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Chapter 5 - Humans & Microbes in Disease

  1. Ecological patterns of living things
    1. Mutualism
    1. Nitrogen-fixing bacteria
    2. Bacteria in the human digestive tract
    1. Anti-microbial agents
    2. HIV-2 infection
    1. Commensalism
    1. Parasitism
    1. Tapeworm
    2. Bacterial infections
    3. Viral infections
  1. Humans and their Microbes
    1. The body's normal flora
    1. Resident and Transient Flora
  1. Infection and Infectious Disease
    1. Microbial Factors

B) Host Factors

    1. Microbe and Host Together
  1. Infection Entry Routes


    1. Establishment of Infection
    1. Respiratory Entry
    1. Localization in the Respiratory Tract
    1. Dissemination of Micro-organisms/Toxins
    1. Gastrointestinal Entry
    1. Localization in the GI Tract
    1. Dissemination of Micro-organisms
    1. Toxins of Intestinal Pathogens

D) Skin and Surface Membrane Routes



    1. Localization in the surface tissues

Example: ringworm, cold sores, yeast infection

    1. Bacterial infections of the skin
    1. Mucous membrane
    1. Conjuctiva


    1. Dissemination of infection
    1. Organisms like staphylococci and streptococci produce substances that enable the spread through the skin. They also present a danger of spreading to the deeper layers of the skin and underlying structures.
    2. Sexually transmitted diseases

Enter through mucous membranes

Syphilis, Gonorrhea, Chlamydia, HPV

Certain mycoplasms


    1. Parenteral entry
    1. Penetration to Deep Tissues
    1. Direct entry of an arganism to the parenteral tissues
    1. Injection of an organism by a biting or bloodsucking insect
    1. Injection of organisms by a contaminated needle, syringe or solution.
    1. Entry of organisma from skin or mucosal surfaces along an indwelling intravenous line or catheter.


    1. Deep Injury to the Skin and Mucosal Barriers
    1. During surgery (peritonitis)
    2. Animal bite (Rabies)
    3. Accidental wounds (Tetanus)
    1. The Toxins of Wound Pathogens
  1. Damaging Microbial Properties
    1. Pathogenicity
    1. Virulence
    1. Invasiveness
    1. Toxigenicity
  1. Other Factors Contributing to Infectious Disease