Lecture 21 Define nosocomial infections and explain their importance Nosocomial infections infection acquired during a hospital stay about 5 15 of patients acquire them Define compromised host patients with compromised immune systems List several methods of disease transmission in hospitals Direct contact Fomites Explain how nosocomial infections can be prevented Barriers and cleanliness Isolation and quarantine Aseptic technique Surveillance and infection control List several reasons for emerging infectious diseases and name one example for each reason Changing sexual mores HIV AIDS Mass food production Campy E Coli More exposure to animals Lyme Disease Increased antibiotic use VRSA SUMMARY Nosocomial infections current situation and history Transmission in the hospital Prevention and control Emerging infectious diseases Major factors contribute to emerging Infections Lecture 22 23 Identify the principal portals of entry Mucous Membranes ex common cold pneumonia TB flu measles Parenteral Route deposited directly into tissue ex Hep B Skin ex conjunctivitis Define LD50 and ID50 Infectious dose for 50 of a population ID50 LD50 lethal does for 50 of a pop Contrast the nature and effects of exotoxins and endotoxins Endotoxins in the lipid portion of LPS of gram negative bacteria Ex Salmonella typhimurium U T I typhoid fever menengitis Released during cell division or destruction Fever weakness shock Stable to heat low toxicity Not easily neutralized Exotoxins metabolic product of growing bacteria Specific for each cell Made of proteins Unstable to heat high toxicity Can be neutralized Small lethal dose Ex tetanus botulism diphtheria scarlet fever gas gangrene Understand virulence factors toxin toxoid and antitoxin Toxin substance that contributes to pathogency Toxoid inactivated toxin often used in vaccines exotoxin Virulence factors Antitoxin antibodies against a specific toxin Outline the mechanism of action of A B toxins membrane disrupting toxins and superantigens A B Toxins most exotoxins released from cell B attaches to host enters by cell mediated endocytosis A portion alters function of host cell protein synthesis B is released from host cell receptor inserted into plasma membrane for reuse Membrane disrupting toxins cause lysis of host cells by disrupting plasma membrane Superantigens provoke a very intense autoimmune response due to release of cytokines from host cell Explain how microbes adhere to host cells and how capsules and cell wall components contribute to pathogenicity Adherence attachment of pathogens to host tissue Adhesins or ligands bind specifically to receptors Describe pathogenicity islands and the roles of plasmids and lysogeny in pathogenicity DNA sequence in genome Plasmids and phage Lecture 24 Differentiate between innate and adaptive immunity Innate defenses present at birth does not involve specific recognition Adaptive based on a specific response once microbe has breached the Describe physical and chemical factors in innate immunity and FIRST LINE intact skin mucous membranes secretions normal innate immunity some examples microbiota SECOND LINE phagocytes inflammation fever antimicrobial substances THIRD LINE ADAPTIVE specialized lymphocytes T and B cells antibodies Describe the role of normal microbiota in innate immunity Define phagocyte and phagocytosis Phagocyte perform phagocytosis Phagocytosis ingestion of a microorganism or other substances by a cell also involved in cleaning debris Chemotaxis adherence ingestion digestion List the stages and functions of inflammation Triggers acute phase proteins are activated Vasodilation dilation of blood vessel triggered by histimne kinin prostaglandins and leukotrienes Phagocyte migrations and phagocytosis Tissue repair Describe the cause and effects of fever Fever caused by hypothalamus releasing prostaglandins reset body temp in response to cytokines released by phagocytes in response to endotoxins When temp returns to normal crisis Describe three pathways of activating complement Classical antibodies bind to antigens microbes activate C1 activates C2 and C4 Alternative doesn t involve antibodies direct contact between compliment proteins and pathogen Lectin macrophages ingest bacteria release cytokines and liver produces lectins proteins that bind to carbohydrates Describe three consequences functions of complement activation Opsonization enhancement of phagocytosis by coating with C3b Inflammation increase blood vessel permeability and chemotactic attraction of phagocytes C3a and C5a Cytolysis microbe bursts due to inflow of extracellular fluid thru transmembrane channel formed by membrane attack complex C5b and C6 9 Understand the actions of interferons bind to cell receptor and trigger gene Interferons antiviral proteins interfere with viral replication expression Alpha luekocytes Beta fibroplasts Gamma Th1 and NK cells Lecture 25 Differentiate between innate and adaptive immunity Adaptive specific antibody and lymphocyte response Differentiate between humoral and cellular immunity Humoral antibodies produced by B cells Recognize antigens by antibodies on surfaces mature in bone Cell mediated involves T cells Recognize antigens by TCRs on surface T cells matures in marrow thymus Define antigen epitope hapten antibody immunoglobulin Ig Antigen substace that causes body to produce specific antibodies Epitope region on antigens recognized by antibody Hapten too small to stimulate antibody formation alone must combine with a carrier molecule Antibody proteins made in response to an antigen that specifically recognize antigens Immunoglobin antibodies characteristics Explain the function of antibodies and describe their structural and chemical Typical 4 protein chains 2 light and 2 heavy joined by disulfide links Name five classes of antibodies Igs and know their differences IgG 80 of serum monomer in lymph blood intestine longest life enhances phagocytosis neutralizes toxins and viruses involved in protecting new borns IgM pentamer around 5 to 10 of serum in blood lymph B cell surface 5 day half life first antibodies in response to initial infection IgA dimer 10 to 15 found in secretions 6 day half life IgD only 2 monomer initiate immune response IgE monomer only 002 allergic reaction response Describe clonal selection and how body can produce many different Stem cells differentiate into mature B cells Some turn to memory cells Some turn to antibody producing plasma cells Describe outcomes or
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