STERILIZATION ,DISINFECTION

AND ANTISEPSIS

PRACTICAL SESSION: 1

COURSE: PRINCIPLES OF DISEASE I

LEVEL 4 MEDICINE

Course Instructors Dr. DOHA SIJA Dr. EIMAN ELNAKEEB Dr. HESHAM AZIZ Dr. MOURAD Dr. MOHAMED RAOUF

Course Coordinator: Dr. RIM MOHAMED

AIM:

To discuss the difference between sterilization , disinfection and antiseptics and the methods to use each of these .

Outcomes:

The effective decontamination of spillage, surfaces and equipment after use.

►Advice on adequacy of sterilization and disinfection procedure used in surgical and medical practice

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INTRODUCTION

Microorganisms are the agents of contamination, infection.

Hence it becomes necessary to remove them from materials and areas.

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Destroying Microorganism

Sterilization Disinfection Antisepsis

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Sterilization

Is the Complete destruction and killing of all microbes, including endospores.

Can be achieved by mechanical means, heat , chemicals or radiation.

The common types of sterilization : heat and chemical.

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Heat methods of sterilization

Kills microorganisms by denaturing their enzymes and other proteins. Heat resistance varies widely among microbes.

fast, reliable, inexpensive

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1.Dry heat A)FLAMING

►Inoculation loop or Wire, the tip of Forceps and spatulas are held in a bunsen flame till they are red hot.

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Flaming

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B)Hot Air Oven

Place objects in an oven (from 50oC to 300oC) . Require between 90 and 120 minutes at 160oC for sterilization

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Uses

►To sterilize Forceps, Scissors, Scalpels, Swabs.

►Pharmaceuticals products like Liquid paraffin, dusting

powder, fats and grease.

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►At temperature below 100°C: Pasteurization: there are two methods of pasteurization, the holder method (heated at 63°C for 30 minutes) and flash method (heated at 72°C for 15 seconds) followed by quickly cooling to 13°C.

►At a temperature 100°C:

Boiling: (100°C) for 10-30 minutes kills most vegetative bacteria and viruses immediately. Some bacterial spores are resistant to Boiling and survive

2. Moist Heat

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At a temperature above

100°C

Autoclave: Chamber which

is filled with hot steam under

pressure. Preferred method

of sterilization, unless

material is damaged by heat,

moisture, or high pressure.

Temperature of steam

reaches 120oC at twice

atmospheric pressure.

All organisms and

endospores are killed

within 15 minutes.

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CHEMICAL

►ETHYLENE OXIDE GAS

ITEMS THAT ARE SENSITIVE HEAT/ MOISTURE.

►HIGHLY FLAMMABLE!!!

MONITOR!!!

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STERILIZATION IS ACHIEVED THROUGH LOW - TEMPERATURES

►HYDROGEN PEROXIDE PLASMA VAPOR

SAFE AND NON-TOXIC

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Disinfection

►Is the process of eliminates most or all microorganisms, with the exception of Endospores (Reducing the number of pathogenic microorganisms to the point where they no longer cause infection)

►Disinfectant: An agent applied to inanimate objects.

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Disinfection

High level disinfectants

Kills all microbes

Intermediate level disinfectants

Kills most microbes and viruses

Low level disinfectants

Kills Some Vegetative Bacteria

Some Viruses and Fungi

Exposure less than 10 mins

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Vegetative

cells

Mycobacteria Spores Fungi Viruses Examples

High level + + + + + Ethylene Oxide,

Gluteraldehyde,

Formaldehyde

Intermediate

level

+ + - + + Phenolics,

halogens

Low level + - - +/- + quaternary

ammonium

compounds

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Disinfection of hands :

** Alcohol-based rubs.

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Antisepsis

is the process of destroying or

inhibiting the growth of microorganisms on the living tissue.

Antiseptics

►Chemicals used to kill microorganisms on the surface of skin and mucous membranes.

►A substance applied on a living tissue.

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Terminology

1/ Bactericide:

An agent that kills bacteria. Most do not kill Endospores.

2/ Bacteriostatic

An agent that inhibits the growth of bacteria, but does not necessarily kill them.

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►Germicide

An agent that kills certain microorganisms.

►Bactericide: An agent that kills bacteria. Most do not kill endospores.

►Viricide: An agent that inactivates viruses.

►Fungicide: An agent that kills fungi.

►Sporicide: An agent that kills bacterial endospores of fungal spores.

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►Degerming: Removal of most microbes in a limited area. Example: Alcohol swab on skin.

►Sanitization: Use of chemical agent on food-handling equipment to meet public health standards and minimize chances of disease transmission. e.g.: Hot soap & water

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