Sterilization and Disinfection Antisepsis Antiseptic agents and fabrics

Sterilization and Disinfection. Antisepsis. Antiseptic agents and fabrics. Vinnitsa National Pirogov Memorial Medical University/ Department of microbiology

Methods of asepsis -mechanical cleaning -chemical treatment -sterilization -disinfection -antisepsis -hermetic closing -isolation

Measures of asepsis Sterilization Disinfection

Physical methods High temperature action Dry heat Moist heat Flaming Boiling Pasteurization n

Physical and other methods n n Radiation action (ionizing and nonionizing radiation ) Ultrasonic and sonic vibration Mechanical methods Chemical methods

Heat sterilization n 1. 2. 3. 4. The factors influencing sterilization by heat are: Nature of heat (dry heat or moist heat) Temperature and time Number of microorganisms present, their characteristics (species, ability to form spores) Type of material from which organisms have to be eradicated

Dry heat sterilization n Hot air oven n 1600 C to 1700 C for 2 to 3 hours n Flaming n Incineration

Moist heat sterilization n Steam under pressure (autoclaving) Steam at atmospheric pressure (1000 C) Tyndallization or fractional steam sterilization

Methods of heat decontamination n Boiling n Pasteurization

Gas sterilization n Ethylene oxide n Formaldehyde gas n Betapropionlactone (BPL)

Methods of disinfection n n The chemicals (disinfectants) are more often used for treatment articles, surfaces, contaminated instruments and clothes Requirements to ideal disinfectant are: n n n Must be effective against a wide variety of infectious agents Should not be toxic to human Should be odorless, stable upon storage, and soluble in water and lipids Should not be corrosive for common materials Should be relatively inexpensive

Determination of disinfectant effectiveness n n Phenol coefficient test Measurement of killing rates with germicides Use dilution testing In-use testing

Antisepsis n n n Antisepsis is the prevention of infection or sepsis by removing or decreasing bacteria on the skin and mucous membranes Antiseptics are chemical antimicrobial agents which are applied to tissue to prevent infection Antiseptic fabrics are the sutures, dressing materials and polymer items which are compose with antiseptics

Classification of the disinfectants and antiseptics n n n n n Surface-active agents (cationic, anionic, nonionic and amphotheric) Halogens (iodine and chlorine) Oxidizing agents Aldehydes Phenolics Alcohols Dyes Heavy metal salts Acids

Mechanisms of disinfectant action n Denaturion of proteins and microbial enzymes Disruption of cell membranes Oxidizing of cellular components

Disinfectant effectiveness depends on n n Concentration Exposition Temperature Presence of organic materials

Antiseptics containing decamethoxine n n n Decasan (0, 02% isotonic solution) Palisan Horosten (hygienic antiseptic) Palisept (ointment) Antifungin Аmosept (film-forming antiseptic) Aspersept (powder) Aurisan, otosan (ear drops) Oftadec (eye drops) Septefril (oral antiseptic in tablets) Rinosept (nasal drops) Deseptol (vaginal suppository)