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 actionDry heatMoist heatFlamingBoilingPasteurization

Physical and other methods

Radiation action (ionizing and non-ionizing radiation )

Ultrasonic and sonic vibration

Mechanical methods

Chemical methods

Heat sterilization

The factors influencing sterilization by heat are:

1. Nature of heat (dry heat or moist heat)

2. Temperature and time3. Number of microorganisms

present, their characteristics (species, ability to form spores)

4. Type of material from which organisms have to be eradicated

Dry heat sterilization

Hot air oven 1600C to 1700C for 2 to 3 hours

Flaming

Incineration

Moist heat sterilization

Steam under pressure (autoclaving)

Steam at atmospheric pressure (1000C)

Tyndallization or fractional steam sterilization

Methods of heat decontamination

Boiling

Pasteurization

Gas sterilization

Ethylene oxide

Formaldehyde gas

Betapropionlactone (BPL)

Methods of disinfection The chemicals (disinfectants) are more

often used for treatment articles, surfaces, contaminated instruments and clothes

Requirements to ideal disinfectant are: 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

Phenol coefficient test Measurement of killing rates

with germicides Use dilution testing In-use testing

Antisepsis

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

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

Denaturion of proteins and microbial enzymes

Disruption of cell membranes Oxidizing of cellular components

Disinfectant effectiveness depends on

Concentration Exposition Temperature Presence of organic materials

Antiseptics containing decamethoxine

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)