MICP

• Symbiosis


  A relationship where unlike organisms exist together
• 3 Types of Symbiotic Relationships


  • Commensalism
  • Mutualism
  • Parasitism
• Commensalism


  One benefit, other is unaffected
• Commensalism


  • Human Body and Normal Flora
• Mutualism


  Both organisms benefit from each other
• Mutualism


  • Intestinal Flora Production of vitamin K
• Parasitism


  One benefit, one is harmed
• Parasitism


  • ticks and dog
• Parasitism


  Organisms depending on the host for survival
• Elements of parasitism


  • Parasite
  • Host
• Classification of Parasites - Based on Habitat

  • Ectoparasites (infestation)
  • Endoparasites (infection)
• Ectoparasites


  Parasites living outside the host's body
• Ectoparasites


  • Fleas, lice
• Infestation


  Invasion of the body by ectoparasites
• Endoparasites


  Parasites living inside the host's body
• Endoparasites


  • Helminths or worms
• Infection


  Entry and multiplication of the parasite within the host
• Classification of Parasites - Based on Independence

  • Facultative Parasites
  • Obligate Parasites
• Facultative Parasites


  Parasites that can live independently of the host
• Facultative Parasites


  • Amoeba
• Obligate Parasites


  Parasites that must live inside a host
• Obligate Parasites


  • Plasmodium, Leishmania, hookworms
• Majority of human-infecting parasites fall into the Obligate Parasites category
• Classification of Parasites - Based on Mode of Living

  • Permanent Parasites
  • Intermittent Parasites
  • Incidental Parasites
  • Transitory Parasites
  • Erratic Parasites
• Permanent Parasites


  Parasites remaining in a host from early life to maturity
• Permanent Parasites


  • Plasmodium
• Intermittent Parasites


  Parasites visiting the host only during feeding time
• Intermittent Parasites


  • Non-pathogenic parasites (leeches, bedbugs etc)
• Incidental Parasites


  Parasites occurring in an unusual host
• Incidental Parasites


  • Dog tapeworm in humans
• Transitory Parasites


  Parasites with larvae developing in a host while the adult is free-living
• Transitory Parasites


  • Echinococcus granulosus or dog tapeworm
• Erratic Parasites


  Parasites seen in an unusual organ, different from their ordinary parasitization
• Erratic Parasites


  • Ascaris lumbricoides in the lungs or kidneys
• Types of host


  • Definitive Hosts
  • Intermediate host
  • Resovoir host
  • Paratenic host
• Definitive Hosts


  Hosts harboring the adult stage or where the sexual phase occurs
• Definitive Hosts


  • Humans for the intestinal roundworm Ascaris
  • Mosquitoes for the malaria parasite Plasmodium
• Intermediate host


  Hosts harboring the larval stage or where the asexual phase occurs
• Intermediate host


  • Cows for the cysticercus larva of the beef tapeworm Taenia saginata
  • Humans for the malaria parasite Plasmodium
• Resovoir host


  Vertebrate hosts acting as additional sources of infection in humans