New urinary microbiome study could be first step in providing personalized care to patients with ureteral stents


LONDON, ONTARIO - For patients with kidney stones, ureteral stents (hollow devices placed in the ureter – the tube between the kidney and bladder) can be used temporarily to relieve urinary obstruction. Despite the use of antibiotics, ureteral stents often become encrusted with minerals and coated with bacteria. This can lead to complications like infection and the need for replacement surgery. 

Published today in Cell Reports Medicine, researchers at Lawson Health Research Institute and Western University conducted a novel microbiome study to examine bacteria associated with ureteral stents. They found that nearly all the stents, whether visibly coated or not, had unique bacterial profiles that were most associated with a patient’s medical condition rather than antibiotic use. For patients with ureteral stents, they may benefit from a personalized approach to care and antibiotic treatment. 

The study included 241 patients from St. Joseph’s Health Care London. The research team collected and analyzed patient urine samples and ureteral stents following surgical removal, as well as relevant patient information such as antibiotic use and history of infections.  

“We wanted to know which bacteria were present and whether the bacteria found in urine samples corresponded to the bacteria found on a patient’s stent,” explains Dr. Kait Al, Postdoctoral Fellow at Lawson and at Western’s Schulich School of Medicine & Dentistry. “We found that there was a bacterial community present on almost all stents, even if they were not visibly affected, and that it differed from the bacterial community found in a patient’s urine.”

These findings challenge long-held beliefs that the urinary tract is a sterile environment devoid of bacteria.

The study revealed that the bacteria present were determined by an individual patient’s medical condition. They differed significantly based on comorbidities like irritable bowel syndrome, obesity and hypertension. Antibiotic use within the past 30 days did not seem to have an effect on the types of bacteria detected on the stents. 

“While more research is needed, our study suggests that antibiotic use during the placement of these stents could one day be more conservative or targeted based on each patient’s condition,” says Dr. Jeremy Burton, Lawson Scientist and Associate Professor at Schulich Medicine & Dentistry.

The team also discovered that in patients needing multiple stents, the bacterial community remained stable over time, suggesting that infections on a patient’s previous stent could direct the course of treatment for their future device placements. 

“This is the largest study of its kind, investigating bacteria both in urine and adhered to ureteral stents,” states Dr. Hassan Razvi, Urologist at St. Joseph’s, Lawson Associate Scientist and Professor at Schulich Medicine & Dentistry. “We hope this will be the first step towards personalized care, ultimately leading to fewer stent-associated infections.” 

The study was made possible through the generous support of The W. Garfield Weston Foundation and St. Joseph’s Health Care Foundation.




Microscopy image of stent


Microscopy image of stent

Scanning electron microscopy images showing organic material, crystals, and bacteria present on the surface of the ureteral stents.


Encrusted stent

Recovered ureteral stent encrusted with minerals and bacteria. 


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About Lawson Health Research Institute

Lawson Health Research Institute is one of Canada’s top hospital-based research institutes, tackling the most pressing challenges in health care. As the research institute of London Health Sciences Centre and St. Joseph’s Health Care London, our innovation happens where care is delivered. Lawson research teams are at the leading-edge of science with the goal of improving health and the delivery of care for patients. Working in partnership with Western University, our researchers are encouraged to pursue their curiosity, collaborate often and share their discoveries widely. Research conducted through Lawson makes a difference in the lives of patients, families and communities around the world. To learn more, visit

About Western

Western delivers an academic experience second to none. Since 1878, The Western Experience has combined academic excellence with life-long opportunities for intellectual, social and cultural growth in order to better serve our communities. Our research excellence expands knowledge and drives discovery with real-world application. Western attracts individuals with a broad worldview, seeking to study, influence and lead in the international community.

About The Schulich School of Medicine & Dentistry

The Schulich School of Medicine & Dentistry at Western University is one of Canada’s preeminent medical and dental schools. Established in 1881, it was one of the founding schools of Western University and is known for being the birthplace of family medicine in Canada. For more than 130 years, the School has demonstrated a commitment to academic excellence and a passion for scientific discovery. 

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