Role of Microbial Biofilms in Dental Caries 낱말 카드

1500

Over how many total genomes have been identified in the human oral microbiome, belonging to bacteria, fungi, and viruses?

700

Approximately how many total bacterial species have been identified in the oral microbiome?

True

True or false: everyone has different oral microbiomes.

Age and host environment

What causes a shift in colonization of different species in the oral cavity?

False

True or false: the microbial community attached to the tooth's surface is the same as those found on the tongue or mucosa.

Specific niche

What describes the microbes that colonize specific sites having specialization in their genetic make-up?

Biogeography

What describes a distinct spatial structure of where these microbes are located within the oral cavity?

Complex structures

What is formed when different microbes aggregate/adhere together, which is needed for their growth?

Small

Are microbial cells small or large compared to host cells?

Rotund microcolonies

What structures are observed during dental caries and can be large or larger than individual host cells?

Structure

What correlates with function in microbial activities?

Biofilms

What are aggregates of microorganisms in which cells are frequently embedded in a self produced matrix?

Extracellular polymeric substances (EPS)

What do cells produce that allows for the cells to adhere to one another and to the surface they attach?

DNA, proteins, polysaccharides

What can EPS be composed of?

Numerous organs and tissues

Where are biofilms found in the body?

60-80%

What percent of human microbial infections are linked to biofilms?

Biofilm matrix

What is composed of EPS and is produced by cells within the biofilm and grows to encase the attached cells?

Support and protection

What is the biofilm matrix function?

90%

The composition of the biofilm matrix varies species to species and can account for what percentage of the biofilms dry weight?

Salivary pellicle

What is made of host and bacterial proteins, DNA, and polysaccharides, and coats the surface of the enamel?

Binding sites

Bacteria use adhesions to attach to ____________ contained within the pellicle.

Pioneer colonizers

What term describes the first bacterial species to adhere to the tooth surface?

Streptococcus

What species is the primary pioneer colonizers?

Bridging species

The attachment of the pioneer colonizers provides binding sites for additional species known as what?

Long, filamentous bacteria (fusobacterium and prevotella)

What type of bacteria are bridging species?

Late colonizers

After further biofilm maturation, what begin to emerge within the biofilm?

Gram negative anaerobes (porphyromonas)

What type of bacteria are late colonizers?

Stable

After formation of the biofilm, the microbial community is stable or unstable?

Commensalism

What type of relationship do oral microbial community members have with the host?

Acidic pH

In oral disease development, several species are lost because they are sensitive to what?

Cariogenic organisms

What species become emergent during oral disease progression that are tolerant to acidic pH?

Streptococcus mutans

A gram-positive, non-motile, facultative anaerobe that is the most abundant bacteria found in carious lesions

Glucosyltransferases (GTFs)

What enzymes does Streptococcus mutans encode for that convert carbohydrates into polymers of glucose?

Glucans

Polymer of glucose

Glucans

What accumulates extracellularly and provide attachment sites for streptococcus mutans binding and encase the cells within a biofilm matrix?

Rotund microcolonies

What structures do glucans aid in forming?

Rotund microcolonies

Extracted teeth from individuals with active caries show presence of what structures dominated by streptococcus mutans?

Acid

The rotund microcolonies are a "dome" that allow what to pool and accumulate at the enamel surface?

Streptococcus mutans

What organism is able to rapidly metabolize a wide range of carbs obtained from the hosts diet?

Fermentation

What process does Streptococcus mutans use to be able to convert carbs into organic acids such as lactate, acetate, ethanol, and formate?

5

Streptococcus mutans is able to survive and continue fermenting in acidic pH values below what?

Acidic end products

What do oral bacterias convert dietary carbohydrates into which reduce the enviornmental pH?

Demineralization

The rotund microcolony structures produced by Streptococcus mutans during biofilm formation trap and concentrate the acidic metabolic end products near the enamel surface leading to what?

Neutralize

What are saliva and other environmental buffers not able to do when acidic metabolic end products are trapped within the microcolony structure?

Grow and thrive

The low environmental pH kills off other oral bacteria, giving cariogenic organisms more space to do what?