Microbiology Chapter 5

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Microbiology Chapter 5
2014-02-15 21:00:11
Microbiology Chapter
Microbiology Chapter 5
Microbiology Chapter 5
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  1. Define Sterilization
    removal/destruction of all microorganisms and virueses in/on a product
  2. Define Sterile
    An item free of microbes, including endospores and viruses, does NOT consider prions
  3. Define Disinfection
    elimination of most or all pathogens on/in a material
  4. Define Disinfectant
    antimicrobial chemicals used to disinfect inanimate objects
  5. Define germicide
    another way to describe disinfectants
  6. Define Bactericidal
    to kill bactria
  7. Define Antiseptics
    Antimicrobial chemicals non-toxic enough to be used on skin/body tissue
  8. Define Pasteurization
    heat treatment used on foods and inanimate objects to destroy pathogens and reduce spoiling agents
  9. Define decontamination
    • used to reduce the number of bacterial agents¬†
    • ex. washing
  10. Define Sanitization
    process that reduces microbial population to an acceptable health standard
  11. Define preservation
    delaying food spoilage or other perishables
  12. Define Bacteriostatic
    chemicals preservatives used in preservation that inhibit bacterial growth
  13. What are healthcare associated infections?
    Infections caused within a hospital
  14. Why are patients susceptible to infections?
    • Usually in a weakened state
    • undergone invasive surgery
    • pathogens can occur in high concentrations in a hospital setting
  15. Which bacteria create endospores?
    Bacillus and Clostridium
  16. How do you kill Protozoan cysts and Oocsts?
  17. Why are Mycobacterium Species difficult to kill?
    Their waxy cell walls make them resitant to most chemicals, therefore more toxic chemicals must be used
  18. How do you kill Pseudomonas Species?
    resistant to some disinfectants, can cause serious healthcare associated infections
  19. What is a D Value?
    The time required to kill 90% of bacterial population
  20. What are Critical Instruments?
    • Instruments that come into direct contact with body tissue
    • ex. Scalpel
  21. What are semicritical instruments?
    • come into contact with mucous membrane, but do not penetrate
    • ex. endoscopic tube
  22. What are non-critical instruments?
    • come into contact with unbroken skin
    • ex. stethoscopes
  23. What are examples of moist heat?
    • Boiling
    • Pasteurization
    • Pressurized Steam
    • Commercial Canning Process
  24. What is required to kill microbes via boiling
    100 C at sea level destroys most microbes except endospores.
  25. What is required to kill microbes via Pasteurization?
    • High-temperature-short-time (HTST)
    • Ultra-high temperature (UHT)
  26. What is needed for Pressurized Steam
    • Autoclave
    • Used for surgical equiptment
  27. How does dry heat kill microbes?
    • not as efficient as Moist Heat
    • needs to be hotter and longer
  28. How does filtration work to remove organisms from Fluids
    Membrane Filters/Microfilters have microscopic pores to allow for passage of luid but not particles
  29. How does filtration work to remove organisms from the Air
    • High-Efficiency- particulate Air Filters (HEPA)
    • removes airboen particles >/3um
  30. What are the three different types of radiation?
    Ionizing, ultraviolet, microwaves
  31. How does Ionizing Radiation destroy/remove microbes?
    removes electrons from atoms therefore destroying the cell's DNA and damaging cytoplasmic membrane
  32. How does Ultraviolet radiation destroy/remove microbes?
    destroys actively multiplying bacteria, not endospores
  33. How do Microwaves destroy/remove microbes?
    Does not destroy microbes, the heat generated does
  34. How does High Pressure destroy/remove microbes?
    • Denatures proteins and altering cell permeability
    • Doesn't affect food taste or color
  35. How are Germicidal Chemicals grouped?
    By their potency
  36. What are the benefits and risks of germicidal chemicals?
    • Less reliant than heat
    • useful for treating heat resistant material
  37. What are the four groupings of Germicidal Chemicals?
    • Sterilants
    • High-level Disinfectants
    • Intermediate-level disinfectants
    • Low Level disinfectants
  38. Describe Sterilants
    • Destroy all microorganisms
    • treat heat-sensitive instruments
  39. Describe High-level disinfectants
    • Destroy all viruses and vegetative microorganisms
    • do not reliably kill endospores
  40. Describe eIntermediate-level disinfectants
    • destroy all vegetative bacteria
    • do not reliabily kill endospores
  41. Describe low level disinfectants
    Destroy fungi, vegetative bacteria except mycobacteria and enveloped viruses
  42. What are points to consider when selecting appropriate germicidal chemicals?
    • Toxicity
    • Activity in the presence of organic matter
    • compatibility w. treated material
    • Residue
    • Cost and Availability
    • Storage and Stability
    • Environmental Risk
  43. Why should toxicity be considered?
    Are the side effects worth the disinfecting qualities
  44. Why should activity in the presence of organic matter be considered when selective a germicidal chemical?
    Some germicides are inactivated by organic matter
  45. Why should compatibility with treated material be considered when choosing a germicidal chemical?
    ex. liquids cannot be used on electrical equiptment
  46. Why should storage and Stability be considered when choosing a germicidal chemical
    some germicides require dilution
  47. Why should environmental risk be considered when selecting a germicidal chemical?
    Some chemicals may need to be neutralized after use