. eCollection 2019.
is an opportunistic intracellular pathogen commonly associated with serious infections and multiple food-borne outbreaks. In this study, we investigated the influence of atmospheric cold plasma (80 kV, 50 Hz) on (EGD-e) and its knockout mutants of , , , , and genes at different treatment time intervals. Further, to ascertain if sub-lethal environmental stress conditions could influence survival and growth responses, atmospheric cold plasma (ACP) resistance was evaluated for the cultures exposed to cold (4°C) or acid (pH 4) stress for 1 h. The results demonstrate that both wild-type and knockout mutants were similarly affected after 1 min exposure to ACP ( > 0.05), with a difference in response noted only after 3 min of treatment. While all strains exposed to acid/cold stress were hypersensitive to ACP treatment and were significantly reduced or inactivated within 1 min of treatment ( < 0.05). The results indicate and are important for general stress resistance and biofilm, respectively, loss of these two genes significantly reduced bacterial resistance to ACP treatment. In addition, exposure to sub-lethal 1min ACP increased the gene expression of stress associated genes. showed the highest gene expression, increasing by 15.60 fold, followed by (7.19) and (8.6) after 1 min exposure. Overall, an increase in gene expression was seen in all stress associated genes analyzed both at 1 min treatment; while long treatment time reduced the gene expression and some cases down-regulated and gene expression. By comparing the response of mutants under ACP exposure to key processing parameters, the experimental results presented here provide a baseline for understanding the bacterial genetic response and resistance to cold plasma stress and offers promising insights for optimizing ACP applications.
是一种机会性细胞内病原体,通常与严重感染和多次食源性疾病暴发有关。在本研究中,我们研究了大气冷等离子体(80 kV,50 Hz)在不同处理时间间隔对(上消化道内镜检查)及其、、、和基因敲除突变体的影响。此外,为了确定亚致死环境应激条件是否会影响生存和生长反应,对暴露于寒冷(4°C)或酸性(pH 4)应激1小时的培养物评估了大气冷等离子体(ACP)抗性。结果表明,野生型和敲除突变体在暴露于ACP 1分钟后受到的影响相似(>0.05),仅在处理3分钟后才观察到反应差异。而所有暴露于酸/冷应激的菌株对ACP处理均高度敏感,在处理1分钟内显著减少或失活(<0.05)。结果表明,和分别对一般应激抗性和生物膜形成很重要,这两个基因的缺失显著降低了细菌对ACP处理的抗性。此外,暴露于亚致死性1分钟ACP会增加应激相关基因的基因表达。暴露1分钟后显示出最高的基因表达,增加了15.60倍,其次是(7.19)和(8.6)。总体而言,在处理1分钟时,所有分析的应激相关基因的基因表达均增加;而长时间处理会降低基因表达,在某些情况下会下调和基因表达。通过比较突变体在ACP暴露下对关键加工参数的反应,本文给出的实验结果为理解细菌对冷等离子体应激的遗传反应和抗性提供了基线,并为优化ACP应用提供了有前景的见解。