BIOL 2421 Microbiology Lecture Outline: Microbial Growth Control   Dr. Weis

I. Definitions and Word Parts

            A. Sterilization

            B. Disinfection

            C. Degerming

            D. Sanitation

            E. –cidal, -static, sepsis

II. Microbial Death

            Constant rate

            Effectiveness

                        * Number

                        * Organic matter

                        * Exposure time

                        * Microbial resistance factors

III. Actions of Agents

            A. Alter Cell Membrane

            B. Alter NA

            C. Alter Proteins

IV. Physical Methods

            A. Heat: kills microorganisms

                        1. Temperatures above 100º

                                     Boiling

                                     Steam under pressure

                                     Dry air oven    

                                     Incineration

                        2. Temperatures below 100 º

                                    Heat pasteurization

            B.  Irradiation: kills microorganisms

                        1. Nonionizing: UV

                        2. Ionizing: gamma, X-rays

                        3. Microwave

            C. Filtration: removes mircroorgansims

            D. Drying: inhibits growth of microorganisms

            E. Low Temperatures: inhibits microbial growth

                        1. Refrigeration

                        2. Freezing

                        3. Subfreezing

            F. Osmotic Pressure

            G. High Pressure

V. Sterilization

            A. Methods

                        1. Moist Heat

                        2. Dry Heat

                        3. Irradiation

                        4. Filtration

                        5. Chemical

                        6. Gas

            B. Practical Importance

VI. Chemical Agents that prevent or inhibit microbial growth

            A. Definition of antimicrobial agent

                        1. Static

                        2. Cidal

                        3. Evaluation of a chemical agent as a disinfectant

            B. Antiseptics

                        * Phenolicsà

                        * Bisphenolsà pHisoHex

                        * Biguaninesà Chlorhexidine

                        * Halogensà Iodines

                        * Quaterinary Ammoniumà Cepacol

            C. Disinfectants

                        * Phenolicsà Lysol

                        * Halogensà chlorine

                        * Alcholols

                        * Heavy metals

                        * Aldehydes

                        * Peroxygens

            D. Food Preservatives

            E. Antibiotics and chemotherapeutic agents

                        1. Define Antibiotic

                        2. Define chemotherapeutic agent

                        3. Examples of Antibiotic

                                    a. Sources

                                    b. Spectrum of Activity

                                    c. MOA

VII. Principles of Selective Toxicity

VIII. Microbial susceptibility and resistance

            Microbial Factors

            Resistance level