OCT 25, 2016 12:34 PM PDT

Cranberries - the new antibiotics?

WRITTEN BY: Kerry Evans
A cranberry a day keeps the doctor away. McGill University researchers found that cranberry extract helped slow the spread of a bacterial infection in fruit flies.
 
The group, led by Eric Déziel and Nathalie Tufenkji, knew that proanthocyanidins (PCAs) found in cranberries have antimicrobial properties. Their most recent work shows that PACs work by keeping bacteria from effectively communicating with each other, diminishing their virulence. "This means that cranberries could be part of the arsenal used to manage infections and potentially minimize the dependence on antibiotics for the global public”, says Tufenkji.
Cranberry extract has antimicrobial properties.
They found that treating cultures of Pseudomonas aeruginosa with cerPAC (cranberry extract rich in proanthocyanidins) decreased the activity of key virulence factors. Specifically, cerPAC decreased the activity of LasA (staphylolytic protease), LasB (elastase), and AprA (alkaline protease), but bacterial growth was not affected. 
 
Next, they determined if cerPAC affected the survival of fruit flies infected with P. aeruginosa. The researchers infected fruit flies with P. aeruginosa and then treated them with cerPAC. The cerPAC treatment increased survival from 168 hours (without cerPAC) to 240 hours.
 
So, what does this cranberry extract actually do to the bacteria? Quorum sensing, a process that bacteria use to sense environmental changes and communicate with their neighbors, helps regulate many virulence factors for P. aeruginosa. With this in mind, the group hypothesized that cerPAC interferes with some aspect of quorum sensing. Indeed, they found that cerPAC decreased the production of two of P. aeruginosa’s quorum sensing molecules, 3-oxo-C12-HSL and C4-HSL.
 
According to Déziel, "cranberry PACs interrupt the ability for bacteria to communicate with each other, spread, and become virulent - a process known as quorum sensing. The cranberry extract successfully interferes with the chain of events associated with the spread and severity of chronic bacterial infections."
 
Cranberry extract doesn’t just affect P. aeruginosa. The group showed that cerPAC inhibited quorum sensing in two other species, Burkholderia ambifaria and Chromobacterium violaceum. In this case, cerPAC interferes with the production of the quorum sensing molecules C8-HSL and C6-HSL, respectively.
 
About the Author
  • Kerry received a doctorate in microbiology from the University of Arkansas for Medical Sciences.
You May Also Like
APR 26, 2020
Cell & Molecular Biology
Nose Cells Found to Be Likely SARS-CoV-2 Entry Points
APR 26, 2020
Nose Cells Found to Be Likely SARS-CoV-2 Entry Points
This work may help explain why the virus is so easy to transmit.
APR 29, 2020
Genetics & Genomics
Toxoplasma Infections Can Cause Epigenetic Changes in Males
APR 29, 2020
Toxoplasma Infections Can Cause Epigenetic Changes in Males
Anywhere from 25 to 80% of the world's population is infected with a parasite called Toxoplasma gondii.
MAY 21, 2020
Clinical & Molecular DX
Fidget Spinner Diagnoses Infections
MAY 21, 2020
Fidget Spinner Diagnoses Infections
The fidget spinner toy craze took the world by storm — a small, boomerang-shaped gadget that rotates hypnotically ...
JUN 10, 2020
Immunology
Natural Killer Cells with "Memory" to Target Hepatitis B
JUN 10, 2020
Natural Killer Cells with "Memory" to Target Hepatitis B
An immune cell type thought to be restricted to the general, first response to pathogenic invaders may actually have som ...
JUN 11, 2020
Cell & Molecular Biology
Changes in Gut Mucus are Connected to Brain Disorders
JUN 11, 2020
Changes in Gut Mucus are Connected to Brain Disorders
In recent years, researchers have learned more about how important the gut is to human health. Trillions of microbes liv ...
JUL 03, 2020
Microbiology
Oxford COVID-19 Vaccine Enters Phase 3 Clinical Trials
JUL 03, 2020
Oxford COVID-19 Vaccine Enters Phase 3 Clinical Trials
Millions of people around the world have been infected with the coronavirus called SARS-CoV-2, which causes COVID-19. Th ...
Loading Comments...