Hopes quicker urinary infection test will help fight against resistant superbugs


A new urinary infection test, which can produce results in four hours, is expected to aid the fight against resistant superbugs.

Traditional culture methods take two to three days to identify bacteria and test their drug resistance from a urine sample.

The new MinION nanopore test developed at the University of East Anglia (UEA) can provide the answers in as little as four hours after a sample is taken.

A quicker test will allow rapid precise tailoring of treatment for patients with resistant infections, it is claimed. This is turn will help combat the spread of antimicrobial resistance, a major emerging threat to public health.

Professor David Livermore, from UEA's Norwich Medical School, said: "Identifying specific pathogens and resistance to antibiotics as quickly as possible is the key to reducing the number of patients who are 'over treated' with broad-spectrum antibiotics while waiting for results to come through from the micro lab - a process that presently takes a couple of days.

"This 'carpet-bombing' approach - of giving a broad spectrum antibiotic whilst you wait for results - leads to poor antibiotic stewardship. It's vital that we move beyond it.

"The way to do so lies in accelerating lab investigation. That way, treatment can be refined earlier. This will benefit the patient, who gets an effective antibiotic, and society, whose diminishing stock of antibiotics is better managed."

Urinary tract infections (UTIs) are one of the most common reasons why patients are prescribed antibiotics. While most are mild, serious infections can lead to a time in hospital and even threaten life.

The MinION device measures changes of electric current as biological molecules, such as DNA, pass through tiny holes in a polymer membrane. This makes it possible to identify DNA sequences and proteins.

A study comparing the effectiveness of MinION and standard methods of testing for urinary infections is reported in the Journal of Antimicrobial Chemotherapy.

Dr Justin O'Grady, from Norwich Medical School, said: "This study is the first to use MinION sequencing to rapidly diagnose pathogens and antimicrobial resistance in clinical samples, without growing them. Improvements in the sequencing technology, data analysis and sample preparation mean we've reduced the turnaround time to four hours.

"Getting results this fast would allow clinicians to adjust antimicrobial very early, even before the second dose is given - most antibiotics are given around once every eight hours."

A number of challenges remain, the researchers point out. The test currently requires heavily infected urine and is best suited to difficult cases.

The device is also unable to spot when mutations in existing genes produce new forms of drug resistance.

Dr O'Grady added: "The technology is developing rapidly and we expect to overcome these limitations in the near future."