Smartphones are ubiquitous in today’s world. So much so that scientists have actively incorporated them into their research, whether it’s using Bluetooth and mobile apps to control lab instrumentation from afar or designing attachments to turn the phone into a powerful $1 microscope.
In the latest example, biological engineers from the University of Bath have developed a test that can quickly diagnose urinary tract infections (UTIs) using a normal smartphone camera.
The World Health Organization estimates UTIs account for more than 8 million office visits to physicians and more than 1 million hospitalizations per year in the United States. Despite the regularity of these infections, there is still not a quick, efficient way to confirm diagnosis. Clinicians can take a sample and send it to a centralized microbiology lab, which can take several days to get results, or they can use a urinalysis test strip that gives an indication of bacterial infection, but does not have the capability to reveal the exact infectious microorganism. This situation often leads to the over-prescription of antibiotics, increasing the risk of an individual’s bacteria becoming resistant to treatment.
Nuno Reis, professor at the University of Bath (UK), has pioneered a new test that works with a smartphone camera to provide a UTI diagnosis immediately.
The test works by passing a urine sample over a ridged plastic micro-capillary strip, containing an immobilizing antibody that recognizes E. coli, which is found in 80 percent of UTIs. If E. coli cells are present in the sample, antibodies in the reagents will bind to it, stopping it from passing the strip. Then, an enzyme is added that causes a color change, which can be picked up by any smartphone camera.
"The smartphone solves one of the biggest problems of the decentralizing of diagnostics because their capabilities are actually very sophisticated in certain conditions. They offer the same functionality as sophisticated scanners that have until now been available only in labs," Reis told Laboratory Equipment.
The system can also measure the concentration of E. coli in the sample by analyzing an image taken by a smartphone. The procedure is simple, relying on widely available reagents, and does not necessitate a power supply—making it an ideal solution for developing and poorer nations.
“The test strips can be manufactured cheaply and there is no need for a dedicated reader— a smartphone does that,” said Reis. “This eliminates economic barriers for adoption of the technology. It also offers high-performance testing in a format that is easily accessible.”
Before moving into clinical trials, Reis said he and his team are expanding the test to detect other gram-negative and gram-positive pathogens relevant to UTIs. The test strips already contain multiple capillaries, so it is just a matter of manufacturing each capillary to identify a different pathogen. Reis is also seeking to integrate the strip with antibiotic susceptibility testing.
Photo credit: University of Bath