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Survey of eucaryotic microbes

Survey of eucaryotic microbes. (continued…). Helminths. Multicellular , have organs mouthparts for attachment to or digestion of host tissues most have well-developed sex organs that produce eggs and sperm. fertilized eggs go through larval period in or out of host body

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Survey of eucaryotic microbes

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  1. Survey of eucaryotic microbes (continued…)

  2. Helminths • Multicellular, have organs • mouthparts for attachment to or digestion of host tissues • most have well-developed sex organs that produce eggs and sperm. • fertilized eggs go through larval period in or out of host body • Some parasitize host tissues (either adults or larvae)

  3. Major groups of helminths • flatworms (_____________) – flat, no definite body cavity; segmented; digestive tract a blind pouch; simple excretory & nervous systems; hooks or suckers for attachment • _____________(tapeworms) – segmented body; basically reproductive factories; absorb food (no digestive tract) • _____________or flukes, are flattened , nonsegmented worms with sucking mouthparts

  4. Major groups of helminths (cont’d) • roundworms (_____________)- round-ish, a complete digestive tract, a protective surface cuticle, spines & hooks sometimes present on mouth; excretory & nervous systems poorly developed

  5. Parasitic Helminths • 50 species parasitize billions of humans • Transmission routes: acquired though… • ingestion of larvae or eggs in food; • from soil or water (ingestion or penetrate skin); • some are carried by insect vectors • Most intestinal helminths identified by __________________________

  6. Parasitic Helminths - some examples • Platyhelminthes: • Cestodes – tapeworms – Taenia spp. • Trematodes – flukes – Schistosoma spp., liver flukes (Fasciola hepatica) • Nematodes – • Pinworms (Enterobius vermicularis) • Ascaris (Ascaris spp.) • Whipworms (Trichuris trichiura) • Hookworms (N. americanus, A. duodenale) • Filiarial worms (Dirofilaria immitis,Wuchereria bancrofti)

  7. Platyhelminthes

  8. Platyhelminthes Taenia saginatta T. solium Fasciola hepatica Schistosoma spp.

  9. Life cycles of Platyhelminthes • Life cycles of platyhelminthes frequently involve two hosts • _____________host – where the adult worm lives • _____________host – where the larva form lives (larva can be encysted in the tissues of this host)

  10. Taenia life cycle

  11. Nematodes • “_____________” • Worm curls up in a ball when outside host • Either adults or larvae (or both) can cause disease/pathology • Like platyhelminths, usually diagnosed by _____________

  12. Intestinal nematodes

  13. Fecal/oral transmission Ascaris lumbricoides life cycle Pinworm life cycle-Enterobius vermicularis

  14. Hookworm life cycle (Ancylostoma duodenale and Necator americanus) Infection is caused by contact with ___________, which burrow in skin and migrate to intestines (via blood stream – “Hepatotracheal migration”)

  15. Filarial nematodes • Larvae (infective stage - _____________) live in blood and/or lymphatics • Transmitted by blood-sucking insects (flies, mosquitoes) • Pathology is associated with __________________________– what are they blocking?

  16. microfilaria Wuchereria bancrofti - elephantiasis Filarial nematodes Dirofilaria immitis How would these be diagnosed?

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