A recently published research report from a team at the UK Institute of Food Research reveals that populations of E. coli isolated from plants are subtly different from those found in the guts of animals. The findings suggest ways that the bacteria have adapted to different environments.
The researchers compared more than 100 isolates taken from the leaves of cultivated vegetables in the UK with a standard reference collection derived from mammals and humans worldwide. They found that the E. coli populations on plants were diverse and complex, but also differed significantly from other populations.
The main difference was found to be the ability to form biofilms, which was much greater in isolates from plants. Plant populations also produced more of the components used to construct biofilms and metabolised plant-derived sugars more readily than isolates from mammals, although less growth was observed with other common carbon sources.
The report authors suggest that biofilms could protect the bacterial cells from desiccation and other stresses and help them survive in harsh environments. They also concluded that environmental conditions have a selective effect on the evolution of different phylogenetic groups of E. coli. It is hoped that understanding more about the way E. coli populations colonise plants will help prevent future food poisoning outbreaks associated with fresh produce.
The report is published in the journal Environmental Microbiology and an abstract can be found here.