Drug may guard against periodontitis, and related chronic diseases
A drug currently used to treat intestinal worms could protect people from periodontitis, an advanced gum disease, which untreated can erode the structures—including bone—that hold the teeth in the jaw. The research was published ahead of print in Antimicrobial Agents and Chemotherapy.
Current treatment for periodontitis involves scraping dental plaque, which is a polymicrobial biofilm, off of the root of the tooth. Despite this unpleasant and costly ordeal, the biofilm frequently grows back. But the investigators showed in an animal model of periodontitis that the drug Oxantel inhibits this growth by interfering with an enzyme that bacteria require for biofilm formation, says corresponding author Eric Reynolds, of the University of Melbourne, Australia. It does so in a dose-dependent manner, indicating efficacy.
The researchers began their search for a therapy for periodontitis by studying the symbioses of the periodontal pathogens, using genomics, proteomics, and metabolomics, in animal models of periodontitis. They soon found that the periodontal biofilm depended for growth on the availability of iron and heme (an iron-containing molecule related to hemoglobin), and that restricting these reduced levels of the enzyme, fumarate reductase. Since Oxantel was known to inhibit fumarate reductase in some bacteria, they then successfully tested its ability to inhibit fumarate reductase activity in Porphyromonas gingivalis, one of the major bacterial components of periodontitis biofilms. Fumarate reductase is absent from humans, making it an ideal drug target.
They also showed that Oxantel disrupted the growth of polymicrobial biofilms containing P. gingivalis, Tannerella forsythia, and Treponema denticola, a typical composition of periodontal biofilms, despite the fact that the latter alone is unaffected by Oxantel.
The researchers found that treatment with Oxantel downregulated six P. gingivalis gene products, and upregulated 22 gene products, all of which are part of a regulon (a genetic unit) that controls availability of heme.
Periodontitis affects an estimated 30-47 percent of the adult population with severe forms affecting 5-10 percent. It also increases the risks of diabetes, heart disease, stroke, arthritis, and dementia, says Reynolds. These risks arise due to the pathogenic bacteria that enter the blood stream from periodontitis, as well as from the chronic inflammation caused by this disease, he says. Additionally, periodontitis correlates with increased risk of cancers of the head and neck, the esophagus, the tongue, and the pancreas, the investigators report.
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Periodontitis means “inflammation around the tooth” - it is a serious gum infection that damages the soft tissue and bone that supports the tooth. All periodontal diseases, including periodontitis, are infections which affect the periodontium. The periodontium are the tissues around a tooth, tissues that support the tooth. With periodontitis, the alveolar bone around the teeth is slowly and progressively lost. Microorganisms, such as bacteria, stick to the surface of the tooth and multiply - an overactive immune system reacts with inflammation.
Untreated periodontitis will eventually result in tooth loss, and may increase the risk of stroke, heart attack and other health problems. Bacterial plaque, a sticky, colorless membrane that develops over the surface of teeth, is the most common cause of periodontal disease.
In dentistry, periodontics deals with the prevention, diagnosis and treatment of diseases involving the gums and structures which support teeth. There are eight dental specialties, of which periodontics is one. If you want dental implants, you see a periodontist.
In most cases, periodontitis is preventable. It is usually caused by poor dental hygiene.
The article can be found online at http://bit.ly/asmtip1111a.
“Antimicrobial Agents and Chemotherapy is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.”
What is the difference between periodontitis and gingivitis?
Gingivitis occurs before periodontitis. Gingivitis usually refers to gum inflammation while periodontitis refers to gum disease and the destruction of tissue and/or bone. Initially, with gingivitis, bacteria plaque accumulates on the surface of the tooth, causing the gums to go red and inflamed; teeth may bleed when brushing them. Even though the gums are irritated and bothersome, the teeth are not loose. There is no irreversible damage to bone or surrounding tissue.
Untreated gingivitis can progress to periodontitis. With periodontitis, the gum and bone pulls away from the teeth, forming large pockets. Debris collects in the spaces between the gums and teeth, and infect the area. The patient’s immune system attacks bacteria as the plaque spreads below the gum line. Bone and connective tissue that hold the tooth start to break down - this is caused by toxins produced by the bacteria. Teeth become loose and can fall out.
Put simply, Periodontitis involves irreversible changes to the supporting structures of the teeth, while gingivitis does not.
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Garth Hogan
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American Society for Microbiology