P127

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What is the function of bacterial Peptidoglycan?: Gives rigid support, protcts agains osmotic pressure.
What is the chemical composition of bacterial peptidoglycan: Sugar backbone with cross-linked peptide side chains.
What is the function of bacterial Cell wall/cell membrane (gram +)?: Major surface antigen
What is the chemical composition of bacterial Cell wall/cell membrane (gram +)? What does it induce?: Teichoic acid induces TNF and IL-1
What is the function of bacterial Outer membrane (gram -)?: Site of endotoxin (lipopolysaccharide); major surface antigen
What is the chemical composition of bacterial Outer membrane (gram -)? What does it induce? What is the antigen?: Lipid A induces TNF and IL-1; polysaccaride is the antigen.
What is the function of bacterial Plasma membrane?: Site of oxidative and transport enzymes.
What is the chemical composition of bacterial Plasma membrane?: Lipoprotien bilayer
What is the function of bacterial Ribosome?: Protein synthesis
What is the chemical composition of bacterial Ribosome?: RNA and protein in 50S and 30S subunits
What is the function of bacterial periplasm?: Sapce between the cytoplasmic membrane and outer membrane in gram-nagative bacteria.
What is the chemical composition of bacterial periplasm?: Contains many hydrolytic enzymes, incuding beta-lactamases.
What is the function of bacterial capsule?: Protects agains phagocytosis
What is the chemical composition bacterial capsule? What bacteria is the exception and how?: Polysaccharide (except Bacillus enthracis, which contains D-glutamate)
What is the function of bacterial Pilus/fimbria: Mediates adherence of bacteria to cell surface; sex pilus forms atttachement between 2 bacteria during conjugation
What is the chemical composition of bacterial pilus/fimbria?: Glycoprotein
What is the function of bacterial Flagellum?: Motility
What is the chemical composition of bacterial flagellum?: Polysaccharide
What is the function of bacterial Spore?: Provides resistance to dehydration, heat, and chemicals.
What is the chemical composition of bacterial spore?: keratin like coat; dipicolinic acid
What is the function of bacterial Plasmid?: Contains a variety of genes for antibiotic resistance, enzymes, and toxins.
What is the chemical composition of bacterial Plasmid?: DNA
What is the function of bacterial Glycocalyx: Mediates adherence to surfaces, especially foreign surfaces (indwelling catheters).
What part of the cell wall is unique to gram positive organisms?: Teichoic acid
What 5 elements of bacterial cell wall and outer structures are common to both gram + and gram - bacteria?: flagella, pillus, capsule, peptigoglycan, cytoplasmic membrane.
What part of the cell wall is unique to gram negative organisms?: Endotoxin/LPS (outer membrane)
How do the peptidoglycan layers of gram + and - bacteria compare?: Gram positives have much thicker peptidoglycan layers than gram negatives.
What does the lag phase represent in the bacterial growth curve?: lag - metabolic activity w/o division
What does the log phase represent in the bacterial growth curve?: log - rapid division.
What does the stationary phase represent in the bacterial growth curve?: stationary - nutrient depletion slows growth
What does the death phase represent in the bacterial growth curve?: death - prolongued nutrient depletion and build up of waste products lead to death
What are the 4 phases of the bacterial growth curve?: lag, log, stationary, death
What is the source of EXOtoxin?: Certain species of SOME gram + and - bacteria
What is the source of ENDOtoxin?: Cell wall of MOST gram - bacteria and LISTERIA
What is the fate of ENDO toxin?: It is kept on the cell
What is the fate of EXOtoxin?: It is secreted from the cell
What is the chemistry of EXOtoxin?: Polypeptide
What is the chemistry of ENDOtoxin?: Lipopolysaccharide
Where is the EXOtoxin gene located?: Plasmid or bacteriophage
Where is the ENDOtoxin gene located?: Bacterial chromosome
What is the level of toxicity of EXOtoxin?: High (fatal dose on the order of 1 micro-gram)
What is the level of toxicity of ENDOtoxin?: Low (fatal dose on the order of hundreds of micrograms)
What are the 2 clinical effects of ENDOtoxin?: Fever, shock
What is the mode of action of ENDOtoxin?: Includes TNF and IL-1
Describe the antigenicity of EXOtoxin.: Induces high-titer antibodies called antitoxins
Describe the antigenicity of ENDOtoxin: Poorly antigenic
Describe the vaccine for EXOtoxin?: Toxoids used as vaccines
Describe the vaccine for ENDOtoxin?: No toxiods formed, no vaccine available.
What is the heat stability of EXOtoxin? What is the exception?: Destroyed rapidly at 60C (except staphylococcal enterotoxin)
What is the heat stability of ENDOtoxin?: Stable at 100C for 1hour.
Name 3 disease that have EXOtoxins.: Tetanus, botulism, diphtheria
Name 2 disease that have ENDOtoxins: Meningococcemia, sepsis by gram - rods
What type of exotoxins bind directly to MHC II and T-cell receptor, activating large numbers of T cells to stimulate release of IL-1 and IL-2?: Superantigens
What is the mechanism of action of superantigens?: Bind directly to MHC II and T-cell receptor, activating large numbers of T cells to stimulate release of IL-1 and IL-2?
Name 2 bacteria that release exotoxins that are superantigens?: S. aureus and S. pyogenes
What are the 2 enterotoxins of S. aureus and what are their effects?: 1. TSST-1 causes toxic shock syndrome (fever, rash, shock). 2. Enterotoxins cause food poisoning.
What is the enterotoxin of S. pyogenes adn what does it cause?: Secarlet fever - strain SPE toxin causes toxic shock-like syndrome.

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