Parasitic protozoa 1 Flashcards
Protozoa are…
- everywhere
- motile
- unicellular eukaryotes
- highly diverse
- symbiotic & commensals: rumen
- parasitic: vertebrate & invertebrate hosts
What are extracellular protozoans?
- live inside body, outside cell
- intestinal tract
- blood
- antigen masking
What are intracellular protozoans?
- penetrate host cells
- invasive
- parasitophorous vacuole
- invade immune cells
What is Sarcodina?
protoplasm amoebae
- contains pseudopodia (extension of cytoplasm shape changes)
- remainder flows forward
- reproduce asexually via binary fission
Amoebae causing emoebic gill disease (AGD)?
Neoparamoeba perurans
translates to: ‘new-by the side of- amoeba inflamming’
N. perurans and economic effects…
- fatal disease
- affects marine fish eg. Atlantic salmon
- costs AUS $230 million /year
- also affects USA, NZ, France, Spain, Ireland & Chile
Characteristics of N. perurans…eg. shape, size etc.
14-50mm sub-spherical many pseudopodia different species very similar identified via PCR
N. perurans life cycle…
live & reproduce on gills & reproduce via binary fission -> trophozoites transferred thru water -> into gills of other fish to start cycle again
N. perurans symptoms, contributing factors & diagnosis…
symptoms: affect gills (resp & excretory system) turn them whitish thru tissue/capillary damage -> extensive multifocal mucoid lesions. Histopath: hyperplastic lamellar fusion
contributing factors: water >16 degrees, crowding & poor water circulation in sea pens
diagnosis: wet mount obs, histopath., molecular techniques (PCR assay)
Entamoeba histolytica…recall everything!
‘inside’ amoeba ‘tissue lysis’
Primary host - human (can also be apes, dogs, cats, pigs)
Live in large intestine
2nd most common cause of parasitic death (1/9 pathogenic)
Life cycle: (draw picture) orally ingested -> LI lives & reproduces -> trophozoites & cysts excreted in faeces (cyst infective) repeat cycle…
clinical signs: mostly asymptomatic, diarrhoea, gas, stomach pain/cramps, bloody diarrhoea, anaemia, fatigue, malnutrition, liver abscesses…
diagnosis: stool sample microscopy (cysts), trophozoites from biopsy, ingested RBCs, WBCs or bacteria
control & prevention: insects (flies/cockroaches), personal hygiene, fruit&veg, pasteurised milk, boiled water
treatment: symptomatic or asymptomatic
What is zoomastigophora?
flagellate - draw!
Structures include: elongated general shape, flagellum, photoreceptor, contractile vacuole, pigment shield, chloroplasts, stored polysaccharides (photosynthesis), nucleus & nucleolus, undulating membrane
Characteristics of zoomastigophora…
move via flagella
also have undulating membrane
reproduce via asexual & binary division
Name the flagellates (include taxonomy)
Diplomonads (Giardia)
Trichomonadida (Trichomonas)
Kinetoplastida (Trypanosoma & Leishmania)
Characteristics of Giardia…
Giardia intestinalis (diplomonad) ‘double one, unit’
Host: diverse including humans
Lifecycle: cyst & trophozoite excreted in faeces -> only cyst survives -> contaminates food/water/hands etc. -> ingested -> intestines -> grow & reproduce -> repeat cycle
Routes of infection: fmily member, water, raw/undercooked food/unprotected anal sex
Clinical signs: diarrhoea (also fatty dia.), abdo. cramping
Diagnosis: stool Ag test, stool exam
Treatment & prevention: if no/mild symptoms - no treatment; meds if severe/persistent; persons working in day care/nursing. Boiling, iodine, hygiene techniques, safe sex, wash/peel fruit
What does Giardia look like?
draw!
