8. Human Microbiome Flashcards
what is a microbiome?
all of the living Microorganisms in an environment
Microbiome vs microbiota
microbiome
- the entire habitat including the Microorganisms their genomes and the surrounding environmental conditions
microbiota
- the microorganisms present in a defined environment
what is one health?
studies looking at the link and interactions between humans, animals and the environment with disease
The importance of environmental biomes
without microorganisms we wouldn’t be here
bacteria and fungi are everywhere and are essential to life
what are the 3 host-microbe interactions?
Commensalism = one party benefits, the other is neutrally affected
Mutualism = both parties benefit
Parasitism = one party benefits, the other is harmed
what is a core microbiota?
a common set of microorganism that are present in a set of host eg all humans
- shared similarities within species but still individualised
- changes over time but many microorganisms present for many years
what can the core microbiota help us identify?
dysbiosis - the state of disease
can be used for diagnosis and monitoring can be used for prophylaxis
what do microorganisms acquired from birth develop into?
a distinct microbiome through environmental and genetic factors
what does a healthy microbiota look like?
- attached to the epithelial cells
- forms a protective layer on top of the cell
- produce antimicrobial peptides as prophylaxis and to keep the microbiota in check
what happens with depleted microbiota?
- less protection
- bacteria can get through the epithelial barrier
- cause disease
what can disrupt the normal microbiota?
- exposure to antibiotics
- changes in health or immunity
- hormonal changes
- local trauma
what microorganisms tend to be in the skin microbiome?
- Staphylococcus aureus
- Pseudomonas
- Streptococcus
what microorganisms tend to be in the Ear microbiome?
- Staphylococcus
what bacteria are mostly in the internal microbiota?
gram negatives and anaerobes
what microorganisms tend to be in the Oropharynx microbiome?
- Staphylococcus
- Viridans streptococci
- neisseria
what microorganisms tend to be in the stomach microbiome?
- helicobactor
what microorganisms tend to be in the small intestines microbiome?
- Lactobacillus
- bacteroides
- enterobacteriaceae
what microorganisms tend to be in the large intestines microbiome?
- Bacteroides
- fusobacterium
- E. coli
- Proteus
- klebsiella
- peptostreptococcus
- Enterococcus
what microorganisms tend to be in the vagina microbiome?
- Lactobacillus
- gardnerella vagunalis
- candida
Strep. Pneumonia
- infects the nasopharynx
- gram positive diplococci
- pneumolysin that breaks down cells
- causes meningitis and sepsis
- it has a range of effect depending where it is found
Pneumonia
- bacterial, viral or fungal
- viral pneumonia is a big problem
- most pneumonia causing microorganisms we can carry as commensals with no problem
what are biofilms?
an aggregate of microorganisms attached to a surface and/or each other, often embedded in a self produced matrix consisting of extracellular polymeric substances
why are bioflims a preferred mode of growth for microorganisms?
- the matrix is a protective physical barrier
- micro niches form with anaerobes on the inside of the biofilm and aerobes on the outside
- quorum sensing can occur easily
- sharing of plasmids and genetic information is easy and efficient
what are the 5 stages of biofilm formation?
- attachment - van Der Waals or ionic forces
- colonisation
- production of matrix - recruit proteins and microbes
- maturation
- dispersion - breakdown of the matrix and leaving the biofilm