Structure, Properties of Parasites, and an
Overview of Common Parasitic Infections
,Structure of Parasites
Protozoa are unicellular eukaryotic organisms; most possess a nucleus,
mitochondria, endoplasmic reticulum, and specialized locomotor organelles
like flagella, cilia, or pseudopodia.
•They exhibit polymorphism: trophozoite (active, feeding) and cyst (resistant,
infective) forms.
•Surface antigens and secretory proteins help in attachment, immune
evasion, and host cell invasion.
•Flagellated protozoa (e.g., Giardia, Leishmania) have kinetosomes and
axonemes essential for motility.
•Apicomplexans (e.g., Plasmodium, Toxoplasma) possess an apical complex
for host cell penetration.
•Protozoa do not have a rigid cell wall but possess a pellicle that provides
structural integrity and motility.
,
Overview of Common Parasitic Infections
,Structure of Parasites
Protozoa are unicellular eukaryotic organisms; most possess a nucleus,
mitochondria, endoplasmic reticulum, and specialized locomotor organelles
like flagella, cilia, or pseudopodia.
•They exhibit polymorphism: trophozoite (active, feeding) and cyst (resistant,
infective) forms.
•Surface antigens and secretory proteins help in attachment, immune
evasion, and host cell invasion.
•Flagellated protozoa (e.g., Giardia, Leishmania) have kinetosomes and
axonemes essential for motility.
•Apicomplexans (e.g., Plasmodium, Toxoplasma) possess an apical complex
for host cell penetration.
•Protozoa do not have a rigid cell wall but possess a pellicle that provides
structural integrity and motility.
,
