New test would cut time to show antibiotics resistance

A diagnostic test is being developed by scientists that would cut the time taken to show resistance to antibiotics from “up to two days” to “less than 45 minutes”.

Tests are being carried out. Picture: Kalinovsky Dmitry

In a research paper published in the journal Biosensors and Bioelectronics, the University of Strathclyde team demonstrated the low-cost, rapid diagnostic system.

To prove it could prescribe the correct antibiotic to a patient for an infection more quickly, the scientists examined the difference in growth profiles between staphylococcus aureus and MRSA.

While the former is a common hospital-acquired bacterial infection sensitive to antibiotics, MRSA can be harder to treat.

Both strains were placed on to electrodes covered in a special hydrogel deposit and the susceptible strain could not grow when the sensor was seeded with antibiotic.

The paper’s lead author, Dr Stuart Hannah, said: “There is a small difference between what makes an organism susceptible to an antibiotic and what makes it resistant.

“In real terms, we were able to distinguish between the two strains in less than 45 minutes, which is a significant improvement on the current gold standard of up to two days.

“The technology uses a low cost, commercially available sensor which acts like a mini culture dish that can deal with any kind of clinical sample.

“The system is modified with a special gel deposit so that we can identify the difference between susceptible and resistant forms of common bacteria.

“Rapid result detection means you could pinpoint bacterial versus viral infections straight away and would be able to start working on the correct treatment more quickly for patients, which is very important for particular infections.”

It is now hoped the test could be used by pharmacists and other points of care, as well as being developed for commercial use.

Dr Hannah suggested all the materials used “can be mass manufactured, which means that it is cheap to produce a working test”.

He added: “With the right commercial backing, a future device could be used at a GPs’ surgery, where they could effectively take a blood sample and do the test and have results within the hour, rather than sending samples to a laboratory and have to wait for a positive result.”