Device may detect urinary tract infections faster

August 11, 2015, American Institute of Physics
Workflow of the Lab-on-a-Disc device. Credit: Ute Neugebauer/ Jena University Hospital

Urinary tract infections can quickly move from being a merely miserable experience to a life-threatening condition. Untreated cases may trigger sepsis, which occurs when the immune system, in an attempt to fight off the infection, inadvertently activates body-wide inflammation that can cause blood clots and leaky blood vessels.

Sepsis is a major killer and accounts for about half of the hospital deaths in the US by some estimates. Hospital patients often acquire via infected catheters and so untreated infections are a huge problem faced by healthcare providers around the world. Early diagnosis could save lives and reduce healthcare costs. With this motivation in mind, a team of researchers in Germany and Ireland set out to speed up the detection process for bacteria that cause infections.

In the journal Biomicrofluidics, from AIP Publishing, the team describes creating a Lab-on-a-Disc platform that combines microfluidics and Raman microscopy, a modern optical detection method.

Their medical diagnostics device is designed to harness centrifugal force—akin to the circular swing of a "Chair-o-Plane" carnival ride, in which a fast rotation creates a force that causes the seats to drift radially away from the ride's center—to capture the tiny bacteria directly from patients' samples of bodily this case, urine.

The work involves extremely small sample sizes, on the scale of a small raindrop, so the device needed to be a microfluidic one.

"Our device works by loading a few microliters of a patient's urine sample into a tiny chip, which is then rotated with a high angular velocity so that any bacteria is guided by through microfluidic channels to a small chamber where 'V-cup capture units' collect it for optical investigation," explained Ulrich-Christian Schröder, a Ph.D. student at the Jena University Hospital and Leibniz Institute of Technology in Germany.

The team's concept then adds Raman spectroscopy to its centrifugal microfluidic platform. "Raman spectroscopy uses the way light interacts with matter to produce 'unique scattering,' the equivalent of a molecular fingerprint, which can then be used to identify the types of bacteria present," said Ute Neugebauer, group leader at the Jena University Hospital and Leibniz Institute of Technology.

What exactly does the team's detect? "In our , we were able to identify Escherichia coli (more commonly known as E. coli) and Enterococcus faecalis—two species known to cause urinary tract infections—within 70 minutes, directly from patients' urine samples," said Schröder.

The speedy diagnosis marks a tremendous reduction in the wait time compared to the lengthy lag—often 24 hours or more—associated with methods routinely used to identify bacteria and diagnose urinary tract infections today, so the team's device shows great potential for improving the future of medical diagnostics.

The team envisions general practitioners, a.k.a. family doctors, using the device to rapidly—while a patient waits—identify the bacteria causing an infection directly within the patient's bodily fluid so that they can prescribe the appropriate medication and treatment. "Our pilot study brings us a step closer toward realizing this vision," said Neugebauer.

The team will continue toward its goal of developing an easy-to-use spectroscopy-based point-of-care medical device for fast and reliable diagnostics. "The next step will involve implementing antibiotic susceptibility testing and automating the sample pre-treatment steps," Neugebauer explained. "Our ultimate vision is to apply the concepts behind our to enable diagnostics devices for use with other bodily fluids."

Explore further: In mice, vaccine stops urinary tract infections linked to catheters

More information: Rapid, culture-independent, optical diagnostics of centrifugally captured bacteria from urine samples, Biomicrofluidics, August 11, 2015. DOI: 10.1063/1.4928070

Related Stories

Study debunks common misconception that urine is sterile

March 30, 2015

Bacteria have been discovered in the bladders of healthy women, discrediting the common belief that normal urine is sterile. This finding and its implications were addressed in an editorial published by researchers from Loyola ...

Urinary tract infections steal from hosts' defense arsenals

July 8, 2012

Humans have known for centuries that copper is a potent weapon against infection. New research shows that the bacteria that cause serious urinary tract infections "know" this, too, and steal copper to prevent the metal from ...

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) Aug 12, 2015
That's a huge improvement on the time deduction for urinary tract infection detect. Besides, as it mentioned in the post that some cases the device can be used to save lives.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.