Residence time and food contact time effects on transfer of Salmonella Typhimurium from tile, wood and carpet: testing the five-second rule
Article first published online: 6 OCT 2006
Journal of Applied Microbiology
Volume 102, Issue 4, pages 945–953, April 2007
How to Cite
Dawson, P., Han, I., Cox, M., Black, C. and Simmons, L. (2007), Residence time and food contact time effects on transfer of Salmonella Typhimurium from tile, wood and carpet: testing the five-second rule. Journal of Applied Microbiology, 102: 945–953. doi: 10.1111/j.1365-2672.2006.03171.x
- Issue published online: 6 OCT 2006
- Article first published online: 6 OCT 2006
- 2006/0018: received 6 January 2006, revised and accepted 28 July 2006
- bacterial transfer;
- five-second rule;
- food contact surface;
- residence time;
Aims: Three experiments were conducted to determine the survival and transfer of Salmonella Typhimurium from wood, tile or carpet to bologna (sausage) and bread.
Methods and Results: Experiment 1. After 28 days, 1·5 to 2·5 log10 CFU cm−2 remained on tile from and the more concentrated media facilitated the survival of S. Typhimurium compared with the more dilute solutions.
Experiments 2 and 3. The bacterial transfer rate to food decreased as the bacterial residence time on the surface increased from 2, 4, 8 to 24 h with transfers of 6·5, 4·8, 4·6 and 3·9 log CFU ml−1 in the rinse solutions, respectively. Over 99% of bacterial cells were transferred from the tile to the bologna after 5 s of bologna exposure to tile. Transfer from carpet to bologna was very low (<0·5%) when compared with the transfer from wood and tile (5–68%).
Conclusions: (i) Salmonella Typhimurium can survive for up to 4 weeks on dry surfaces in high-enough populations to be transferred to foods and (ii) S. Typhimurium can be transferred to the foods tested almost immediately on contact.
Significance and Impact of the Study: This study demonstrated the ability of bacteria to survive and cross-contaminate other foods even after long periods of time on dry surfaces, thus reinforcing the importance of sanitation on food contact to minimize the risk of foodborne illness.