Evaluation of Potential for Translocation of Listeria monocytogenes from Floor Drains to Food Contact Surfaces in the Surrounding Environment Using Listeria innocua as a Surrogate

Jasdeep K. Saini, James L. Marsden, Daniel Y. C. Fung, Beth Ann Crozier-Dodson

Food Science Institute, Department of Animal Sciences and Industry, Kansas State University, Manhattan, US.
Food Science Institute, Department of Animal Sciences and Industry, Kansas State University, Manhattan, US..

DOI: 10.4236/aim.2012.24073                

Abstract

Floor drains in processing environments harbor Listeria spp. due to continuous presence of humidity and organic substrates. Cleaning and washing activities in food-processing facilities can translocate the bacterial cells from the drain to the surrounding environment, thus contaminating food products still in production. This study evaluated the potential for translocation of Listeria monocytogenes from drains to food contact surfaces in the surrounding environment using Listeria innocua as a surrogate. A 7 × 7 × 8-foot polycarbonate flexi-glass chamber with a 10-inch-diameter drain mounted on an aluminum cabinet was used. Stainless steel coupons (6.4 × 1.9 × 0.1 cm, 12 per height) were hung at 1, 3, and 5 feet inside the chamber. Four treatment sets; non-inoculated, non-treated; non-inoculated, treated; inoculated, treated; inoculated non-treated; and two subtreatments of 8 h and 48 h were performed. For the inoculated sets, meat slurry (10 gof ground beef in 900 mL water) and a four-strain cocktail of Listeria innocua at 7 - 8 log CFU/mL were used. For the treated sets, in addition, a commercial cleaner and sanitizer was applied. The drain was cleaned using a pressure hose (40 - 50 psi) after 8 h and 48 h. Coupons were then removed and enriched in listeria enrichment broth to establish if any cell translocated from the drain onto the stainless steel coupons via aerosols generated during washing. Confirmation was done using VIP Listeria rapid test kits. Results indicated translocation at all three heights ranging from 2% - 25%. Significantly higher translocation (p < 0.05) was found at 1 foot (up to 25%), followed by 3 feet (up to 11%) and 5 feet (up to 2.7%). This research indicated that translocation of Listeria spp. from drains to food contact surfaces does occur and increases with increased proximity to the drain.

Keywords

Listeria Monocytogenes; Listeria Innocua; Drain; Translocation; Stainless Steel Coupons

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	P. J. Eginton, H. Gibson, J. T. Holah, P. S. Handley and P. Gilbert, “The Influence of Substratum Properties on Attachment of Bacterial Cells,” Colloids and Surfaces B: Biointerfaces, Vol. 5, No. 3-4, 1995, pp. 153-159. doi:10.1016/0927-7765(95)01219-9
[2]	E. A. Zotolla, “Microbial Attachment and Biofilm Formation: A New Problem in Food Industry?” Food Technology, Vol. 48, 1994, pp. 107-114.
[3]	D. Senczek, R. Stephan and F. Untermann, “Pulsed-Field Gel Electrophoresis (PFGE) Typing of Listeria Strains Isolated from a Meat Processing Plant over a 2-Year Period,” International Journal Food Microbiology, Vol. 62, 2000, pp. 155-159. doi:10.1016/S0168-1605(00)00395-0
[4]	P. Berche, J. L. Gaillard and S. Richard, “Invasiveness and Intracellular Growth of Listeria monocytogenes,” Infection, Vol. 16, No. 2, 1988, pp. 145-148.
[5]	USFDA/CFSAN and CDC, “Executive Summary, Reducing the Risk of Listeria monocytogenes FDA/CDC 2003 Update of the Listeria Action Plan, 2003. http://www.cfsan.fda.gov/~dms/lmr2plan.html
[6]	M. L. Gray and A. H. Killinger, “Listeria monocytogenes and Listeria Infections,” Bacteriology Reviews, Vol. 30, 1966, pp. 309-382.
[7]	E. T. Ryser and E. H. Marth, “Listeria, Listeriosis and Food Safety, Incidence and Control of Listeria in Food Processing Facilities,” CRC Press, Taylor and Francis Group, 2007, pp. 681-766.
[8]	T. Zhao, M. P. Doyle and P. Zhao, “Control of Listeria monocytogenes in a Biofilm by Competitive-Exclusion Microorganisms,” Applied Environmental Microbiology, Vol. 72, 2004, pp. 3996-4003. doi:10.1128/AEM.70.7.3996-4003.2004
[9]	I. C. Blackman and J. F. Frank, “Growth of Listeria monocytogenes as a Biofilm on Various Food Processing Surfaces,” Journal of Food Protection, Vol. 59, 1996, pp. 827-831.
[10]	H. Gibson, J. H. Taylor, K. E. Hall and J. T. Holah, “Biofilms and Their Detection in the Food Industry,” R&D Report No. 1 Chipping Campden, Campden and Chorleywood Food Research Association, 1994.
[11]	A. D. Hoffman, K. L. Gall, D. M. Norton and M. Wiedmann, “Listeria monocytogenes Contamination Patterns for the Smoked Fish Processing Environment and for Raw Fish,” Journal of Food Protection, Vol. 66, 2003, pp. 52-60.
[12]	J. T. Holah, “Industrial Monitoring: Hygiene in Food Processing,” In: L. F. Melo, T. R. Bott, M. Fletcher and B. Capdeville, Eds., Biofilms: Science and Technology, Kluwer Academic Publishers, Dordrecht, 1992, pp. 645-660.
[13]	J. T. Holah, R. P. Betts and R. H. Thorpe, “The Use of Direct Epiflourescent Microscopy (DEM) and the Epifluorescent filter technique (DEFT) to Assess Microbial Populations of food contact surfaces,” Journal of Applied Bacteriology, Vol. 65, 1988, pp. 215-221. doi:10.1111/j.1365-2672.1988.tb01888.x
[14]	C. B. Dalton, C. C. Austin, J. Sobel, P. S. Hayes, W. F. Bibb, L. M. Graves, B. Swaminathan, M. E. Proctor and P. M. Griffin, “An Outbreak of Gastroenteritis and Fever Due to L. monocytogenes in Milk,” New England Journal of Medicine, Vol. 336, 1997, pp. 100-105. doi:10.1056/NEJM199701093360204
[15]	G. Zhang, L. Ma, O. A. Oyarzabal and M. P. Doyle, “Aerosol Studies with Listeria innocua and Listeria monocytogenes,” Journal of Food Protection, Vol. 70, 2007, pp. 1857-1865.
[16]	I. C. Blackman and J. F. Frank, “Growth of Listeria monocytogenes as a Biofilm on Various Food Processing Surfaces,” Journal of Food Protection, Vol. 59, 1996, pp. 827-831.
[17]	D. H. Kang and D. Y. C. Fung, “Thin Agar Layer Method for Recovery of Heat-Injured Listeria monocytogenes,” Journal of Food Protection, Vol. 62, 1999, pp. 1346- 1349.
[18]	G. Wulff, L. Gram, P. Ahrens and B. F. Vogel, “One Group of Genetically Similar Listeria monocytogenes Strains Frequently Dominate and Persist in Several Fish Slaughter and Smokehouses,” Applied and Environmental Microbiology, Vol. 72, 2006, pp. 4313-4322. doi:10.1128/AEM.02288-05
[19]	J. L. K. Kornacki, “Detecting Sources of Listeria monocytogenes in Ready-to-Eat Food Processing Environments,” 2012. http://www.fsis.usda.gov/PDF/Seminar_Detecting_Sources_of_LM.pdf
[20]	J. Thimothe, K. K. Nightingale, K. Gall, V. N. Scott and M. Wiedmann, “Tracking of Listeria monocytogenes in Smoked Fish Processing Plants,” Journal of Food Protection, Vol. 67, 2004, pp. 328-341.
[21]	T. Suslow and L. Harris, “Guidelines for Control of Listeria monocytogenes in Small to Medium Scale Packaging and Fresh-Cut Operations,” 2000. http://anrcatalog.ucdavis.edu/pdf/8015.pdf