Fidget Spinner Rapidly Detects Urinary Tract Infections

More than half of all women experience at least one episode of urinary tract infection (UTI) in their lifetime, with men also facing increasing risks of infection as they age. Current detection of UTIs relies on patients reporting symptoms followed by a laboratory culture of the urine for known bacterial culprits, which typically takes a few days.

Doctors tend to prescribe antibiotics to suppress any suspect cases of UTI before they get the test results, contributing to the increasing problem of antibiotic resistance. Dipstick tests that reduce the time taken for diagnoses come with a high chance for false positives. The point-of-care detection of pathogens in biological samples in resource-limited settings should be inexpensive, rapid, portable, simple and accurate.

A multidisciplinary and international team of scientists led by the Ulsan National Institute of Science and Technology (Ulsan, Republic of Korea) developed a fidget spinner-based device to detect UTIs from urine samples. The device was field tested on 39 patients in Tiruchirappalli, India who would have all been given antibiotics based on their symptoms alone. The team reported 59% of the patients were found to be over/under-treated with antibiotics, something that can be rectified using this novel device.

The custom-made fidget spinner rapidly concentrates pathogens in 1-mL samples of undiluted urine by more than 100-fold for the on-device colorimetric detection of bacterial load and pathogen identification. The test of the rectangular device with one or two nudges spins for a long time pushing any bacteria onto a membrane. This is then dyed, with a color change visible to the naked eye in less than one hour, which indicates the amount of bacterial load.

The device enabled the on-site detection of infection with the naked eye within 50 minutes in urine samples from the patients suspected of having a urinary tract infection. The team also showed that, in 30 clinical samples of urinary tract infection, the device can be used to perform an antimicrobial susceptibility test for the antimicrobial drugs ciprofloxacin and cefazolin within 120 minutes.

Another test gave a preliminary indication of the presence of antibiotic resistance. By testing the spun samples treated with different drugs and comparing them to untreated samples, the team was able to quickly make a decision on which antibiotic might work best to treat the UTI. While this does not compare to laboratory based tests for microbial resistance, it is still a useful add-on for resource poor settings that do not typically test for resistance.

The authors concluded that the test can be performed by novices and that there is no extensive training that is required to learn how to spin the device and read the results. The ease-of-use, low price point, availability of quick results, and immediate benefits such as reduction in prescription of antibiotics, makes the new spinner an attractive alternative for diagnosing UTIs. The study was published on May 18, 2020 in the journal Nature Biomedical Engineering.

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Ulsan National Institute of Science and Technology