Control of Microbial Growth

Germ Theory of Disease

States that microorganisms, specifically pathogens, are the cause of many diseases.

Sterilization

The process of killing all microorganisms, including spores, used in medical settings.

Commercial Sterilization

Kills all pathogens and most spores, commonly used in food preservation.

Disinfection

The elimination of most pathogens on surfaces, often using disinfectants like bleach.

Antisepsis

Application of antiseptic agents to body surfaces to prevent infection.

Decontamination

The process of removing or neutralizing hazardous substances.

De-germing

Reduction of microbial numbers on skin or surfaces, often through washing hands.

Sanitation

Reducing microbial counts to safe levels, used in food service and public health.

-cide

A suffix indicating that a chemical kills organisms.

-static

A suffix indicating that a substance inhibits growth but does not kill.

Fomites

Inanimate objects or materials that can carry infection.

Factors influencing microbial effectiveness

Includes time, temperature, pH, concentration of the agent, organic matter presence, and microorganism nature.

Mechanisms of microbial control

Include altering cell membrane permeability, disrupting cell walls, damaging proteins, and damaging nucleic acids.

Pasteurization

Mild heating process to kill specific pathogens without altering food quality.

Autoclave

A device that sterilizes equipment using steam under pressure.

Heavy metals

Control microbial growth by binding to proteins and disrupting metabolic processes.

Antimicrobial Drugs

Substances that kill or inhibit growth of microorganisms, including antibiotics.

Antibiotic Resistance

Develops when bacteria evolve mechanisms to survive antibiotic exposure.

Use-dilution tests

A method to evaluate the effectiveness of disinfectants on microbial growth.

Hydrogen Peroxide

A peroxygen that kills microbes by producing reactive oxygen species.

Glutaraldehyde

A chemical disinfectant favored for its broad-spectrum efficacy and effectiveness in the presence of organic matter.

Ionizing Radiation

High-energy radiation that damages DNA and cellular structures, used for sterilization.

Non-ionizing Radiation

Includes UV light which damages DNA, impairing microbe reproduction.

Alcohols

Kill microbes by denaturing proteins and disrupting membranes.

Halogens

Includes chlorine and iodine used for their disinfecting and antiseptic properties.

Filtration

Method to remove microorganisms from liquids or air by passing them through a filter.

Surfactants

Agents that reduce surface tension and can disrupt microbe membranes.

Phenolics

Disinfectants derived from coal tar that disrupt cell membranes.

Chemical Food Preservatives

Substances like nitrites and sulfites added to food to prevent spoilage.

Modes of Action of Antimicrobial Drugs

Include inhibiting cell wall synthesis, disrupting membrane function, and inhibiting nucleic acid synthesis.