Artificial nose to identify bugs
Sunday 8th September 2013, 8:10PM BST.
An artificial nose that can swiftly sniff out blood poisoning bacteria has been developed by scientists.
The device can test for the bugs in just 24 hours instead of the usual 72 – a difference that could save lives.
Researchers hope it can be used to prevent sepsis, a potentially fatal condition that occurs when the immune system overreacts to infectious bacteria spreading through the body.
In some cases it can rapidly lead to septic shock, organ failure and death. An estimated 20% and 35% of victims of severe sepsis die.
The new device consists of a small plastic bottle with a chemical sensing array (CSA) or “artificial nose” attached to the inside.
A blood sample is injected into the bottle which is then shaken to agitate a nutrient solution and encourage bacteria to grow.
Signature odours released by the bugs change the colours of 36 pigment dots on the sensor. Different patterns of colours correspond to different bacteria strains.
Dr James Carey, from the National University of Kaohsiung in Taiwan, said: “We have a solution to a major problem with the blood cultures that hospitals have used for more than 25 years to diagnose patients with blood-borne bacterial infections.
“The current technology involves incubating blood samples in containers for 24 to 48 hours just to see if bacteria are present.
“It takes another step and 24 hours or more to identify the kind of bacteria in order to select the right antibiotic to treat the patient. By then, the patient may be experiencing organ damage, or may be dead from sepsis.”
Dr Carey, who worked with US colleagues from the University of Illinois, presented the research at the 264th national meeting of the American Chemical Society in Indianapolis.
An earlier device could detect odours from bacteria only after the bugs were first growing in laboratory culture dishes.
The new “nose” takes less time to grow the bacteria and is more sensitive.
Currently it can identify eight of the most common disease-causing bugs with almost 99% accuracy under clinically relevant conditions, said Dr Carey.
The scientists are working to expand the nose’s capabilities so that it can detect other kinds of sepsis-triggering microbes.
But even the existing device has the potential to curb the toll of sepsis, especially in developing countries or areas with few medical facilities, they claim.
“Our CSA blood culture bottle can be used almost anywhere in the world for a very low cost and minimal training,” said Dr Carey.
“All you need is someone to draw a blood sample, an ordinary shaker, incubator, a desktop scanner, and a computer.”