A Plymouth scientist is developing a test to help doctors decide whether a patient really needs antibiotics.
Microbiologist Dr Tina Joshi is working on a device to speed up the diagnosis time for bugs and recommend treatments.
She says it could halve the number of antibiotics being prescribed.
When antibiotics were introduced in the 1940s, they were hailed as a "wonder drug".
But there are major concerns that over-prescription has led to increasing resistance to treatments.
Dr Joshi says in the last 70 years there have been no changes in diagnosis techniques...