MC3 report 1

• Factors that affect Microbial Growth:

  • Availability of Nutrients: nutrients like carbohydrates, proteins, lipids, and minerals impact growth rate
  • Moisture: essential for metabolic processes; low moisture levels slow down growth
  • Temperature: crucial for enzyme activity; each microorganism has optimum, minimum, and maximum growth temperatures
  • pH: microorganisms have pH preferences; most prefer neutral or slightly alkaline conditions
  • Osmotic Pressure and Salinity: affect cell function due to solute concentration
  • Barometric Pressure: minor changes usually don't affect bacteria; some thrive at high pressure
  • Gaseous Atmosphere: different microbes require different gaseous atmospheres
• Categories of Bacteria Based on Growth Temperature:

  • Thermophiles: 50-60°C optimum
  • Mesophiles: 20-40°C optimum
  • Psychrophiles: 10-20°C optimum
• Define the following terms:

  • Sterilization: destruction of all microbes
  • Disinfection: elimination of most pathogens from nonliving objects
  • Pasteurization: method to disinfect liquids
  • Disinfectants: chemicals to destroy pathogens on nonliving materials
  • Antiseptics: solutions to disinfect living tissues
  • Sanitization: reduction of microbial populations to safe levels
  • Microbicidal agent: kills microbes
  • Microbistatic agent: inhibits microorganism reproduction
  • Sepsis: presence of pathogens in blood or tissues
  • Asepsis: absence of pathogens in blood or tissues
  • Aseptic technique: measures to ensure absence of living pathogens
  • Antisepsis: inhibiting growth of pathogens
• Differentiate sterile technique from clean technique:

  Sterile Technique:

  • Excludes all microorganisms
  • Used in critical procedures
  • Involves sterile equipment and environments

  Clean Technique:

  • Minimizes microorganisms
  • Used in less invasive procedures
  • Includes handwashing and maintaining a clean environment
• To prepare for a clean technique:

  • Wash your hands with soap and running water for at least 1 minute, paying attention to backs, palms, fingers, thumbs, and between fingers
  • Dry hands with a clean paper towel
  • Use the special flap to pull back the paper wrapper of your pad or kit
  • Pinch the other sections on the outside and pull them back gently
  • Throw the wrapper away
• Gloves preparation:

  • Wash hands again
  • Dry hands with a clean paper towel
  • Pinch the glove wrapper to pick it up and place it on a clean, dry surface next to the pad
  • Open the outer wrapper and place the open package on a clean, dry surface next to the pad
• Putting on gloves:

  • Carefully put gloves on
  • Wash hands again
  • Open the wrapper so that the gloves are lying out in front of you
  • Grab the other glove by the folded wrist cuff with your writing hand
  • Slide the glove onto your hand
  • Leave the cuff folded
  • Pick up the other glove by sliding your fingers into the cuff
  • Slip the glove over the fingers of this hand
  • Both gloves will have a folded-over cuff
• Clean technique for wound cleaning:

  1. Wash Your Hands

  2. Apply Gentle Pressure to the Wound

  3. Rinse with Water

  4. Use an Antibiotic Cream or Ointment

  5. Bandage the Wound (Sometimes)
• Methods to inhibit bacterial growth:

  • Physical and chemical methods are essential in controlling infectious diseases caused by harmful microbes and unwanted microbial contamination
  • Physical methods include temperature, desiccation, radiation, ultrasound waves, filtration, and gaseous atmosphere
• Heat as a method to inhibit microbial growth:

  • Heat is commonly used on inanimate objects and materials
  • Time and temperature determine its effectiveness
  • Understanding the interaction of time and temperature is crucial for indicating the thermal death point of microorganisms
  • Heat can be used at higher temperatures for shorter durations or lower temperatures for longer durations, depending on the pathogen's thermal death point
• Ultrasonic cleaning is frequently used in hospital settings for delicate equipment
• Ultrasonic cleaning effectiveness in removing organic debris makes it valuable for maintaining instrument hygiene
• Ultrasonic cleaning requires subsequent washing and sterilization for complete decontamination
• Filtration methods include the use of filters with various pore sizes to filter microorganisms from liquids
• Materials used for filtration include sintered glass, plastic films, unglazed porcelain, asbestos, diatomaceous earth, and cellulose membrane filters
• Cotton plugs are used as effective filters in test tubes, flasks, or pipettes to prevent the entry of microorganisms
• Dry gauze and paper masks serve a dual purpose by preventing the outward transmission of microbes and protecting the wearer from inhaling airborne pathogens
• Manipulating atmospheric conditions can effectively inhibit the growth of microorganisms
• Aerobes and microaerophiles can be targeted for inhibition by placing them in an oxygen-deprived atmosphere
• Obligate anaerobes can be eliminated by introducing oxygen into their environment or placing them in an atmosphere containing oxygen
• Chemical disinfectants play a vital role in inhibiting the growth or directly killing pathogens on surfaces and objects
• Disinfectants employ diverse tactics to tackle microbes, targeting cell membranes, internal components, cell walls, or nucleic acids
• Factors influencing disinfectant effectiveness include prior cleaning, microbial load, concentration, contact time, surface type, temperature, and pH
• The selection of the appropriate disinfectant depends on surface type, bioburden, and potential harm to patients and materials
• Antiseptics reduce the number of microorganisms on the skin's surface and are commonly used in various medical settings
• Antiseptics are used for hand washing, preoperative skin disinfection, mucous membrane disinfection, and treating infected skin or oral infections
• Strong antiseptics can cause skin irritation or chemical burns and should be neutralized before use
• Various factors affect the efficiency of disinfectants, including prior cleaning, organic load, bioburden, concentration, contact time, surface type, temperature, and pH
• Understanding disinfectant mechanisms and optimizing conditions are critical for effective microbial control
• Medical asepsis aims to prevent the spread of disease in medical facilities through procedures like hand washing and surface cleaning
• Advantages of medical asepsis include diminished risk of healthcare-associated infections, prevention of contamination, favorable public health impact, and preservation of healthcare worker well-being
• Disadvantages of medical asepsis include costs of cleaning and sanitizing equipment, risk of exposure to hazardous chemicals, and risk of tissue damage
• Surgical asepsis aims to prevent pathogenic germs during invasive procedures like surgery
• Advantages of surgical asepsis include preventing infections during surgical procedures and reducing healing time
• Disadvantages of surgical asepsis include equipment costs and the need for meticulous procedures to prevent infections
• Microorganisms can easily enter the body from the external environment
• Specialised exchange surfaces are required in multicellular organisms for efficient gas exchange of carbon dioxide and oxygen
• Advantages of aseptic techniques:

  • Prevent microorganisms from entering internal tissues and causing infections
  • Reduce the likelihood of microbes entering the body from the external environment
• Disadvantages of aseptic techniques:

  • Equipment is frequently expensive and has single usage
  • Time-consuming preparation for surgery due to necessary precautions and sterilization methods
  • High cost of surgery due to maintaining high conditions of asepsis
• Categories of disinfectants:

  • Chemical sterilant: Quickly eliminates enveloped viruses and vegetative bacteria
  • High-level disinfectant: Crucial in healthcare settings to eliminate endospore-forming bacteria
  • Intermediate-level disinfectant: Kills a greater variety of pathogens than low-level disinfectant but does not kill bacterial spores
  • Low-level disinfectant: Used for non-critical items that encounter skin