'Gatekeepers' open bugs to attack

Bacteria have a canny way of protecting themselves from attack by toxic chemicals, aiding their survival and development. They have small channels in their cell wall, some of which can shut if there is no threat or open to help fight the toxins.

These tiny channels act as molecular ‘gatekeepers’. They control the flow of ions into and out of the cell and in that way safeguard bacteria, including the superbugs, E.coli, Salmonella and Legionella. If the channels could be kept open artificially, bacteria could be killed or their growth hindered.

Stuart Conway from Oxford University’s Department of Chemistry is part of a team studying the survival mechanisms of bacteria. The group’s latest research used synthetic chemicals to open and close the protective channels.

The new study, published in this week's PNAS, reveals that the channels work like molecular switches, sensing the presence of toxic chemicals. Some chemicals keep the channels shut but other chemicals can open them up, helping the bacteria to survive.

When a toxin is detected, the channels open, increasing the acidity, or pH, of the cell, which prevents damage. When the threat has passed, the channels close, allowing the cell to revert back to its normal pH.

Stuart, and colleagues from the University of Aberdeen and University of St Andrews, see the channels as targets for new antibiotic drugs. They hope further research will facilitate the development of alternative treatments to tackle bacteria that are resistant to existing antibiotics.

'We are very excited about applying our chemical tools to the study of fundamental biological problems, which may ultimately allow us to develop new leads for novel antibiotic drugs,' Stuart told us.

Dr Stuart Conway is based at Oxford University's Department of Chemistry.