Oral Ecology Flashcards
How does a pathogen infection a host
Enter
Attach
Colonize
Evade host immunity
Produce harmful proteins
Disseminate
Release form host
Pathogenicity
Ability to cause disease
Virulence
Ability to cause severe disease
Pathogen
Pathogen is an organism capable of causing disease
Koch postulate
- Pathogen must be present in every case of the disease
- Isolate pathogen form host and reproduce in culture
- Reintroduce grown pathogen in a susceptible host
- Microbe must be recovered from an experimentally infected host
Do oral microorganisms exist in isolation
No
Ratio of microorganisms to body cells
10:1
Estimate of the number of bacteria, fungi and viruses in our body
Fungal 10^12- 10^13
Bacteria 10^13-10^14
Virus 10^14-10^15
Microbiome
All microorganisms in a particular ecosystem
Usually describes the community of microorganisms in a particular place
How many different species of microbes are there on our body
10k
How do we acquire our resident flora?
From delivery (c section vs natural birth)
From feeding (formula vs breast milk)
What we eat influences the gut microbiome
From socialising
Geographical location
Family members
Host interactions
Maternal diet
Do families have more similar microbiome
Yes
Benefits of normal flora
- Synthesis of vitamins K and B12
- Prevent colonisation by pathogens, competes with pathogens
- Stimulate the production of antibodies, builds tolerance
- Anti inflammatory
How does the body create tolerance
Exposure to microbes and the normal flora
Body stimulates low levels of antibodies against normal flora , preventing infection of invasion
Does the microbial biomass increase or decrease from the stomach to the colon
Increase from 10^2 to 10^11 in the colon
What affects the microbial biomass
Low pH
Saliva
Immune system
Finding a place to attach on the intestinal wall
Surviving a widely varied diet
What does a faecal transplant do
You place a donor’s faeces in the colon of the patient and over the next few weeks the patient;s gut microbiome will change
What factors influence the microbiome
Drugs
Lifestyle
Geography
Diet
Infections
Effects of drugs and antibiotics on the microbiome
Antibiotics kills infectious bacteria but also disrupts the natural flora
digestive problems
Increased susceptibility to infections
Accumulation of antibiotic resistance
Chemotherapy drugs can modify gut flora; and the gut flora can also alter drugs. This can cause unwanted side effects like digestive problems, nausea etc
Factors in the oral cavity affecting bacterial growth
Saliva
PH
Temperature
Immune system
What is bio geography
Different locations in the mouth have different microbiome
Eg. Subgingival plaque vs dorsum of tongue
Factors that drives dysbiosis of the oral microbiome
Genetic
Salivary flow rate
Oral hygiene
Diet
Smoking
Antimicrobial agents
What happens when you eat a high carb diet
Organic acids produced (H+) which causes demineralisation
Incipient dysbiosis
In gingivitis
There is dysbiosis but still proportionate host response
Frank dysbiosis
Pathogenic biofilm
There is disproportionate host response
How can you determine oral disease risk using technology?
Collecting microbiome data using 16s rRNA gene
Depending on what type of microorganisms you have in your mouth, there is different oral disease risk
What systemic diseases are linked to the oral environment
Obesity
Diabetes
Liver diseases
Pancreatic cancer
Colon cancer
Why should we know about oral microbiome as a diagnostic tool?
You can predict the oral disease risk and use it as a preventative tool.
16s rRNA
