EXAM 2 STUDY GUIDE

Sterilization

Complete removal or destruction of all forms of microbial life.

Pasteurization

Heat treatment to reduce microbial load, especially in beverages.

Sanitization

Reduction of microbial populations to safe levels as determined by public health standards.

Antisepsis

Application of chemicals to living tissues to inhibit or eliminate microbes.

Disinfection

Destruction of most microbial life, excluding endospores, on inanimate objects.

Preservation

Methods to inhibit microbial growth to extend the shelf life of foods or other perishable items.

Physical methods

Heat, filtration, radiation.

Chemical methods

Disinfectants, antiseptics, antibiotics.

Decimal reduction time (D value)

Time required to kill 90% of organisms under specific conditions.

Critical items

Items that come into contact with sterile tissues or the vascular system.

Semicritical items

Items that come into contact with mucous membranes or nonintact skin.

Non-critical items

Items that come into contact only with intact skin.

Moist heat:

Boiling (kills vegetative cells but not endospores), pasteurization (kills pathogens without altering taste), autoclave (steam under pressure, sterilizes).

Dry heat

Hot air ovens (oxidizes cell components, sterilizes), incineration (burns microbes to ashes).

Membrane filtration

Uses filters with defined pore sizes to physically remove microbes.

HEPA filters

High-efficiency particulate air filters used in cleanrooms and ventilation systems to remove particles including microbes.

Ionic radiation

X-ray, gamma-ray (damages DNA, sterilizes).

UV radiation

Damages DNA, used for surface sterilization.

Microwaves

Heat generated by molecular friction, effective for heating food but not for sterilization.

High-level

kill all microbes

intermediate-level

kill fungal spores, tubercle bacilli, and viruses

low-level

kill vegetative bacteria and fungi

Chemical germicides

Used when heat or radiation may damage materials or is impractical.

Bacterial endospores

Highly resistant to heat and chemicals.

Protozoan cysts

Resistant to desiccation and disinfectants.

Naked viruses

Generally more susceptible to environmental conditions

Enveloped viruses

Less resistant to environmental conditions.

Vegetative bacterial cells

Vary in susceptibility, affected by factors like cell wall structure and metabolic state.

Selective toxicity

Ability to inhibit or kill a pathogen without harming the host.

Therapeutic

Pertaining to the treatment of disease.

Bacteriostatic

Inhibits bacterial growth.

Bactericidal

Kills bacteria.

Broad-spectrum

Effective against a wide range of bacteria.

Narrow spectrum

Effective against a limited range of bacteria.

Antagonistic

Interaction where the effect of one drug reduces the effectiveness of another.

Synergistic

Interaction where the effect of two drugs together is greater than the sum of their individual effects.

Additive

Interaction where the effect of two drugs together is equal to the sum of their individual effects.

Half-life

Time taken for the concentration of the drug in the body to decrease by half.

Horizontal Gene Transfer

Transfer of genetic material between organisms that are not parent and offspring.

Transformation

Uptake and incorporation of foreign DNA from the environment.

Transduction

Transfer of genetic material mediated by bacteriophages.

Conjugation

Direct transfer of DNA through cell-to-cell contact facilitated by conjugative plasmids or other conjugative elements.

Homologous Recombination

Process by which similar or identical sequences of DNA are exchanged between two DNA molecules.

Plasmids

Extrachromosomal DNA elements capable of autonomous replication.

Transposons

DNA segments capable of moving within the genome.