Treating infections can be challenging because it takes time to figure out if harmful bacteria are present and to figure out which antibiotic would work best. Thankfully, a team of scientists at Britain’s University of Southampton developed a simple, inexpensive, single-use test that answers both questions on the spot. The team published their research and results in the journal Biosensors and Bioelectronics.
Typically, when someone wants to check if they are infected, they go to the doctor and take a blood or urine sample, which gets sent off to a lab for analysis. The results usually take a few days to get back, while doctors prescribe a broad range of antibiotics. However, these medications aren’t as effective as those that target the specific bacteria that are causing the infection. The over-use of antibiotics is also a concern for contributing to the development of antibiotic resistance. Disadvantages such as these inspired scientists to make a better solution.
The device consists of three laser-cut layers, sealed within a plastic case. The top layer contains four commonly-used antibiotics in four small squares, the middle is made of absorbent paper, and the bottom consists of an agar bacteria-culturing gel.
How does it work? The user applies a patient’s biofluid sample to the device’s paper inlet tab; then, they cover the tab with tape to keep it from becoming contaminated or drying out. The fluid soaks through the paper until it reaches all four of the antibiotic squares. The paper will turn blue if there are any harmful bacteria present in the sample. There will be an apparent non-blue spot around any of the squares that contain an antibiotic that is effective against the present bacteria. However, if the test paper is blue, but there are no clear spots, then it means the patient needs another antibiotic.
Dr. Collin Sones, the lead scientist, said:
By enabling doctors to quickly determine if an infection is caused by bacteria, and if the bacteria are resistant to four common antibiotics, this device could cut down on unnecessary antibiotic prescriptions and help fight the growing threat of antibiotic resistance.
When the scientists used the device to analyze artificial urine that contained E. coli bacteria, it was found to be just as reliable as traditional lab tests.
