39. Good Hand Washing Practices Save many Lives Soap, Water and common sense are yet the best antiseptics William Osler
40.
41. Physical Antimicrobials Used for sterilizing medical supplies DNA damage Radiation, X-rays Line-drying laundry Strong vis. Light Limited penetration DNA damage (thymine dimers) Radiation, UV Used in food preservation (less effective against fungi) Plasmolysis of contaminants Osmotic Pressure, Addition of salt or sugar Bacteriostatic Decreased chemical reaction rate Cold, Refrigeration Used for food & drug preservation; Does not necessarily kill so used for Long-term storage of bacterial cultures Desiccation and low temperature Cold, Lyophilization (also desiccation) Used for heat sensitive liquids Separation of bacteria from liquid (HEPA: from air) Filtration 170°C for 2 hours ; Used for glassware & instrument sterilization Oxidation & Denatures proteins Dry Heat, Hot air oven Used for inoculating loop Incineration of contaminants Dry Heat, Flaming Kills pathogens in food products Denatures proteins Moist Heat, Pasteurization 121°C at 15 p.s.i. for 30 min k ills everything Denatures proteins Moist Heat, Autoclaving Kills vegetative bacterial cells and viruses Endospores survive Denatures proteins Moist Heat, boiling Comments Mechanisms of Action Agent
42. Chemical Antimicrobials * Type of Disinfectant: H = High level; I = Intermediate level; L = Low level
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