Parasitic protozoa 1 Flashcards
(35 cards)
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!
Characteristics of Trichomonadida…
Tritrichomonas (3-hair-uncut) foetus
- pear shaped, 3 anterior flagella, 1 posterior flagella, undulating membrane, no cyst stage.
- venereal, in human (T. vaginalis)
- Cattle: bulls (penis membranes inside sheath); cows (vagina, uterus, oviduct; swine (nasal); cats (digestive system)
- notifiable disease (infections 5 - 50% in Aus & USA)
- Lifecycle: stays in trophozoite form to decrease energy use, asexual binary fission (no cyst)
Name 2 symptoms of Tritrichomonas foetus in cattle (include bulls & cows)…
cows: vaginitis, placentitis, abortion
bulls: pain on micturition, decreased sexual servicing
Diagnosis of Tritrichomonas foetus in cattle (include bulls & cows)…
Bulls: 2 weeks sexual rest before testing, observing smegma
Cows: vaginal mucus/foetal tissue -> culture -> microscopy exam; PCR faster diagnosis
What are kinetoplastids?
kineto: moveable, plast: form
Leishmania & Trypanosoma
What is an amastigote?
a kinetoplastid without flagellum
What is a promastigote?
‘pro’ - anterior: an elongated kinetoplastid with flagellum at posterior end
What is an epimastigote?
‘epi’ - close: elongated kinetoplast posterior but not past nucleus with undulating membrane
What is a trypomastigote?
‘trypo’ - boring: kinetoplast with flagellum and undulating membrane all the way along parasite
A bit about Leishmania…
- Endemic to Mediterranean basin, Balkans, Asia, Africa, Sth America
- Can be cutaneous or visceral
- Lifecycle: see slide 52
- Clinical signs: weight loss, enlarged spleen & liver, decrease RBC prod. -> anaemia (no treatment -> death)
- Diagnosis: blood smear, biopsy of infected area, microscopy, culture, PCR
- Treatment: Cutaneous - liquid nitrogen (cryotherapy) or drugs
- Prevention/control: pesticides -> target vector
