No fridge too far as study opens a cold war on bacteria

The invisible residents of Ireland's fridges are about to be outed

The invisible residents of Ireland's fridges are about to be outed. Lurking listeria, skulking salmonella or coy camplyobacter will be swabbed from their hiding places, identified and examined in a survey of 2,500 domestic fridges which will get under way next month.

Researcher Dr Declan Bolton, of the National Food Centre, Teagasc, said two-thirds of food poisoning outbreaks originate in the home.

"As a society we're all guilty. We come home tired. We take short cuts . . . and it's not just the ordinary consumer. When I asked a group of visiting food scientists what was the correct way to clean a fridge, none of them knew the right answer (use a solution of 5 per cent baking soda.)"

He said some products required more care than others. For instance, 13 per cent of raw chickens have salmonella, while 29 per cent have camplyobacter. Therefore, correct handling, storage and cooking were very important.

READ MORE

Funded by the Food Safety Promotion Board (FSPB), the project is a cross-Border endeavour which also involves Dr Ian Blair of the University of Ulster. As a pragmatic measure they have "redrawn the Border" so they both do an equal share of the work, Dr Bolton said.

He is concerned that individual consumers may be reluctant to open their fridges to researchers. "This is not about what's in an individual's fridge, although if we find pathogens lurking we will, of course, advise that person. It's about protecting all consumers. Most people who get food poisoning have a bellyache for a few days but for the elderly, the very young and the immunocompromised it can be a serious matter. We owe it to them to be able to protect them."

The three-year study will develop and apply novel detection methods to determine the incidence of a range of significant food-poisoning bacteria, including salmonella, camplyobacter, listeria, aeromomas, yersinia and E.Coli O157.

Fridge temperatures will also be monitored and data obtained on the effect of dynamic temperature conditions on the growth and virulence of patterns of bacteria.

These is increasing evidence that domestic chill storage conditions can induce stress adaptations in pathogens, including heat or stress resistance, enhanced expression of pathogenic characteristics and the development or transfer of antibiotic resistance.

Previous studies by members of the project team have established that a significant proportion of domestic fridges operate under conditions which are likely to support sub-optimum but nevertheless significant rates of growth of pathogens.

The team has also established that temperature fluctuations within domestic fridges are more rapid and more extreme than temperature fluctuations within other elements of the food production and distribution chain. The implications of these fluctuations on pathogen physiology have not been established.

And it's not just the fridges which will be examined. Consumers will be asked to answer an 80question, multiple-choice questionnaire in an attempt to identify deficiencies in knowledge or practices which may be putting consumers at risk. This will help the FSPB to target their educational initiatives, according to Dr Thomas Quigley, of the board.

Just under a quarter of respondents to a recent survey published by the FSPB said they knew the recommended temperature of their fridge/freezer. When asked further, only half of those who said they knew the correct temperature could cite it (0C to 5C), with only 17 per cent able to cite the correct temperature for their freezer (minus 18C).

This project will analyse its results in terms of socioeconomic grouping, age profile and rural versus urban dwellers.

The research team will set up two websites in July which will provide information and advice to the public and industry.

(Consumer website: www.dotHYGIENE.com; industry website: www.dotHACCP.com).