Skip to main content
Back

Unit 4 Microbiology Key Concepts Flashcards

Control buttons has been changed to "navigation" mode.
1/23
  • Colonization vs Infection vs Disease

    Colonization: microbes present, no harm.
    Infection: microbes multiplying.
    Disease: infection plus damage or symptoms.

  • Definition of Opportunistic Pathogens

    Cause disease only when conditions are right, such as immunocompromised state, dysbiosis, or wrong location.

  • Classic Opportunistic Pathogens

    Candida, E. coli (UTIs), and Pseudomonas are common opportunistic pathogens.

  • Virulence Factors and Their Functions

    Capsule: blocks phagocytosis.
    Adhesins: stick to host cells.
    Toxins: damage tissues.
    Enzymes: break down tissues.
    Biofilms: protect and help persistence.

  • What are Biofilms?

    Bacteria living in a protective matrix found in dental plaque, catheters, and chronic wounds; resist antibiotics and immune response.

  • First Line of Defense Components

    Physical and chemical barriers: skin, mucus, tears, urine, coughing, lysozyme, stomach acid (HCl), and sebum.

  • Second Line of Defense Characteristics

    Innate immunity: phagocytes, inflammation, complement, interferons, fever; fast and nonspecific with no memory.

  • Third Line of Defense Features

    Adaptive immunity: B cells produce antibodies, T cells mediate cell response; specific and has memory; slow first time, fast second time.

  • Phagocytosis Steps (CAI-PLD)

    1. Chemotaxis
    2. Adherence
    3. Ingestion
    4. Phagosome formation
    5. Lysosome fusion
    6. Destruction of microbe.

  • What is Opsonization?

    Proteins like antibodies and complement tag bacteria to enhance phagocytosis; think of it as "seasoning before eating."

  • Extravasation Process

    Immune cells exit blood vessels by rolling, adhesion, diapedesis, and migration into tissues.

  • Signs of Inflammation

    Redness, heat, swelling, and pain caused by vasodilation and fluid leakage.

  • Complement System Functions

    Opsonization, inflammation, and formation of Membrane Attack Complex (MAC) that punches holes in bacteria.

  • Role of Interferons in Viral Defense

    Released by infected cells to warn nearby cells and block viral replication; key in antiviral signaling.

  • Benefits of Fever in Infection

    Slows microbial growth, boosts immune response, and increases metabolism.

  • Functions of B Cells in Adaptive Immunity

    Produce antibodies and create memory B cells for faster future responses.

  • Functions of T Cells in Adaptive Immunity

    Helper T cells coordinate immune response; Cytotoxic T cells kill infected cells.

  • Antibody Functions

    Neutralize toxins, agglutinate pathogens, opsonize microbes, and activate complement system.

  • IgM vs IgG Antibodies

    IgM indicates current infection; IgG indicates past infection or immunity.

  • What are Antigens?

    Anything that triggers an immune response, such as proteins, toxins, or surface markers.

  • Immune Memory Importance

    Allows faster immune response upon re-exposure; basis for vaccines.

  • Types of Immune Disorders

    Hypersensitivity: overreaction (e.g., allergies).
    Autoimmune: body attacks itself (e.g., lupus).
    Immunodeficiency: weak immune system (e.g., HIV/AIDS).

  • Exam Traps to Remember

    Opsonization means tagging; phagocytosis steps are CAI-PLD; complement system creates holes (MAC); opportunistic pathogens affect weak hosts.