mod 2

• Protozoa are single-celled eukaryotic microorganisms belonging to kingdom Protista.
• The body wall of protozoa is covered by a cell membrane.
• The cytoplasm of protozoa is made up of ectoplasm and endoplasm.
• The nucleus of protozoa is usually single but may be double or multiple.
• Reproduction in protozoa can be asexual (e.g. binary fission, schizogony, endodyogeny) or sexual (e.g. gametogony).
• Entamoeba histolytica, with four nuclei, is an example of a protozoa of medical importance.
• Protozoa can be divided into the following groups: Amoebae, Flagellates, Apicomplexa, and Ciliate.
• Amoebae have pseudopodia as a means of locomotion and include Entamoeba histolytica in the large intestine and free-living amoebae in the CNS and eye, such as Naegleria and Acanthamoeba.
• Flagellates have flagella as an organ of locomotion and include Hemoflagellates like Trypanosoma and Leishmania, Gastrointestinal parasites like Giardia lamblia, and Urogenital parasites like Trichomonas vaginalis.
• Apicomplexa have a structure called an apical complex which serves as the organ of attachment to host cells and have an alternating sexual and asexual life cycle.
• Apicomplexa of medical importance include Plasmodium and Babesia in blood, Toxoplasma gondii and Sarcocystis in tissue, and Cryptosporidium, Cystoisospora, and Cyclospora in gastrointestinal parasites.
• Ciliate have cilia for locomotion and include Balantidium coli in gastrointestinal parasites.
• Microsporidia of medical importance include Enterocytozoon bieneusi in gastrointestinal parasites.
• Helminths are metazoa which are multicellular worms and their body has a cuticle or integument which is the outer covering.
• Most helminths require more than one intermediate host for completion of their life cycle.
• Helminths, unlike protozoa, do not multiply in the human body apart from few exceptions (those helminths showing autoinfection).
• Heavy worm load follow multiple infections.
• Helminths are classified into two phyla: Platyhelminthes and Nemathelminthes.
• Trematodes (flukes) and cestodes (tapeworms) belong to the phylum Platyhelminthes.
• Nematodes (roundworms) belong to the phylum Nemathelminthes.
• Entamoeba Histolytica

  Large Intestine

  CNS
• Trichomonas Vaginalis

  Vagina, Urethra

  Vaginitis, Urethritis
• Giardia Lamblia

  Small Intestine

  Malabsorption, Diarrhea
• Acanthamoeba

  CNS, Eye

  (PAM) Primary Amoebic Meningoencephalitis
• Trypanosoma Brucei

  Blood, Lymph Node, CNS

  Sleeping Sickness
• Trypanosoma Cruzi

  Colon, Heart

  Chagas' Disease
• Leishamania Donovani

  Reticuloendothelial System (liver, spleen, bone marrow)

  Kala Azar, Post Kala Azar Dermal Leishmaniasis
• Leishmania Tropica

  Skin

  Cutaneous Leishmaniasis (oriental sore)
• Leishmania Braziliensis

  Naso-Oral Mucosa

  Mucocutaneous Leishmaniasis
• Toxoplasma Gondii

  CNS, eye, musculoskeletal

  Toxoplasmosis
• Microsporidia

  Gastrointestinal Tract (GIT)

  Diarrhea
• Plasmodium

  Erythrocytes

  Malaria
• Babesia

  Erythrocytes

  Babesiosis
• Cystoisospora

  Small Intestine

  Diarrhea
• Cryptosporidium Parvum

  Small Intestine

  Diarrhea
• Balantidium Coli

  Large Intestine

  Dysentery