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64 Cards in this Set

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Historical microbial control methods

Salting foods

Smoking foods



Exposing food clothing and bedding to sunlight

4 possible outcomes of microbial control outside the body






Destruction of all microbial life


Destroys most life, reducing contamination on inanimate surfaces


Also called degermation

Kills most but not all microbes, only on a living surface (skin)


Also called sanitization

The mechanical removal of most microbes from an animate or inanimate surface

More resistant



Staph & pseudomonas

Protozoan cysts

Less resistant

Enveloped viruses

Gram- pos bacteria


Gram- neg bacteria

Protozoan trophozoites

Bacterial endospores

The most resistant microbe

Destruction of endospores is the goal of sterilization

Sterilized products are essential to human well-being

Surgical instruments


Commercially packaged foods


The growth of microorganisms in blood and other tissues


Any practice that prevents the entry of infectious agents into sterile tissues and prevents infection


Chemical destroys bacteria except for those in the endospore stage


Capable of killing endospores


Prevents the growth of bacteria on tissues or objects does not kill

Microbistatic agents

Chemicals used to control microorganisms in the body (antiseptics and antibiotics)

Critical medical devices

Expected to come into contact with sterile tissues

Semi critical medical device

Come into contact with mucosal membranes

Noncritical medical device

Those that do bot touch the patient or are only touching intact skin

Factors that effect death rate of microbes

The number present

Type of growth

Temp & pH

Concentration of the agent

Mode of action of the agent

Presence of solvents, interfering organic material, or inhibitors

Cellular targets of physical and chemical agents

The cell wall

The cell membrane

Cellular synthetic processes (DNA, RNA)



Polar molecules with hydrophillic ans hydrophobic regions

Physically bind to the lipid bilayer and penetrate

Open up leaky spots that allow injurious chemicals to seep into the cell and important ions leak out

Native state

The normal 3-dimensional shape of a protein that allows proper function


Disruption of a proteins native shape, rendering them nonfunctional

Moist heat (denaturation)

Irreversible solidification of an egg white when boiled/cooked

Methods of physical control



Ultrasonic waves


Moist heat as an agent of microbial control

Hot water, boiling water, & steam

Ranges from 60 C - 135 C

Operates at lower temperatures and shorter exposure times than dry heat

Dry heat as an agent of control

Air with a low moisture content that has been heated by a flame or elastic heating coil

Ranges from 160 C +

Lack of water increases protein configurations

At high temps, dry heat oxidizes cells, burning them to ashes

Thermal death time

The shortest length of time required to kill all test microbes at a specified temp

Thermal death point

The lowest temperature required to kill all microbes in a sample in 10 mins


Dehydration of vegetative cells directly exposed to normal room air

Desiccation can kill pathogens or even preserve foods


Combination of freezing and drying

Common method of preserving microbes and other cells in a viable state


Energy emitted from atomic activities and dispersed at high velocity through matter or space

(Gamma, UV, X-ray)


Bombardment of microbes with radiation

Ionizing radiation

Ejects orbital electrons from an atom, causing ions to form. Causes most damage to proteins

Nonionizing radiation

Excites atoms, raising them to higher energy state

Leads to formation of abnormal bonds within DNA

Cold sterilization

Ionizing radiation used as an effective alternative for sterilizing.

Used for materials sensitive to heat and chemicals.

UV Radiation

100 nm to 400nm

Lethal at ~260 nm

Germicidal lamp: 254 nm

Not as penetrating as ionizing radiation

UV Radiation: non-ionizing effects

Absorped by DNA

Form pyrimidine dimers

(Thymine & cytosine)

Interfere with dna replication & transcription

Antimicrobial chemicals




Or a mixture of the two

Aqueous solutions

Solutions containing pure water as the solvent


Antimicrobial chemicals dissolved in pure alcohol or water-alcohol mictures

Factors affecting the microbial activity of chemicals

Nature of microbes being treated

Nature of material being treated

Degree of contamination

Time of exposure

Strength and chemical action of the germicide


Fluorine, Bromine, Chlorine, and Iodine

Microbicidal and sporicidal

1/3 of all antimicrobial chemicals


Gaseous chlorine, hypochlorites, and chloramines

Kill bacteria, endospores, fungi? & viruses

Less effective if exposed to light, alkaline pH, and excessive organic matter


Free iodine (I2) & Iodophors

All classes of organisms are killed by iodine if proper concentrations and exposure times are used


First used as the major antimicrobial chemical

Toxic and irritating side effects


Destroy vegetative bacteria, fungi, & some viruses

Able to act in the presence of organic matter

Too toxic to be used as an antisepsis


Ethyl and isopropyl are the only appropriate microbial control

Greater efficacy at 70%

More effective against enveloped viruses than naked viruses

Hydrogen peroxide

Germicidal effects are due to toxic reactive oxygen

Bactericidal, virucidal, fungicidal, and sporicidal & high concentrations

Quaternary ammonium compounds (Quats)

Disinfectants: mixed with cleaning agents to sanitize a variety of objects/surfaces

Preservatives for ophthalmic solutions and cosmetics

Perfect antimicrobial therapy

Soluble in the body

Be selective (toxic to microbe nontoxic to the host)

Remains potent and active

Chemotherapeutic drug

Any chemical used in the treatment, relief, or prophylaxis of a disease


Use of a drug to prevent imminent infection of a person at risk


Use of a drug to prevent imminent infection of a person at risk

Antimicrobial chemotherapy

The use of chemotherapeutic drugs to control infection


All-inclusive terms for any antimicrobial drug regardless of what type of microorganism it targets


Substances produced by natural metabolic processes of some microorganisms or scientists that can inhibit or destroy infection

Semisynthetic drugs

Chemically modified in the laboratory after being isolated from natural sources


Only affects small amount of bacteria


Treats a large number of bacteria all equally

Synthetic antibiotic

Mimicking a drug that is naturally occurring. Completely chemically modified in the lab.

3 factors must be known before treatment begins

-identity of microorganism

- the degree of microorganisms sensitivity to drugs

- the overall medical condition of the patient

Testing for drug susceptibility

Kirby-bauer technique:

Test the bacterium with various antibiotics and observe the zone of inhibition