bact/host interactions Flashcards
what is mutualism or symbiosis?
bacteria and host are benefited
what is commensalism
bacteria are benefited and the host is ‘unaffected’
what is parasitism
bacteria are benefited and the host is harmed
what is another name fore normal flora?
commensals
where are commensals located?
skin and mucous membranes
what is bacterial antagonism
where bacteria compete for attachment, nutrients and produce substances that inhibit
what are probiotics
beneficial bacteria
the use of probiotics enables what ?
competitive exclusion
what is a pathogen
any disease-causing microorganism
what is etiology?
the cause of the disease
what is pathogenesis
the process of disease development
what is pathogenicity
capacity of an organism to cause the disease
what is virulence
relative pathogenicity
what is attenuation
reduction in virulence
what is invasiveness
ability to enter, establish and spread in the body
what are Koch’s (4) postulates
- pathogen must be present in every case of the disease
- pathogen must be isolated from the infected host and grown in pure culture
- pathogen must cause the disease when inoculated into another host
- pathogen must be recovered from the inoculated host
are there exceptions to Koch’s postulates?
yes
-e.g. more than one bacteria cause one disease (V/v), polymicrobial infections, etc
what is an opportunistic pathogen?
causes disease only when conditions are favorable
what is a primary pathogen?
causes disease on its own
what is a secondary pathogen?
follows a primary pathogen, on its own it may or may not cause the disease
what is an extracellular pathogen?
grows and multiplies in the space and fluid surrounding the cells
what are intracellular pathogens
grows and multiplies inside the cells
what are the two types of intracellular pathogens
facultative and obligate
what are facultative intracellular pathogens?
grows and multiplies inside cells and outside cells
-can be cultured in bacteriological media