Navigation Links
How cavity-causing microbes invade heart

Scientists have discovered the tool that bacteria normally found in our mouths use to invade heart tissue, causing a dangerous and sometimes lethal infection of the heart known as endocarditis. The work raises the possibility of creating a screening tool perhaps a swab of the cheek, or a spit test to gauge a dental patient's vulnerability to the condition.

The identification of the protein that allows Streptococcus mutans to gain a foothold in heart tissue is reported in the June issue of Infection and Immunity by microbiologists at the University of Rochester Medical Center.

S. mutans is a bacterium best known for causing cavities. The bacteria reside in dental plaque an architecturally sophisticated goo composed of an elaborate molecular matrix created by S. mutans that allows the bacteria to inhabit and thrive in our oral cavity. There, they churn out acid that erodes our teeth.

Normally, S. mutans confines its mischief to the mouth, but sometimes, particularly after a dental procedure or even after a vigorous bout of flossing, the bacteria enter the bloodstream. There, the immune system usually destroys them, but occasionally within just a few seconds they travel to the heart and colonize its tissue, especially heart valves. The bacteria can cause endocarditis inflammation of heart valves which can be deadly. Infection by S. mutans is a leading cause of the condition.

"When I first learned that S. mutans sometimes can live in the heart, I asked myself: Why in the world are these bacteria, which normally live in the mouth, in the heart? I was intrigued. And I began investigating how they get there and survive there," said Jacqueline Abranches, Ph.D., a microbiologist and the corresponding author of the study.

Abranches and her team at the University's Center for Oral Biology discovered that a collagen-binding protein known as CNM gives S. mutans its ability to invade heart tissue. In laboratory experiments, scientists found that strains with CNM are able to invade heart cells, and strains without CNM are not.

When the team knocked out the gene for CNM in strains where it's normally present, the bacteria were unable to invade heart tissue. Without CNM, the bacteria simply couldn't gain a foothold; their ability to adhere was about one-tenth of what it was with CNM.

The team also studied the response of wax worms to the various strains of S. mutans. They found that strains without CNM were rarely lethal to the worms, while strains with the protein were lethal 90 percent of the time. Then, when Abranches' team knocked out CNM in those strains, they were no longer lethal those worms thrived.

The work may someday enable doctors to prevent S. mutans from invading heart tissue. Even sooner, though, since some strains of S. mutans have CNM and others do not, the research may enable doctors to gauge a patient's vulnerability to a heart infection caused by the bacteria.

Abranches has identified five specific strains of S. mutans that carry the CNM protein, out of more than three dozen strains examined. CNM is not found in the most common type of S. mutans found in people, type C, but is present in rarer types of S. mutans, including types E and F.

"It may be that CNM can serve as a biomarker of the most virulent strains of S. mutans," said Abranches, a research assistant professor in the Department of Microbiology and Immunology. "When patients with cardiac problems go to the dentist, perhaps those patients will be screened to see if they carry the protein. If they do, the dentist might treat them more aggressively with preventive antibiotics, for example."

Until more research is done and a screening or preventive tool is in place, Abranches says the usual advice for good oral health still stands for everyone.

"No matter what types of bacteria a person has in his or her mouth, they should do the same things to maintain good oral health. They should brush and floss their teeth regularly the smaller the number of S. mutans in your mouth, the healthier you'll be. Use a fluoride rinse before you go to bed at night. And eat a healthy diet, keeping sugar to a minimum," added Abranches.


Contact: Tom Rickey
University of Rochester Medical Center

Related medicine news :

1. Orthodontic Retainers Can Harbor Harmful Microbes
2. Scientists sequence gut microbes of premature infant
3. Gut microbes promote cell turnover by a well-known pathway
4. Researchers engineer microbes for low-cost production of anti-cancer drug, Taxol
5. Study reveals a secret to the success of notorious, disease-causing microbes
6. New weapon against highly resistant microbes within grasp
7. Scientists Map Genetic Codes of Human Microbes
8. You Are What Microbes You Eat
9. Border patrol: Immune cells protect body from invaders, according to Penn study
10. Genetic study shows that low body fat may not lower risk for heart disease and diabetes
11. Class of Drugs Linked to Higher Heart Risk in Older Diabetics
Post Your Comments:
(Date:11/30/2015)... ... 2015 , ... The Foundation for Breast and Prostate Health ... forces with the award-winning creator and writer of Downton Abbey Julian Fellowes to ... the Union League of Philadelphia. , The benefit, titled “An Evening with ...
(Date:11/30/2015)... ... November 30, 2015 , ... California-based i2i Systems, a pioneer ... that Michigan-based Family Health Center (FHC) has selected i2iTracks as their population health ... awarded the largest Affordable Care Act grant for Federally Qualified Health Centers in ...
(Date:11/30/2015)... ... , ... In an interview with Andy Mitchell of Peconic Bay Medical Center, ... east end. During the broadcast, entitled “Eyes: the Window to the Soul,” Dr. Buono ... and how a visit with his grandmother to her physician put him on a ...
(Date:11/30/2015)... ... November 30, 2015 , ... ... Kreithen”), one of the leading plastic surgery practices in Florida, is proud to ... to consult for surgical innovations giant Ethicon Inc., a Johnson & Johnson Company. ...
(Date:11/30/2015)... ... November 30, 2015 , ... Vasont Systems, a top component ... (VUI) extension unites with Syncro Soft’s latest software update, oXygen XML editor Version ... with the latest release of oXygen® XML editor and the Vasont® CCMS. ...
Breaking Medicine News(10 mins):
(Date:11/30/2015)... Medical Systems (NYSE: VAR ) has signed a Memorandum of ... the largest hospital chain in India , to ... country. The MoU was signed by Dr. K. Prabakar , ... Varian,s India managing director, in ... intends to deploy its Access to Care program by leveraging the ...
(Date:11/30/2015)... NAMUR , Belgium , Nov. 30, ... life sciences company focused on developing blood-based diagnostic tests for ... announced the Company will present at the LD Micro Conference, ... Los Angeles, CA. Attending from VolitionRx will ... and Scott Powell , Vice President of Investor Relations. ...
(Date:11/30/2015)... Mexico Healthcare and Life Sciences Report 2015 . --> ... Pharmaboardroom releases its new 98-page Mexico Healthcare and Life Sciences ... country of over 122 million people. --> Latin ... --> It offers companies, investors, policymakers, and stakeholders with an ... largest pharma and healthcare market in Latin America ...
Breaking Medicine Technology: