Nav: Home

Discovery raises hopes of preventing streptococci infections

October 18, 2019

Researchers at the University of Dundee have discovered an enzyme they believe could be key to preventing Group A Streptococcus infections that cause more than 500,000 deaths worldwide each year.

Group A Streptococcus can lead to illnesses such as strep throat, scarlet fever, sepsis and toxic shock syndrome as well as several long-term autoimmune diseases with high mortality rates.

Working with colleagues at the University of Edinburgh and the Russian Academy of Sciences, the Dundee researchers found an enzyme that is required to produce a carbohydrate on the surface of the streptococcal bacterium which enables it to infect humans and animals.

The team, led by Dr Helge Dorfmueller, is based is based in the Division of Molecular Microbiology at the University's School of Life Sciences. Their research reveals new opportunities to inhibit this enzyme and, ultimately, fight Group A Streptococcus infections. The fact this enzyme works through a novel mechanism of action that can also be found in other streptococcal species increases the impact and relevance of this finding.

Dr Dorfmueller said, "Strep throat is the most common Group A Streptococcus infection and can often be fought by the body's immune system. Unfortunately, the very same bacterium also causes a plethora of severe and potentially fatal illnesses, such as sepsis and toxic shock syndrome.

"We knew that the carbohydrate coating was an essential component of Group A Strep, but we wanted to find out more about how this worked. What we have now shown is that the enzyme initiates the synthesis of the bacterial coating.

"Surprisingly, we also found that this enzyme fulfils the same function in many other types of streptococci. This includes Group B Streptococci, that can cause severe infections in newborns, and Group C and G Streptococci that cause similar disease as Group A, including bacteraemia and endocarditis, in humans and animals."

The newly discovered enzyme, called α-D-GlcNAc-β-1,4-L-rhamnosyltransferase, is not present in humans or animals, therefore providing a novel opportunity for drug discovery programmes.

Antimicrobial resistance is a global problem, and existing antibiotics fail to work in around 20% of cases of strep throat. The long-term aim of the Dundee team is to aid the development of a new class of antimicrobial drug that could completely inhibit or reduce the enzyme's activity. The next step towards this goal will see them work with the University's Drug Discovery Unit to develop compounds that could target this enzyme.

The research was jointly led by PhD student Azul Zorzoli and Ben Meyer, a former postdoc in Dr Dorfmueller's lab. Azul explained, "If you picture a tennis ball, this carbohydrate would be the furry layer that covers the ball. This layer is an essential structural component of the cell and is used by the bacterium to facilitate infection. In our recent study, we show how this protein initiates the production of this carbohydrate through a mechanism never described before.

"Our research provides the opportunity to target this enzymatic step for drug discovery. For instance, these findings can become a cornerstone to potentially develop a new compound to inhibit streptococci, leading to novel therapeutic strategies. Because this step is exclusive to bacteria, compounds targeting this enzyme should have minimal off-target effects, making it an excellent candidate as an antimicrobial drug."
-end-
The research was funded by the Wellcome Trust and the Royal Society. It has been highlighted as the Editor's pick in the edition of the Journal of Biological Chemistry published today.

University of Dundee

Related Bacterium Articles:

Tuberculosis bacterium uses sluice to import vitamins
A transport protein that is used by the human pathogen Mycobacterium tuberculosis to import vitamin B12 turns out to be very different from other transport proteins.
Bacterium makes complex loops
A scientific team from the Biosciences and Biotechnology Institute of Aix-Marseille in Saint-Paul lez Durance, in collaboration with researchers from the Max Planck Institute of Colloids and Interfaces in Potsdam and the University of Göttingen, determined the trajectory and swimming speed of the magnetotactic bacterium Magnetococcus marinus, known to move rapidly.
Researchers show how opportunistic bacterium defeats competitors
The researchers discovered that Stenotrophomonas maltophilia uses a secretion system that produces a cocktail of toxins and injects them into other microorganisms with which it competes for space and food.
Genetic typing of a bacterium with biotechnological potential
Researchers at Kanazawa University describe in Scientific Reports the genetic typing of the bacterium Pseudomonas putida.
How the strep bacterium hides from the immune system
A bacterial pathogen that causes strep throat and other illnesses cloaks itself in fragments of red blood cells to evade detection by the host immune system, according to a study publishing December 3 in the journal Cell Reports.
The cholera bacterium can steal up to 150 genes in one go
EPFL scientists have discovered that predatory bacteria like the cholera pathogen can steal up to 150 genes in one go from their neighbors.
Exploiting green tides thanks to a marine bacterium
Ulvan is the principal component of Ulva or 'sea lettuce' which causes algal blooms (green tides).
The cholera bacterium's 3-in-1 toolkit for life in the ocean
The cholera bacterium uses a grappling hook-like appendage to take up DNA, bind to nutritious surfaces and recognize 'family' members, EPFL scientists have found.
Excellent catering: How a bacterium feeds an entire flatworm
In the sandy bottom of warm coastal waters lives Paracatenula -- a small worm that has neither mouth, nor gut.
Cancer prevention drug also disables H. pylori bacterium
A medicine currently being tested as a chemoprevention agent for multiple types of cancer has more than one trick in its bag when it comes to preventing stomach cancer, Vanderbilt researchers have discovered.
More Bacterium News and Bacterium Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Biology Of Sex
Original broadcast date: May 8, 2020. Many of us were taught biological sex is a question of female or male, XX or XY ... but it's far more complicated. This hour, TED speakers explore what determines our sex. Guests on the show include artist Emily Quinn, journalist Molly Webster, neuroscientist Lisa Mosconi, and structural biologist Karissa Sanbonmatsu.
Now Playing: Science for the People

#569 Facing Fear
What do you fear? I mean really fear? Well, ok, maybe right now that's tough. We're living in a new age and definition of fear. But what do we do about it? Eva Holland has faced her fears, including trauma and phobia. She lived to tell the tale and write a book: "Nerve: Adventures in the Science of Fear".
Now Playing: Radiolab

The Wubi Effect
When we think of China today, we think of a technological superpower. From Huweai and 5G to TikTok and viral social media, China is stride for stride with the United States in the world of computing. However, China's technological renaissance almost didn't happen. And for one very basic reason: The Chinese language, with its 70,000 plus characters, couldn't fit on a keyboard.  Today, we tell the story of Professor Wang Yongmin, a hard headed computer programmer who solved this puzzle and laid the foundation for the China we know today. This episode was reported and produced by Simon Adler with reporting assistance from Yang Yang. Special thanks to Martin Howard. You can view his renowned collection of typewriters at: antiquetypewriters.com Support Radiolab today at Radiolab.org/donate.