PG 5- Control of Microbes: Physical and Chemical Methods

UNIT 2 MICROBIO

the absolute destruction, removal, or inactivation of all forms of life and microbial agents from a surface, fluid, or object. (kills/removes everything, including spores)

Sterilization

the process of eliminating or reducing most pathogenic (disease-causing) microorganisms

from inanimate objects and surfaces. (kills many microbes on objects)

Disinfection

the process of using chemical agents (antiseptics) to destroy, inhibit, or reduce the number of pathogenic microorganisms on living tissue. (reduces microbes on LIVING tissue)

Antisepsis

having the ability to directly kill bacteria:

Bactericidal

having the ability to inhibit or stall the growth and reproduction of bacteria without necessarily killing them outright. (stops bacterial growth)

Bacteriostatic

an inorganic, water-soluble chemical compound that is antiseptic and highly valued for its potent antimicrobial and chemical cauterizing properties. (Used for Burn Victims)

Silver Nitrate

a standardized, culture-based laboratory assay/test used to determine how susceptible a specific bacterium is to various antimicrobial agents

Disk Diffusion Test

an antimicrobial agent that is effective against a wide range of diverse microorganisms: (works againts both bacteria and viruses)

Broad Spectrum

A physical method of sterilization using steam + heat + pressure to destory all microbial life:

Autoclaving

A mechanical separation process used to remove solid particles or microorganisms from a fluid (either a liquid or a gas) by passing it through a porous material. (physically removing microbes)

Filtration

the emission and propagation of energy through space or a material medium in the form of waves or fast-moving particles. (highly effective physical sterilization method used to control microbial growth)

Radiation

a food preservation process that uses mild heat treatment to destroy pathogenic microorganisms and extend the shelf life of perishable foods and beverages. (but WITHOUT sterilizing!)

Pasteurization

a low-temperature dehydration process, removing water. It is a foundational method for the long-term archiving and storage of bacterial cultures, fungi, yeasts, and proteins. It involves freezing a substance and then placing it under a vacuum to remove water through sublimation—meaning the frozen water changes directly from a solid (ice) to a gas (vapor) without ever melting into a liquid.

Freeze-Drying

a synthetic, broad-spectrum antimicrobial agent that has been widely used as an antibacterial and antifungal ingredient in consumer, commercial, and healthcare products:

Triclosan

Protein channels found in the outer membrane of many Gram Negative bacteria, allowing certain small molecules/nutrients to enter the cell. ( but can restrict larger antibiotics from entering)

Bacterial Porins

an antimicrobial agent that is effective against only a specific, limited subset of microorganisms:

Narrow Spectrum

a chemical substance applied directly to living tissues, such as human skin, wounds, or mucous membranes, to destroy, inhibit, or stop the growth of pathogenic microorganisms

Antiseptic

a chemical agent or compound designed to inactivate or destroy microorganisms on inanimate (non-living) objects and surfaces

Disinfectant

A clear, colorless, and highly volatile liquid compound that is a rapidly bactericidal agent that destroys pathogens on contact through membrane dissolution:

Ethanol

a clear, colorless, and highly flammable secondary alcohol, that acts as a rapid bactericidal agent by launching a non-specific physical assault on cells lipid membranes

Isopropanol

a non-metallic halogen element (atomic number 53, symbol I) and ANTISEPTIC that serves as a highly potent, broad-spectrum topical antiseptic and disinfectant. It destroys microorganisms through a rapid, multi-pronged chemical attack on protein bonding

Iodine

a highly reactive halogen element (atomic number 17, symbol Cl) and DISINFECTANT that serves as a powerful, broad-spectrum disinfectant and bleaching agent. It kills microbes through a non-specific, aggressive chemical assault on protein bonding

Chlorine

Variations in the force driven by water movement across a semipermeable cell membrane, caused by a difference in solute concentrations between the inside and outside of a cell. (ex: Salt drying and freeze drying)

Osmotic Pressure Changes