Faster diagnosis of antibiotic-resistant infections

Australian researchers have pioneered a faster method for finding the best antibiotic to treat an infection, in a breakthrough with the potential to save lives and preserve the usefulness of antibiotics.

Currently, doctors must wait for researchers to grow a big enough sample of bacteria before they can determine whether it will respond to antibiotic treatment or not — a task which can take 2–6 days. Patients with serious infections cannot wait that long for treatment, so doctors must prescribe broad-spectrum antibiotics while they wait for lab results. This is leading to the rise of antibiotic-resistant superbugs.

In a project led by the Harry Perkins Institute of Medical Research, the researchers developed a way of determining antibiotic susceptibility for a patient’s individual strain of bacteria in a matter of hours, rather than days. As noted by lead researcher Kieran Mulroney (pictured), it’s important that doctors can identify the appropriate treatment to prescribe as soon as possible.

“For patients with serious infections, every hour without appropriate antimicrobial treatment can mean as much as a 10% increase in risk of mortality,” said Mulroney. “If we can treat them with appropriate antibiotics 21 hours faster, the chance of that patient surviving is much higher.”

Published in the journal Scientific Reports, the new method involves taking a small number of bacteria and exposing them to antibiotics for a short window of time.

“Then we use an instrument called a flow cytometer to look at individual bacterial cells and determine the damage the drug is doing,” Mulroney explained. “We can accurately measure the level of drug resistance, and from that provide an answer for doctors about the correct drug to use.”

Mulroney hopes his team’s invention can be optimised for use in clinics soon to help reduce the threat of antibiotic resistance. The most recent estimates suggest that if we do not take action against this serious threat to public health, as many as 250 million people may die by 2050.