The Control of Microbial Growth

These flashcards cover key terms and concepts related to the control of microbial growth, including definitions and important practices in microbial control.

Sterilization

The removal or destruction of all forms of microbial life, including endospores.

Disinfection

The process of reducing or inhibiting microbial growth on inanimate surfaces.

Antisepsis

The process of reducing or inhibiting microorganisms on living tissue.

Degerming

The mechanical removal of microbes from a limited area, such as skin.

Sanitization

Treatment intended to lower microbial counts on eating and drinking utensils to safe public health levels.

Biocide

A chemical that kills microorganisms, usually with exceptions such as endospores.

Germicide

A type of biocide specifically designed to kill microbes.

Bacteriostasis

Inhibition of bacterial growth without necessarily killing the bacteria.

Asepsis

Absence of significant contamination; techniques used to maintain a sterile environment.

Commercial Sterilization

Sufficient heat treatment to kill endospores of Clostridium botulinum in canned food.

Decimal Reduction Time (DRT)

The time required to kill 90% of a microbial population at a specific temperature.

Thermal Death Point (TDP)

The lowest temperature at which all the microbes in a liquid culture will be killed in 10 minutes.

Moist Heat Sterilization

Kills microorganisms primarily by denaturing proteins.

Autoclaving

A method of sterilization using steam under pressure, effective against all forms of microorganisms.

Filtration

The process of passing a liquid or gas through a filter that retains microorganisms.

Low Temperatures

Prevent microbial growth by refrigeration which has a bacteriostatic effect.

Desiccation

The removal of water that inhibits microbial growth but allows survival.

Osmotic Pressure

Process of preserving food that involves using high concentrations of salts or sugars to create a hypertonic environment.

Ionizing Radiation

High-energy radiation that penetrates deeply and kills microorganisms primarily by damaging DNA.

Nonionizing Radiation (UV Light)

Low-energy radiation that damages DNA by forming thymine dimers.

Alcohols

Effective disinfectants that denature proteins and dissolve lipids.

Heavy Metals

Compounds like silver and copper that exert antimicrobial effects through denaturation of proteins.

Quaternary Ammonium Compounds (Quats)

Surface-active agents that disrupt plasma membranes; effective against gram-positive bacteria.

Aldehydes

Strong disinfectants that inactivate proteins by forming covalent cross-links.

Supercritical Fluids

Substances used for sterilizing that have properties of both liquids and gases.

Sterilization

The removal or destruction of all forms of microbial life, including endospores.

Disinfection

The process of reducing or inhibiting microbial growth on inanimate surfaces.

Antisepsis

The process of reducing or inhibiting microorganisms on living tissue.

Degerming

The mechanical removal of microbes from a limited area, such as skin.

Sanitization

Treatment intended to lower microbial counts on eating and drinking utensils to safe public health levels.

Biocide

A chemical that kills microorganisms, usually with exceptions such as endospores.

Germicide

A type of biocide specifically designed to kill microbes.

Bacteriostasis

Inhibition of bacterial growth without necessarily killing the bacteria.

Asepsis

Absence of significant contamination; techniques used to maintain a sterile environment.

Commercial Sterilization

Sufficient heat treatment to kill endospores of Clostridium botulinum in canned food.

Decimal Reduction Time (DRT)

The time required to kill 90% of a microbial population at a specific temperature.

Thermal Death Point (TDP)

The lowest temperature at which all the microbes in a liquid culture will be killed in 10 minutes.

Moist Heat Sterilization

Kills microorganisms primarily by denaturing proteins.

Autoclaving

A method of sterilization using steam under pressure, effective against all forms of microorganisms.

Filtration

The process of passing a liquid or gas through a filter that retains microorganisms.

Low Temperatures

Prevent microbial growth by refrigeration which has a bacteriostatic effect.

Desiccation

The removal of water that inhibits microbial growth but allows survival.

Osmotic Pressure

Process of preserving food that involves using high concentrations of salts or sugars to create a hypertonic environment.

Ionizing Radiation

High-energy radiation that penetrates deeply and kills microorganisms primarily by damaging DNA.

Nonionizing Radiation (UV Light)

Low-energy radiation that damages DNA by forming thymine dimers.

Alcohols

Effective disinfectants that denature proteins and dissolve lipids.

Heavy Metals

Compounds like silver and copper that exert antimicrobial effects through denaturation of proteins.

Quaternary Ammonium Compounds (Quats)

Surface-active agents that disrupt plasma membranes; effective against gram-positive bacteria.

Aldehydes

Strong disinfectants that inactivate proteins by forming covalent cross-links.

Supercritical Fluids

Substances used for sterilizing that have properties of both liquids and gases.

Factors Affecting Disinfectant Efficacy

Concentration of disinfectant, presence of organic matter, pH, time of exposure, and nature of the microbial population.

Phenolics

Disinfectants that injure lipid-containing plasma membranes, leading to leakage; effective against Mycobacteria.

Halogens

Antimicrobial agents like iodine and chlorine that impair protein synthesis and alter plasma membranes.

Peroxygens

Oxidizing agents such as hydrogen peroxide and peracetic acid that are effective antiseptics and sterilants.

Plasma Sterilization

A method using gaseous plasma to sterilize heat-sensitive instruments, often using hydrogen peroxide gas.