BIOL 596 General Parasitology

Lecture outlines (by weeks)

 

I. Introduction (week 1)

Introduction to Parasitology. Parasitism as a type of symbiosis. Definition of parasitic organism. Parasites vs  free-living organisms . Major taxonomic groups of parasites: Protozoa, Platyhelminthes, Nematoda, and Arthropoda. Host-parasite relationship and co-evolution. Parasitic diseases of humans, domestic animals, and wildlife. Relatioship of Parasitology  to other sciences. Careers in Parasitology

 

II. Basic Principles and Concepts in Parasitology (week 1)

Types of parasites and their hosts. Direct and indirect life cycles of parasites. Parasite ecology. Strategy of adaptation to parasitism. Major routes of parasite transmission. Host/parasite interaction: host’s immunological response to parasitic organisms (innate and acquired immunity). Parasite immune evasion mechanisms. Parasitic diseases and AIDS . 

 

III. Protozoa (week 2-6)

Diversity, abundance, and geographic distribution of parasitic protozoans. Taxonomy, phylogeny, and evolution. Comparative morphology and ultrastructure. Physiology: locomotion, feeding, metabolism, and reproduction. Direct and indirect life cycles. Strategy of defense mechanisms in parasites and their hosts. Human and animal diseases caused by parasitic protozoans and routes of their transmission. Protozoans as opportunistic parasites in immunodefficient hosts.

 

Protozoa. Flagellates from Anoxic Environment (lumen dwelling flagellates).

     Phylum Retortomonada. Ord. Diplomonadida. Giardiaduodenalis (lamblia) – common intestinal

     parasite of humans. Evolutionary position (organism from point of divergence (between pro- and

     eukaryotes). Geographic distribution. Morphology and ultrastructure. Life cycle. Routes of transmission.

    Giardiasis in humans and animals.  Rate of infection. Diagnostic, treatment, prevention, and control.

     Phylum Axostylata.  Ord. Trichomonadida. Trichomonas spp. – worldwide distributed sexually

     transmitted parasites of humans and mammals. Phylogeny, and evolution. Life cycle. Trichomoniasis:

     rate of infection. Diagnosis, treatment, prevention, and control.

 

Phylum Sarcodina. Ord. Amoebida. Taxonomy and phylogeny. Amebas in eukaryote evolutionary history.

     Morphology and ultrastructure. Diseases caused by the amebas.

      Entamoeba histolytica- cosmopolitan intestinal parasite of humans, the 3rdcommon cause of parasitic
      death in the world. Morphology and ultrastructure. Life cycle. Intestinal and extra- intestinal forms of
     amebiasis. Route of transmission.Diagnosis, treatment, prevention and control. Other amebas infecting
     mammals.

      Naegleria fowleri (facultative parasite), causative agent of primary amebic eningoencephalitis (PAM).

 

Phylum Ciliophora. Taxonomy and phylogeny. Biology, morpology, and ultrastructure.

     Balantidium coli- the only protozoan parasite of humans. Geographic distribution. Life cycle.

     Pathogenesis. Diagnosis, prevention, and control.

     Ichthyophthyrius multifiliis  (“Ich”)- dangerous parasite of freshwater fish. “White spot disease” in

     aquaculture. Diagnosis and tratment.

 

 

Hemoflagellates (Kinetoplastids). African and American Trypanosomes.

     Phylum Euglenozoa. Ord.Trypanosomatida. Taxonomy and phylogeny.  Major morphological stages of

     trypanosomatids (general morphology & ulfrastructure). Type of the life cycle. Salivarian and

    stercorarian  trypanosomatids. Tissue- and blood-dwelling trypanosomatids, intra-  and  extracellular

  

    trypanosomatids. Host/parasite interaction: strategy of antigenic variations as a defensive  mechanism

    of extracellular  parasite against host’s immunity.  Anatomical seclusion  (becoming intracellular even

    in  the cells of the immune system)  as a defensive  mechanism of  intracellular  parasite against host’s

    immunity.

 

     Trypanosoma brucei spp., Trypanosoma cruzi, and Leishmania spp.- dangerous parasites of

     humans, cattle, and wildlife. Geographic distribution and rate of infection.  Life cycles (parasite

     development in definitive and intermediate hosts). Pathogenic effect. Clinical symptoms of sleeping

     sickness (T.brucei spp. or African trypanosomes), Chagas’ disease (T. cruzi or American

     trypanosomes), and  leishmaniasis (Leishmania spp.). Diagnosis, treatment, prevention, and control.

 

 

Phylum Apicomplexa. Taxonomic position. Phylogeny and evolution. Morphology and ultrastructure. Specificity of the life cycles. Stages of development, types of reproduction. Strategy of parasite adaptation to the hosts. Diseases caused by Apicomplexa in humans and animals.

Class Coccidea. Ord. Eimeriida. Toxoplasma gondii - causative agent of one of the most wide spread

      and dangerous disease in humans and animals. Life cycle (parasite development in definitive and

      intermediate hosts). Major routes of transmission.  Toxoplasmosis: rate of infection. Motherhood

     and toxoplasmosis, congenital  toxoplasmosis. Toxoplasmosis in immunocompetent and 

     immunocompromise hosts.  Diagnosis, treatment, prevention and control.

      Ord. Adeleida. Cryptosporidium parvum-  causative agent of transient human diarrhea. Life cycle.

     Cryptosporidiosis in immunocompetent and immunocompromise hosts.C. parvum  as indicator of

      water quality.

      Ord. Haemosporida. Plasmodium spp.- the most dangerous parasites of human population causing

      malaria..Rate of the infection, global rate of human death. Major species of Plasmodium infecting

      humans. Geographic distribution.Life cycle in insect and human hosts. Parasite development in

      the intermediate  and definitive hosts. P. vivax and benign tertian malaria. P. falciparum and malignant 

      tertian malaria, P. malariae and quartan malaria. Malaria as re-emergent disease. Diagnosis,

      treatment,  prevention and control. Antimalarial vaccine.

 

Midterm 1.

 

IV. Phylum Platyhelminthes (flatworms) (week 7-10)

Diversity, abundance, and geographic distribution. Classification, taxonomy, phylogeny, and evolution. Comparative anatomy, functional morphology and ultrastructure. Comparative physiology. Reproduction, embryogenesis, and development. Flatworms with direct life cycles (Turbellaria, Monogenea). Flatworms with indirect life cycles (Trematoda, Cestoidea). Defense mechanisms of parasites against host’s immunity. Human and animal diseases cased by Platyhelminthes.

 

Class Monogenea. Phylogeny and evolution. Morphology and life cycles. Stages of development. Types of reproduction. Gyrodactylus spp. , Dactylogyrus spp., and  Diplozoon paradoxum-  - widespread ectoparasites of economically important fish.  Monogeneans in amphibians.

 

Class Trematoda, s/class Digenea (flukes)- parasites of all classes of vertebrates. Classification, phylogeny and evolution. Basic life cycles. Stages of development. Comparative anatomy and functional morphology of adult worms and larval stages.  Host-parasite interaction and adaptation to parasitism... Routes of transmission. Human and animal diseases caused by digenetic trematodes.

      Fam. Schistosomatidae- the 2rdcommon cause of parasitic death in the world. Geographic

      distribution. Specificity of the life cycles. Route of transmission. Host-parasite interaction.

    

    Schistosoma haematobium  and urinary schistosomiasis. S. mansoni and schistosomiasis of large

      intestine. S.   japonicum and

     schistosomiasis of small intestine. Diagnosis, treatment, prevention and control.

     “Swimmer’s  itch”, or cercarial dermatitis in humans causeds by  bird schistosomes.

      Fam. Fasciolidae. Fasciola hepatica (sheep liver fluke) – a causative agent of human fasciolosis.

     Fasciolopsis buski, parasite of humans and swine. Diagnosis, prevention, and control.

      Fam Clonorchiidae and Opisthorchiidae- harmful parasites of humans. Liver flukes,Clonorchis

     sinensis (Chinese liver fluke), and Opisthorchis felineus  (cat  liver fluke). Life cycles. 

     Pathogenesis. Diagnosis, tretment, prevention and control.

      Fam. Troglotrematidae.  Paragonimus westermani (lung flukes). Morphoogy. Life cycle.

     Pathogenesis. Diagnosis, treatment, prevention and control,

 

Class Cestoidea (tapeworms)- parasites of all classes of vertebrates. Classification. Taxonomy and phylogeny.  Diversity, abundance, and geographic distribution. Host- parasite co- evolution. Adaptation to parasitism. Seudophyllidean and cyclophyllidean cestodes. Basic life cycles. Stages of development: eggs, larval stages (metacestodes), and adult worms. Physiology, functional morphology, and ultrastructure. Routes of transmission. Human and animal diseases caused by the tapeworms.

Ord. Pseudophyllidea. Fam. Diphyllobothriidae. Diphyllobothrium latum- broad fish tapeworm,

     parasite of humans and puscivorous carnivores. Geographic distribution. Variations in the life cycle.

     Pathogenesis. Diagnosis, treatment, prevention and control. 

     Diphyllobothrium spp. – parasites of fish, birds, and mammals.

     Fam. Bothriocephalidae. Bothriocephalus acheilognathi- worlwide distributed Asian fish tapeworm.        

 Ord. Cyclophyllidea. Fam. Taeniidae- the most medically important tapeworms of humans.  Taenia

      saginata (beef tapeworm)- one of the most common tapeworm of  humans. Geographic distribution.  

     Morphology and life cycle. Stages of development (cysticercus). Routes of transmission. Diagnosis,

     prevention and control.  Taenia solium (pork tapeworm)- the most dangerous adult tapeworm of

     humans. Specificity  of the life cycle; humans as a definitive and as accidental intermediate host. 

     Routes of infection. Taeniasis. Cysticercosis and neurocysticercosis. Diagnosis,  treatment, prevention,

     and control.

      Echinococcus  granulosus- parasite of carnivores animals. Geographic distribution. Life cycle with

     herbivorous animals as an  intermediate host. Humans as accidental intermediate host. Cystic

     echinococcosis (hydatid disease) in  humans and animals. Diagnosis, treatment, prevention and control.

      Fam. Hymenolipedidae. Hymenolepis nana (dwarf tapeworm)- the only cestode parasite with

      alternative (direct or indirect) life cycle. Diagnosis, treatment, prevention and control.

      Fam. Dilepididae. Dipylidium caninum- common cestode of dogs and cats, and occasionally children.

     Diagnosis, treatment, prevention, and control.

Midterm 2.

 

V. Phylum Nematoda (roundworms) (week 11-14)

Diversity, abundance, and geographic distribution. Taxonomy, phylogeny, and evolution. Comparative anatomy, functional morphology, and ultrastructure of major systems and organs. Physiology: behavior, nutrition, and reproduction. Basic life cycles (direct and indirect). Stages of development. Major types of juvenile stages. Developmental arrest as a common adaptation to environmental condition. Host/parasite interaction. Human and animal diseases caused by nematodes.

Class Enoplea.

       Fam. Trichuridae. Trichuris trichiura  (whipworm)- parasite of humans. Morphology. Life cycle.

       Trichiriasis. Diagnosis, treatment, prevention, and control.

       Fam. Trichinellidae. Trichinella spiralis- one of the most clinically important nematode parasites of
       humans and carnivores. The largest intracellular parasite with highly specific life cycle. Trichinosis as
       zoonosis. Route of transmission. Epidemiological cycles. Diagnosis, treatment, prevention,
      and control.

 Class Rhabditea. Rhabditean nematodes as a bridge between free-living and parasitic organisms.

       Fam. Strongyloididae. Strongyloides stercoralis (threadworm)- harmful human parasite with both

       free-living and parasitic patterns of the life cycle. Routes of tranjsmission. Pathogenesis.  Three

      stages of strongyloidiasis.

      Diagnostic, treatment, prevention and control.

       Fam. Oxyuridae. Enterobius vermicularis (pinworm)- the most common human nematodes.

       Morphology, life cycle. Pinworm disease: diagnostic, treatment, prevention and control.

       Fam. Ancylostomatidae (hookworms). Ancylostoma duodenale and Necator  americanus

      (American killer)- the most common hookworms of great economic and medical importance.

       Morphology and life cycle.Routes of transmission. Cutaneous larva migrans. Phases (stages) of

       hookworm disease. Diagnostis,   treatment, prevention, and control.

       Fam. Ascarididae. Ascaris lumbricoides (large intestinal human roundworm). Specificity of the life

       cycle. Routes of infection. Intestinal and extra-intestinal ascariasis. Wandering worm syndrom.

       Diagnosis, treatment, prevention, and control.

       Toxocara canis – parasite of domestic dogs and other canids. Dangerous parasite of humans

       (acidental intermediate host). Specificity of the life cycle. Routes of infection. Visceral larva migrans

       and ocular larva migrans.  Diagnosis, treatment,  prevention, and control.

      Anisakis spp. and anisakiasis in humans and other mammals. Diagnosis, treatment, prevention and

      control.

       Fam. Oncocercidae (filarial worms). Wuchereria bancrofti, causative agent of elephantiasis

      (lymphatic  filariasis). Oncocerca volvulus and River blindness. Other filarial worms

       causing  severe diseases of humans. Dirofilaria immitis (dog heartworm). Life cycles. Routes of

       infection. Diagnostic, treatment, prevention, and control.

       Fam. Dracunculidae. Dracunculus medinensis (Guinea worm)-large roundworm widely distributed

       in the Miiddle East and Africa. Life cycle, routes of infection. Disease: treatment, prevention, and

       control.

VI. Phylum Arthropoda (week 13-14)

Insects, parasites and vectors of parasitic diseases.

General morphology, biology, ecology, and behavior. Developmental stages.  Basic life cycles. Adaptation to parasitism. Arthropod-transmitted infections.

     Anoplura, the lice. Pediculus humanus humanus (human body louse) as vectors of epidemic (louse-

     borne) typhus, trench fever and relapsing fever.

     Siphonoptera, the fleas.   Xenopsylla cheopis, or oriental flea and Pulex irritans, or  human flea. Fleas

     as vectors of plague and murine typhus.

     Diptera, the flies as vectors of severe human diseases.

     Mosquitoes. Culex pipiens, Aedes dorsalis and Anopheles spp., the most important insect vector of

     malaria, encephalitis, dengue, and Nile virus.

     True flies. Glossina spp. as a transmitter of sleeping sickness. Sand flies and leismaniasis, black

     flies and oncocerciasis.

    Arachnida, parasites and vectors of parasitic diseases. Acari, Ticks and Mites. 

    Ticks: Ixodes spp. as vectors of Lyme disease,  tick-borne encephalitis, relapsing fever  and other

    diseases of humans. Immunity to ticks.     Mites, important parasites of humans, domestic animals, and   

    wildlife causing and transmitting epidermal  and respiratory diseases.

                                                            Final exam

 

                                

                                                     Lab outlines (by weeks)

Week 1.

# 1. Introduction. Basic goals, study methods, and equipment. Dissecting and compound microscopes. Standardization and caalibration of compound microscope and measurement of microscopic objects.

Weeks 2-6. Protozoa

# 2. Lumen-dwelling flagellates (flagellates from anoxic environment). Microscopic identification of Giardia duodenalis (trophozoites and cysts, fecal smears) and Trichomona vaginalis (trophs, vaginal smears).

# 3. Amebas and ciliates, arasites of human’s intestinal tract.

      Microscopic ID of trophozoites and cysts of Entamoeba histolytica (fecal smears, intestinal tissues) and Balantidium coli (fecal smears).

# 4. Hemoflagellates. Microscopic identification of African trypanosomes (bllod smears) and American trypanosomes (blood, tissues) and leishmanias (culture).

Practical exercise # 1. Protozoan parasites of the earthworm. Dissection of the earthworm. Collection and processing of Monocystis, Sporozoa (wet mounts, smears). Identification of different stages of Monocystis life cycle.

# 5. Apicomplexans. Coccidia Toxoplasma gondii. M icroscopic ID of pseudocysts in fixed tissues. Malaria plasmodiums. Microscopic ID of Plasmodium falciparum, P. malariae, and P. vivax in bllod smears& fixed tissues.  Plasmodium parasites in mosquito.

Slide preview.

 Quiz 1 (Protozoa).

 

Weeks 7-10. Platyhelminthes

# 6. Practical exercise # 2. Study of living larval trematodes. Parasitological examination of the California hornhell snail, Cerithidea californica. Collection, identification, and preservation of parasites. Lab report.

# 7. Digenetic trematodes. General morphology of trematodes (fixed specimens). Microscopic identification of Schistosoma spp Fasciola spp., Clonorchis sinensis, and Paragonimus westermani (adult worms and eggs).

# 8. Cestodes. Microscopic identification of eggs, larval and adult stages of Diphyllobothrium latum, Taenia spp, and Echinococcus granulosus (microscopic slides, fixed specimens). Slide prereview

Quiz 2, part A. (Platyhelminthes, trematodes & cestodes).

 

Weeks 11- 14. Nematoda

# 9. General morphology of nematodes. Microscopic identification of eggs and adult stage of Trichuris trichiura and Trichinella spiralis.

     Practical exercise # 3. Parasitological examination of fish. Collection, identification, and preservation of parasites.

# 10. Microscopic identification of eggs and adult stage of hookworms, Ancylostoma spp. and Necator americanus. Microscopic ID of pinworm Enterobius vermicularis (eggs, adult worms).

# 11. General morphology of Ascaris lumbricoides (fixed specimens, slides). Microscopic identification of Ascaris lumbricoides eggs Microscopic ID of filarial worms Wuchereria bancrofti, Oncocerca volvulus, and Dirofilaria immitis.

Slide preview.

 

 Quiz 2, part B. Nematodes