A strain of bacteria that causes potentially fatal food poisoning exerts its effect through interacting with 'friendly' bacteria and stress hormones.

Researchers at the University of Texas have been studying how a dangerous bacterium called enterohemorrhagic Escherichia coli (EHCC) exerts its effects. EHCC, which is transmitted through contaminated food and water, causes bloody diarrhea and may lead to kidney failure. In the USA, there are 73,000 cases of EHCC infection each year, causing 61 deaths.

The team found that the EHCC bacteria travel through the digestive tract until they reach the intestine. Here an interaction between the natural 'friendly' gut bacteria, the stress hormone epinephrine, and EHCC leads to activation of many different genes in the latter. These release toxins which cause the symptoms of bloody diarrhea. The researchers think they could break up this interaction using beta-blockers - drugs more often used to treat high blood pressure and heart failure. This would be a better treatment for EHCC infection than antibiotics, which tend to worsen the tendency to kidney failure.

Source

Proceedings of the National Academy of Sciences 30th June 2003