[News release] Plant chemical could prevent tooth decay

From a May 2015 University of Edinburg news release

View image | gettyimages.com

Oral care products containing a natural chemical that stops bacteria harming teeth could help fight decay, research shows.

The plant natural product acts against harmful mouth bacteria and could improve oral health by helping to prevent the build-up of plaque.

The compound – known as trans-chalcone – is related to chemicals found in liquorice root.

Oral bacteria

This exciting discovery highlights the potential of this class of natural products in food and healthcare technologies.

The University study shows that it blocks the action of a key enzyme that allows the bacteria to thrive in oral cavities.

The bacteria – Streptococcus mutans – metabolise sugars from food and drink, which produces a mild acid and leads to the formation of plaque.

Without good dental hygiene, the combination of plaque and mouth acid can lead to tooth decay.

Preventing biofilms

Researchers found that blocking the activity of the enzyme prevents bacteria forming a protective biological layer – known as a biofilm – around themselves.

Plaque is formed when bacteria attach themselves to teeth and construct biofilms.

Preventing the assembly of these protective layers would help stop bacteria forming plaque.

Oral care products that contain similar natural compounds could help people improve their dental hygiene.

Blocking enzyme function

The study is the first to show how trans-chalcone prevents bacteria forming biofilms.

The team worked out the 3D structure of the enzyme – called Sortase A – which allows the bacteria to make biofilms.

By doing this, researchers were able to identify how trans-chalcone prevents the enzyme from functioning.

The study, published in the journal Chemical Communications, was supported by Wm. Wrigley Jr. Company.

We were delighted to observe that trans-chalcone inhibited Sortase A in a test tube and stopped Streptococcus mutans biofilm formation. We are expanding our study to include similar natural products and investigate if they can be incorporated into consumer products.

Dr Dominic Campopiano

School of Chemistry

What Bacteria Don’t Know Can Hurt Them

Bacterial clusters living in the lungs of a cystic fibrosis patient are highly resistant to killing by antibiotics. (Credit: Singh lab)

From the 17 November 2011 Science Daily article

Many infections, even those caused by antibiotic-sensitive bacteria, resist treatment. This paradox has vexedphysicians for decades, and makes some infections impossible to cure.

A key cause of this resistance is that bacteria become starved for nutrients during infection. Starved bacteria resist killing by nearly every type of antibiotic, even ones they have never been exposed to before.

What produces starvation-induced antibiotic resistance, and how can it be overcome? In a paper appearing this week in Science, researchers report some surprising answers.

“Bacteria become starved when they exhaust nutrient supplies in the body, or if they live clustered together in groups known as biofilms,” said the lead author of the paper, Dr. Dao Nguyen, an assistant professor of medicine at McGill University.

Biofilms are clusters of bacteria encased in a slimy coating, and can be found both in the natural environment as well as in human tissues where they cause disease. For example, biofilm bacteria grow in the scabs of chronic wounds, and the lungs of patients with cystic fibrosis. Bacteria in biofilms tolerate high levels of antibiotics without being killed…

Read article

 

Related articles

• Health Tip: Why Antibiotic Resistance Is Serious (nlm.nih.gov)
• Antibiotic Resistance – A Public Health Issue (regcompliance.wordpress.com)
• GPs told to resist antibiotics requests for coughs and colds (guardian.co.uk)
• Growth Promotion Use Of Antibiotics In Farming: Evidence Supports Ban (medicalnewstoday.com)
• Highly Treated wastewater has higher “Super bacteria” !! (biowaves.wordpress.com)
• How to Trick Antibiotic Resistant Bacteria into Being Harmless (lockergnome.com)
• Key regulators for biofilm development discovered (physorg.com)
• Wastewater treatment fosters antibiotic resistance? (junkscience.com)
• Antibiotic-resistant infections spread through Europe (independent.co.uk)
• GPs ‘Must Stop’ Overuse Of Antibiotics (news.sky.com)
• Fighting fire with fire: ‘Vampire’ bacteria has potential as living antibiotic (eurekalert.org)
• Are antibiotics bad for your stomach? (zocdoc.com)
• Bacteria responsible for common infections may protect themselves by stealing immune molecules (eurekalert.org)

Streptococcus Enzyme Could Compete With Toothbrushes, Dental Floss

Streptococcus Enzyme Could Compete With Toothbrushes, Dental Floss

From a March 21 2011 Science Daily news article

ScienceDaily (Mar. 21, 2011) — Investigators from Japan show in vitro that the bacteriumStreptococcus salivarius, a non-biofilm forming, and otherwise harmless inhabitant of the human mouth, actually inhibits the formation of dental biofilms, otherwise known as plaque. Two enzymes this bacteria produces are responsible for this inhibition.

The research is published in the March 2011 issue of the journalApplied and Environmental Microbiology.

[For suggestions on how to get this article for free or at low cost, click here]

 

Related Articles

• A Guide to Flossing Your Teeth (everydayhealth.com)
• A Guide to Nighttime Oral Care (everydayhealth.com)
• Bad breath could signal other health problems (charlotte.news14.com)

Preventing Bacterial Infections from Medical Devices – Research Study Results

Preventing Bacterial Infections from Medical Devices – Research Study Results

This scanning electron micrograph shows a clump of Staphylococcus epidermidis bacteria (green) in the extracellular matrix, which connects cells and tissue. Image courtesy of NIAID/Rocky Mountain Laboratories.

From the US National Institutes of Health (NIH) Research Matters news release

New research has identified a protein that helps bacteria break away from medical devices like catheters and spread throughout the body. The finding gives insight into how bacterial communities called biofilms cause disease and provides a potential target for future treatments.

Biofilms are complex, multi-layered microbial communities. They can form on biological surfaces like teeth, or on medical devices that are placed inside a patient, like catheters. Bacteria in biofilms are resistant to antimicrobial agents and difficult to treat. Biofilms made up of Staphylococcus epidermidis bacteria are a major cause of infection in hospitals, and can lead to sepsis.

A research team led by Dr. Michael Otto of NIH’s National Institute of Allergy and Infectious Diseases (NIAID) set out to determine how bacteria from biofilms detach and disperse. They looked at a protein released by S. epidermidis called phenol-soluble modulin beta, or PSMβ. They chose PSMβ because of its structure, which hinted that it might act like a type of molecule, called a surfactant, that can help bacteria spread.The scientists first confirmed that S. epidermidis in biofilms make PSMβ protein. Then, to test whether the protein promotes biofilm formation, they cultured mutant bacteria that can’t make their own PSMβ. They found that adding medium levels of PSMβ to the cultures led to more biofilm formation, but high levels led to less. This suggested that PSMβ may play a dual role, helping biofilms form while also helping bacteria detach from them.

To look at detachment more directly, the researchers genetically engineered bacteria to turn green upon making PSMβ. When examined under a microscope, the bacteria making PSMβ were seen mostly at the outer layers of the biofilm, or detached and floating in fluid. Moreover, a strong green signal usually appeared just before bacteria disappeared from that area. This suggested that bacteria made PSMβ immediately before leaving the biofilm.

To see if PSMβ could help bacteria spread in a living organism, the team put 2 catheters in mice. One catheter had normal S. epidermidis on it. The other had a mutant lacking PSMβ. Within a few days, the normal bacteria spread to the organs and body fluids, but the PSMβ-lacking bacteria barely migrated at all.

In an attempt to stop the bacteria from spreading, the team treated mice with antibodies against PSMβ. The antibodies prevented bacteria from spreading to all the organs except for the lymph nodes, where numbers were significantly reduced.

PSM proteins have also been found in other Staphylococcus species. Although this research is still in its early stages, it opens up new avenues for curbing biofilm-related infections. “This is very important particularly because it links this mechanism of biofilm detachment to spread of infection in vivo,” Otto says.

—by Allison Bierly, Ph.D.