דו״ח מאומת

Non-typhoidal Salmonellae are common foodborne pathogens that can cause gastroenteritis and other illnesses in people. This is the first study to assess the transfer of Salmonella enterica from raw chicken carcasses to ready-to-eat chicken salad in Cambodia. Twelve focus group discussions in four Cambodian provinces collected information on typical household ways of preparing salad. The results informed four laboratory experiments that mimicked household practices, using chicken carcasses inoculated with Salmonella. We developed four scenarios encompassing the range of practices, varying by order of washing (chicken or vegetables first) and change of chopping utensils (same utensils or different). Even though raw carcasses were washed twice, Salmonella was isolated from 32 out of 36 chicken samples (88.9%, 95% CI: 73.0-96.4) and two out of 18 vegetable samples (11.1%, 95% CI: 1.9-36.1). Salmonella was detected on cutting boards (66.7%), knives (50.0%) and hands (22.2%) after one wash; cross-contamination was significantly higher on cutting boards than on knives or hands (p-value < 0.05). The ready-to-eat chicken salad was contaminated in scenario 1 (wash vegetables first, use same utensils), 2 (wash vegetables first, use different utensils) and 3 (wash chicken first, use same utensils) but not 4 (wash chicken first, use different utensils) (77.8%, 11.1%, 22.2% and 0%, respectively). There was significantly higher Salmonella cross-contamination in scenario 1 (wash vegetables first, use same utensils) than in the other three scenarios. These results show how different hygiene practices influence the risk of pathogens contaminating chicken salad. This information could decrease the risk of foodborne disease in Cambodia and provides inputs to a quantitative risk assessment model.…

PMID: 35913927

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 food were determined in various food handling scenarios. Skinless raw chicken breasts were artificially contaminated with C. jejuni and diced on cutting boards of three different materials. Whether cold water, cold water with detergent, or hot water was used, statistically significant differences were found between the transfer rates of C. 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 C. jejuni to cucumber cut on bamboo, wooden, and plastic cutting boards 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 kitchenware and cook's hands 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 proper cleaning to prevent cross-contamination during food handling; therefore, high-quality consumer education to reduce the risk of foodborne infection is urgent and necessary.…

PMID: 33232459

Contaminated poultry is the major vehicle for consumer's exposure to Campylobacter. This study aimed to perceive potential cross-contamination events during preparation of raw poultry that can contribute to the spread of Campylobacter spp. in domestic kitchen environments and to understand consumers' meanings and justifications on preparation of a poultry dish at home. A total of 18 households were visited to observe consumers preparing a recipe that included poultry. Poultry samples and swabs from the kitchen surfaces and utensils, such as kitchen cloth, hand towel, sponge, cutting boards and the sink, were collected before and after food preparation and tested for the presence of Campylobacter spp. Genotypic characterization of 72 Campylobacter spp. isolates was carried out through Pulse-Field Gel Electrophoresis (PFGE). Fourteen chicken samples were contaminated with Campylobacter spp. (77.8%). Twelve consumers (66.6%) washed the chicken meat under running tap water and eight (44.4%) used cutting boards. Also, only five consumers washed their hands properly prior to or during meal preparation. Cross-contamination events were detected in four kitchens, between the raw chicken and two cutting boards, two sinks and one kitchen cloth. The poultry samples presented different levels of contamination (< 4.0 × 10…

PMID: 33277046

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 food were determined in various food handling scenarios. Skinless raw chicken breasts were artificially contaminated with C. jejuni and diced on cutting boards of three different materials. Whether cold water, cold water with detergent, or hot water was used, statistically significant differences were found between the transfer rates of C. 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 C. jejuni to cucumber cut on bamboo, wooden, and plastic cutting boards 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 kitchenware and cook's hands 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 proper cleaning to prevent cross-contamination during food handling; therefore, high-quality consumer education to reduce the risk of foodborne infection is urgent and necessary.…

PMID: 33232459

Cross contamination of foodborne pathogens from raw meats to ready-to-eat foods has caused a number of foodborne outbreaks. The cross contamination and transfer rates of Salmonella enterica from chicken to lettuce under various food-handling scenarios were determined. The following scenarios were tested: in scenario 1, cutting board and knife used to cut chicken (10(6) CFU/g) were also used for cutting lettuce, without washing; in scenario 2, cutting board and knife were washed with water separately after cutting chicken, and subsequently used for cutting lettuce; and in scenario 3, cutting board and knife were thoroughly washed with soap and hot water after cutting chicken, and before cutting lettuce. In each scenario, cutting board, knife, chicken and lettuce were sampled for population of S. enterica. For scenario 1, both before and after cutting lettuce, the cutting board and knife each had about 2 logs CFU/cm(2) of S. enterica, respectively. The cut lettuce had about 3 logs CFU/g of S. enterica. In scenario 2, fewer organisms (0.5-2.4 logs CFU/g or cm(2)) were transferred. The transfer rates in both scenarios ranged from 0.02 to 75%. However, in scenario 3, <1 log CFU/g or cm(2) organisms were detected on lettuce, cutting board or knife, after washing and cutting lettuce. This shows that the FDA recommended practice for cleaning cutting boards is effective in removing S. enterica and preventing cross contamination.…

PMID: 20630321

To determine the effect of hygiene measures on cross-contamination of Campylobacter jejuni at home and to select a safe tracer organism for C. jejuni. Comparative tests were conducted with nonpathogenic Escherichia coli and Lactobacillus casei and L. casei was chosen as the safe tracer organism. Salads containing chicken breast fillet contaminated with a known number of C. jejuni and L. casei were prepared according to different cross-contamination scenarios and contamination levels of salads were determined. Cross-contamination could be strongly reduced when cleaning cutting board and cutlery with hot water (68 degrees C), but generally was not prevented using consumer-style cleaning methods for hands and cutting board. Dish-washing does not sufficiently prevent cross-contamination, thus different cutting boards for raw meat and other ingredients should be used and meat-hand contact should be avoided or hands should be thoroughly cleaned with soap. Lactobacillus casei can be used as a safe tracer organism for C. jejuni in consumer observational studies. Cross-contamination plays an important role in the transmission of food-borne illness, especially for C. jejuni. This study delivers suitable data to quantitatively assess the risk of campylobacteriosis caused by cross-contamination and it shows the effect of different preventive hygiene measures.…

PMID: 18341559

Campylobacter jejuni is one of the major causes of food poisoning in humans. C. jejuni is also widespread in food animals, and meat and meat products derived from food animals are the most common vector of bacterial transmission to humans. To determine the role of packing and storage conditions on the replication of C. jejuni on chicken, the virulent strain C. jejuni 81116 was artificially inoculated onto chicken skin pieces (1 cm2) and stored at different temperatures and under various packaging conditions. C. jejuni 81116 remained viable at -20 and -70 degrees C and was able to replicate at 4 degrees C and at ambient room temperature. C. jejuni 81116 was also inoculated onto chicken skin and subjected to repeated freeze thawing and the viability of the inoculum was quantified. C. jejuni 81116 could withstand repeated freeze thawing similar to that which may occur in the domestic home. Under all freezing conditions, C. jejuni 81116 retained a high level of viability and quickly replicated to levels which exceeded Australian food authorities' permitted bacteria level on raw food products after the sample was thawed.…

PMID: 9874337

Based on the need for a scientific basis for existing requirements in EU legislation on freezing of meat or for its possible amendment, the opinion compares microbial growth of relevant pathogenic, spoilage and indicator microorganisms within five scenarios of chilling, storage and defrosting of bovine, ovine and porcine meat, using predictive microbiology models that considered various conditions of temperature and, where possible, pH and a_w. Results obtained were compared to a reference scenario: storing meat at 7°C, aerobically, until 15 days post-slaughter. Storage of meat for 6 weeks, vacuum-packed immediately after stabilisation or 15 days post-slaughter, resulted in more growth of at least some of the bacteria assessed compared to the reference scenario, both at 3°C (certainty level 66%-90%) and at 7°C (certainty level 95%-99%). Predictions allowed estimating time at which equivalent microbial growth (i.e. ≤ 0.5 log₁₀ difference) to the reference scenario is reached ('equivalence time'), assuming different initial contamination levels of relevant spoilage bacteria. When storing meat at 7°C, vacuum-packed immediately after stabilisation, equivalence time was determined by <i>Salmonella</i> and reached in 5-6 days of post-slaughter storage (certainty level 66%-90%). When storing meat at 3°C, equivalence time was determined by spoilage lactic acid bacteria and reached in 29-30 days post-slaughter (certainty level 66%-90%). However, when initial contamination with spoilage bacteria was high (e.g. 5 log₁₀ CFU/cm²), predicted spoilage levels of 7 log₁₀ CFU/cm² were reached after 15-16 days. When considering also expected growth during post-defrosting storage at 4°C for 7 days, equivalence times were of 5-6 days (unchanged) and 13-16 days, respectively, though meat would have to be frozen immediately after stabilisation when initial contamination with spoilage bacteria is high. Predicted levels of indicator microorganisms for verification are provided for different assumed initial contamination levels, representing examples to be further adjusted based on actual measurements in practical settings.…

PMID: 41608239