A group of researchers at the James Hutton Institute in Scotland have presented the results of a study at the Annual Meeting of the Society for General Microbiology held in Liverpool, United Kingdom, showing that the disease caused by the E. Coli O157: H7 interacts directly with the plant cells, becoming attached to the plant's surface, where the bacterium is able multiply.
Outbreaks of food poisoning linked to the disease caused by the Escherichia coli bacterium are normally associated with contaminated meat products, but between 20 and 30% of them occur when people eat infected vegetables.
The researchers have identified that the 'E. Coli O157: H7' uses structures to attach itself to their surface, known as flagella and commonly used for bacterial mobility to penetrate cell walls. The team demonstrated that purified flagella were able to interact directly with the lipid molecules found in the membranes of plant cells, and that E. Coli bacteria lacking flagella were unable to do so.
Once attached, the E. Coli is able to grow in and colonise the plant surface. At this point, it can be removed by washing, but the researchers showed that a small number of bacteria are capable of invading the inside of the plant, where they become immune to washing. They also found out how the E. coli O157: H7 is able to colonise the roots of both spinach and lettuce.
"Our long term goal is to better understand these interactions so that we can reduce the risk of foodborne illnesses," explains the director of the study, Nicola Holden.
Researchers believe that the E. coli O157: H7 uses the same method to colonise both the plant surface and the intestines of animals. The study shows that these bacteria are not simply transported through the food chain in an inert condition, but are actively interacting with plants and animals.
Source: hortoinfo.es