BT1: Intro to bacteriology 1 Flashcards
State the 6 different shapes of bacteria.
Cocci
Bacillus
Spirochete
Filamentous
Spirillum
Appendaged or budding bacteria
How are bacteria arranged?
As chains (strepto) or clusters (stapho).
State the 5 shapes of colonies.
Circular
Rhizoid
Filamentous
Irregular
Spindle
State the 6 margin shapes of colonies.
Entire
Undulate
Lobate
Rhizoid
Filamentous
Curled
State the 5 elevations of colonies.
Flat, raised, convex, pulvinate, umbonate.
What colour do the types of gram-bacteria stain?
Gram-positive stains purple
Gram-negative stains pink.
What is the difference between gram positive and negative bacterial cell wall?
Gram positive bacteria has a thick peptidoglycan cell wall.
Gram negative bacteria has a thin peptidoglycan cell wall and the outer membrane contains lipopolysaccharide (LPS).
What is the acid fast cell wall?
A cell wall composed of mycolic acid, arabinogalactan, capsular complex free lipids & lipoarabinomannan.
Stains red with modified ZN stain.
Define bacterial capsule.
A protective coating secreted on the outer surface of the cell wall.
Define flagella.
Filamentous proteins that provide the bacteria with motility.
Define fimbriae.
Special adhesins, non-filamentous flagella that provide bacteria with motility.
Define endospores.
Highly differentiated cells that are resistant to damage.
What is the other name for fimbriae?
Pili
What is the function of the bacterial capsule?
It protects the bacteria against phagocytosis because it makes the bacteria slippery.
What is the composition of bacterial capsules?
Usually polysaccharides & sometimes polypeptides.
How does flagella provide motility to bacteria?
The filament is associated with a complex motor protein. The filament rotates to provide motility.
What does TLR stand for?
Toll-like receptor
What do TLR do?
They recognise bacterial features (fimbriae, flagella, LPS, peptidoglycan cell wall).
Where are TLR found?
Attached to leukocytes.
What does TLR1 recognise?
Lipoproteins
What does TLR4 recognise?
LPS & lipoteichoic acid
What does TLR5 recognise?
Flagellin monomers
What does TLR9 recognise?
Unmethylated DNA motifs
What does MAMPs stand for?
Microbial-Associated Molecular Patterns
