Microbiologie: Les grands groupes de microorganismes (monde microbien) Flashcards
What are the steps for the classification of living beings?
D, K, P, C, O, F, G, S (sub-s)
Domaine, règne (not defined for bacteria), embranchement, classe, ordre, famille, genre, espèce —> souche (sous-espèce)
What is the classification for E. Coli? (D, K, G, S, S)
D: Bacteria
K: N/A
G: Escherichia
S: coli
sub-S: Sakai (sérotype O157:H7)
What are the classification types according to domain?
- Bacteria —> procaryotes (no nucleus/sophisticated organelles)
- Archaea —> procaryotes (no nucleus/sophisticated organelles)
- Eukaryotes —> have nucleus
What is the most evolved plyla of bacteria?
Proteobacteria —> most pathogens belong in this phylum
What is believed to be the origin of mitochondria and chloroplasts?
Mitochondria: endosymbiotic bacteria
Chloroplasts: chloroplasts
Where are most archaea found?
Extreme environments except for methanogens which are in the gut
What are the kingdoms (règnes) in pro and eukaryotes?
Prokaryotes: N/A
Eukaryotes: protists (unicellular eukaryotes), *fungi* (mycètes), plants (*Algus vertes*) and animals
How are viruses and prions categorized?
They are not considered living, but are associated to all other branches of living things
Although their specific hosts are usually limited to certain taxonomic ranks and sometimes even limited to one species
How do viruses work?
They are semi-autonomous replicons that need to infect host in order to replicate using the hosts own “machinery”, once replicated they can leave host and infect others
Why are viruses so hard to treat?
They use our own bodies mechanisms so it would be hard to treat them without killing our own cells
How do prions work?
They are misfolded proteins that work as pathogenic agents able to cause a cascade of conformational changes in healthy proteins that can lead to damage within cells and tissues
**DO NOT REPLICATE —> CAUSE A CASCADE**
What does the word microorganism mean?
Term representing bacteria, viruses, fungi, and protozoa
What do bacteria, viruses, fungi, and protozoa have in common? (7)
- Small size, need a microscope to see them
- Omnipresent/abundant in nature
- Unicellular (some fungi can be uni and pluricellular)
- Simple organization/structure
- Includes prokaryotes and eukaryotes
- Able to accomplish metabolic processes (except viruses)
- Capable to reproduce autonomously (except viruses)
What are the different ways to classify and identify bacteria?
Classification: taxonomy
Identification: knowing what it is
- Genotype: genetic constitution
- Phenotype: observable characteristics
What are the 5 tools used for classification and identification?
- Morphology: form, elevation, border, colour, transparency, and surface aspect
- Biochemical
- Serological (antibodies)
- Physico-chemical
- Genetics