LMSM, Laboratoire de Microbiologie-Signaux et Microenvironnement, EA 4312, Université de Rouen, Evreux, France.
J Appl Microbiol. 2013 Jan;114(1):186-95. doi: 10.1111/jam.12029. Epub 2012 Oct 30.
Pulsed light (PL) technology is a surface decontamination process that can be used on food, packaging or water. PL efficiency may be limited by its low degree of penetration or because of a shadow effect. In these cases, surviving bacteria will be able to perceive PL as a stress. Such a stress was mimicked using low transmitted energy conditions, and its effects were investigated on the highly environmental adaptable bacterium Enterococcus faecalis V583.
In these laboratory conditions, a complete decontamination of the artificially inoculated medium was performed using energy doses as low as 1.8 J cm(-2) , while a treatment of 0.5, 1 and 1.2 J cm(-2) led to a 2.2, 6 and 7-log(10) CFU ml(-1) reduction in the initial bacterial population, respectively. Application of a 0.5 J cm(-2) pretreatment allowed the bacteria to resist more efficiently a 1.2 J cm(-2) subsequent PL dose. This 0.5 J cm(-2) treatment increased the bacterial mutation frequency and affected the abundance of 19 proteins as revealed by a global proteome analysis.
Enterococcus faecalis is able to adapt to a PL treatment, providing a molecular response to low-energy PL dose, leading to enhanced resistance to a subsequent treatment and increasing the mutation frequency.
This study gives further insights on Ent. faecalis capacities to adapt and to resist to stress.
脉冲光 (PL) 技术是一种表面去污工艺，可用于食品、包装或水。PL 的效率可能受到其低穿透程度或阴影效应的限制。在这些情况下，幸存的细菌将能够将 PL 视为一种压力。使用低透射能量条件模拟这种压力，并研究其对高度适应环境的细菌粪肠球菌 V583 的影响。
在这些实验室条件下，使用低至 1.8 J cm(-2) 的能量剂量即可对人工接种的培养基进行完全去污，而 0.5、1 和 1.2 J cm(-2) 的处理分别导致初始细菌种群减少 2.2、6 和 7-log(10) CFU ml(-1)。应用 0.5 J cm(-2) 的预处理可以使细菌更有效地抵抗随后的 1.2 J cm(-2) PL 剂量。这种 0.5 J cm(-2) 的处理增加了细菌的突变频率，并通过全蛋白质组分析影响了 19 种蛋白质的丰度。
粪肠球菌能够适应 PL 处理，对低能量 PL 剂量产生分子反应，从而增强对后续处理的抵抗力并增加突变频率。
本研究进一步了解了 Ent。粪肠球菌适应和抵抗压力的能力。
