Intro to microbiology Flashcards
What are commensal microbiota?
microbial flora associated with the human body that can be beneficial.
What is Koch’s Postulates?
criteria used to decide if a micro-organism caused a disease
What does Koch’s postulates state?
Causative organism must:
- be isolated
- cultivated artificially
- typical symptoms of infection must result
- should be recoverable from individuals infected experimentaly
What is Koch’s Postulates for genes?
Genes encode virulence factors.
-introduction of gene should transform strain into one that causes disease
What are the structural components of a virus?
1) have a nucleic acid core
2) protein coat
3) Enveloped or naked
3) DNA or RNA
A virus has a nucleic acid core surrounded by a protein coat. What is the protein coat made up of?
Protein coat is made up of units called capsomeres.
All fungi are …
a) eukaryotic
b) prokaryotic
All fungi are EUKARYOTES
What is the cell wall of fungi made of?
Chitin
Moulds are fungi that grow in mats of tiny filaments. What are the filaments and mats known as?
Filaments = hyphae mats = mycelia
What is the role of septa in moulds?
Septa separate the mats of fungi into compartments
What is the name of unicellular fungi?
yeasts
What type of fungi is ringworm and athlete’s foot?
mould
What is thrush caused by?
Candida Albicans
What type of cells are protists?
a) unicellular eukaryotes
b) unicellular prokarytoes
Protists are unicellular eukaryotes
What are the 4 classes of protista?
1) apicomplxa (formerly sporozoa)
2) flagellat protista
3) ciliate protista
4) amoebae
Give examples of diseases caused by protists
1) toxoplasmosis
2) amoebic meningitis
3) malaria
4) trypanosomiasis
5) leishmaniasis
6) amoebic dysentery
What protist can cause a foul smelling vaginal discharge?
Trichomonas vaginalis
What type of cell are bacteria?
a) eukaryotes
b) prokaryotes
prokaryotes
Bacteria lack a membrane bound nucleus.
What is the difference between gram positive and gram negative bacteria?
Gram positive:
- thick peptidoglycan wall
- stain violet / purple
Gram Negative :
- thin peptidoglycan wall
- stain red / pink
What is the function of a capsule (in bacteria)
Some bacteria are enclosed within a capsule.
This helps protect the bacterium (even inside phagocytes) so helps to prevent the bacteria from being killed.
Where do “coagulase negative” staphylococci live?
skin
What are endospores?
endospores are produced by bacteria. They are resistant so protect against heat and radiation.
What are the different routes of person to person infection?
1) airborne (inhilation of infetious droplets)
2) faecal-oral
3) sexually transmitted
4) direct inoculation
5) animals
6) objects
What diseases are spread via faecal-oral route?
- Typhoid
- cholera
- dysentery
- Hepatitis A
- poliomyelitis
What diseases are spread via animals?
- malaria (mosquitoes)
- salmonella enterica
What are fomites?
vectors of infection that are objects such as pens
In what diseases does an individual not need to encounter the live micro-organism but can get the disease due to exposure from the toxin?
1) tetanus
2) botulism
3) ergotism
What are the mechanisms by which bacteria cause diseaseʔ
1) produce structure which enable them to ATTACh to the surface at which they cause disease.
2) poduce toxins
3) produce aggressins
