Oral Microbiology Lecture 2: Biofilms

What is dental plaque an example of?

Biofilm

What are the four general stages in biofilm formation?

1. Attachment to surface

2. Secrete matrix components

3. 3D shape

4. Detachment of biofilm residents

How much of human bacterial infections involve biofilm-associated organisms?

80%

What are free-floating microorganisms called?

Planktonic

What is the difference between microorganisms that grow planktonically and those that grow in biofilms?

Express distinct set of genes

What is the communication technique used between cells in biofilms?

Quorum sensing

What three characteristics of biofilms make them more tolerant to antimicrobial agents?

1. Drug-neutralizing enzymes

2. Resistant structure

3. Slow replication

What is the main way to treat a biofilm?

Physical removal

What surfaces of the mouth does plaque accumulate most often on?

Non-shedding surfaces

What are the four steps for dental plaque formation?

1. Pellicle formation

2. Early colonizers

3. Co-aggregation

4. Mature biofilm

Are pellicles that form on different oral surfaces identical or different?

Different

Which bacteria group are the early colonizers in dental plaque formation?

Streptococcus mutans

What is the most common bacteria to join in co-aggregation for dental plaque formation?

Actinomyces

What are the three bacteria in the red complex for periodontitis?

1. T. denticola

2. T. forsynthia

3. P. gingivalis

What type of pathogens cause most dental diseases?

Opportunistic

Which cognitive disease is associated with the red complex for periodontitis?

Alzheimer's

Which malignancy is associated with F. nucleatum and F. alocis?

Colorectal cancer