Lecture 7: Acid fast bacteria Flashcards
(10 cards)
Give an example of an acid fast bacteria.
M. Tuberculosis.
What’s so special about acid fast bacteria? What’s so not special?
Thick waxy walls with a peptidoglycan base layer.
There are also additional layers of arabinogalactan, mycolic acid and lipids.
Because it’s so resistant to everything, it results in slow growth, and can take up to 12-18 hrs to proliferate.
Name the components of a flagellum. What is the flagellum made of? And by what bacteria is it characterised by?
Basal bodies, hook, filament. Made of flagellin protein, and characterised by cholera bacteria.
On what kind of bacteria are pilli mostly found?
On gram -ve and gram+ve bacteria.
What are capsules made of?
Polysaccharides.
Give an example of a bacteria with a capsule.
Streptococcus pneumoniae, very virulent. Cannot be stained, so negative staining used.
What are endospores?
Spores formed by bacteria which are specialised dormant structures. They cannot replicate, but are very resistant to heat, UV, chemicals and dehydration. As such, they have become the benchmark in sterilisation.
Bacillus anthracis is an example. Clostridium tetani is also another example, but is also a strict anaerobe.
What are the 5 oxygen relationship bacteria?
Strict aerobes: Require O2.
Strict anaerobes: Dies in O2.
Facultative anaerobes: Prefer O2, but can do without.
Aerotolerant anaerobes: Cannot grow in O2, but can live.
Microaerophiles: Best grown in low O2.
True or false? The way bacteria use pyruvate is not a method of classification.
False. Bacteria can be divided into those that ferment and produce lactic acid, or propionic acid, or ethanol etc.
What are the 3 sub categories of bacteria classification?
Morphology: gram positive?negative? Acid fast? Rod/cocci?
Biochemical behaviour: Product from pyruvate?
Surface antigens: Serotype, such as O, H in E. coli.
