Related Experiment Video
Updated: Jun 14, 2026
09:51
Purification of a High Molecular Mass Protein in Streptococcus mutans
Published on: September 14, 2019
Late Established Mutans Streptococci in Children over 3 Years Old
Mitsugi Okada1, Yoshiko Taniguchi, Fumiko Hayashi
1Department of Special Care Dentistry, Hiroshima University Hospital, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
International Journal of Dentistry
|March 27, 2010
Summary
This study found Streptococcus sobrinus is acquired later than Streptococcus mutans in children over three years old. Polymerase chain reaction (PCR) assays tracked bacterial acquisition over one year.
Area of Science:
- Oral microbiology
- Pediatric dentistry
- Infectious disease epidemiology
Background:
- Mutans streptococci, including Streptococcus mutans and Streptococcus sobrinus, are key pathogens in early childhood caries.
- Previous research suggests common acquisition of mutans streptococci around 26 months of age.
Purpose of the Study:
- To determine the specific timing of Streptococcus mutans and Streptococcus sobrinus acquisition in children aged 3-5 years.
- To compare the acquisition timelines of S. mutans and S. sobrinus within this age group.
Main Methods:
- Utilized polymerase chain reaction (PCR) assays to detect S. mutans and S. sobrinus in plaque samples from 57 children (3-5 years old).
- Collected samples at baseline and after a 1-year follow-up period.
- Analyzed prevalence and new acquisitions of both bacterial species.
Main Results:
- At baseline, prevalence was 61.4% for S. mutans and 54.4% for S. sobrinus.
- After 1 year, new S. mutans acquisition occurred in 18.2% of eligible subjects, while new S. sobrinus acquisition occurred in 57.7%.
- The age of first detection for S. mutans ranged from 49-71 months, and for S. sobrinus from 49-81 months, indicating later S. sobrinus establishment.
Conclusions:
- S. sobrinus appears to be established in the oral cavity later than S. mutans in children over three years old.
- Findings suggest distinct acquisition patterns for these cariogenic bacteria in preschool-aged children.
- Further research may inform targeted preventive strategies based on acquisition timing.
Related Concept Videos
01:28Development of the Oral Microbiota
The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
01:29Microbiota of the Respiratory Tract
The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...
01:30Development of Human Microbiota
The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from the skin...
01:27The Oral Microbiota
The oral microbiome includes a complex ecosystem comprising over 700 microbial species, identified through genomic sequencing and culture-based analyses to date. This community includes a core microbiome, found universally among individuals, and a variable component influenced by environmental factors such as diet, lifestyle, and host genetics. Site-specific conditions, including oxygen gradients, pH levels, and nutrient availability, determine the spatial distribution of these microorganisms...
01:29Staphylococcal Skin Infections
Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
01:25Clinical Significance of Antibiotic Resistance
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...