Research by the Health Protection Agency (HPA) has revealed that over half the cleaning cloths used in restaurant and take-away kitchens were found to contain unsatisfactory levels of bacteria which are a sign of poor hygiene and cross contamination. The findings are presented in a poster presentation at the HPA’s annual conference – Health Protection 2010 – at the University of Warwick today.

Cloths used in kitchens need to be changed or disinfected frequently to stop bacteria growing which could cause food poisoning. Any breakdown in these procedures means that bacteria can be spread from the cloths to the hands of catering staff and then spread to work surfaces and equipment. Where kitchens prepare both raw and ready-to-eat foods, there should be separate cloths for both areas to reduce the risk of spread of bacteria.

The team sampled 133 cloths, from 120 establishments in the North east of England, and found that 56 per cent contained unacceptable levels of bacteria. The most common of which were Enterobacteriaceae (found on 86 cloths) E. coli (21 cloths), Staphylococcus aureus (six cloths) and Listeria (five cloths).

Although the recommended advice for restaurants is to use disposable cloths that are changed regularly, the study found that only a third (32 per cent) of the catering premises reviewed adhered to this. The remaining two thirds (68 per cent) used re-usable cloths and 15 per cent were unsure as to how often these were replaced.

One of the most important factors in reducing the spread of bacteria around the kitchen is to separate cloths used for raw and ready-to-eat food areas but the research found that 24 cloths had been used between these two areas.

The researchers also found that there was no consistent approach to disinfection of re-usable cloths or in the method of disinfection. The majority disinfected their re-usable cloths every 10-24 hours but a number left it longer than 24 hours and some didn’t know how often cloths were disinfected.

Dr John Piggott, the lead author from the HPA’s Food, Water and Environmental Microbiology laboratory in Leeds said: “It’s of concern that despite recommendations to use disposable cloths the majority of restaurants we surveyed were re-using cleaning cloths and some were unaware how often they changed them.

“Although many disinfected their cloths using bleach or other disinfectants, soaking does not remove the food on which the bacteria grow. The disinfectant qualities of bleach do wear off after a period of time so soaking large amounts of cloths together can result in bacteria contaminating more cloths and creating more potential problems.

“All of the premises in our study were given advice on how to practice better hygiene and they will be revisited to make sure that procedures have improved.”

Dr Paul Cosford, executive director of health protection services at HPA, said: “This interesting study looked at a small number of premises, but the findings indicate problems with poor hygiene practices at some of these establishments. Exposure to this harmful bacteria can cause food poisoning which is unpleasant for most people but for some – particularly the very young, very old and pregnant women – it can have serious consequences.

“The HPA plays an important role in monitoring the hygiene standards at commercial premises and these worrying findings should serve as a timely reminder to all caterers to dish the dirty dishcloths and stick to disposable ones.”

Notes

The study was carried out by the HPA’s Food, Water and Environmental Microbiology laboratories and was done in collaboration with the Local Authorities in the North East.

Looking for Enterobacteriaceae is a commonly used assessment of general hygiene status. These bacteria include species that originate from the intestinal tract of animals and humans, as well as plants and the environment. All Enterobacteriaceae are killed by the heat processes used in food production and should be readily removed from the factory, equipment and surfaces by appropriate cleaning procedures.

The presence of more than 10,000 of these bacteria on a cloth indicates insufficient cleaning and a potential cross contamination risk. The detection of E. coli can signify a risk that faecal pathogens are present and is another indicator of poor hygiene standards.

Staphlycoccus aureus was found in six of the cloths sampled and these bacteria have the potential to cause food poisoning.

The presence of Listeria species was found in five cloths and can also be used as an indicator to assess the hygienic status of the cloth. Listeria is less sensitive than many other bacterias to the cleaning procedures used in food processing environments and can survive in both food processing premises and on equipment if inappropriate hygiene measures are used.

The isolation of Listeria monocytogenes from three cloths indicates a more serious issue as these bacteria can cause serious illness. Vulnerable groups, such as pregnant women, those with an impaired immune system, the elderly, and hospital in-patients, are at particular risk of infection following exposure to low levels of listeria in food.

Source: Health Protection Agency