Half an hour instead of three days

A test has been developed that quickly determines the effectiveness of antibiotics

Nika Schultz, Faina Idea

Bacteria are developing antibiotic resistance at an alarming rate, and according to a report published last year, these so-called superbugs will kill 10 million people a year by 2050. One of the main issues is the speed of prescribing a new antibiotic when the prescribed medication is incapacitated, and now a new test developed by scientists can help doctors quickly prescribe the best type of antibiotic to fight a specific infection.

Preventing a return to the "dark ages of medicine" is a top priority for healthcare organizations, and researchers are developing a whole arsenal in the war against superbugs. New gels and materials can kill them more effectively, while other methods include improving existing drugs or neutralizing bugs. And, of course, the key strategy remains the search and development of new antibiotics.

According to researchers from the California Institute of Technology (Caltech), when treating bacterial infections in patients, doctors tend to ignore first-line antibiotics and prescribe more powerful drugs immediately. They do this because of the high probability that weak drugs simply will not work, but this practice develops resistance to the second line of antibiotics in bacteria. And scientists warn that this last line of defense is beginning to fail.

Instead of doctors simply assuming that first-line antibiotics won't work, the Caltech team's test will allow them to quickly identify which bacteria are causing a particular infection and prescribe the appropriate medication. As a rule, this kind of analysis can take up to three days, but a new analysis can be completed in 30 minutes, that is, within one visit to the doctor.

Drawings from press releases published on ScienceDaily (1) and EurekAlert! (2) portals – VM.

The researchers focused on urinary tract infections to develop the test. To test the resistance of any bacteria that may be present, the doctor first takes a urine sample from the patient. Half of the sample is exposed to an antibiotic for 15 minutes, while the other half is tested without adding any drugs. Then the bacteria from both samples go through the process of searching for specific DNA markers. This process combines a method of detecting markers using a device called SlipChip. In fact, the target DNA markers will appear on SlipChip in the form of fluorescent green spots, and the fewer of them there are, the more effective the antibiotic works.

If the treated and untreated samples have the same number of points, the drug clearly had no effect. But if significantly fewer spots appear in the treated sample, then this antibiotic can be prescribed to the patient, saving second-line drugs for more urgent cases.

Using 54 urine samples from E. coli patients, the researchers compared their test results with a standard test, which usually takes two days. Their new method showed a 95 percent match with the results of the existing test.

Article by Schoepp et al. Rapid pathogen-specific phenotypic antibiotic susceptibility testing using digital LAMP quantification in clinical samples is published in the journal Science Translational Medicine – VM.

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