Assessing the cross contamination and transfer rates of Salmonella enterica from chicken to lettuce under different food-handling scenarios

2010 ◽  
Vol 27 (6) ◽  
pp. 791-794 ◽  
Author(s):  
Sadhana Ravishankar ◽  
Libin Zhu ◽  
Divya Jaroni
Author(s):  
Sinh Dang-Xuan ◽  
Hung Nguyen-Viet ◽  
Phuc Pham-Duc ◽  
Delia Grace ◽  
Fred Unger ◽  
...  

Pork is the most commonly consumed meat in Vietnam, and Salmonella enterica is a common contaminant. This study aimed to assess potential S. enterica cross-contamination between raw and cooked pork in Vietnamese households. Different scenarios for cross-contamination were constructed based on a household survey of pork handling practices (416 households). Overall, 71% of people used the same knife and cutting board for both raw and cooked pork; however, all washed their hands and utensils between handling raw and cooked pork. The different scenarios were experimentally tested. First, S. enterica was inoculated on raw pork and surfaces (hands, knives and cutting boards); next, water used for washing and pork were sampled to identify the presence and concentration of S. enterica during different scenarios of food preparation. Bootstrapping techniques were applied to simulate transfer rates of S. enterica cross-contamination. No cross-contamination to cooked pork was observed in the scenario of using the same hands with new cutting boards and knives. The probability of re-contamination in the scenarios involving re-using the cutting board after washing was significantly higher compared to the scenarios which used a new cutting board. Stochastic simulation found a high risk of cross-contamination from raw to cooked pork when the same hands, knives and cutting boards were used for handling raw and cooked pork (78%); when the same cutting board but a different knife was used, cross-contamination was still high (67%). Cross-contamination between was not seen when different cutting boards and knives were used for cutting raw and cooked pork. This study provided an insight into cross-contamination of S. enterica, given common food handling practices in Vietnamese households and can be used for risk assessment of pork consumption.


Author(s):  
Yao Bai ◽  
Xiao-Hui Lin ◽  
Jiang-Hui Zhu ◽  
Sheng-Hui Cui ◽  
Li-Xia Guo ◽  
...  

Numerous outbreak investigations and case-control studies of campylobacteriosis have provided evidence that handling Campylobacter -contaminated chicken products is a high risk factor for infection and illness. In this study, the cross-contamination and transfer rates of Campylobacter jejuni from chicken to ready-to-eat foods were determined in various food-handling scenarios. Skinless raw chicken breasts were artificially contaminated with Campylobacter jejuni and diced on three kinds of texture cutting boards. Whether cold water or cold water with detergent or hot water was used, statistically significant differences were found between the transfer rate of Campylobacter jejuni to unwashed and washed cutting boards or hands, respectively. When both kitchen knife and cutting board were reused after dicing the artificially contaminated chicken, the transfer rates of Campylobacter jejuni to cucumber cut on bamboo, wooden and plastic cutting board were 16.28%, 12.82% and 5.32%, respectively. The transfer rates from chicken to bread, a large lift-up water faucet handle and a small twist faucet handle via unwashed hands were 0.49%, 4.64% and 3.14%, respectively. This research provides scientific evidence that various types of contaminated kitchen-ware and cook’s hand are vital potential vehicles for the cross-contamination of Campylobacter from raw chicken to ready-to-eat food, and emphasizes the importance of timely and properly cleaning to prevent cross-contamination during food handling, therefore a high quality consumer education to reduce the risk of foodborne infection is urgent and necessary.


2001 ◽  
Vol 64 (1) ◽  
pp. 72-80 ◽  
Author(s):  
YUHUAN CHEN ◽  
KRISTIN M. JACKSON ◽  
FABIOLA P. CHEA ◽  
DONALD W. SCHAFFNER

This study investigated bacterial transfer rates between hands and other common surfaces involved in food preparation in the kitchen. Nalidixic acid–resistant Enterobacter aerogenes B199A was used as a surrogate microorganism to follow the cross-contamination events. Samples from at least 30 different participants were collected to determine the statistical distribution of each cross-contamination rate and to quantify the natural variability associated with that rate. The transfer rates among hands, foods, and kitchen surfaces were highly variable, being as low as 0.0005% and as high as 100%. A normal distribution was used to describe the variability in the logarithm of the transfer rates. The mean ± SD of the normal distributions were, in log percent transfer rate, chicken to hand (0.94 ± 0.68), cutting board to lettuce (0.90 ± 0.59), spigot to hand (0.36 ± 0.90), hand to lettuce (−0.12 ± 1.07), prewashed hand to postwashed hand (i.e., hand washing efficiency) (−0.20 ± 1.42), and hand to spigot (−0.80 ± 1.09). Quantifying the cross-contamination risk associated with various steps in the food preparation process can provide a scientific basis for risk management efforts in both home and food service kitchens.


2016 ◽  
Vol 79 (7) ◽  
pp. 1252-1258 ◽  
Author(s):  
E. GKANA ◽  
A. LIANOU ◽  
G.-J. E. NYCHAS

ABSTRACT It is well established that a high percentage of foodborne illness is caused by failure of consumers to prepare food in a hygienic manner. Indeed, a common practice in households is to use the same kitchen equipment for both raw meat and fresh produce. Such a practice may lead to cross-contamination of fruits and vegetables, which are mainly consumed without further processing, with pathogenic microorganisms originating from raw meat. The present study was performed to examine the transfer of the pathogenic bacterium Salmonella enterica serovar Typhimurium from inoculated beef fillets to tomatoes via contact with high-density polyethylene (PE), stainless steel (SS), and wooden (WD) surfaces and through cutting with SS knives. Furthermore, the following decontamination procedures were applied: (i) rinsing with tap water, (ii) scrubbing with tap water and liquid dish detergent, and (iii) using a commercial antibacterial spray. When surfaces and knives that came into contact with contaminated beef fillets were not cleaned prior to handling tomatoes, the lowest level of pathogen transfer to tomatoes was observed through PE surfaces. All of the decontamination procedures applied were more effective on knives than on surfaces, while among the surface materials tested, WD surfaces were the most difficult to decontaminate, followed by PE and SS surfaces. Mechanical cleaning with tap water and detergent was more efficient in decontaminating WD surfaces than using commercial disinfectant spray, followed by rinsing only with water. Specifically, reductions of 2.07 and 1.09 log CFU/cm2 were achieved by washing the WD surfaces with water and detergent and spraying the surfaces with an antibacterial product, respectively. Although the pathogen's populations on SS and PE surfaces, as well as on tomatoes, after both aforementioned treatments were under the detection limit, the surfaces were all positive after enrichment, and thus, the potential risk of cross-contamination cannot be overlooked. As demonstrated by the results of this study, washing or disinfection of kitchen equipment may not be sufficient to avoid cross-contamination of ready-to-eat foods with foodborne pathogens, depending on the decontamination treatment applied and the material of the surfaces treated. Therefore, separate cutting boards and knives should be used for processing raw meat and preparing ready-to-eat foods in order to enhance food safety.


2006 ◽  
Vol 72 (1) ◽  
pp. 66-70 ◽  
Author(s):  
Petra Luber ◽  
Sigrid Brynestad ◽  
Daniela Topsch ◽  
Kathrin Scherer ◽  
Edda Bartelt

ABSTRACT Numerous outbreak investigations and case-control studies for campylobacteriosis have provided evidence that handling Campylobacter-contaminated chicken products is a risk factor for infection and illness. There is currently extremely limited quantitative data on the levels of Campylobacter cross-contamination in the kitchen, hindering risk assessments for the pathogen commodity combination of Campylobacter and chicken meat. An exposure assessment needs to quantify the transfer of the bacteria from chicken to hands and the kitchen environment and from there onto ready-to-eat foods. We simulated some typical situations in kitchens and quantified the Campylobacter transfer from naturally contaminated chicken parts most commonly used in Germany. One scenario simulated the seasoning of five chicken legs and the reuse of the same plate for cooked meat. In another, five chicken breast filets were cut into small slices on a wooden board where, without intermediate cleaning, a cucumber was sliced. We also investigated the transfer of the pathogen from chicken via hands to a bread roll. The numbers of Campylobacter present on the surfaces of the chicken parts, hands, utensils, and ready-to-eat foods were detected by using Preston enrichment and colony counting after surface plating on Karmali agar. The mean transfer rates from legs and filets to hands were 2.9 and 3.8%. The transfer from legs to the plate (0.3%) was significantly smaller (P < 0.01) than the percentage transferred from filets to the cutting board and knife (1.1%). Average transfer rates from hands or kitchen utensils to ready-to-eat foods ranged from 2.9 to 27.5%.


2008 ◽  
Vol 105 (5) ◽  
pp. 1392-1401 ◽  
Author(s):  
E.D. van Asselt ◽  
A.E.I. de Jong ◽  
R. de Jonge ◽  
M.J. Nauta

2008 ◽  
Vol 71 (12) ◽  
pp. 2448-2452 ◽  
Author(s):  
LAY-CHING CHAI ◽  
HAI-YEN LEE ◽  
FARINAZLEEN MOHD GHAZALI ◽  
FATIMAH ABU BAKAR ◽  
PRADEEP KUMAR MALAKAR ◽  
...  

Campylobacter jejuni was found to occur at high prevalence in the raw salad vegetables examined. Previous reports describe cross-contamination involving meat; here we investigated the occurrence of cross-contamination and decontamination events in the domestic kitchen via C. jejuni–contaminated vegetables during salad preparation. This is the first report concerning quantitative cross-contamination and decontamination involving naturally contaminated produce. The study was designed to simulate the real preparation of salad in a household kitchen, starting with washing the vegetables in tap water, then cutting the vegetables on a cutting board, followed by slicing cucumber and blanching (heating in hot water) the vegetables in 85° water. Vegetables naturally contaminated with C. jejuni were used throughout the simulation to attain realistic quantitative data. The mean of the percent transfer rates for C. jejuni from vegetable to wash water was 30.1 to 38.2%; from wash water to cucumber, it was 26.3 to 47.2%; from vegetables to cutting board, it was 1.6 to 10.3%; and from cutting board to cucumber, it was 22.6 to 73.3%. The data suggest the wash water and plastic cutting board as potential risk factors in C. jejuni transmission to consumers. Washing of the vegetables with tap water caused a 0.4-log reduction of C. jejuni attached to the vegetables (most probable number/gram), while rapid blanching reduced the number of C. jejuni organisms to an undetectable level.


2018 ◽  
Vol 81 (4) ◽  
pp. 569-581 ◽  
Author(s):  
ELLEN W. EVANS ◽  
ELIZABETH C. REDMOND

ABSTRACT The incidence of foodborne illness is higher in older adults because of their increased susceptibility; therefore, food safety practices are important. However, inadequate knowledge and negative attitudes toward food safety have been reported, which may increase use of unsafe food handling practices. Data on the actual food safety behaviors of older adults are lacking. In this study, food safety practices of older adults were observed and linked to microbiological analysis of kitchen surfaces to identify suspected routes of contamination. Older adults (≥60 years, n = 100) prepared a set meal in a model domestic kitchen sanitized according to a validated protocol to ensure minimal and consistent microbiological loads. Food safety behaviors were observed using ceiling-mounted cameras and recorded using a predetermined behavioral checklist. Surface microbiological contamination also was determined after food preparation. Overall, older adults frequently implemented unsafe food handling practices; 90% failed to implement adequate hand decontamination immediately after handling raw chicken. For older adults who used a larger number of adequate hand decontamination attempts, microbiological contamination levels in the kitchen following the food preparation session were significantly lower (P &lt; 0.001). The novel utilization of behavioral observation in conjunction with microbiological analysis facilitated identification of potentially unsafe food handling practices as suspected routes of microbiological cross-contamination in a model domestic kitchen. Findings indicate the potential impact on domestic food safety of unsafe food handling practices used by older adult consumers. This innovative approach revealed that a large proportion of older adults implement behaviors resulting in microbiological cross-contamination that may increase the risk of foodborne illness in the home.


2011 ◽  
Vol 74 (9) ◽  
pp. 1513-1523 ◽  
Author(s):  
SARA B. FEIN ◽  
AMY M. LANDO ◽  
ALAN S. LEVY ◽  
MARIO F. TEISL ◽  
CAROLINE NOBLET

Although survey results measuring the safety of consumers' food handling and risky food consumption practices have been published for over 20 years, evaluation of trends is impossible because the designs of published studies are not comparable. The Food Safety Surveys used comparable methods to interview U.S. adults by telephone in 1988, 1993, 2001, 2006, and 2010 about food handling (i.e., cross-contamination prevention) and risky consumption practices (eating raw or undercooked foods from animals) and perceived risk from foodborne illness. Sample sizes ranged from 1,620 to 4,547. Responses were analyzed descriptively, and four indices measuring meat, chicken, and egg cross-contamination, fish cross-contamination, risky consumption, and risk perceptions were analyzed using generalized linear models. The extent of media coverage of food safety issues was also examined. We found a substantial improvement in food handling and consumption practices and an increase in perceived risk from foodborne illness between 1993 and 1998. All indices were stable or declined between 1998 and 2006. Between 2006 and 2010, the two safe food handling practice indices increased significantly, but risk perceptions did not change, and safe consumption declined. Women had safer food handling and consumption practices than men. The oldest and youngest respondents and those with the highest education had the least safe food handling behaviors. Changes in safety of practices over the survey years are consistent with the change in the number of media stories about food safety in the periods between surveys. This finding suggests that increased media attention to food safety issues may raise awareness of food safety hazards and increase vigilance in food handling by consumers.


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