Scientists have discovered that a prevalent bacterium in human dental plaque reproduces through an extraordinary method of cell division. This finding could transform our comprehension of oral health and the complex microbial ecosystems within our mouths.
The Microscopic Jungle in Your Mouth
Your mouth is home to a diverse array of microorganisms, rivaling some of the most biodiverse ecosystems on Earth. With over 500 different species of bacteria coexisting in structured communities called biofilms, the human oral cavity is a thriving microcosm of life.
Researchers from the Marine Biological Laboratory (MBL) and ADA Forsyth have uncovered a remarkable mechanism of cell division in Corynebacterium matruchotii, one of the most common bacteria found in dental plaque. Unlike most bacteria that divide into two daughter cells, C. matruchotii can split into multiple cells simultaneously, a rare process known as multiple fission.
Dr. Jessica Mark Welch, senior scientist at ADA Forsyth and adjunct scientist at the MBL, explains the significance: “Corynebacterium cells in dental plaque are like big, bushy trees in a forest. They create a spatial structure that provides habitat for many other species of bacteria around them.”
The study, published in Proceedings of the National Academy of Sciences, observed C. matruchotii cells dividing into as many as 14 different cells at once, depending on the length of the original mother cell. This unique growth pattern, coupled with their ability to grow only at one end (a process called “tip extension”), allows these bacteria to form dense networks at the core of dental plaque biofilms.
Implications for Oral Health and Beyond
This discovery sheds new light on how bacteria in our mouths proliferate, compete for resources, and maintain their structural integrity within the complex environment of dental plaque. Understanding these processes could have far-reaching implications for oral health management and our broader understanding of microbial communities within the human body.
Scott Chimileski, MBL research scientist and lead author of the study, suggests that this unusual cell cycle may be an evolutionary adaptation to the dense, competitive habitat of dental plaque. “Something about this very dense, competitive habitat of the dental plaque may have driven the evolution of this way of growing,” he notes.
The research builds on a 2016 study that used advanced imaging techniques to visualize the spatial organization of dental plaque. That earlier work revealed that C. matruchotii cells form the backbone of structures within plaque called “hedgehogs” due to their appearance.
Why it matters: This research provides crucial insights into the formation and maintenance of dental plaque, which could lead to more effective strategies for oral hygiene and the prevention of dental diseases. Moreover, it enhances our understanding of microbial communities within the human microbiome, potentially informing broader health research and treatments.
The study also raises intriguing questions about bacterial adaptation and evolution. As Gary Borisy, principal investigator at ADA Forsyth, points out, “Who would have thought that our familiar mouths would harbor a microbe whose reproductive strategy is virtually unique in the bacterial world?”
While regular brushing remains essential for oral health, this research underscores the resilience and complexity of the microbial communities in our mouths. The scientists found that C. matruchotii colonies could grow up to half a millimeter per day, explaining why plaque reforms so quickly even after thorough brushing.
As research in this field progresses, it may lead to new approaches in dental care and a deeper understanding of the delicate balance of microorganisms that contribute to our overall health.
Quiz:
- What unique form of cell division does Corynebacterium matruchotii exhibit?
- How many different species of bacteria are estimated to live in the human mouth?
- What term do scientists use to describe the bacterial structures in dental plaque that resemble small hedgehogs?
Answer Key:
- Multiple fission
- Over 500 species
- Hedgehogs
