1/3 Kingsley Oral Ecology, Biofilms, and Plaque Flashcards
Oral microbiome follows predictable pattern known as:
Succession
Between fetal development and birth, the oral cavity is:
Sterile
When does the oral microbiome start to develop?
few hours after birth
Primary oral colonizer is:
Streptococcus salivarius
S. salivarius - gram positive or gram negative?
Gram positive
When does primary tooth eruption begin?
6-8 months
Primary tooth colonizers
- Streptococcus sanguinis
- Streptococcus mitis
S. sanguinis also known as:
S. sanguis
S. mitis is also known as:
S. mitior
Primary tooth colonizers attach to the salivary pellicle via:
Sucrose-independent adhesion
Salivary pellicle has varied composition but is mostly:
Salivary proteins
Components of salivary pellicle
- Mucins
- Lysozyme
- Amylase
- IgA/IgM
- other proteins
True or false: Mucins are an example of GAGs
True
____ have a high molecular weight and are heavily glycosylated
Mucins
Mucins are a major family of _____
non-immunoglobin agglutinins (NIA)
Salivary proteins - list examples
- mucins
- lysozyme
- lactoferrin
- statherins
- proline-rich proteins (PrP)
- IgA, IgM
Salivary proteins such as _____ are part of innate immunity. ____ is anti-bacterial, and _____ is anti-microbial
lactoferrin and lysozyme; Lysozyme; Lactoferrin
IgA and IgM are major oral _____
Immunoglobin agglutinins
_____ is well conserved in many Streptococcal species and is responsible for ____ adhesion
Type I pili (Ag I/II); sucrose-independent adhesion
AbpA and AbpB are examples of:
amylase-coated enamel binding protein
sucrose independent adhesion
S. mitis and S. sanguis initially adhere to salivary pellicle via ____ adhesion
Sucrose independent
Primary tooth colonizers are gram ___ ____
gram positive cocci
S. sanguis and S. mitis function after colonization
- modify pellicle
- create food
- binding surfaces for other bacteria
S. mutans binds before or after S. sanguis and S. mitis?
After
S. mutans function after colonization
creates exopolymers and glucans (a true biofilm)
Primary tooth colonizers allow secondary colonizers to adhere, such as:
- Gram negatives
- anaerobes
Primary tooth colonizers can modify and inactivate _____ via _____
Salivary proteins; bacteria proteases
Biofilm is also known as:
Extracellular Polysaccharide Substance (EPS)
Biofilm is a material secreted or excreted by:
Bacteria (oral microbes)
Major components of biofilm
- glucans
- fructans
Glucans and fructans are made by:
Bacterial glycosyltransferase (GTF)
Biofilm allows for _____ adhesion via what protein?
sucrose-dependent adhesion; glucan binding protein
Glucosyltransferase and Glucan Binding Protein are major ____
Pathogenic virulence factors
Tertiary colonizers are mainly:
Gram negative microbes
Secondary colonizers are mainly:
- gram positive and gram-negative microbes
- include bridge species such as Eubacterium yurii and Fusobacterium nucleatum
____ colonizers facilitate co-aggregation, corn cob formation, and drive biofilm formation
Secondary
Primary colonizers include:
- Gram-positive microbes
- streptococcal species that bind salivary pellicle
Co-aggregation (corn cob formation) can occur in a ____ or ____ fashion
Homotypic or heterotypic
Co-aggregation is driven by:
E. yurii and F. nucleatum (drive heterotypic biofilm formation)
Dental plaque is constantly _____ over time
Changing and evolving
Co-aggregation changes biofilm ____ content over time
Lipid
Plaque lipids are mainly derived from:
Gram-negative bacteria
Lipids have affinity for what ions?
- calcium (Ca2+)
- phosphate (PO4 3-)
Saliva contains what ions?
- Ca2+
- Mg2+
- PO43-
What drives calculus formation?
- calcium and phosphate ions from saliva imbed into dental plaque lipids
- forms insoluble calcium phosphate crystals
Most toothpastes contain _____ compounds to chelate calcium ions
pyrophosphate
Many/most toothpastes contain ____ which help to chelate pyrophosphate
Fluoride
How is fluorapatite created?
Fluoride with calcium and phosphate
Fluoride inhibits bacterial glycolysis by inhibiting ____
Enolase
Besides fluoride toothpaste, fluoride can be applied via:
Fluoride varnish
Supragingival calculus is usually located in what spots?
- lingual surfaces of mandibular incisors [proximity to opening of Wharton’s ducts (submandibular gland)]
- buccal surfaces of maxillary molars (proximity to opening of Stenson’s ducts)
_____ calculus contains more gram-positive organisms
Supragingival
_____ calculus contains more gram-negative organisms
Subgingival
Clinical significance of biofilm involves resistance to antimicrobial agents. There is a ____ greater amount of ____ cells than single cells
1000x; planktonic
Biofilm formation allows for communication in the form of ___ ___
Quorum sensing
Quorum sensing allows bacteria to secrete certain molecules such as:
Iron-binding siderophores
Biofilms found in dentistry
- teeth
- tongue
- dental instrument tray
- dental water line biofilm
Scardovia wiggsiae is a _____ bacillus and causes _____
gram-positive anaerobic; caries
Causative agent for early childhood dental caries with S. mutans
Scardovia wiggsiae
Scardovia wiggsiae has a ____ fluoride tolerance and ____ enolase activity than S. mutans
higher; lower
Scardovia wiggsiae allows metabolic activity and the production of _____ to continue which is a virulence mechanism
Acetate
Scardovia wiggsiae found alone in ____ patients; much higher SW in ____ ortho vs ____ ortho
Orthodontic; pediatric vs adult
Scardovia wiggsiae is higher among ______ patients
Pediatric ortho
Do sealants work to reduce Scardovia wiggsiae counts?
No - because they are anaerobic (reduces initially but rebounds)
Scardovia wiggsiae is found in ____ and other sites such as ___ and ____
mostly on tooth biofilm
saliva; GCF; dorsum of tongue
True or false: majority of SW-positive samples harbor SW at more than one oral site (tooth biofilm)
True
Selenomonas noxia is associated with ____ and is predominant in 98% of ____ patients
periodontitis; obese
Scardovia wiggsiae is resistant to:
Enolase inhibitors (fluoride varnish doesn’t work so people still get cavities)
S. noxia is more prevalent in ____ ____ patients
Pediatric ortho
There are no differences between ___ and _____ regarding prevalence of S. noxia
Ortho and non-ortho
Periodontal pathogens are more common in:
Adults
S. noxia is found in what sites in the mouth?
- tongue dorsum
- lower lingual incisor
- upper buccal molar
Akkermansia muciniphila is more common in:
non-orthodontic patients
Slackia exigua is more common in ___ and ___ patients
Pediatric and orthodontic
Sucrose-independent adhesion requires what structures/proteins?
- Ag I/II (Type I Pili conserved in many Streptococcal species)
- AbpA & AbpB (amylase-coated enamel binding protein)
Three main roles of fluoride
- makes fluorapatite
- chelates pyrophosphates
- blocks enolase (enolase inhibitor)