Sterilization Techniques and Methods
41 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary mechanism of action for moist heat sterilization?

  • Coagulating proteins in microorganisms (correct)
  • Disrupting the DNA of pathogens
  • Oxidizing cellular components
  • Destroying the cell membrane of microorganisms

    • At what temperature is milk typically pasteurized using the Holder method?

  • 72°C for 15-20 seconds
  • 56°C for one hour
  • 100°C for 10 minutes
  • 63°C for 30 minutes (correct)

    • Which of the following correctly describes the use of boiling in sterilization?

  • It guarantees the destruction of all endospores
  • It can kill vegetative forms of bacterial pathogens (correct)
  • It is effective against all types of viruses reliably
  • It is a preferred method for sterilizing vaccines

    • What is a key feature of the autoclave designed by Charles Chamberland?

    <p>It uses steam under pressure for sterilization</p> Signup and view all the answers

    What temperature and duration are generally used for a vaccine preparation in a hot water bath?

    <p>60°C for 1 hour</p> Signup and view all the answers

    What is the primary action of hydrogen peroxide as an oxidizing agent?

    <p>Inhibiting enzymatic activity by attacking sulfhydryl groups</p> Signup and view all the answers

    Which of the following is a disadvantage of metallic salts used as disinfectants?

    <p>They have limited fungicidal activity.</p> Signup and view all the answers

    What types of surfaces can ethylene oxide effectively sterilize?

    <p>Glass, metal, paper surfaces, and organics</p> Signup and view all the answers

    Which filter types are commonly used for sterilization by filtration?

    <p>Candle filters, sintered glass filters, and membrane filters</p> Signup and view all the answers

    What type of radiation is considered suitable for rapid mass sterilization?

    <p>Non-ionizing radiation such as UV rays</p> Signup and view all the answers

    What is the primary method by which dry heat sterilization kills microorganisms?

    <p>Oxidation effects</p> Signup and view all the answers

    At what temperature is a holding period of 2 hours most effective for dry heat sterilization?

    <p>160°C</p> Signup and view all the answers

    Which of the following agents is NOT classified as a chemical agent for sterilization?

    <p>Filtration</p> Signup and view all the answers

    What type of filtration is used for liquids?

    <p>Water filtration</p> Signup and view all the answers

    Which treatment method is specifically described as ideal for destroying contaminated materials?

    <p>Flaming/incineration</p> Signup and view all the answers

    Which of the following methods involves using a Bunsen flame?

    <p>Incineration</p> Signup and view all the answers

    What is the range of temperatures that a dry oven operates within for sterilization?

    <p>50°C to 300°C</p> Signup and view all the answers

    Which chemical agent is specifically used for inanimate objects?

    <p>Disinfectants</p> Signup and view all the answers

    At what temperature and duration is flash sterilization achieved?

    <p>132º for 3 minutes</p> Signup and view all the answers

    Which of the following chemical agents is NOT effective against spores?

    <p>Ethanol</p> Signup and view all the answers

    Which statement correctly describes the action of hydrogen peroxide?

    <p>Limited by the organism's ability to produce catalase</p> Signup and view all the answers

    What is the recommended concentration of alcohol for disinfection purposes?

    <p>60-90% in water</p> Signup and view all the answers

    Which of the following uses formaldehyde?

    <p>To preserve anatomical specimens</p> Signup and view all the answers

    What is the primary goal of sterilization?

    <p>Removing all microorganisms including their spores.</p> Signup and view all the answers

    Chlorine compounds are primarily utilized for which purpose?

    <p>Disinfecting water supplies</p> Signup and view all the answers

    Which method is commonly used for sterilization of surgical instruments that can be damaged by moist heat?

    <p>Ethylene oxide gas exposure.</p> Signup and view all the answers

    What is a key property of phenolic derivatives in antisepsis?

    <p>They possess microbicidal properties</p> Signup and view all the answers

    What does disinfection achieve?

    <p>It kills many but not all microorganisms, including some bacterial spores.</p> Signup and view all the answers

    Iodine solutions are known for what type of action against bacteria?

    <p>Moderate action against spores and actively bactericidal</p> Signup and view all the answers

    What physical condition is required for autoclaving?

    <p>Steam at 121°C under a pressure of 15 lb/in² for 15 minutes.</p> Signup and view all the answers

    Which process involves the mechanical removal of microbes from surfaces?

    <p>Degermation</p> Signup and view all the answers

    What was a significant advancement in the mid-1800s to prevent surgical infections?

    <p>Aseptic techniques developed by Lister.</p> Signup and view all the answers

    Which of the following is a method of microbial growth control?

    <p>Damage to nucleic acids and alteration of membrane permeability.</p> Signup and view all the answers

    What does a bacteriostatic agent do?

    <p>Inhibits the growth of bacteria</p> Signup and view all the answers

    What were the death rates due to nosocomial infections in surgeries prior to modern aseptic techniques?

    <p>10%.</p> Signup and view all the answers

    Which of the following is NOT considered an antiseptic?

    <p>Corrosive phenol-containing disinfectants</p> Signup and view all the answers

    What is a characteristic of bacterial spores that makes sterilization challenging?

    <p>They are highly resistant to environmental factors.</p> Signup and view all the answers

    What is considered the absence of significant contamination?

    <p>Asepsis</p> Signup and view all the answers

    Which process specifically targets the destruction of vegetative pathogens?

    <p>Disinfection</p> Signup and view all the answers

    What term describes an agent that kills spores?

    <p>Sporicidal</p> Signup and view all the answers

    What is the difference between antiseptics and disinfectants?

    <p>Disinfectants can be corrosive, while antiseptics must be safe for skin.</p> Signup and view all the answers

    Study Notes

    Sterilization, Disinfection, and Antisepsis

    • Microorganisms cause contamination, infection, and decay
    • Early civilizations used methods like salting, smoking, pickling, and sun exposure to preserve food
    • Aseptic techniques were developed in the mid-1800s to prevent contamination of surgical wounds
    • Nosocomial infections caused significant patient deaths before aseptic techniques
    • Methods of microbial growth control include altering membrane permeability, damaging proteins, and damaging nucleic acids
    • Prions are the most resistant, followed by bacterial spores, mycobacteria, and cysts of protozoa
    • Viruses with lipid envelopes are the least resistant

    Definition of Sterilization

    • Sterilization is the process of eliminating all microorganisms, including spores.
    • It is essential for surgical procedures and other medical applications where contamination cannot be tolerated.

    Methods of Sterilization

    • Physical Agents:

      • Heat: Dry heat (e.g., incineration, dry oven) and moist heat (e.g., steam under pressure, autoclave). Dry heat sterilization is more powerful than moist heat sterilization.
        • The autoclave works under pressure (121°C or 132°C for various time intervals)
        • Temperature is controlled by a thermostat and double-walled insulation conserves energy.
        • Autoclaves are either vertical or horizontal cylinders with an opening for placing items to be sterilized. A pressure gauge measures the pressure, and a safety valve allows steam to escape
      • Radiation: Ionizing radiation (e.g., X-rays, gamma rays, cosmic rays) and non-ionizing radiation (e.g., UV rays).

    • Chemical Agents:

      • Gases: Ethylene oxide, hydrogen peroxide vapor, and others
      • Liquids: Various chemical solutions
        • Alcohols like ethanol or isopropyl alcohol frequently used as disinfectants, are often used in concentrations between 60%-90%
        • They also effectively disinfect clinical thermometers.
        • They can effectively disinfect the skin prior to venipunctures.
      • Other Methods: Various chemical methods are employed for sterilization
        • Formaldehyde and glutaraldehyde are frequently used as disinfectants.
        • Phenols are employed to disinfect various surfaces and objects in hospitals.

    • Mechanical Removal: Filtration (air and liquids)

      • Candle, Asbestos, and sintered glass filters are used for sterilization.

    Methods of Disinfection

    • Disinfectants kill many microorganisms but not all
    • Antiseptics are less toxic chemical solutions
    • Often, disinfectants and antiseptics are used together to ensure proper procedures

    Principles of effective disinfection

    • Concentration of disinfectant
    • Organic matter
    • pH
    • Time

    Terminology

    • Degermation: Mechanical removal of microbes
    • Sepsis: Bacterial contamination
    • Asepsis: The absence of significant contamination
    • Bactericidal: Kills bacteria
    • Bacteriostatic: Inhibits bacteria growth but doesn't kill
    • Sporicidal: Kills spores
    • Sterilization: Kills all organisms, including spores
    • Disinfection: Kills many organisms (not all), not spores
    • Antiseptic: Disinfectant use directly on exposed body surfaces
    • Sanitization: Mechanical removal of microbes

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Sterilization, Disinfection, and Antisepsis PDF

    Description

    Test your knowledge on various sterilization techniques, including moist heat sterilization, pasteurization methods, and the use of radiation. This quiz explores key concepts such as the functioning of autoclaves, chemical agents for disinfecting, and filtration methods. Perfect for students in microbiology or healthcare fields.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser