Clever bacteria evolves to survive

Researchers at the University of Sheffield have discovered vital information about how bacteria manage to survive in an enormous range of habitats, including human beings.

The team of scientists, led by Professor Jeff Green from the University of Sheffield´s Department of Molecular Biology and Biotechnology, has shown that a protein found in the bacterium E. coli, can sense the presence of oxygen.

Some strains of E. coli can cause food poisoning in humans, and this research has provided a vital insight into how this bacterium manages to survive in our bodies. The most recent outbreak of E. coli in the UK, which occurred in Wales in 2005, killed one boy and made 156 people ill. The findings of an official report into this outbreak are due later today (Thursday 19 March 2009).

The research findings, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), revealed the important mechanisms by which bacteria adapt to environmental changes associated with disease. The E. Coli bacterium is commonly found in our intestinal tract, which has an absence of oxygen. A protein in the bacterium is able to switch on specific genes in the absence of oxygen, to help it survive. It can additionally switch off these genes when it is exposed to oxygen.

Professor Jeff Green said: "Our research findings present an exciting breakthrough in our understanding of how bacteria manage to survive. E. Coli can cause serious food poisoning in humans, and it is vital to increase our understanding of how the bacteria operates. The work has shown that evolution can use a basic framework, and through mutation, it can generate variants that can be selected to operate over widely different ranges of oxygen availability. This has implications for the ability of bacteria to survive and thrive in an enormous range of habitats, including human beings."

The research was published in the Proceedings of the National Academy of Sciences.