Ring forms: Difference between revisions
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(Created page with " ---- '''What is a ring form''' <gallery mode="nolines" widths="220px" heights="220px" > File:Ring_cartoon.jpg|link={{filepath:|MFETr.jpg}} </gallery> The earliest stage following red cell invasion has a typical ting form: *a = chromatin dot *b = digestive vacuole *c = parasite cytoplasm ---- <span style="color:navy>'''Description'''</span> At the earliest stage of red cell infection parasites have a ring form and distinction between species may not be easy (or ev...") |
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At the earliest stage of red cell infection parasites have a ring | At the earliest stage of red cell infection parasites of all species have the form of a "ring". Distinction between species at this stage may not be easy (or even possible). However as the parasite mature and develop differences between species become more apparent. In some species the ring appearance is maintained until late stages of maturation, in others there is loss of a typical ring appearance | ||
*''P.falciparum'' Typically small and delicate, | *''P.falciparum'': Typically the rings small and delicate, rings tend to persist from early trophozoite until late stages although they may thicken | ||
*''P.ovale'' | *''P.ovale'': Typical rings are large and robust and this shape may persist until late stages of development (contrast with ''P.vivax'') | ||
*''P.malariae'' | *''P.malariae'': Rings are small but more substantial that ''P.falciparum'' becomeing solid or bad and losing the ring appearance as they develop | ||
*''P.knowlesi'' Early forms resemble ''P.falciparum'' | *''P.knowlesi'': Early forms resemble ''P.falciparum''; as they mature they often extend and become solid or band-like resembling ''P.malariae | ||
*''P.vivax'' Early stages appear as rings | *''P.vivax'': Early stages appear as rings becoming irregular then eventually taking on a more typical amoeboid appearance at later stages | ||
Revision as of 17:25, 8 March 2024
What is a ring form
- Ring cartoon.jpg
The earliest stage following red cell invasion has a typical ting form:
- a = chromatin dot
- b = digestive vacuole
- c = parasite cytoplasm
Description
At the earliest stage of red cell infection parasites of all species have the form of a "ring". Distinction between species at this stage may not be easy (or even possible). However as the parasite mature and develop differences between species become more apparent. In some species the ring appearance is maintained until late stages of maturation, in others there is loss of a typical ring appearance
- P.falciparum: Typically the rings small and delicate, rings tend to persist from early trophozoite until late stages although they may thicken
- P.ovale: Typical rings are large and robust and this shape may persist until late stages of development (contrast with P.vivax)
- P.malariae: Rings are small but more substantial that P.falciparum becomeing solid or bad and losing the ring appearance as they develop
- P.knowlesi: Early forms resemble P.falciparum; as they mature they often extend and become solid or band-like resembling P.malariae
- P.vivax: Early stages appear as rings becoming irregular then eventually taking on a more typical amoeboid appearance at later stages
These changes are illustrated for early and late trophozoite below:
P.falciparum
Small and often delicate rings at early stages, these thicken at later stages, although they remain relatively small with a "ring appearance"
P.ovale
Robust rings that enlarge during parasite development, although the ring form can often still be distinguished
P.malariae
Small but more robust than P.falciparum, the parasites become more solid as they develop and may extend as a band across the cells
P.knowlesi
small or normal P.malariae (round)
normal sized P.falciparum (round)
ormal or enlarged P.ovale (may become ovoid)
P.vivax
small or normal P.malariae (round)
normal sized P.falciparum (round)
ormal or enlarged P.ovale (may become ovoid)
Species significance
These changes can be very helpful in identifying malaria species