Session 2 Flashcards
(20 cards)
What are the three shapes of bacteria?
- coccus (ball)
- spirillus (wiggly line)
- bacillus (rectangle)
How can cocci be arranged?
- clusters
- chains
Why would a bacteria be gram positive or gram negative?
Gram positive - first stain given retained as outer layer of peptidoglycan is quite thick.
Gram negative - don’t retain first stain due to thin outer layer membrane is thin.
What’s an obligate anaerobe?
Requires an oxygen free environment for survival
Name 6 gram positive cocci.
- staph aureus
- coagulase negative staph
- alpha haemolytic strep
- beta haemolytic strep
- streptococcus pneumoniae
- enterococcus faecalis
She came after Betty saw Ethan
Name 4 gram positive bacilli.
- listeria monocytogenes
- bacillus anthracis
- bacillus cereus
- clostridium difficile
‘Later Betty brought’
Name 4 gram negative cocci.
- Neisseria meningitidis
- neisseria gonorrhoeae
- moraxella catarrhalis
- acinetobacter baumannii
Nancy nice monkey anklets
Name 6 gram negative bacilli.
Escherichia Coli Klebsiella pneumoniae Proteus species Salmonella typhi Pseudomonas aeruginosa Haemophilus influenzae
Ethan knocked Percy’s sandwich pretty horribly
What are the mechanisms of bacterial pathogenesis?
Virulence factors
- host entry
- adherence
- invasiveness
- iron sequestration
Toxins
- exotoxins
- endotoxins
Give 4 differences between prokaryotes and eukaryotes
- nucleus: eukaryotes is membrane bound, prokaryotes is circular
- cell wall: eukaryotes in plants, prokaryotes usually present
- ribosome: eukaryotes 80s prokaryotes 70s
- membrane bound organelles: eukaryotes yes prokaryotes no
What are the two types of fungi?
Yeasts- single called
Molds - multicellular
What yeast causes thrush?
Candida albicans
What are the two types of parasites?
- Protozoa (single called)
- helminths (multicellular)
What are the mechanisms of infection?
- inoculation
- ingestion
- inhalation
- vector
- vertical transmission
What is supportive treatment?
- symptom relief
- physiological restoration
What is specific treatment?
- antimicrobials
- surgery
What type of bacteria is sepsis usually associated with???
Gram negative
What are the two main groups of toxins that arise from bacteria and what is the difference?
Endotoxins — part of the bacteria structure e.g. outer lipopolysaccharide layer found in gram negative bacteria
Exotoxins - proteins secreted by bacteria that go out into the surrounding blood and tissue. They can damage tissue by a number of different mechanisms.
What’s the best way to diagnose a viral infection??
Viral PCR
What colour to gram Positive stain?
Purple
Negative are later stained pink as don’t retain first stain
