Millions of people in the U.S. and around the world suffer from urinary tract infections every year. Some groups are especiallyprone to chronic UTIs, including women, older adults, and some veterans.
These infections are typically treated with antibiotics, butoverusing thesedrugscan make the microbes they target resistant and reduce the medicines†effectiveness.
To solve this problem of chronic UTIs and antibiotic resistance, we combined our expertisein microbiologyand engineering to create a living material that houses a specific strain of beneficialE. coli. Our research shows that the“good†bacteria released from thisbiomaterialcan compete with “bad†bacteria for nutrients and win, dramatically reducing the number of disease-causing microbes.
With further development, we believe this technique could help manage recurring UTIs that do not respond to antibiotics.
Bringing Bacteria to the Bladder
For the microbes living in people, nutrients are limited, and their presence varies between different parts of the body. Bacteria have tocompete with other microbes and thehostto acquire essential nutrients. By taking up available nutrients, beneficial bacteria canstop or slow the growth of harmful bacteria. When harmful bacteria are starved of important nutrients, they arenâ€t able to reach high enough numbers to cause disease.
Delivering beneficial bacteria to the bladder to prevent UTIs in challenging, though. For one, these helpful bacteria can naturally colonize only in people who areunable to fully empty their bladder, a condition called urinary retention. Even among these patients, how long these bacteria can colonize their bladders varies widely.
Current methods to deliver bacteria to the bladder are invasive and requirerepeated catheter insertion. Even when bacteria are successfully released into the bladder,urine will flush out thesemicrobesbecause they cannot stick to the bladder wall.
This microscopy image shows the bladder of a mouse (blue) covered with E. coli (pink) and the white blood cells (yellow) attacking them. (Credit: Valerie Oâ€Brien, Matthew Joens, Scott J. Hultgren, James A.J. Fitzpatrick, Washington University, St. Louis/NIH via Flickr, CC BY-NC)
Biomaterials to Treat UTIs
Since beneficial bacteria cannot attach to and survive in the bladder for long, we developed a biomaterial that could slowly release bacteria in the bladder over time.
Our biomaterial is composed of livingE. coli embedded in agel matrix structure. It resembles a piece of jelly about 500 times smaller than a drop of water and can release bacteria for up to two weeks in the bladder. By delivering the bacteria via biomaterial, we overcome the need for the bacteria to attach to the bladder to persist in the organ.
We tested our biomaterial by placing it in human urine in petri dishes and exposing it to bacterial pathogens that cause UTIs. Our results showed that when mixed in a 50:50 ratio, theE. coli outcompeted the UTI-causingbacteriaby increasing to around 85% of the total population. When we added moreE. coli than UTI-causing bacteria, which is what we envision for future development and testing, the proportion ofE. coli increased to over 99% of the population, essentially wiping out the UTI-causing bacteria. Moreover, the biomaterial continued to releaseE. coli in human urine for up to two weeks.
Our findings suggest thatE.coli could stick around and survive in the bladder for extended periods of time andsuccessfully decrease thegrowthof many types of bacteria that cause UTIs.
UTIs can be painful.
(Credit: Images we create and what actually happens are always beautiful when we have imagination/iStock via Getty Images Plus)
Improving Biomaterials
Our findings show thatE. coli can not only control harmful bacteria itâ€s closely related to but also abroad range of disease-causingbacteriain humans and animals. This means scientists might not need to identify different types of beneficial bacteria to control each pathogen – and there are many – that can cause a UTI.
Our team is currently evaluating how effectively our biomaterial can cure UTIs in mice. We are also working to identify the specific nutrients that beneficial and harmful bacteria compete over and what factors may help beneficial bacteria win. We could add these nutrients to our biomaterial to be released or withheld.
This research is still at an early stage, and clinical uses are not in development yet, so if it does reach patients, it will be well in the future. We hope that our technology could be refined and applied to control other bacterial infections and somecancers caused by bacteria.
Sarguru Subash is an Associate professor at Texas A&M University. This article is republished fromThe Conversation under aCreative Commons license. Read theoriginal article.
