OCT 16, 2018 12:51 PM PDT

Simple Test Rapidly Diagnoses Antibiotic-resistant Infections

WRITTEN BY: Carmen Leitch

If we get a bacterial infection, doctors use antibiotics to treat it. But sometimes people are infected by pathogens that are resistant to the effects of antibiotics, a growing problem worldwide. If clinicians could find out quickly when people are dealing with drug-resistant microbes, they can act rapidly to treat those persistent infections instead of cycling through standard therapeutics before finding out that none of them work. Researchers at the University of California, Berkeley have developed a test that can indicate whether antibiotic-resistant strains of bacteria are to blame for a patient’s infection.

"Health organizations around the world are supporting the development of tools that specifically identify pathogens that are resistant to antibiotics because there are limited tests available that can do it quickly," said Tara deBoer, a postdoctoral fellow in the College of Engineering at UC Berkeley. "Our test is simple and gives us information on a short timescale."

So-called superbugs that can evade the effects of drugs are responsible for the deaths of around 700,000 people every year, a number that the United Nations has warned will rise much higher in the near future. By diagnosing these infections and moving rapidly to treat them with the proper drugs, we may be able to limit their spread.

The new, inexpensive, simple diagnostic test has been called DETECT. It uses urine samples to identify molecules carried by antibiotic-resistant germs. The test doesn’t require an expensive machine to run it, and can be applied in a clinical setting. The work will be reported in the October 18 issue of the journal ChemBiochem.

"In theory, DETECT will allow you to diagnose antibiotic-resistant bacterial infections in a doctor's office just by collecting urine and mixing it with the DETECT reagents," noted Niren Murthy, a professor of engineering at Berkeley.

"Drug-resistant infections are a silent pandemic that actually kill more people every year than Zika or Ebola," added Lee Riley, professor of epidemiology and infectious diseases in the School of Public Health at UC Berkeley. "The faster you can start the right drug, the better the chances of survival or avoiding complications."

Many of humankind's first antibiotics that a lot of us are familiar with, like amoxicillin, penicillin, and ampicillin, act on a structure in bacteria called beta-lactam. The drugs stop bacterial cell walls from being constructed, so microbes cannot reproduce and the infection is snuffed out.

For a variety of reasons, including antibiotic misuse, some pathogens have evolved and have overcome antibiotics. There are strains of Salmonella, E. coli, and Shigella that now make enzymes that can digest those antibiotics; they are called beta-lactamases, and render the drugs ineffective.

Urine samples are tested in a plate similar to this one / Credit: Carmen Leitch

The DETECT system can indicate when those beta-lactamases are present in urine. "What our technology does is detect the molecules that are actually breaking down the antibiotics," deBoer explained.

There was already a way to detect beta-lactamases. For this work, the researcher had to make it sensitive enough to see them in patient samples, something that was labor-intensive with previous methods.  They tested their invention and found that of 40 patients with urinary tract infections, around 25 percent of them were resistant to antibiotics.

"DETECT tells you not only who has antibiotic-resistant infections but also tells you who could be treated by early-generation antibiotics, allowing you to spare higher-end antibiotics and slow the spread of drug resistance," Murthy said.

The team is now working to bring DETECT from the bench to the bedside. They also want to create a test that can detect beta-lactamases in blood samples.

"I think we are on the verge of having this applicable in a hospital setting," Riley said.


Sources: AAAS/Eurkealert! Via UC Berkeley, ChemBiochem

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 07, 2020
Clinical & Molecular DX
An 8 Minute DNA Test For Salmonella
MAY 07, 2020
An 8 Minute DNA Test For Salmonella
Australian researchers have created a sensitive, super-fast test for five different serotypes of Salmonella which could ...
JUN 01, 2020
Microbiology
The Most Common Marine Microbe Has a Virus in Its Genome
JUN 01, 2020
The Most Common Marine Microbe Has a Virus in Its Genome
Single-celled ocean microbes known as Pelagibacter or SAR11 make up about 25 percent of the plankton on the planet.
JUN 22, 2020
Microbiology
A Human Gut Microbe Can Help Maintain Healthy Cholesterol Levels
JUN 22, 2020
A Human Gut Microbe Can Help Maintain Healthy Cholesterol Levels
The world is full of microorganisms, and our bodies are one of the many places they have colonized. These gut microbes c ...
JUL 03, 2020
Cell & Molecular Biology
A Gut Pathogen Moves With Help From Its Environment
JUL 03, 2020
A Gut Pathogen Moves With Help From Its Environment
Campylobacter jejuni is a foodborne bacterial pathogen that causes millions of cases of food poisoning each year.
JUL 05, 2020
Microbiology
Stimulating Antibiotic Production in Bacteria
JUL 05, 2020
Stimulating Antibiotic Production in Bacteria
The microorganisms of the world have to compete for survival, and they sometimes do battle with one another. Some use an ...
JUL 22, 2020
Infographics
The Science of Sourdough
JUL 22, 2020
The Science of Sourdough
During the coronavirus stay-at-home order, many people have taken up the art of making sourdough bread and have learned ...
Loading Comments...