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There are 5 stages of pathogenisis name them in order
- Stage 1 - Transmission from source to portal of entry
- Stage 2 - Evasion of primary host defenses (innate immunity)
- Stage 3 - Adherence to mucous membranes
- Stage 4 - Colonization by growth in numbers
- Stage 5 - Exotoxin/endotoxin production
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What are common modes of transmission for bacteria?
- Airborne
- Fecal contamination of food and water
- Transfer of blood
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What type of transmission includes airborne, fecal, trasnsfer of blood. Horizonontal or vertical?
Horizontal
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What type of transmission includes transplacental, within birth canal, or breast milk? Horizontal or vertical
Vertical
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What type of conditions cause host defenses to fail?
- Low antibody counts
- Low complement counts
- Low WBC counts
- Pyrogenic bacteria(staph, strep)
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Characteristics of bacterium
What are thin rod-like projections from bacterial surface that allow bacterium to attach to urinary tract epithelium?
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Characteristics of bacterium
What are fingers that attach to urethra to cause infection called?
- Fimbriae
- Such as in gonnorhea
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Characteristics of bacterium
What are surface protiens that deter binding and interact with factor XII
- Culri
- Such as in E Coli/Salmonella
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What role does collagenase play in bacterial colonization?
Breaks down the surface so can get in the cell
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What role does hyaluronides play in bacterial colonization?
Spreading factor, cells no longer stick together
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What role does coagulase play in bacterial colonization?
- acceleratees clot formation
- prevents bacteria from phagocytosis by walling off
- coats organisms by fibrin (clotting)
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What role does protease play in bacterial colonization?
Allows adherence to mucous membranes
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What role does leukocidins play in bacterial colonization?
Destroy neutrophils and macrophages (kills WBCs)
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Exotoxin or Endotoxin
Proteins released during bacterial growth?
Exotoxin
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Exotoxin or Endotoxin
Lipopolysaccharides contained in the cell walls of gram-negative bacteria and relased during lysis of the bacteria
Endotoxin
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Exotoxin or Endotoxin
Can damage cell membranes, activate second messengers, and inhibit protein synthesis
Exotoxin
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Exotoxin or Endotoxin
Immunogenic and elicit production of antibodies...thus vaccines available
Exotoxin
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Exotoxin or Endotoxin
Stimulate the realsease of inflammatory mediators, produce fever, and local systemic effects
Endotoxin
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Exotoxin or Endotoxin
Not made by bacteria, but part of the cell wall
Endotoxin
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Why is pseudomonas considered an opportunistic bacteria?
- Can infect any tissue (usually only with immune compromised)
- Resistant to antibiotics due to its "biofilm" protection
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What is the property of skin with pseudomonas? (think of inclass example)
- Wetness
- endothelium is wet
- sputum is increased drainage
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What is the organism that resists phagocytosis, multiplies rapidly, destroys complement, Produces hemolytic toxins, and nucleases pus?
Streptococcus Group A
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What is the most fatal form of streptococcus group A?
- Necrotizing fasciitis
- stimulates T cells to produce large amounts of cytokines to attract macrophages and leukocytes, which leads to degranulation, damage to endothemlium, and other exotoxins destroy proteins of host tissue. (self destruction)
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What is the type of streptococcus infection that cuases bacterial endocarditis from organisms that gain access to blood?
Heart valves
Strep Veridans
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What are some of the causes for strep veridans
- Tooth extraction
- poor oral hygiene
- decayed teeth
- Drug users with contaminated needles
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What happens to the heart with strep veridans infection?
Scar tissue builds up into a cauliflower-type growth and interferes with proper valve function
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What is the property of skin with Staphylococcal infection?
Walling off - produces coagulase that produces a wall and is creamy white and stiff like jello.
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Where do staph infections come from?
clothing, bedding, droplets, human carriers - skin, bone, respiratory tract, blood stream
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What is the organism that hydrolyzes the beta-lactam ring of penicillin, thereby inactivating the molecule?
Saphylococcal bacteria
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Systemic Inflammatory Response (SIRS) requires 2 or more changes in the following 4 factors. What are the 4 factors?
- Body Temperature
- Heart Rate
- Respiratory function
- Peripheral leukocyte count
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Sepsis must meet the criteria for SIRs(systemic inflammatory response) AND what other condition?
Must of documented infection.
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