L6 Flashcards
the process of destroying all forms of life, including spores and viruses
Sterilization
the process of destroying vegetative pathogens, but not necessarily spores or viruses
Disinfection
Physical methods
Heat, Filtration, Radiation
Moist heat
boiling, pasteurisation, autoclaving
Dry heat
hot air oven, incineration, flaming
Its disinfecting only, NOT sterilizing process
Boiling
Spores not killed by this method
Boiling
kills most of the pathogenic organisms, particularly viruses
and bacteria causing waterborne diseases
Boiling
Pasteurization Kills milk-borne vegetative pathogens such as:
Staphylococcus, Mycobacterium tuberculosis, Brucella, Salmonella,
Coxiella, Listeria
Are Spores killed in pasteurization
no
Slow pasteurization
heating at 63 to 65°C for 30 minutes
Rapid, high, or flash pasteurization
heating at 72°C for 15-20 seconds followed by rapid cooling
Sterilization under 15 pounds pressure and temperature of 121°C for 15 minutes
Autoclaving (Steam under pressure)
Most common method of sterilization for materials not damaged by heat or moisture
Autoclaving
Hot air oven
1700C for 30 minutes, 1600 C for 60 minutes, and 1500 C for 150 minutes
Inert materials like oils, and powders that are not damaged by excessive temperature, but damaged by
steam
it should be at a high height
Incinerator: burning
Disadvantage – air contamination
Flaming
HEPA (High Efficiency Particulate Air)
Filtration
they prevent bacteria but not virus because virus is very small in Nanos
Filtration
Ionizing radiation
X-rays and Gamma rays used commercially in sterilization of Medical equipments and disposable plastic supplies(syringes
Non- Ionizing irradiation
UV rays are used in UV lamps as germicidal lamps, Room surfaces
is highly effective on G+ve bacteria,tuberculocidal
Phenol & Phenolics
Used as disinfecting materials contaminated with organic materi
Phenol & Phenolics
Chlorine & Hypochlorite : used as disinfectant in
hospital environment Ex?
CHLOROX
Not sporicidal, surgical hand scrub, hand wash & mouth wash (Rexidin)
Biguanide (Chlorhexidine)
G+ve & G-ve bacteria & acid-fast bacilli.
Combined with other disinfectants, as iodine
for increased effectiveness
Iso-propyl alcohol 70% (v/v)
used in mouthwashes & antidandruff shampoos
Zinc chloride
Used as topical antimicrobial and antiseptic cream for burn patients
Silver nitrate
what is the bacteria that can grow in disinfectants?
Pseudomonads bacteria can grow in them
To Disinfect medical equipments like endoscopes and
others
Glutaraldehyde & Formaldehyde
to Preserve fresh tissues, Prepare vaccines and Fumigation
Formaldehyde
A sterilizing gas - kills all microbes & spores
Ethylene oxide
Cold sterilization - sterilizes without heat
Ethylene oxide
contact lenses disinfection
Oxidizing agent - Hydrogen peroxide
