Effects of a pulsed light-induced stress on Enterococcus faecalis
Article first published online: 30 OCT 2012
© 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 114, Issue 1, pages 186–195, January 2013
How to Cite
Massier, S., Bouffartigues, E., Rincé, A., Maillot, O., Feuilloley, M.G.J., Orange, N. and Chevalier, S. (2013), Effects of a pulsed light-induced stress on Enterococcus faecalis. Journal of Applied Microbiology, 114: 186–195. doi: 10.1111/jam.12029
- Issue published online: 12 DEC 2012
- Article first published online: 30 OCT 2012
- Accepted manuscript online: 4 OCT 2012 10:50AM EST
- Manuscript Accepted: 25 SEP 2012
- Manuscript Revised: 16 SEP 2012
- Manuscript Received: 30 JUL 2012
- Conseil Général de l'Eure
- Grand Evreux Agglomeration
- Région Haute Normandie
- European Union (FEDER)
- Plate Forme Technologique d'Evreux Normandie Sécurité Sanitaire
- food preservation;
- microbial contamination;
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.
Methods and Results
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-log10 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.
Significance and Impact of the Study
This study gives further insights on Ent. faecalis capacities to adapt and to resist to stress.