Being able to quickly confirm the presence of infectious bacteria in a patient’s bloodstream, and then identifying the specific species and strain, can make the difference between life and death for that patient. While traditional detection and identification methods are fairly accurate, they can also take too long to perform. A chemist from the University of Illinois, however, has developed an inexpensive new system that is much quicker – and it works by sniffing out the harmful bacteria.
Hospitals typically test for infectious bacteria by incubating blood samples in vials for 24 to 48 hours, at which point a carbon dioxide sensor in the vial indicates whether or not bacteria is present. After that, however, it is still necessary to determine what type of bacteria it is, and that process can take up to one more day. “In 72 hours they may have diagnosed the problem, but the patient may already have died of sepsis,” said U Illinois’ Prof. Ken Suslick.
To address the problem, Suslick developed a so-called “artificial nose.” More specifically, it’s a system incorporating cards printed with an array of 36 cross-reactive pigment dots, that change color as they detect chemicals in the surrounding air – chemicals such as those produced by metabolizing bacteria, which some microbiologists can distinguish between simply using their sense of smell.