The effect of ozone and open air factor on surface-attached and biofilm environmental Listeria monocytogenes
Article first published online: 3 JUN 2013
© 2013 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 115, Issue 2, pages 555–564, August 2013
How to Cite
Nicholas, R., Dunton, P., Tatham, A. and Fielding, L. (2013), The effect of ozone and open air factor on surface-attached and biofilm environmental Listeria monocytogenes. Journal of Applied Microbiology, 115: 555–564. doi: 10.1111/jam.12239
- Issue published online: 17 JUL 2013
- Article first published online: 3 JUN 2013
- Accepted manuscript online: 27 APR 2013 10:05AM EST
- Manuscript Accepted: 22 APR 2013
- Manuscript Revised: 17 APR 2013
- Manuscript Received: 12 DEC 2012
- Quantum Information
- Bristol Centre for Nanoscience
- food contact surfaces;
- Listeria monocytogenes ;
- open air factor;
The effects of gaseous ozone and open air factor (OAF) on environmental Listeria monocytogenes attached to three common food contact surfaces were investigated.
Methods and Results
Listeria monocytogenes on different food contact surfaces was treated with ozone and OAF. Microbiological counts, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed. Ozone at 10 ppm gave <1-log reduction when L. monocytogenes was attached to stainless steel, while 45 ppm gave a log reduction of 3·41. OAF gave better log reductions than 10 ppm ozone, but lower log reductions than 45 ppm. Significant differences were found between surfaces. Biofilm organisms were significantly more resistant than those surface attached on stainless steel. SEM and AFM demonstrated different membrane and cell surface modifications following ozone or OAF treatment.
The strain used demonstrated higher resistance to ozone than previous studies. This may be due to the fact that it was isolated from a food manufacturing premises that used oxidizing disinfectants. OAF was more effective at reducing the levels of the organism than an ozone concentration of 10 ppm.
Significance and Impact of the Study
Pathogen management strategies must account for resistance of environmental strains when validating cleaning and disinfection. OAF has shown potential for surface decontamination compared with ozone. SEM and AFM are valuable tools for determining mechanisms of action of antimicrobial agents.