MICRO-LESSON-4

Sterilization

The process of destroying, removing, eliminating, and inactivating all forms of microbes from culture media and surfaces.

Disinfection

The process of elimination of microorganisms from inanimate objects or surfaces.

Decontamination

The treatment of an object or inanimate surface to make it safe to handle.

Antiseptic

An agent that kills or inhibits the growth of microbes but is safe to use on human tissue.

Sanitizer

An agent that reduces, but may not eliminate, microbial numbers to a safe level.

Cidal

An agent that kills microorganisms and viruses.

Static

An agent that inhibits the growth of microorganisms.

Autoclaving

A method of sterilization that employs steam under pressure.

Boiling water

The use of (100°C) to kill vegetative cells.

Hot air sterilization

The use of high dry temperatures to sterilize glassware and metal instruments.

Incineration

The destruction of disposable or expendable materials by burning.

Refrigeration

The use of low temperatures (5°C) to slow the growth of microorganisms.

Freezing

The use of low temperatures (-10°C) to stop microbial growth.

Desiccation

The process of drying that has a static effect on microorganisms.

Ultraviolet Radiation

The use of UV lights to reduce microbial populations. Hospital operating rooms

Ionizing Radiation

The use of X-rays and gamma rays to sterilize pharmaceuticals and medical supplies.

Filtration

The use of microbiological membrane filters to sterilize materials such as vaccines, antibiotics, solutions

Disinfectant

Chemical agents used to eliminate microorganisms from inanimate objects or surfaces. too toxic

Antiseptics

Chemical agents that kill or inhibit the growth of microbes but are safe to use on human tissue.

Soaps and detergents

Surface-active agents that aid in the mechanical removal of microorganisms.

Chlorine

A chemical used in the chlorination of drinking water, swimming pools, and sewage.

Iodine and iodophors

Chemical agents that denature microbial proteins and are used as antiseptics.

Aldehydes

Chemical agents that denature microbial proteins and it is used in embalming, preserving biological specimens, and in preparing vaccines.

Hand washing effectiveness

The practice of washing hands to remove transient flora, reduce resident flora, and disinfect the skin.

Physical agents

include such methods of control as high or low temperature, desiccation, radiation, and filtration

chemical agents

refers to the use of disinfectants, antiseptics, antibiotics, and chemotherapeutic antimicrobial chemicals

70% solutions of ethyl or isopropyl alcohol

are effective in killing vegetative bacteria, enveloped viruses, and fungi.

Iodophores

are a combination of iodine and an inert polymer such as polyvinylpyrrolidone

23-40%

Reduces the number of people who get sick with diarrhea

16-21%.

Reduces respiratory illness

PHENOL (5-10%)

was the first disinfectant commonly used.

PHENOL DERIVATIVES

Because of phenol toxicity and odor—— are now generally used.

Bacillus, Clostridium

Endospores that are hard to eliminate

Orthophenylphenol

is the agent in Lysol®, O-syl®, Staphene®, and Amphyl®.

Hexachlorophene

in a 3% solution is combined with detergent and is found in PhisoHex®.

Triclosan

is a chlorine-containing phenolic antiseptic very common in antimicrobial soaps and other products.

chlorhexidine

is a common handwashing agent and surgical hand scrub.

Soaps

are only mildly microbicidal. Their use aids in the mechanical removal of microorganisms by breaking up the oily film on the skin (emulsification)

staphylococci and diphtheroid bacilli

normal flora are mainly nonpathogenic