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parasitology, parasites - Coggle Diagram
parasitology
adaptations
survive phagocytosis
form vacuole to live within cells
resist acidic environment
multiplies by ingesting host metabolites
exploit host immune response
Leishmania, Trypanosoma cruzi and Toxoplasma gondii
survive in macrophages
perturb immune response induction
Giardia, Malaria and Trypanosoma brucei
antigenic variation
stop host developing immunity
chronic invasion
giardia
flagella can move
concave shape
removal blocked
malaria
changes shape of blood cell
blood cells filtered in spleen
malaria sequester in capillaries
Toxoplasma gondii and Trypanosoma cruzi
hide as dormant stages in immunoprivileged sites
hookworm
attach to esophageal muscles
has teeth
absorbs nutrients through surface
immune evasion trypanosomes
live outside of cells
surface proteins are decoy
change so avoid immune system
advantages and disadvantages
advantages
unlimited food
protection from predators
transportation
disadvantages
animals have immune system
systems in host can remove parasites
transmission
transmission
direct
trichomonas
inhabits urogenital tract
STD
enatmoeba histolytica
picked up by host from soil
giardia lamblia
lives in intestines
transmitted via poop
synchronising host and parasite life cycles
nematodirum battus
hatching delyaed until warm spring when lambs graze
lambs kept inside longer
hookworm
arrested development
dormant in host tissue in dry season
sensitive to desiccation
migrate to intestine and mature in rainy season
trichinella
transferred by eating infected muscle
carnivorism
found in pigs
indirect
intermediate hosts
vectors
schistosomes
snail releases Schistosome cercariae
parasite enters through skin
excreted in faeces
definitive host
has sexual stages
only in cats
has to go from intermediate to cat
eg toxoplasma gondii
human parasite interactions in history
2nd plague
black death
economic impact in europe
impact in england
impact in yorkshire
smallpox in americas
yellow fever in caribbean
typhus and DDT
microparasites
ebola
virus
salmonella
bacteria
giardia
protozoa
summary
small
multiply in host
cause transient infectoin
sterile immunity
eukaryotic parasites
similar in structure to host
chemotherapy
looks for unique pathways/ structural differences
immunity relies on unique antigens
macroparasites
includes
ectoparasites
ascaris
ticks
helminths
malaria
summary
largre
don't multiply in host
chronic infection
concomitant immunity
presence of parasite = protects against duperinfection
density dependent disease
classification
entamoeba histolytica
human pathogen
life cycle
direct transmission
two stages
cysts
trophozoites colonise large intestine
invade large intestine lining
causes symptoms
extra intestinal amoebiasis
trophozoites invae blood vessels
transported to other organs
gut infection
can cause fatal liver disease
treated with metronidazole
adpatations
upregulated adhesion
increased phagocytosis
proteins involved
lectin mediating epithelial adherence
pore forming peptide that lyses host cells
proteases that degrade host tissue
naegleria fowleri
facultative pathogen
can live without host
poorly adapted
opportunistic
enter nose during swimming in warm water
enter brain
destroy neurones
attaches to olfactory nerves
causes meningitis
almost always fatal
ubiquitous
mroe common with global warming
parasites
malaria
summary
plasmodium genus
200 species
host specific
mosquito vector
apicomplexa
top end is apical end
organelles focused here
intracellular parasites
human malaria species
falciparum
severe clinical disease
death
cerebral malaria
renal failure
malignant tertian malaria
goes through rbc
replicates every 48hrs
cyclical fevers
part of life cycle in them
sexual cycle
gametocytes at 2% parasitaemias
10 days to mature
males exflagellate
fuse to form zygote in mosquito midgut
anopheline mosquitoes
need haemoglobin to make eggs
vivax
equal prevalence to falciparum
benign tertian malaria
less mortality
relapsing malaria
parasites in dormant hypnozoite stage for long periods in liver
found in se asia
ovale
curtisi and wallikeri
not clear if separate species
tertian malaria
long incubation period
3 month interval relapses
found in africa
sporadically elsewhere
malariae
quartan malaria
slower cycle
3 day fevers not 2
no hypnozoite stage
relapses can occur 50 years post infection
knowlesi
zoonotic
found in humans
monkey malaria
occurs in se asia forests
most viable = most pathogenic
longer host life = more likely to transmit
human malaria summary
200 mil cases per year
619000 mortality per year
60% worlds population exposed to malaria
confined to tropical and subtropical zones
endemic
mosquito vector live here
life cycle
most of life are haploid
sexual stages in mosquito gut
fuse to become zygote
ookinete form
diploid
reduction division
form oocyst on gut wall
sporozoites
long, thin, crescent shape
injected into blood
infect liver
infect hepatic parenchymal cell
may pass kupffer cell
male and female
male
micro
have flagella
female
macro
adaptations
intracellular
shape
rests against cell rotate until apical end contacts cell membrane
apical complex
necessary to bind to cells
contain proteins
change characteristics of rbc
change gene expression via topology
pathogenesis
pathology due to rbc stages
anaemia
relapsing fever
hepatosplenomegaly
cerebral malaria
1% of infections
involves CNA
unarousable coma
block inside of capillaries to brain
cytoadherent pRBCs
later staegs
knob structure on rbc
expressed in trophozoites
prevent spleen clearing parasites
form rosettes
block capillaries
host factors
socioeconomic
genetic
immunological
host susceptibility
natural resistance
p. vivax
west africa
lack of rbc membrane protein
p. falciparum
sickle cell anaemia
haemoglobin gene mutation
single AA change
reduces oxygen carrying capacity so cells fragile
homozygotes die in childhood
glucose 6 phosphate dehydrogenase deficiency
treatment and prevention
drugs
chloroquine and primaquine
main drugs
chloroquine is safest
primaquine can remove infection from liver
resistance to drugs
DDT
2 drugs taken at one
no prophylaxis
novel compounds
artemisinin
chinese herbal medicine
act quickly
break endoperoxide bridge
hydroxyl and superoxide released
works inside parasite in rbc
vaccines
candidate antigens
vaccine trials
RTS,S/AS02A
tested on kids
1-4 years old
mozambique
39% cases prevented
29% severe cases prevented
efficacy reduces over time
limited success
liver best to focus on
parasite can't get around immune response
would affect liver health
stage specific antigens
LSA1
liver stages
MSA1/AMA1
surface proteins when parasite is extracellular
Circumsporozoite protein
sporozoite specific
covers surface
centre made of amino acids
provoke immune response
high antibody titres
involved in
sporogany
salivary gland incasion
gliding motility
liver cell invasion
Rapid detection test
inspect blood stain
used in areas without microscopes
like covid test
parasite factors
species of malaria
strain
drug resistance
vector specificity