Normal microbiota Flashcards
What affects normal microbiota?
Age, genes and gender
What are the sterile sights on the body free of microorganisms?
Blood
Cerebro spinal fluid
Brain
Muscles
What are the beneficial effects of normal flora?
Inhibits pathogens due to being out competed by flora.
Production of vitamins and flora induces antibody production.
What are the harmful effects of normal flora?
Bacterial synergism.
Potential to cause disease if they gain access to comprimised tissue or if host becomes immunocomprimised.
How does skin act as a defence against pathogens?
Hostile environment due to low moisture and high concentration of salt. Acidic pH, shedding of skin, lysozymes found in sweat and there are antimicrobial peptides.
How do normal microbiota form in the mouth?
The mouth is a good environment if microorganisms grow in the form of biofilms so to be able to stick.
Give an example of a bacteria that grows in the nose and throat
Staphylococci
How can microorganisms survive in the stomach?
If they transit rapidly or if particularly resistant to gastric pH
How does the small intestine stop colonisation of harmful bacteria?
Bile, shear forces and proteolytic enzymes. Plus oxygen concentration declines towards ileum.
How is normal flora altered in the large intestine?
Stress, altitude, diet, disease and antibiotics
How does the vagina protects itself from colonisation?
Complex microbiota over a large surface area, secretions and glycogen production which gives low pH
What’s the role of normal microbiota?
Colonisation inhibition:
Occupying adhesion sites, alteration of physiochemical environment (pH)
Host nutrition:
Breakdown of residual nutrients in intestines and synthesis of vitamins.
Detoxification:
Metabolic diversity of gastrointestinal bacteria can aid detoxification of harmful dietary compounds.
