Urinary tract infections (UTIs) affect 150 million people a year, with symptoms ranging from discomfort to fever and even confusion. Health care costs can run to US$3.5 billion each year. Suspected UTIs are among the most common causes of visits to primary care settings, and it can take up to three days to get a definitive diagnosis.
Scientists led by PhD student Linda K. Nartey in the Goodlett lab at the University of Victoria have developed a faster and more accurate way to identify these infections, which means faster, more effective treatment and relief for the people suffering the symptoms.
The new technique looks for specific lipids from bacterial cell membranes; it takes an hour. And even better, it's more accurate than the current method. With a much lower false-positive rate, it can rule out a UTI with 99 per cent accuracy."
Linda K. Nartey, PhD student and lead author of the study
Improving on tradition
Traditional diagnosis of UTIs begins with a quick dipstick check for certain chemicals, explains David Goodlett, biochemistry professor and director of the UVic Genome BC Proteomics Centre. If those are present, there's probably an infection and the sample is then cultured to grow the bacteria and identify the species by proteomics. After that, an appropriate treatment can be determined. Altogether, the process can take 24 to 72 hours.
In an article published in the Journal of Clinical Microbiology in October 2024, Nartey, Goodlett, Chen and colleagues reported that using lipids to identify the presence and species of bacteria was faster, more accurate and more precise than the conventional technique.
This is the first time the method has been used in a blind study on clinical samples, and clinicians are very interested in translating it to broader use.
"For many years, identifying pathogens in urine has been a lengthy process," says Michael Chen, a physician and head of medical biochemistry at Island Health, and the clinical partner for this research. "We're looking for novel ways to improve diagnostic process by reducing time to diagnosis for better patient outcome."
Benefits for people and planet
While the speed and accuracy of the initial lipidomics test can save time, money and patient uncertainty, a positive result must still be cultured to identify the specific organism. At the same time, there are environmental upsides. Because there are fewer false-positive samples that must be cultured, there's reduced use of plastic test equipment and reagents, for example.
The lipidomics-based method does require a mass spectrometer, which is already available in the core laboratories used for protein-based pathogen identification but not in all clinical settings. However, Goodlett maintains that for physicians and patients within reach of a facility that has one, the technique can save time and other resources.
The published method, they found, does not detect Gram-positive bacteria as efficiently as it does Gram-negative, so the team developed an additional step to ensure that the presence of both types of microbes can be captured. Nartey is writing a further paper on the enhanced method and another clinical cohort will be tested for the new process. Nartey and Chen are also writing a case study on the decrease in single-use plastics and energy consumption with the innovative method.
"The quality of the technique, its cost effectiveness and benefits to the environment and to patients," says Chen, "these are important to both academia and health care. Ultimately, it makes a positive contribution to society."
