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Cell Structure of Plasmodium Falciparum

Welcome back

So, this week we will explore a little deeper into the world in of Plasmodium falciparum. We will get up close and personal with these parasites. But not too close.

The size and shape of these parasites depend on stages in development. The following includes a table of the various existing forms in humans along with their relative sizes and shapes:

 

Ring form:	Usually Ring Shaped.
Trophozoites	small, delicate and measures 1.25 -1.5 µm in size. They are kidney-shaped
Schizonts:	4.5-5 µm in diameter and occupy about 2/3rd of the infected RBC. Once they have matured they contain 10-30 merozoites that are arranged in a grape-like cluster.
Gametocytes:	The sexual forms of this parasite are usually 7-14 microns are and are banana shaped.
Sporozoites	Sickled shaped structure with equally pointed ends. Size includes 10-15 µm in length
Ookinete and Oocyst:	Spherical shaped.

 

http://www.infectionlandscapes.org/2011/03/malaria-part-1-parasite.html

Plasmodium Falciparum are single-celled eukaryotes. To study their movement, we can thank Alfonse Laveran who studied these organisms extensively in the bodies of individuals affected in North Africa. Fun fact, he won a Nobel Prize in Physiology for his discoveries of parasitic protozoans and their causative nature of diseases like malaria. While in their adult stage they are not motile, and their mode of movement is classified as Sporozoa. There are stages during its life cycle when it is motile and those stages include the sporozoite, trophozoite, and merozoite stages.

https://www.researchgate.net/figure/Schematic-representation-of-the-Plasmodium-falciparum-mitochondrial-genome-In-green-are_fig8_277721542

The mitochondrial genome of these parasites is 5967bp, shown in the schematic above. The green shows the three protein-coding genes of the mitochondrial genome of the parasites. On the Cytochrome b gene, used for Plasmodium diagnostic in this study, the position of the two SNVs (single nucleotide variations) (Délicat-Loembet et. Al 2015). The genome of the parasite continues with around 24-megabase genome which is AT-rich and is organized into 14 chromosomes. Over 5,300 genes have been described by these parasites. Within the genome more data has been recorded in which there exist 59 var, 149 rif, and 28 stevor genes. There are also reports of multiple pseudogenes and truncations.

The Plasmodium species have a very unusual gram stain and have been shown to elicit a positive or negative stain depending on the overall form. The CDC website showcases gram stains of each form of the Plasmodium Falciparum parasite.

https://www.cdc.gov/dpdx/resources/pdf/benchAids/malaria/Pfalciparum_benchaidV2.pdf

Anatomical Schematic of Plasmodium Falciparum

 

 

http://jcs.biologists.org/content/116/18/3825