THE PROTOZOA

• UNICELLULAR - EUCARYOTIC MICROORGANISMS

• FOUND IN THE KINGDOM PROTISTA• NO COMMON BASIC STRUCTURE, SIZE OR

SHAPE• SIZE VARIES GREATLY - 2 TO 5,000

MICROMETERS• DISTRIBUTION

– FREE LIVING FORMS

I. Protozoan Characteristics (65,000, 12 are extinct) – Environment Found In

• Ocean – a. Zooplankton (primary energy source in aquatic eco.)

– Vegetation – Rivers – Ponds – Soil – Bodies of other organisms

• Found: in cells, tissue and blood stream of Host

• Cause: malaria, amebic dysentery, giardiasis

• Heterotrophic – Ingest small molecules or cells

• a. Food Vacuoles - break food down

• Reproduction – Asexual ,

• Binary Fission -2 identical individuals

• Multiple Fission - more than 2 indenticals indo

– Sexual – a. Conjugation -, exchange genetic material

Reproduction

• Classification - according to how they move or not– FivePhyla/Plus Euglenophyta

• Sarodina , move by psuedopods (false feet)

• Ciliophora - move by cilia (eyelash like)

• Zoomastigina - move by flagella (whiplike)

• Sporozoa - none motile

• Euglenophyta - flagella (both plant/animal

– PARASITIC FORMS (MANY ANIMALS CARRY PROTOZOANS AS NORMAL FLORA)

– FACTORS AFFECTING DISTRIBUTION OF FREE LIVING FORMS• NaCl CONCENTRATION• pH• TEMPERATURE• OXYGEN REQUIREMENTS

• NUTRITION– FREE LIVING FORMS - PHAGOCYTOSIS

OF PARTICULATE MATTER– COMPLEX NUTRITIONAL NEEDS– ALL ARE CHEMOHETEROTROPHS– STORAGE PRODUCTS - GLYCOGEN,

STARCH AND LIPIDS• REPRODUCTION

– ASEXUAL – BINARY FISSION, MULTIPLE FISSION OR BUDDING

– SEXUAL - SYNGAMY OR CONJUGATION• CLASSIFICATION (ORGANELLES OF

MOTOLITY)– KINGDOM: PROTISTA

• PHYLUM: PROTOZOA– GROUPINGS: AMOEBA,

FLAGELLATES, CILIATES, SPOROZOA• AMOEBA - PSEUDOPODIA - NO CELL WALL

– AMOEBA PROTEUS - FREE LIVING AMOEBA

Diseases

– ENTAMOEBA HISTOLYTICA• Causes: Amoebic Dysentery

– diarrhea dehyd, bloody stool, death

– ACANTHAMOEBA Sp.• Causes: 1. Granulomatous Amoebic Encephalitis

2. Keratitis

• FLAGELLATES - FLAGELLA (MOST HUMAN PATHOGENS IN THIS GROUP)– MOST PRIMITIVE OF THE PROTOZOANS– CHARACTERISTICS OF FLAGELLA

EUGLENA Sp.

PATHOGENIC FLAGELLATES

• GIARDIA LAMBLIA• TRICHOMONAS VAGINALIS• TRYPANOSOMA SP.

CILIATES

• MOST ADVANCED OF THE PROTOZOA• ORAL GROOVE• CONTRACTILE VACUOLE• NUCLEAR DIMORPHISM• REPRODUCTION• ASEXUALLY BY BINARY FISSION• SEXUALLY BY CONJUGATION• PATHOGENIC CILIATE – BALANTIDIUM

COLI

• Treatment for protozoan infections is usually an antibiotic called metranidazole also called flagyl.

SPOROZOA

• ALL OBLIGATE INTRACELLULAR PARASITES

• ALL HAVE COMPLEX LIFE CYCLES• PATHOGENIC SPOROZOAN-PLASMODIUM

Sp.• CAUSATIVE AGENT OF MALARIA• FOUR SPECIES CAUSE MALARIA

1. P. MALARIAE2. P. OVALE3. P. VIVAX4. P. FALCIPARUM

• LIFE CYCLE OCCURS IN TWO ORGANISMS

– MOSQUITO (ANOPHELES Sp.) AND ANIMAL BODY

– SEXUAL CYCLE IN MOSQUITO– ASEXUAL CYCLE IN HUMAN BODY

• 3 IMPORTANT STAGES IN LIFE CYCLE– SPOROZOITE– MEROZOITE– GAMETOCYTE

• LIFE CYCLE OF PLASMODIUM

• SYMPTOMS OF MALARIA• MOST DEADLY FORM IS P.FALCIPARUM• HOW MALARIA KILLS

• TREATMENT FOR MALARIA - QUININE AND ITS DERIVATIVES

– CHLOROQUINE– PRIMAQUINE– MEFLOQUINE - LARIUM– SIDE EFFECTS OF LONG TERM USE

OF QUININE» HALLUCINATIONS» CONVULSIONS» EMOTIONAL CHANGES

– VACCINE????

• TOXOPLASMOSIS• CAUSED BY TOXOPLASMA GONDII• SEEN MOSTLY IN PEOPLE WITH

COMPROMISED IMMUNE SYSTEMS• CATS ARE AN ESSENTIAL PART OF THE

LIFE CYCLE OF THIS PROTOZOAN• THE ORGANISM REPLICATES IN THE

INTESTINE OF THE CAT.• IT PASSES OUT OF THE CAT IN ITS FECAL

MATERIA• PEOPLE INJEST THE ORGANISM