Comparison of Sampling Procedures for Recovery of Listeria monocytogenes from Stainless Steel Food Contact Surfaces

2012 ◽  
Vol 75 (6) ◽  
pp. 1077-1082 ◽  
Author(s):  
DIEGO GÓMEZ ◽  
AGUSTÍN ARIÑO ◽  
JUAN J. CARRAMIÑANA ◽  
CARMINA ROTA ◽  
JAVIER YANGÜELA
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Cost Effective ◽  
Sampling Procedure ◽  
Human Origin ◽  
Sampling Device ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Sampling Procedures

A number of techniques exist for microbiological sampling of food processing environments in food industries. In the present study the efficacies of nine sampling procedures for the recovery of Listeria monocytogenes from food contact surfaces, including a new sampling device consisting of a miniroller, were evaluated and compared. A stainless steel table was inoculated with L. monocytogenes strain 935 (serovar 4b, human origin) and L. monocytogenes strain 437/07 (serovar 1/2b, food origin), at 105 CFU/100 cm2. L. monocytogenes strain 935 was best recovered with the minirollers (recovery of up to 6.27%), while poor recoveries (<0.30%) were obtained with the towel (one-ply composite tissue), alginate swab, metallic swab, and Petrifilm methods. In the case of L. monocytogenes strain 437/07 the replicate organism detection and counting (RODAC) ALOA contact plates yielded the best recoveries (4.15%), followed by the minirollers (up to 1.52%). Overall, recovery percentages with the minirollers were higher with stomacher homogenization than with Vibromatic agitation. The recovery percentages obtained for the Listeria strain of human origin were higher than those obtained with the food strain for all sampling procedures except Petrifilm and RODAC ALOA. With the miniroller device coated with wool fiber, the recovery of L. monocytogenes can be improved from 2 to 17 times over recoveries obtained with the sponge and cotton swab. This is the first report of a miniroller device for microbiological sampling in the available literature. The novel sampling procedure is convenient to apply on surfaces, is cost-effective, and results in better recovery of L. monocytogenes than do the conventional methods.

scholarly journals Evaluation of Quantitative Recovery Methods for Listeria monocytogenes Applied to Stainless Steel

2007 ◽  
Vol 90 (3) ◽  
pp. 810-816 ◽  
Author(s):  
David Kang ◽  
Joseph D Eifert ◽  
Robert C Williams ◽  
Steven Pao
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
304 Stainless Steel ◽  
Contact Method ◽  
Cell Recovery ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Quantitative Recovery

Abstract The ability of Listeria monocytogenes to attach to various food contact surfaces, such as stainless steel, polypropylene, and rubber compounds, is well documented. The retention of these or other pathogenic bacteria on food contact surfaces increases the risk of transmission to food products. The objective of this study was to compare several methods for quantitative recovery of Listeria monocytogenes from stainless steel surfaces. A cocktail of 4 serotypes of Listeria monocytogenes mixed in equivalent concentrations was inoculated onto type 304 stainless steel coupons in a 2 2 cm area. After 1 h exposure, coupons were sampled by one of the following methods: (1) swabbing with a premoistened Dacron swab; (2) rinsingwith phosphate-buffered saline; (3) direct contact onto tryptic soy agar containing 0.6% yeast extract (TSA + YE) plates for 10 s; (4) sonication in an ultrasonic water bath (40 kHz); (5) contact with the bristles of a sonicating brush head for 1 min; and (6) indirect contact (24 mm distance) with a sonicating brush head for 1 min. The 3 sonication methods yielded higher recovery than the other 3 methods (P < 0.05). Brushing the coupons with the sonicating brush head (contact or noncontact) yielded a recovery level of about 60%. The lowest cell recovery (about 20%) was observed with the swab and direct agar contact methods. After a 12 h exposure, recoveries ranged from 17.4 (brush contact method) to 2% (swab method).

Establishment of incubation conditions to optimize the in vitro formation of mature Listeria monocytogenes biofilms on food-contact surfaces

Food Control ◽  
2018 ◽  
Vol 92 ◽  
pp. 240-248 ◽  
Author(s):  
C. Ripolles-Avila ◽  
A.S. Hascoët ◽  
A.E. Guerrero-Navarro ◽  
J.J. Rodríguez-Jerez
Keyword(s):  
Listeria Monocytogenes ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces

Control of Listeria innocua Biofilms on Food Contact Surfaces with Slightly Acidic Electrolyzed Water and the Risk of Biofilm Cells Transfer to Duck Meat

2018 ◽  
Vol 81 (4) ◽  
pp. 582-592 ◽  
Author(s):  
HYE RI JEON ◽  
MI JIN KWON ◽  
KI SUN YOON
Keyword(s):  
Stainless Steel ◽  
Food Processing ◽  
Biofilm Formation ◽  
Listeria Innocua ◽  
Potential Hazard ◽  
Processing Efficiency ◽  
Electrolyzed Water ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces

ABSTRACT Biofilm formation on food contact surfaces is a potential hazard leading to cross-contamination during food processing. We investigated Listeria innocua biofilm formation on various food contact surfaces and compared the washing effect of slightly acidic electrolyzed water (SAEW) at 30, 50, 70, and 120 ppm with that of 200 ppm of sodium hypochlorite (NaClO) on biofilm cells. The risk of L. innocua biofilm transfer and growth on food at retail markets was also investigated. The viability of biofilms that formed on food contact surfaces and then transferred cells to duck meat was confirmed by fluorescence microscopy. L. innocua biofilm formation was greatest on rubber, followed by polypropylene, glass, and stainless steel. Regardless of sanitizer type, washing removed biofilms from polypropylene and stainless steel better than from rubber and glass. Among the various SAEW concentrations, washing with 70 ppm of SAEW for 5 min significantly reduced L. innocua biofilms on food contact surfaces during food processing. Efficiency of transfer of L. innocua biofilm cells was the highest on polypropylene and lowest on stainless steel. The transferred biofilm cells grew to the maximum population density, and the lag time of transferred biofilm cells was longer than that of planktonic cells. The biofilm cells that transferred to duck meat coexisted with live, injured, and dead cells, which indicates that effective washing is essential to remove biofilm on food contact surfaces during food processing to reduce the risk of foodborne disease outbreaks.

Concentration and Detection of Caliciviruses from Food Contact Surfaces

2002 ◽  
Vol 65 (6) ◽  
pp. 999-1004 ◽  
Author(s):  
ANIL TAKU ◽  
BALDEV R. GULATI ◽  
PAUL B. ALLWOOD ◽  
KERRIN PALAZZI ◽  
CRAIG W. HEDBERG ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Food Service ◽  
Contact Period ◽  
Norwalk Virus ◽  
Buffer Solution ◽  
Simple Method ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Elution Method

Outbreaks of human Norwalk virus (NV) and Norwalk-like viruses often originate in food service establishments. No reliable method is available for the detection of these human caliciviruses on food contact surfaces. We describe a simple method for the detection of NV from stainless steel work surfaces using cultivable feline calicivirus (FCV) as a model. Stainless steel surfaces were artificially contaminated with known amounts of FCV, followed by its elution in a buffer solution. Three methods of virus elution were compared. In the first method, moistened cotton swabs or pieces of nylon filter (1MDS) were used to elute the contaminating virus. The second method consisted of flooding the contaminated surface with eluting buffer, allowing it to stay in contact for 15 min, followed by aspiration of the buffer (aspiration method) after a contact period of 15 min. The third method, the scraping-aspiration method, was similar to the aspiration method, except that the surfaces were scraped with a cell scraper before buffer aspiration. Maximum virus recovery (32 to 71%) was obtained with the scraping-aspiration method using 0.05 M glycine buffer at pH 6.5. Two methods (organic flocculation and filter adsorption elution) were compared to reduce the volume of the eluate recovered from larger surfaces. The organic flocculation method gave an average overall recovery of 55% compared to the filter-adsorption-elution method, which yielded an average recovery of only 8%. The newly developed method was validated for the detection of NV by artificial contamination of 929-cm2 stainless steel sheets with NV-positive stool samples and for the detection of the recovered virus by reverse transcription–polymerase chain reaction.

Inhibition of Initial Attachment of Injured Salmonella Typhimurium onto Abiotic Surfaces

2017 ◽  
Vol 81 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Woo-Ju Kim ◽  
Ki-Ok Jeong ◽  
Dong-Hyun Kang
Keyword(s):  
Hydrogen Peroxide ◽  
Stainless Steel ◽  
Lactic Acid ◽  
Salmonella Typhimurium ◽  
Food Processing ◽  
Food Contact ◽  
Abiotic Surfaces ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Biofilm Development

ABSTRACT Following sanitation interventions in food processing facilities, sublethally injured bacterial cells can remain on food contact surfaces. We investigated whether injured Salmonella Typhimurium cells can attach onto abiotic surfaces, which is the initial stage for further biofilm development. We utilized heat, UV, hydrogen peroxide, and lactic acid treatments, which are widely utilized by the food industry. Our results showed that heat, UV, and hydrogen peroxide did not effectively change populations of attached Salmonella Typhimurium. Cells treated with hydrogen peroxide had a slightly higher tendency to adhere to abiotic surfaces, although there was no significant difference between the populations of control and hydrogen peroxide–treated cells. However, lactic acid effectively reduced the number of Salmonella Typhimurium cells attached to stainless steel. We also compared physicochemical changes of Salmonella Typhimurium after application of lactic acid and used hydrogen peroxide as a positive control because only lactic acid showed a decreased tendency for attachment and hydrogen peroxide induced slightly higher numbers of attached bacteria cells. Extracellular polymeric substance produced by Salmonella Typhimurium was not detected in any treatment. Significant differences in hydrophobicity were not observed. Surface charges of cell membranes did not show relevant correlation with numbers of attached cells, whereas autoaggregation showed a positive correlation with attachment to stainless steel. Our results highlight that when lactic acid is applied in a food processing facility, it can effectively interfere with adhesion of injured Salmonella Typhimurium cells onto food contact surfaces.

Sign in / Sign up

Export Citation Format

Share Document