A small handheld device the size of a USB stick, developed by researchers at McMaster University in Canada, can accurately detect bacterial urinary tract infections in minutes after analyzing a droplet of urine.
The electronic device works in a similar way to a blood-glucose monitor and also has the potential to analyze other bodily fluids such as blood or saliva.
This study, led by Yingfu Li, a professor of biochemistry and biomedical sciences, and Leyla Soleymani, an associate professor in engineering physics, produced a proof-of-concept prototype which was tested for its ability to detect urinary tract infections. But the team thinks that the test can be adapted to detect other bacterial infections and even viruses.
“It’s going to mean that patients can get better treatment, faster results and avoid serious complications. It can also avoid the unnecessary use of antibiotics, which is something that can buy us time in the battle against antimicrobial resistance,” says Soleymani, co-corresponding author on the paper describing the research published in Nature Chemistry, in a press statement.
Currently, detecting the presence of a bacterial infection requires time and dedicated lab equipment. Samples have to be cultured and the bacterial DNA amplified, for example via PCR. This new test can be done in under an hour and the test does not need to be sent to a lab.
The new device detects the presence of a specific type of bacteria in a sample using electroactive RNA-cleaving DNAzymes (eRCDs) integrating into a two-channel electrical chip. The enzymes recognize and cut the bacterial DNA at certain sites releasing a DNA barcode that triggers an electronic signal on the chip inside the device. When connected with a smartphone it can provide a results readout.
The device is sensitive and able to detect low levels of pathogenic Escherichia coli (10 colony forming units) from a panel containing many different bacterial species.
In a trial of the prototype on urine samples from 41 patients with known infection status, the device had an ability to detect all patients with the condition (sensitivity) of 100%. The tests’ ability to detect patients without bacterial infection (specificity) was a bit lower at 78%, suggesting it may detect some false positive cases.
The prototype device showcases how collaborative working between specialties can help solve medical problems. “Clinicians identified testing delays as a problem that needed to be resolved,” says Soleymani. “We wanted to build a system that could give as much information as possible to the physician during the patient’s first visit.”
“This will give doctors the science to support what they already suspect based on their skills and experience,” adds Li.
The team behind the device now want to test it further for bacterial detection and are exploring industry partnerships to try and speed up the future rollout of a final version of the device. They are also currently testing the technology for detection of the SARS-CoV-2 virus.
“This technology is very versatile and we’re getting very close to using the same technology for COVID-19 testing,” says Li.