pathogenicity and virulence Flashcards
habitat of saprophytic bact
environment, water, soil - recycling
mucus membranes, skin of animals and humans
pathogenic bact habitat
mainly animals, humans
environment
replication mainly in infected host
saprophytes host-mo interaction
symbiosis/mutualism
example of symbiosis
- bact of caecum of rabbit and horses, rumen of ruminants
- natural bacteriota
pathogenic bact host-mo interaction
parasitism
predator prey interactio
example of parasitism
fac pathogens - predisposing factors are needed for disease production
example of predator prey interactions
obligate pathogens
sources of infection
environment carrier animals through mouth, nose, eyes genitals skin faecal-oral route
infection host spectrum
euryxenic
stenoxenic
examples of euryxenic host spectrum
erysipelothrix rhusiopathiae
bacillus anthracis
examples of stenoxenic host spectrum
actinobacillus pleuropneumoniae, salmonella typhi
whats pathogenicity
ability of a microbe to damage a host
is pathogenicity quantitative
no qualitative
whats virulence
degree of pathogenicity
is virulence quantitative
yes
whats virulence connected to
certain bact isolate
whats pathogenicity connected to
one bact species - one host species
name three virulence variants
virulent
moderately virulent
avirulent
when can we measure virulence
only in animal trials
only in target animal species
validity of virulence
only in relation to certain strain and certain host species
whats MLD
min lethal dose
what MID
min infective dose
can virulence change
yes
causes for incr of virulence
passage in the host species
recombination - induced or spontaneous