Ch. 8

• sterilization


  destruction of all viable organisms
• disinfection


  killing, inhibition, or removal of disease causing organisms
• sanitation


  reduction of microbial population to safe levels
• antisepsis


  prevention of infection in living tissue by microorganisms
• -cidal


  agent kills; germicide (not endospores though), bacteriocide, virucide, fungicide, etc.
• -static


  agent inhibits growth; bacteriostatic, fungostatic, etc.
• microbial death


  occurs exponentially; is a measure of an agents efficiency given that VBNC cells are dead as well (decimal reduction time = time to kill 90%)
• condition influencing agent efficiency 


  population size and composition, concentration of agent, duration of exposure, temperature, and environmental conditions (biofilm, etc.)
• mechanical removal methods


  filtration, membrane filters (for liquid, porous), and HEPA filters
• moist heat


  not boiling; destroys viruses, fungi, and bacteria
• steam sterilization


  100 C in autoclave; effective against all types of microorganisms
• dry heat


  160-170 C for 2-3 hours; less effective than moist heat
• UV radiation


  wavelength of 260; causes thyme dimers preventing replication and transcription, limited to surface sterilizaiton though
• ionizing radiation


  gamma rays; not effective against viruses
• alcohols


  ethanol and isopropanol; not sporicidal and not effective for all viruses
• gases


  oxides, -actones; used on heat sensitive materials
• phenol coefficient test


  potency of disinfectant is compared to phenol; may be misleading
• use dilution test


  determines the rate at which bacteria are destroyed by agent
• biological control agents


  predation (Bdellovirbrio), viral-mediated lysis, and toxin-mediated killing using bacteriocins