What does Sterilization mean?

destruction of all microbes. Pathogens are dead.

What does Disinfection mean?
Types of Disinfection ?

Use of a chemical agent OR physical agent (disinfectant) to inhibit/destroy microbes on inanimate objects or surfaces.
-Not all of the pathogens are eliminated.
Types of Disinfection :
-Antisepsis
-Sanitization
-Pasteurization

Types of Disinfection:
Antisepsis

disinfection of tissue via a chemical agent (antiseptic). Must be safe to use on human/animal tissue.
Examples:
H2O2, Alcohol, bacterial cream.

Types of Disinfection:
Sanitization

reduce the number of pathogens on a surface to meet public health standards.

Types of Disinfection:
Pasteurization

use heat to kill pathogens and reduce the number of spoilage organisms.

What does Action of antimicrobial control agents mean?

Definition: How do they actually kill microbes.

Types of Action of antimicrobial control agents? 3

- Alteration of membrane permeability
Example: shrivle or burst microbe.
-Denature proteins
Example: unfold proteins (can't function), effects enzymes (blocks metabolism)
-Damage nucleic acids (DNA/RNA)
Example: affects DNA replication, translation, trans

What are the physical methods of microbial growth control?

1 Heat
2 Cold
3 Drying
4 Filtration
5 Osmotic pressure
6 Radiation (2 types)
- Ionizing radiation
- Non-Ionizing radiation

Physical methods of microbial control:
Heat
Action:

Action:
denatures proteins, widely applicable, inexpensive, fast, reliable. (The higher the temp decreases the time.)

Physical methods of microbial control:
Heat
Examples:

-bacti-cinerator = sterilant
-Autoclave = sterilization, penetrates and used for liquids, uses high temp and steam (messes with osmotic pressure)
-Dry heat = can be sterilant, not for liquids. doesn't penetrate.
-Boiling water = not reliable sterilization

Physical methods of microbial control:
Cold
Action:

Action: decreases metabolism, growth, reproduction.
-most pathogens (mesophiles = moderate temp loving microbes)

Sterilization and disinfection, things to consider?

-number of microbes
-duration of exposure
-type of microbes
-temperature, (cold effects duration of exposure.)
-concentration of chemical agent.
-pH, they like basic less than acidic.
-endospore formation, clostridium, bacillus will produce unless done fa

Physical methods of microbial control:
Drying
Action?

Action:removing water, decrease metabolism.
-Lyophilization, removal of H2O under vacuum.
-dried things have longer shelf life.

Physical methods of microbial control:
Filtration

Action: filter traps microbes
Examples:
-water filtraiton, beverages (beer)
-hospital surgical mask
-blood products, vaccines.

Physical methods of microbial control:
Osmotic pressure:

Action: shrivel or burst microbe.
Examples: jam, jelly, maple, syrup.

Physical methods of microbial control:
Radiation:

Action: damage is done to the DNA.
2 types:
1.Ionizing radiation: X-Rays, Gamma Rays.
-Used: to preserve food. Popular in Europe. Doesn't make food nuclear.
2.Non-Ionizing radiation: Ultra Violet Light
-Used: in labs, and morgues, operating rooms.

Chemical methods of microbial growth control:
types most commonly used
-Organics (blood, saliva, pus, feces, and vomit) will decrease effectiveness of most chemicals.
For the test you do have to know the different chemicals, the way they work, who they wo

Most commonly used:
-phenol/phenol derivatives
-Soap/Detergents
-Alcohol
-Heavy metals
-Chlorine
-Iodine and Iodine derivatives (Iodophores)
-Aldehydes
-Gaseous Sterilizers
-Hydrogen peroxide

Chemical methods of microbial growth control:
phenol/phenol derivatives
In 1857 Dr. Lister used phenol on his patients. Had to use a 5-10% solution, caustic to skin, damaged lungs, toxic, nervous system damage

Action: alters membrane permeability.
Effective against:
some bacteria, viruses, fungi
Effectiveness:
low effectiveness, ONLY disinfectant.
Examples:
surface cleaners for hospitals, personal care products, MOST COMMON: Triclosan, now less effective

T/F: A phenolic derivatives is a chemically altered phenol to decrease the bad side effects. This decreased the expense and side effects

TRUE

Chemical methods of microbial growth control:
Soap/Detergents

Action: detergents break up oil on our skin, this decreases surface tension, more easily to wash off microbes.
Effective against: broad range of microbes.
-polar end sticks to H2O, non-polar end grabs microbes. like bile for GI.
-microbes use oil to stick

What is the difference between soaps and detergents?

Soap made of:
lye + animal fat; pH 9-10
-Very expensive, not common.
Detergent made of: a petroleum products, more soluble in water than soap.
-We use detergents not soap.

T/F: Both soaps and detergents are surfactants?
What are surfactants?

TRUE
surfactants = decrease surface tension in water.

Chemical methods of microbial growth control:
Alcohol

Action: denatures proteins, damages membrane (dissolves lipids).
-needs H2O to be effective, 70% best.
Effective against: Most bacteria, viruses, and fungi.
Effectiveness: Medium level.
Examples:
-Skin antiseptic, duration of exposure problem. 30 seconds

Chemical methods of microbial growth control:
Heavy metals

Action: denatures proteins.
Effective against: some bacteria and fungi.
Effectiveness: low level of activity.

Chemical methods of microbial growth control:
Heavy metals types: 3

Mercury
Zinc
Silver

Chemical methods of microbial growth control:
Heavy metals types: silver uses
For the test you do have to know the different chemicals, the way they work, who they work against.

Examples:
-silver nitrate drops used in newborns eyes to protect against STD's
-Silver ointment for burns and wounds. silvadine.
-silver particles in some workout clothes/plastic storage containers.
-silver is in catheters. Foley's

Chemical methods of microbial growth control:
Heavy metals types: Mercury
Uses/example

can be used as a skin antiseptic. ( Not sold in the USA ) unless in the hospital or clinical settings.
used as a preservative.
-Thimerosol
Example:
eye solutions, anti-venoms, tattoo ink, was used in vaccines (people are stupid).

Chemical methods of microbial growth control:
Heavy metals types: Zinc
Uses?

Used in several dandruff shampoos, effective in controlling fungus (dandruff). Head & shoulders
Used in mouth wash. No alcohol present in the solution. (Biotene has enzymes as alternative no Zinc based)

Chemical methods of microbial growth control:
Chlorine
For the test you do have to know the different chemicals, the way they work, who they work against.

Action: denatures proteins.
Effective against: a broad range of microbes
Examples: bleach has Sodium hypochlorite (house hold bleach)
10% bleach and 90% water = decontamination
100% needed for C-deff.

Chemical methods of microbial growth control:
Iodine and Iodine derivatives (Iodophores)
For the test you do have to know the different chemicals, the way they work, who they work against.

Action: denatures proteins.
Effective against: board range of microbes.
-used as skin antiseptic.
Examples:
-Betadine = pre-op skin antiseptic
-wescodyne = surface disinfectant, Iodophore based.

T/F: Iodophores are chemically altered Iodine that decrease surface tension, staining, and irritation?

TRUE!
Iodophores are better antiseptics than iodine alone due to the improved chemical qualities.

Chemical methods of microbial growth control:
Aldehydes
For the test you do have to know the different chemicals, the way they work, who they work against.

Action: denatures proteins
Effective against: ALL MICROBES, STERILANT.
Effectiveness: high level
Examples:
-Formaldehyde. Is a gas, expensive.
-Glutaraldehyde chemical relative of formaldehyde/formalin.

T/F: Formalin is a 37% aq solution of this?

TRUE

T/F: Glutaraldehyde is less expensive, safer, less irritating, more effective option than formaldehyde?
USED FOR?

TRUE
Used for:
-histology to fix slides.
-embalming.
-cleaning respiratory therapy equipment.
-Dialysis equipment.
-Fiber optic endoscope.
-instruments.

Chemical methods of microbial growth control:
Gaseous Sterilizers
For the test you do have to know the different chemicals, the way they work, who they work against.

Action: Denatures proteins.
Effective against: ALL MICROBES. STERILIZERS.
Effectiveness: HIGH LEVEL
Examples:
-Ethylene Oxide
-Chlorine dioxide

F/T: Chlorine dioxide is good for use on entire buildings, and when we send out things into space?

TRUE

T/F: Chlorine dioxide is not very dangerous. It is not toxic to humans, and is not highly explosive/expensive?

False!
Used during the 911 attacks of anthrax.

T/F: Ethylene oxide is good for things that are heat sensitive?

True.
-Used for plastics, suture, artificial heart valves, heart-lung machines, mattresses.

T/F: Ethylene Oxide is not toxic to humans, does not need to be used in a closed system?

False!
-Duration of exposure is 1-3 hours.

Chemical methods of microbial growth control:
Hydrogen Peroxide
For the test you do have to know the different chemicals, the way they work, who they work against.

Action: The free radicals that are produced harm cell components.
-carbohydrates, lipids, fats, and nucleic acids.
Effective against: broad range of microbes.
-Especially: OBLIGATE ANAEROBES.
Effectiveness: ONLY a disinfectant.

What are obligate anaerobes?

microbes that are poisoned by oxygen.

Why is it that obligate anaerobes are especially affected by hydrogen peroxide?

they do not produce the enzyme needed to break apart the free radicals (oxidase). the free radicals build up, damaging macromolecules.
-This will first INHIBIT, then KILL them.

T/F: obligate anaerobes are able to use O2 if there is not sulfate/nitrate available?

TRUE

T/F: It is not better to use H2O2 if you are treating a deep wound because obligate anaerobes are not effected by hydrogen peroxide?

FLASE!
Obligate anaerobes are especially affected by H2O2.

What does it mean when you spray H2O2 on a wound and it starts to fizz?

It means that the bacteria present produce the enzyme oxidase and are able to break apart the free radicals being produced so that their macromolecules are not effected by them.

How Does H2O2 work:
summary

If you do aerobic energy production you produce free radicals. Including superoxides and peroxides.
you produce an oxidase that beaks these free radicals apart.
-if not broke apart would cause damage to macromolecules of life.
-H2O2 via oxidase breaks up