Researchers from the James Hutton Institute in Scotland outlined their findings at the Annual Meeting of the Society for General Microbiology in Liverpool. They discovered that the bacteria were able to use their flagella to penetrate plant cell walls and attach themselves in a process similar to that used to colonise the intestines of animals. They demonstrated that purified flagella could interact directly with lipid molecules in the plant cell membranes, while E. coli cells without flagella could not bind to the cells.
After attachment the bacteria were able to multiply, although they could still be removed from the plant surface by washing. However, a small number of cells were found to be able to invade the plant tissues and were protected from washing. The researchers have also shown that E. coli O157:H7 cells can colonise the roots of spinach and lettuce.
Lead researcher Dr Nicola Holden commented, “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 the interactions so we can reduce the risk of foodborne disease.”
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