Bacterial pathogenicity Flashcards
what are pathogenic bacteria?
bacteria that cause disease
what is a commensal organism?
organism in normal flora
what is pathogenicity?
ability to cause disease
what is virulence?
ability to cause severe disease
what are micro-organisms?
agents of infectious disease that are ubiquitous (found everywhere), most are harmless
give examples of microorganisms?
bacteria, fungi, virus, prion, parasite
what is colonisation?
when a microbe multiplies in a host
if a microbe form an individuals flora causes disease, the disease is said to be?
endogenous infection
if a microbe from outwit a patients body causes infection, the infection is said to be a?
exogenous infection
what does Koch’s Postulates or germ theory of disease ultimately show?
1 organism causes a particular disease
how may infection be transmitted?
- person to person
- fomites (object carrying infection)
- insect
- water
- food
how are prokaryotic cells different from eukaryotic?
Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle.
what is the prokaryotic capsule?
polysaccharide layer that lies outside the cell envelope of bacteria
what are fibre and what do they do?
arms- attach to specific surfaces
what is the function of a flagellum?
allow prokaryote to swim
pili are present in which type of bacteria?
gram negative
what are pili?
hair-like appendage found on the surface of many bacteria, they allow bacterial attachment
describe the structure of pili?
hollow core
which microbe accounts for the majority of urinary tract infections (UTI)?
E coli
what is the main defence to UTIs?
flushing action of urine
which protein binds specific e coli strains?
Tamm Horsfall protein
give examples of encapsulated infections?
meningitides, pneumonia, otitis media, sinusitis
what is the function of a capsule on prokaryotic cell?
immune evasion, adhesion
what are produced inside gram positive bacteria as part of growth and metabolism?
exotoxins
what are exotoxins?
toxins produced inside gram positive bacteria as part of growth and metabolism
toxins that are part of gram negative bacterial cell walls and are liberated when bacteria die are known as?
endotoxins
what are endotoxins?
toxins that are part of gram negative bacterial cell walls and are liberated when bacteria die
give a example of an endotoxin
lipopolysaccharide (LPS)
what is more potent, exotoxins or endotoxins?
exotoxins
