The findings, published in PLoS Biology, could point to new ways to use existing treatments to tackle diseases that are rapidly developing resistance to current antibiotics.
The researchers compared the efficacy of combination treatment – two antibiotics prescribed simultaneously – with a sequential treatment in which the antibiotic could change at each round of treatment.
The lab-based study was carried out on E.coli that had a propensity for genetic resistance to the two antibiotics used – erythromycin (a macrolide) and doxycycline (a tetracycline).
The researchers found that sequential treatment could eliminate the bacteria at dosage levels so low that they would normally be ineffective used alone or in combination treatment.
Dr Andrew Green, GPC clinical and prescribing lead, said: ‘It is absolutely true that we are more aware of antibiotic resistance than ever before.
‘Most GPs will remember the surprise the first time they came across a little old lady who’s never been near a hospital, with a multi-resistant UTI, and now it’s not uncommon.’
New methods to treat bacterial disease were ‘welcome’, but further study was required before the sequential treatment was recommended for everyday practice, he added.
‘This study is purely lab-based, and in the human body both bacteria and antibiotics behave in very different ways to how they do in the laboratory.’