Lecture 20 Flashcards
Phenolics
- Introduced by Lister
- Phenol Coefficient Test
- chemical rated against phenol
- Used as the standard against which other antiseptics and disinfectants are evaluated
- Mode of Action
- Disrupt cell membranes and cell walls
- Coagulates proteins (denature)
- bactericidal, fungacidal, virucidal, NOT sporicidal
Phenolics–Cresol (Creosote)
*Commercial wood preservative (railway ties, electrical poles)
Phenolics–Lysol
- 2% cresol + soap
- Disinfecting inanimate objects or organic wastes
- Especially M. Tubercolosis
Phenolics–Hexaclorphene
- Effective against Staph. and Strep.
- May cause neurological damage to infants
- Used to be used in newborn soap
Phenolics–Triclosan
- Anti-bacterial additive to soaps
- Now found in our bloodstrea
Phenolics–Hexylresorcinol
*Used in mouthwash and throat lozenges
Phenolics–Chlorhexidine
- Surgical scrub
* Antiseptic
Halogens–Iodine-I2
- Wide spectrum and very effective antiseptic
- Can be sporicidal
- Mode of action
- Combines with tyrosine and denatures proteins
Halogens–Tincture of Iodine
- 2% Iodine and 70% alcohol
* Antiseptic
Halogens–Chlorine Cl2
- Bactericidal, fungicidal,virucidal, and sporicidal
- Mode of action:
- Denatures enzymes/proteins
- Available in gaseous form
- Used to sanitize sewage, water supplies, swimming pools, restaurants.
- Derivative:
- Hypochlorites (chlorine bleach)
- Chloramines
Alcohols
- Mode of action:
- Coagulates proteins
- Dissolves membrane lipids
- Bactericidal- including M. tubercolosis
- Fungicidal, not sporicidal
Alcohol–Ethyl, Isopropyl
- Solution of 50-90%
- 70% being very effective, 30% water
- Also used to enhance effectiveness of other reagents
Hydrogen Peroxide
- Mode of action:
- Produce highly reactive hydroxyl-free radicals that damage proteins and DNA while also decomposing to O, gas
- Toxic to anaerobes
- Used:
- Antiseptic
- Mouth wash
- Disinfectant
Surface-Active Agents/Surfactants
Mode of action:
- Reduces surface tension of water
- Decrease surface tension between molecules of a liquid
Surface-Active Agents/Soaps
- Break down surface tension
- Mechanically remove soil and grease containing microbes from your skin
- Limited microbiocidal power
Surface-Active Agents/Detergents
*Alter membrane permeability
Surface-Active Agents/Quaternary Ammonia Compounds (Quarts)
- Act as surfactants that alter membrane permeability of some bacteria and fungi
- Effective against Gram + bacteria
- Not sporicidal, not effective against Gram - bacteria
Heavy Metals–Oligodynamic Action
- Effective in minute amounts
- Mode of Action
- Inactivate proteins
Heavy Metals–Mercury
- Merhiolate- Antiseptic
* Mercurochrome
Heavy Metals–Silver
- Silver nitrate
- Antiseptic/Disinfectant
- Used to prevent Opthalamia neonatorum before erythromycis
Heavy Metals–Copper
*Inhibits algae in swimming pools
Heavy Metals–Zinc
- Zinc chloride (mouth wash)
* Zinc oxide (anti-fungal agent found in paint)
Aldehydes
- Mode of action:
- Inactivate proteins
Aldehydes–Formaldehyde
- Used as Formalin
- Disinfectant
- Preservative (fabrics, organism, etc)
- Emballment
- Vaccine and Toxoid production
Aldehydes–Glutaraldehyde
- Wide spectrum germicide
* In 2% solution (Cidex) used as sterilant for heat sensitive instruments
Gaseous Chemosterilizers
- Ethylene oxide
- Used in chemiclave
- Mode of action:
- Denatures proteins
- Bactericidal, fungicidal, virucidal, sporicidal
- Used to sterilize
- Plastic petri dish
- Mattresses in hospitals
- NASA space crafts
Dyes
- Crystal violet
- Mode of action:
- Bacteriostatic
- Effective against Gram + bacteria, some yeasts and molds
