Svetlana Ernstovna Mogilevtseva
Alexey Romanovich Lyashuk
Class 3.
Topic: Medical protozoology. Apicomplexa and
Ciliophora.
Plasmodium falciparum
Balantidium coli
Toxoplasma gondii
, 1. Characteristic features of the phylum Apicomplexa.
Malaria parasites: varieties, Latin name and taxonomy; morphology, transmission
routes and sources of infection, life cycle, laboratory diagnostics and preventive
measures.
• Phylum Apicomplexa.
• Class Sporozoa
They are intracellular parasites.
• Their life cycle is often associated with the change of hosts and alternation
of sexual and asexual reproduction.
• Asexual reproduction occurs in the body of an intermediate host through
endodyogeny or schizogony. As a result many daughter organisms -
merozoites - are formed from the trophozoite.
Schizogony of malarial parasites in liver cells and red blood cells.
, Phylum Apicomplexa.
Class Sporozoa
• Sexual reproduction occurs in the body of the definitive host. It begins with
gametogenesis when male and female gametes are formed. Then
fertilization and the formation of the zygote occur. The zygote covered with
membranes is called an oocyst. Sporogony occurs in the oocyst and
sporozoites are formed.
Sexual reproduction of malaria Plasmodium in the body of a mosquito
, Morphology of Toxoplasma gondii as an
example
• Trophozoites do not have organelles of
locomotion, digestive and contractile
vacuoles. Feeding and excretion occur by
means of osmosis.
• On the outside of the body is covered with a
three-layer pellicle. Under the pellicle there
are fibrils and microtubules (1) which perform
supporting and contractile functions ensuring
the movement of the parasite.
• At the anterior end of the body there is a
conoid (2) which looks like a truncated cone
the walls of which consist of spirally twisted
fibrils. In Haemosporida there is no conoid. At
the top of the conoid there are two dense
polar rings. The conoid performs a supporting
function and participates in the process of
penetration of the parasite into the host cell.
Rhoptries (5) are located near the conoid,
they secrete a substance that dissolves the
plasma membrane of the host cell.