Microbial Control pt. 1

• Sterilization


  Destruction or removal of all forms of microbial life, including endospores but with the possible exception of prions
• Commercial sterilization


  Sufficient heat treatment to kill endospores of Clostridium botulinum in canned food
• Disinfection


  Destruction of vegetative pathogens on inanimate objects
• Antisepsis


  Destruction of vegetative pathogens on living tissue
• Degerming


  Removal of microbes from a limited area, such as the skin around an injection site
• Sanitization


  Treatment intended to lower microbial counts on eating and drinking utensils to safe public health levels
• Biocide


  Kills microorganisms (usually with certain exceptions, such as endospores)
• Germicide


  Kills microorganisms
• Bacteriostasis


  Inhibits the growth and multiplication of bacteria
• Asepsis


  Absence of significant contamination
• Sterilization is the removal or destruction of all living microorganisms
• Heating is the most common method used for killing microbes, including the most resistant forms, such as endospores
• A sterilizing agent is called a sterilant
• Liquids or gases can be sterilized by filtration
• The heat treatment required to ensure absolute sterility would unnecessarily degrade the quality of canned food
• The endospores of a number of thermophilic bacteria, capable of causing food spoilage but not human disease, are considerably more resistant to heat than C. botulinum
• Complete sterilization is often not required in other settings
• The body's normal defenses can cope with a few microbes entering a surgical wound
• A drinking glass or a fork in a restaurant requires only enough microbial control to prevent the transmission of possibly pathogenic microbes from one person to another
• Disinfection


  Control directed at destroying harmful microorganisms
• Disinfection might make use of chemicals, ultraviolet radiation, boiling water, or steam
• When disinfection is directed at living tissue, it is called antisepsis, and the chemical is then called an antiseptic
• Many chemicals suitable for wiping a tabletop would be too harsh to use on living tissue
• Degerming


  Mostly results in the mechanical removal, rather than the killing, of most of the microbes in a limited area
• Sanitization


  Intended to lower microbial counts to safe public health levels and minimize the chances of disease transmission from one user to another
• Sanitization is usually accomplished by high-temperature washing or, in the case of glassware in a bar, washing in a sink followed by a dip in a chemical disinfectant
• Sepsis


  Bacterial contamination
• Aseptic techniques are important in surgery to minimize contamination from the instruments, operating personnel, and the patient
• When bacterial populations are heated or treated with antimicrobial chemicals, they usually die at a constant rate
• The more microbes there are to begin with, the longer it takes to eliminate the entire population
• Most disinfectants work somewhat better in warm solutions
• The presence of organic matter often inhibits the action of chemical antimicrobials
• Microbes in surface biofilms, when they are encased in the mucoid matrix, are difficult for biocides to reach effectively
• Disinfectants work somewhat better under warm conditions
• Fats and proteins are especially protective, and a medium rich in these substances protects microbes, which will then have a higher survival rate
• Heat is also measurably more effective under acidic conditions
• Chemical antimicrobials often require extended exposure to affect more-resistant microbes or endospores
• Damage to the lipids or proteins of the plasma membrane by antimicrobial agents causes cellular contents to leak into the surrounding medium and interferes with the growth of the cell
• Breakage of hydrogen bonds results in denaturation of proteins
• Damage to DNA and RNA by heat, radiation, or chemicals is frequently lethal to the cell