New strategy to kill bugs -- even those in hiding

In a paper, which appeared this month in the Institute of Electrical and Electronics Engineers (IEEE) Transactions on Evolutionary Computing, Dr Ole Steuernagel and Dr Daniel Polani from the University's Science and Technology Research Institute describe how to apply antibiotics to wipe out bacteria that form active as well as inactive subpopulations.

"One of the difficulties of applying antibiotic strategies against bugs is that some of the microbes tend to go into hibernation," said Dr Steuernagel. "Although the medication can wipe out the active populations, it often misses the hibernating ones because they are metabolically inactive. It may not be enough just to kill off the active bacteria, the hibernating rest will 'wake up' and reestablish themselves."

Through use of an optimization approach called 'multiobjective optimization' that is tailored to such multifaceted scenarios, the researchers found that the best solution is to kill the microbes early and late during the therapy period, but not during the intermediate period.

"This is the first time that this approach has been used in a bug eradication scenario and our solutions should be more efficient than existing approaches to kill hibernating bugs," said Dr Steuernagel. "Current practice does not take account of persistence due to hibernation although this may well be a problem. After all, microbes which are known to hibernate include Escherichia coli, multiply resistant Staphyloccus aureus (MRSA -- "superbug"), Mycobacterium tuberculosis, Pseudomonas aeruginosa."