Term
How is the gram Stained performed?
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Definition
1) Pour on crystal violet stain (a blue dye) and wait 60 seconds 2) Wash off with water and flood with iodine soln. Wait 60 seconds 3) Wash off with water ad then decolorize with 95% alcohol 4) finally counter-stain with safranin (a red dye) |
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Term
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Definition
| Is this bacteria Psuedomonas Aerginosa Gram Negative or Gram Positive? |
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Term
| How do Gram Negative Bacteria stain and how do Gram positive Bacteria Stain? |
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Definition
Gram Negative stain Red (safran) Gram positive stain Blue (crystal violet) |
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Term
What is the gra-positive cell envelope consist of?
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Definition
- Cell Envelope has:
- Outer Cell Wasll
- composed of complex cross-linked peptidoglycan, teichoic acid (an antigen determinant), polysaccharies, and other protiens
- Inner Cell Wall
- touches cytoplasmic membrane
- Cytoplasmic Membrane
- proteins that span the lipid bilayer
- Bacterial cytoplasmic membrane with no cholesterol or sterols
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Term
| What does a gram negative cell wall consist of? |
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Definition
Gram negative cell envelope has 3 layers not including periplasmic space (which is filled with a gel that has proteins and enzymes: - Cytoplasmic membrane
- surrounded by THIN Peoptidolycan layer
- small helicallipoprotein= Murein
- origiates from peptidoglycan layer and extens outward to bind to third outer membrane
- Inner cell membrane contains PL bilayer with embedded proteins
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Term
| Which bacteria have LPS (- or +). What is the LPS composed of ? |
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Definition
Gram Negative bacteria have the LPS. The Outer most portion of the cell Membrane contains the LPS. Lipopolysaccaride is composed of 3 covalently linked components: 1. Outer Carbohydrate chains of 1050 oligosacharide units that extend in surrouding media. O- Antigen. 2. Core Polysccharide (water soluable) 3. Lipid A= Interior to Core polysaccharide *Disaccharide with multiple fatty acid tails reaching into the membrane * Lipid A is toxic to humans and is considered the Gram - ENDOTOXIN |
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Term
| What are the outcomes of LPS released into our systemic circulation? |
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Definition
| When bacterial cells are lysed by our immune system fragments of membrane containing lipid A are released int circulation causing fever, diarrhea, and possibly fatal septic shock. |
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Term
| Which type of bacteria (+ or -) are sensitive to antibiotics. |
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Definition
| Gram Positive bacteria peptidoglycan layer does not block diffusion of low molecular weight compounds, so substances that damage the cytoplasmic membrane (like antibiotics, dyes adn detergents can pass through) |
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Term
| What are the 6 Gram Positive Bacteria? |
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Definition
- Streptococcus
- Stapyoccous
- Bacillus
- Clostridum
- Corynebacteria
- Listeria
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Term
| Which of the Gram Positive are Rods? |
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Definition
3) Bacillus 4) Clostridum 5) Corynebacterium 6) Listeria |
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Term
| Which Gram + bacteria produce spores? |
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Definition
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Term
| Which of the Gram + Bacteria Do NOT produce spores? |
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Definition
5) Corynebacterium 6) Listeria |
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Term
| What are the Gram - Cocci and Gram - Spiral-shaped organisms? |
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Definition
Gram negative cocci= Neisseria Gram negative spirals= Spirochetes including Treponema pallidum (causes syphillis) ***the rest are gram-negative rods or pleomorphic*** |
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Term
| Are Mycobacteria Gram Positive or negative? What is the best stain to see them with? |
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Definition
| Mycobacteria is Gram -. THe best stain is the Acid-Fast stain |
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Term
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Definition
Proteins released by both gram - and gram + bacteria. That cause many disease manifestations. Released by all the major gram + Genera E listeria, which produces and an ENdotoxin. Ex. of Exotoxin= Anthrax, Botulism, tetanus, Cholera |
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Term
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Definition
Endotoxin is Lipid A, a piece of outer membrane LPS of Gram - bacteria. Endotoxin is not a protein excreted from cells, it is a normal part of outer membrane tha sort of sheds off. Listeria monocytogenes= Gram +, but has Endotoxin |
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Term
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Definition
AKA Endotoxic Shock is a common and deadly response to both Gram -/+ bacteria. Sepsis refers to bacteremia that causes a systemic immune response to the infection. Causing high/low temperature, elevation of WBC count, and fat heart rate or breathing rate. Sepsis that results in dangerous drops in blood pressure and organ dysfunction is called septic shock. Also called endotoxic shock, bc it ofen triggers the immune response that results in sepsis and shock. |
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Term
| What is Mechanism of Action of septic shock? |
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Definition
- Localized site of infection from Gram +/- Bacteria or fungi
- From this site or from the blood the organisms release structural components like endotoxin/exotoxin that ciruculate in bloodstream and stimulate immune cells like macrophages and neutrophils
- These cells releas a host of proteins in rsponse to the stimulus call endogenous mediators of Sepsis
- Including Tumor Necrosis Factor/ (Cachectin (causes weight loss in cancer patients)
- TNF triggers the release of the cytokine, IL01 from the macrophages and endothelial cells and this triggers the release of other cytokines and PGs
- THe mediators act on the blood vessesl and organs to produce vasodilation, hypotension and organ system dysfunction
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