infectious agents Flashcards
infectious agent replication: explain how each of the different types of infectious agent replicate, recall the distinguishing features of each type (25 cards)
define virus
obligate parasite
what does a virus use to replicate
host cell nuclear synthetic machinery
what can viruses be made from
RNA or DNA
what do viruses do within a cell
hijack nuclear and protein machinery to produce more copies then bud out
what type of virus is HIV
retrovirus
what is a retrovirus
RNA virus which uses reverse transcriptase to produce DNA which incorporates itself into the nucleus of a host cell to produce many more RNA copies and proteins
components of bacteria
peptidoglycan cell wall, chromosomal DNA, some have plasmids
how do bacteria divide
binary fission
Shigella spp. transmission
fecal-oral
what does Shigella spp. target
GIT
how does Shigella spp. move
uses host actin
what does meningitis block
blood supply to limbs
stages of meningitis
colonisation → septicaemia (septic shock → severe inflammatory response) → cerebrospinal fluid and brain
4 types of fungi
yeasts/filaments, cutaneous, mucosal, systemic mycoses
Candida as yeast and filament
yeast (bud), filament (hyphae) or both
main feature of protozoan
unicellular
how do protozoa divide
binary fission or trophozoites (feed off host)
transmission of protozoa
ingestion or vector
what type of protozoa is malaria
plasmodium
what is the vector for malaria
female Anopheles mosquito
what are the symptoms of Leishmaniasis
skin lesions, swollen liver
what are the vectors for Leishmaniasis
sand flies and dogs
what three types of worm are Heminth parasite
roundworms, flatworms, tapeworms
where do heminth parasites have their lifecycle
outside a human host
