This study investigated the factors and mechanisms by which significant foodborne pathogens enter the domestic kitchen, adapt to the conditions they find there, persist and spread, and are frequently transferred to human hosts.
It examined the challenges posed by Campylobacter, Salmonella and Escherichia coli, with particular reference to the responses and adaptations of these organisms to the challenges they face in persisting and spreading within domestic kitchen environments, cleaning and food production processes.
It observed considerable differences across the Campylobacter strains obtained from farms, chicken processing plants, kitchens, human infections, and culture collections. In this area, particular benefit was gained from the development of a novel method of objectively assessing the relative amounts of biofilm produced by equivalent populations of Campylobacter.
The observed significant impact of co-flora and/or co-flora-associated biofilm on Campylobacter persistence is a key finding and will change the way the risks posed by Campylobacter are viewed. As well as offering a potential explanation for the frequently observed, yet physiologically unexplained persistence of this organism under adverse conditions, the recognition of these important protective effects provides a new approach in attempts to reduce the incidence of campylobacteriosis.
The observed periods of persistence of foodborne pathogens in the presence of food debris varied widely among commonly-used kitchen surfaces, ranging from Formica (longest), through polypropylene, stainless steel and granite, to wood (shortest).
Data from scenario studies of the factors involved in pathogen spread during food receipt and storage, combined with data on the previous unreported extended survival of foodborne pathogens within domestic kitchens underline the importance of positive steps to prevent pathogen access to kitchens. The study demonstrates the ease with which poor practice during sourcing, receipt and storage of high risk foods can lead to widespread contamination of domestic kitchens.
The subsequent scenario on cross contamination during kitchen cleaning reinforces the risks in incorrect (but all too common) use of dishcloths along with the inappropriate (‘spray and wipe’) application of commercially available domestic biocides in the spread of contamination with foodborne pathogens. These findings, along with the previously unreported capacity of dishcloths to harbour foodborne pathogens for at least 24 hours confirm threats to the safety of ‘tomorrow’s’ meal and well as ‘today’.
The study demonstrated the considerable risks posed by inadequate care/poor consumer practices in the receipt and storage of high risk retail products within the domestic environment, the prevention of pathogen spread during kitchen cleaning activities, and the prevention of food recontamination or persistence of contamination during food preparation. Recommendations in relation to these findings include further expansion of consumer education in:
- The risks posed by poor domestic practices in the receipt/storage of high risk foods, giving this aspect higher profile in general consumer advice and campaigns, as the first step in reducing the access of foodborne pathogens to domestic kitchen environments and operations.
- Methods of reducing/eliminating food safety risks associated with cleaning pathogen-contaminated spills (selection and appropriate application of detergents and biocides. ‘Spray, wait, wipe’, disposable or adequately treated fabric/disposable towels)
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