medical parasitology

1. Life Saving College Of Nursing
M. Farooq Marwat
RN, Dip. Card, BSN

2. Objectives:
At theend of this presentation, thestudentwill beable to :
⚫Understand the Protozoa
⚫Know about the characteristics of Protozoa
⚫Know about the Morphology of Protozoa
⚫Know about the Types of Protozoa
⚫Know about the Methods of reproduction in
Protozoa
⚫Know about the disease cause by Protozoa
⚫Know about the drugs used against Protozoa

3. Protozoa

4. Protozoa:
⚫Theword protozoa iscome from Greek protozoon word
meaning “First Animal”.
⚫Protozoa are unicellular (may be Multicellular) Eukaryotic
microorganism.
⚫Protozoa constitute a large group of about 65,000 species.
Most of which are harmless free living and inhabits water
and soil
⚫A few species are pathogenic in nature parasitize human
and other animals causing hundreds of million of
infections in ayeararound theworld

5. Characteristics
⚫Mostly Unicellularorganism with fully functional cell
⚫Live freely, may be parasitic orsymbiotic
⚫Protozoaare chemo-hetrotrops
⚫Theyare motile have locomotiveorganelles. E.g.
Flagellaand Cilia for movement

6. Morphology
⚫Protozoa are Eukaryotic resemble to animal cell,
contain majorcell organelles (including Nucleus,
Mitochondria)
⚫Theirorganellesare highly specialized for feeding,
reproduction and movement
⚫Thecytoplasmof protozoaaredivided intoan outer
layer called Ectoplasm and an inner layer called
Endoplasm

7. Protozoa

8. Morphology
⚫Ectoplasm helps in movement, feeding and Protection
⚫Endoplasm houses Nucleus, mitochondria and food
⚫Some protozoa havespecial appendages Flagella and
cilia that helps in their movements
⚫Freshwaterprotozoa have contractilevacuoles to
pumpoutexcess water
⚫Theirshape may remain constant (specially in Ciliates)
orchange constantly (as seen in Amoeba)

9. Ectoplasm and Endoplasm

10. Morphology
⚫The size of Protozoa is range between 3 to 300
micrometer.
⚫Fewciliate and Amoebaare largerenough to be seen
with naked eyes (theyareabout 4 to 5 mm).
⚫Except Sporozoates, all typesof protozoaare motile
either through Flagella, ciliaor Pseudopodia
⚫Have Eyespot thatcan detectchange in light
⚫ Respond to light & learn by trial & error

11. Eyespots
Eyespot

12. Nutrition
⚫Mostlyprotozoa feed on dead plantsand animal debris
whilesome (trophozoites) feed on bacteriaand Algae.
⚫Parasitic Protozoa feeds on the fluids and tissuesof
their host(e.g. Plasmaand blood cells)
⚫Some Protozoa live in symbioticrelationshipwith
otherplantsand animals

13. Classification of Protozoa
⚫Protozoaare classified on the basis of their motility
and method of reproduction
⚫Theyareclassified into Four main types
⚫Flagellates
⚫Ciliates
⚫Sarcodina
⚫Sporozoates

14. Flagellates
⚫Flagellates move by helpof Flagella (a tail-like
structure ). The movement is whip like
⚫Exampleof Flagellatesare
⚫Trypnosoma, Leishmenia (blood pathogen)
⚫Giardia (intestinal parasite)
⚫Trichomonas (reproductivetract pathogen)

15. Ciliates
⚫Ciliates protozoa have movement through cilia( fine
hair like structureattached with their body).
⚫Some protozoa have special kind of cilia for feeding
and attachment.
⚫Most are harmless. Only one species Balantidium Coli
is pathogenic for human causes a rare and server form
of Dysentery.

16. Ciliates

17. Sarcodina
⚫Major loco-motororganelles in Sarcodina is
pseudopodia (Pseudo means false, podia means Foot)
⚫Commonexampleof Sarcodina is Amoeba
⚫Mostspecies are harmless
⚫Enaemoba is a parasitic for human causes intestinal
disease

18. Sporozoates
⚫Sporozoatesare theonly non-motile form of protozoa.
⚫Sporozoates havewell developed sexual and asexual
stages
⚫Entiregroup is parasitic in natureand are harmful
⚫Somecommonexamples of Sporozoatesand their
infectionsare
⚫Plasmodium (causativeagentof Malaria, causes 100 to
300 million infection world wide)
⚫Toxoplasma Gondii (causes Toxoplasmosis)

19. Reproduction in Protozoa
⚫Protozoacan reproduce theiroff spring by both Sexual
and Asexual methods
⚫Asexual methodsof reproduction are:
⚫Budding
⚫Binary Fission
⚫Schizogonyor Multiple Fission
⚫Sexual Methods
⚫Conjugation
⚫Gametogony

20. Schizogony
⚫It is the method of multiple fission in which
first the nucleus undergoes multiple
division, form many nuclei that a small
portion of cytoplasm concentrate around
each nucleus and than protozoan cell is
divide into many daughtercells

21. Schizogony

22. Sexual Reproduction
⚫Conjugation:
⚫Two protozoa meet togetherand exchange
theirgenetic material
⚫Gametogony:
⚫Unionof twosexuallydifferentiated cells

24. Disease Caused Protozoa
Disease Causative Agent
Malaria Plasmodium
(P. Falciparum, P. Oval,P. Vivax,
P.malariae)
Giardiasis (diarrhea) Giardia intestinalis
Amoebic Dysentery Entamoeba histolytica
Toxoplasmosis
(immune deficiency )
Toxoplasma Gondii
Cryptosporidiosis Cryptosporidia
Sleeping sickness Trypanosoma
Leishmmaniasis (kala-azar) Leishmania

25. Antiprotozoal Drugs
⚫Examplesof antiprotozoal drugs include: Chloroquine
Mef loquineand Pyrimethamine.
Theseare used in malaria treatment.
⚫Metronidazolewasdeveloped as an antiprotozoal
drug. It induces strand breaks in the DNA of sensitive
organisms and alsodisrupts membrane integrity.

26. ⚫Otherantiprotozoal agents are Sulphonamidesand
trimethoprim, inhibit folicacid synthesis