 |
| Image created by Dr. Michael J. Miller |
The method uses rapid DNA sequencing to identify organisms causing the infections and predict antibiotic resistance. This advancement is expected to improve care for sepsis patients and help reduce unnecessary antibiotic use. Currently, up to 245,000 people develop sepsis each year in the UK, with 48,000 of those dying as a result.
The current practice involves growing bacteria from a blood sample, a process that takes between one to three days. Once the bacteria are grown, they are tested against different antibiotics to determine which ones are effective.
The new method, developed by a team supported by the NIHR Biomedical Research Centre (BRC): Oxford, uses genetic sequencing to identify bacteria in real time.
This allows doctors to know within hours which antibiotics will be effective.
The study was led by Professor David Eyre, Professor of Infectious Diseases at the University of Oxford’s Big Data Institute.
Professor Eyre explained: “We know that treating these bloodstream infections rapidly is vital to increase the chances of survival.
“But clinicians often need to start giving antibiotics before the lab results are available.
“All too often, the first antibiotics given to a patient do not kill the bacteria, so we need to change antibiotics, which delays patients getting the most effective treatment.”
The team utilised an Oxford Nanopore sequencing device to read all the DNA in a positive blood sample.
This enabled them to identify the infecting organism and look for known genetic markers of antimicrobial resistance.
Dr Kumeren Govender, co-author and BRC Oxford researcher, said: “In nearly 300 samples, we showed that this was a highly accurate method for finding the bacteria that standard lab testing found, and it did this much quicker than standard testing –around three and a half hours after we first detected bacteria growing, instead of 12.
"We were also able to identify resistant infections 20 hours faster than the current standard testing.”
This study was the largest of its kind to use metagenomic sequencing on routine blood samples in a clinical setting.
In addition to the common pathogens found by routine testing, this sequencing approach identified 18 additional bacteria that standard testing had not previously found.
Professor Eyre, who also co-leads the NIHR BRC: Oxford’s Modernising Medical Microbiology and Big Infection Diagnostics Theme, said these findings demonstrate the potential of sequencing to improve diagnosis of bloodstream infections and inform decisions about the most effective antibiotic treatments.
His team will now conduct another BRC Oxford-supported study comparing this sequencing method with four other potential new methods for identifying pathogens or antibiotic resistance in bloodstream infections.
The team will also carry out a national survey of NHS hospitals to determine where these tests might have the most benefit for patients, alongside a health economics study to estimate which technology or technologies provide the best value for money for the NHS.