Microbiology Chapter 23
Betadine
A compound of iodine and a surfactant such as a detergent that can slowly release free iodine
Formalin
A concentrated liquid form of formaldehyde used as a disinfectant , in which HCHO gas is dissolved in water
Ultraviolet Light
A form of non ionizing radiation that can effectively control the growth of microorganisms placed directly in its path
Scrubbing
A manual process by which microorganisms are removed from a surface
Benzalkonium Chloride
A topical antiseptic used on the skin before surgery, in nasal sprays and as a preservative in eye drops
Alcohols
Act as surface tension reducers and are mostly used on skin as an antiseptic. Known to kill most vegetative cells, but not spores. Active against the tuberculosis organism.
Phenolic Compounds
Act by disrupting the cell membrane, causing bacterial lysis (decline of disease process) and inactivating essential enzymes and proteins.
How Bleach Works
Acts by liberating free Cl and the subsequent oxidation of essential cellular enzymes and proteins. These might also act on the cell membrane to adversely affect the diffusion of nutrients or wastes via. the cell.
Bactericides
Agents that destroy bacteria but not necessarily their spores.
Fungicides
Agents that destroy fungi and their spores
Larvicides
Agents that destroy insect larvae
Insecticides
Agents that destroy insects.
Viricides
Agents that destroy viruses
Sporicides
Agents that kill bacteria and mold spores
Ceepryn Chloride (Cepacol)
Found in throat lozenges. Disadvantages may cause respiratory irritation, birth defects in pregnant women.
Halogen Properties
Strong oxidizing properties and are very effective in controlling microorganisms
Germicides
Substances that destroy microorganisms, but not necessarily their spores
Disinfection
The destruction of infectious agents by chemical or physical means directly applied to an inanimate object. The destruction or inhibition of disease-causing microorganisms by chemical or physical means.
Thermal Death Point
The lowest temperature at which all microorganisms are killed in ten minutes
Thermal Death Time
The minimum time it takes to kill all microorganism present by heat
Antiseptics
The process by which microbial growth is inhibited on living tissue to prevent infection
Sterilization
The process of completely removing or destroying all life forms or their products on or in a substance
Halogens
The six elements found in the next to the last column on the far right side of the periodic table
Decimal Reduction Time
The time in minutes it takes by heat to kill 90% of the present microorganisms
Disadvantages to Alchols
Volatile and flammable, are inactivated by organic matter and not capable of killing some pathogens or spores
Aldehydes
Chemicals that react with the amino acids and hydroxyl groups in organic compounds. They inactivate proteins and nucleic acids and are strong reducing agents.
Halogens most widely used as disinfectants
Chlorine and Bromine
Disinfectant
Destroys or inhibits disease causing microorganisms; kills most vegetative microorganisms, but does not inactivate microbial endospores
Joseph Lister
First used phenol as a disinfectant during surgery to disinfect wounds
The Halogens
Fluorine(F), Chlorine (Cl), Bromine (Br), Iodine (I) and Astatine(At)
Disadvantage of Cl Compounds
Inactivated by organic matter and are corrosive in nature
Hypochlorites
Bleaches
Freezing
Both refrigeration and freezing are commonly used to preserve food by reducing microbial growth in cold environments.
Types of Disinfectants
Hypochloride, alcohol, aldehyde
Heat
Kills microorganisms by denaturing the proteins they contain
Cresol (lysol)
Molecules look like phenol but have methyl groups attached. Crude cresols from colloidal (milky) suspensions in water are good disinfectants because each colloidal droplet contains concentrated cresol.
Idiophones/Iodines
Non-irritating, non-staining, virtually odorless and very effective solutions of organic compounds of iodine. They combine actively with amino acids affecting the structural change in the pr steins made from the iodinated amino acids. It kills bacteria, molds and some viruses quickly by altering key protein molecules such as enzymes.
Concentration
Optimum concentration for disinfectant activity must be rigorously followed.
Antisepsis
Preventing or inhibiting the growth of pathogenic microorganisms
Sanitation
Process to promote and establish conditions which minimize or eliminate biohazards
Hexachlorophene
Retains a residual antibacterial dactivity after use and is a good skin degerming agent. May only be purchased via a prescription.
Quaternary Ammonium Compounds
also known as quits, commonly used as a topical antiseptic before surgery, in nasal sprays to reduce airborne transmission of disease.
Glutaraldehyde
an effective disinfectant and is actually a cold chemical sterilant when activated in a 2 percent solution.
Cremation Temperature
approximately 1600F
Disadvantages of Aldehydes
corrosive, irritating to skin and senses.