Chapter 12THE PROTOZOA

• UNICELLULAR - EUCARYOTIC MICROORGANISMS

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

SHAPE• SIZE VARIES GREATLY - 2 TO 5,000 m

Distribution– FREE LIVING FORMS – 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– ASEXUAL – BINARY FISSION, MULTIPLE

FISSION OR BUDDING

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

Classification

– KINGDOM: PROTISTA• PHYLUM: PROTOZOA

– GROUPINGS: AMOEBA, FLAGELLATES, CILIATES, SPOROZOA

» AMOEBA - PSEUDOPODIA - NO CELL WALL

» AMOEBA PROTEUS - FREE LIVING AMOEBA

Classification (continue)

– ENTAMOEBA HISTOLYTICA• Causes: Amoebic Dysentery

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

2. Keratitis

Classification (continue)

• 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 PORTOZOA• 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????