Normal microbiome of humans Flashcards
Most microoganisms in human microbiome are
Most are commensals, few contribute to health (beneficial) and fewer pose direct threats to health
When do humans are colonized with microbiome and changes with
Colonized at birth
Changes over time and according to the condition of the host (diet, environment, sex, occupation, etc.)
Microorganisms in human gut are usually associated with
Human body tissue
What is the change of the microbiome through 2 years of life
- At first only firmicutes (first 5 days)
- Then changes when there is fever or when introduced to solid food
What is the stability of the microbiome throughout the life
In infancy- the diversity is very low and the stability is low
Throughout the childhood and into the adulthood the stability increases
From the adulthood into the senior stability decreases
What is microbial cloud
The microbes that the person are emitting the organisms and you can differentiate two people with this clouds
Explain the structure of the skin
The upper layer->dead layer
Then underneath -> living actively replicating cells
Subaceous glands, apocrine sweat glands: secretes salt water, with various amounts of proteins, lipids, and sugars. Secrections are slightly acidic and have some antimicrobial effects (lipids and proteins)
Sebaceous glans surrounds the hair follicle
What is the purpose of the dead cell layer
Forms a tough layer barrier that prevents microorganisms from penetrating deeper tissues
What is the usual conditions on the skin
Dry, acid environment that does not support the growth of most microorganisms
The ducts that carry secretions to the surface are colonized by
A few well-adapted species (gram-positive)
The normal microbiome of the skin secretes
Bacteriocin that kills incoming competitors and protects- to a certain extent- against colonization by harmful bacteria
What anaerobes (aerotolerant) bacteria inhibit the skin
Propionobacterium acnes (in hair canals)
What organisms populate the skin
Yeasts, molds, bacteria
What organisms in specific populate the skin
Actinobacteria and firmicutes (gram-positive)
Proteobacteria -(gram-negative)
The type of microbiome on the skin depends on
The type of skin ( moist, etc.)
What bacteria populate the skin
Mycobacterium
Staphylococcus
Streptococcus