New research shows how pathogenic E. coli binds to fresh vegetables
Researchers from the James Hutton Institute in Scotland have identified that E. coli O157:H7 uses whip-link structures on its surface known as flagella – typically used for bacterial motility – to penetrate the plant cell walls. The team showed that purified flagella were able to directly interact with lipid molecules found in the membranes of plant cells. E. coli bacteria lacking flagella were unable to bind to the plant cells.
Once attached, the E. coli are able to grow on, and colonise, the surface of the plant. At this point, they can be removed by washing, although the researchers showed that a small number of bacteria are able to invade inside the plant, where they become protected from washing. The group have shown that E. coli O157:H7 is able to colonise the roots of both spinach and lettuce.
Dr Nicola Holden, who led the research, says: "This work shows the fine detail of how the bacteria bind to plants. We think this mechanism is common to many foodborne bacteria and shows that they can exploit common factors found in both plants and animals to help them grow. Our long term aim is to better understand these interactions so we can reduce the risk of food-borne disease."
By understanding the mechanisms of how the bacteria interact with plants, the researchers are hoping to find targeted ways to stop the binding, reducing the risk of food contamination.
Source: www.sgm.ac.uk