Protozoa

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

– 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

– ENTAMOEBA HISTOLYTICA • Causes: Amoebic Dysentery

– 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. MALARIAE 2. P. OVALE 3. P. VIVAX 4. 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