Campylobacter spread through sticky microfilms, study

Campylobacter respond to the stressful environments by rapidly forming a slimy microfilm that sheds cells into the foods, scientists have observed, a finding that could help develop new antimicrobial approaches.

Campylobacter is the most common form of food poisoning, affecting some 500,000 people in the UK alone. It is often caused by eating undercooked chicken or turkey, and its fierce capacity to spread mean the presence of only a few bacteria can be enough to cause vomiting, cramps, and diarrhoea.

For a new study, published in the journal Applied and Environmental Microbiology, a team from the Institute of Food Research (IFR) set out to examine how the campylobacter survives in the environment.

Under laboratory conditions, they watched as bacteria left in the air formed a sticky film – a reservoir of cells that encases them and protects them from the oxygen. The films were also seen to shed cells, which could explain how the bacteria end up in food.

Dr Mark Reuter explained that the observation that campylobacter sense stress and respond to it has big implications. “Now we need to focus in on those systems that actually sense the stress, particularly the oxygen sensors,” he said.

His colleague Dr Arnoud van Vliet added that future investigations could lead to new ways of protecting food, such as “disrupting the biofilm matrix or prevention of the biofilm formation”.

In addition to being found in poultry meat, campylobacter can also occur in red meat, unpasteurised milk and untreated water.

The new research was funded by the Biotechnology and Biological Sciences Research Council, of which IFR is a part. Countering campylobacter is a key activity this year of the Cross Government Research and Innovation Strategy for Food.

Source

Applied and Environmental Microbiology, Vol 76, No 7 2122-2128

DOI: 10.1128/AEM.01878-09

“Biofilm formation by campylobacter jejuni is increased under aerobic conditions”

Authors: Mark Reuter, Arthur Mallett, Bruce Pearson, and Arnoud van Vliet