CONTROL OF MICROBIAL GROWTH NOTES SANG CLASSMATE KO AH

• Birth of the "Aseptic technique"


  1840
• Physicians Ignaz Semmelweis and Joseph Lister


  • Developed the first microbial control practices
• Microbial control techniques


  • Hand washing with the microbe-killing chloride of lime
  • Aseptic surgery
• Sterilization


  Removal or destruction of ALL living microorganisms
• Heating


  The most common method used for killing microbes, including resistant endospores
• Sterilant


  A sterilizing agent
• Commercial sterilization


  Limited heat treatment where food (e.g. canned food) is subjected to heat enough only to destroy the endospores of Clostridium botulinum
• Limited heat is given because heat required to ensure absolute sterility could also degrade the quality of food
• Disinfection


  Methods of microbial control directed at destroying harmful/pathogenic microorganisms
• Disinfectants


  Chemicals used for disinfection
• Antisepsis


  Disinfection directed at or applied to living tissue such as the skin or a wound
• Antiseptic


  Chemical used for antisepsis
• Disinfectants can be used as antiseptics and vice versa, but certain disinfectants (e.g. muriatic acid) can be harmful to living tissue
• Degerming/Degermation


  Mechanical removal of microbes in a limited area
• Sanitization


  Methods of lowering microbial counts to safe public health levels and minimize the chances of disease transmission from one user to another
• Sanitization in restaurants


  • High temperature washing
  • Chemical disinfectant
• Sanitization in restaurants is usually evaluated by sanitary inspectors
• Terminology related to control of microbial growth


  • Sterilization
  • Disinfection
  • Antisepsis
  • Degerming
  • Sanitization

  
• Treatments causing microbial death


  • Biocide
  • Germicide
• Biocide


  Killing of microorganisms in general
• Germicide


  Killing of germs, or pathogenic microorganisms
• Germicides

  • Fungicides kill fungi
  • Virucides kill viruses
• Treatments that inhibit growth & multiplication


  • Bacteriostasis/Bacteriostatic
• Bacteriostasis/Bacteriostatic


  An agent that slows down bacterial growth. Once removed, bacterial growth might resume.
• Handwashing greatly decreased infection rate in patients with surgery or delivery
• Handwashing is the best way to prevent transmission of pathogens
• Methods of control of microbial growth


  • Sterilization
  • Disinfection
  • Antisepsis
  • Degerming
  • Sanitization
• Treatments for microbial death


  • Biocide
  • Germicide
  • Bacteriostasis
  • Asepsis
• Sepsis


  Greek for decay or putrid - Indicates bacterial contamination & spread
• Asepsis


  Indicates the absence of significant contamination. "Aseptic" refers to any area/item free of any pathogen
• When bacterial populations are heated or treated with antimicrobial chemicals, they usually die at a constant rate
• If the death curve is plotted logarithmically, the death rate is constant
• Factors that influence effectiveness of antimicrobial treatment

  • Number of microbes
  • Environmental influences
  • Time of exposure
  • Microbial characteristics
• The more microbes there are to begin with, the longer it takes to eliminate the entire population
• The presence of organic matter often inhibits the action of chemical antimicrobials
• Organic matter that inhibits antimicrobials

  • Blood
  • Vomitus
  • Feces
• Certain disinfectants work best in warm temperature
• Acidic conditions make heat treatment more effective
• Fats & proteins in suspending medium protects microbes, making heat treatment less effective
• Chemical antimicrobials often require extended exposure to affect more-resistant microbes or endospores