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112 Cards in this Set

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Sepsis
refers to microbial contamination.
Asepsis
is the absence of the significant contamination.
Aseptic surgery techniques
prevent microbial contamination of wounds
Steralization
removal of ALL microbial life including SPORES.
Commercial Steralization
Killing C. botulinum endospores
Disinfection
removal of vegetative (normal, non-spore) pathogens
Killing pathogens on inanimate (non-moving) objects.
Antisepsis
Removal of pathogens from LIVING TISSUE.
Disinfectant for external skin, mouth and vagina.
Degerming
Removal of microbes from limited area
Sanitazation
Lower microbial counts on eating utensils
Biocide/Germicide
Kills (cide) microbes.
Bacteriostasis
Slows down (stasis) growth and reproduction, inhibits but does not kill microbes.
Physical methods of killing/removing bacteria
Heat
Radiation
Filtration
To sanitize
to remove pathogens from inanimate object, and it can be ether mechanical (whipeing) or chemical cleaning. When you do not need to sterilize or disinfect.
Aseptsis
Prevents contamination of OBJECT by microbes. (Used in medicine)
Contamination
Presence of living microbes on an object.
Infection
Presence of living, multiplying microbes in host tissues. It is often pathogenic (disease causing)
If there is less microbes present they get killed faster or slower.
faster
Microbes can be harder to kill in certain ________.
Environments
Microbial characteristics like heat tolerance determine speed of ______ when treated.
deth
Damaged microbial membrane results in
leakage of cellular contents and inhibition of cell growth.
In proteins heat and chemicals break down ______ and _______ bonds in enzyme structure resulting in inactivation
hydrogen and covalent
inactivation
Heat, radiation or chemicals damage _______ acids inhibiting cell _______
and metabolism.
nucleic
replication
Physical methods of microbial control
Heat
Radiation
Filtration
Thermal death point (TDP)
lowest temperature at which all cells in culture are killed in 10 minutes.
Thermal death time (TDT)
Minimal time to kill all cells in a culture at a given temperature.
Decimal Reduction Time (DRT)
How may minutes it takes to kill 90% of a population at a given temperature.
Thermal Death Time (TDT)
Minimal time to kill ALL cells in a culture at a given temperature.
Factors influencing Heat Sterilization
Length of exposure
Temperature
Is wet or dry heat used
Mechanism of action: HEAT
Inactivates enzymes
Causes structural changes
Oxidizes causing membrane disruption
"Moist" heat
Effective qickly against most pathogens.
100*C 10-30minuts
Disinfectant: Spores and some viruses are still resistant.

Safe for CLEAN instruments that DO NOT penetrate tissue.

For soiled items add detergent.
Pasteurization
Kills non-spore forming pathogens (T.B., Brucella, Salmonella, Streptococcus) and reduces spoilage organisms and pathogens (Lactobacilus and Streptococcus).

63*C for 30min

High temperature for SHORT time 72*C for 15 sec.

Ultra HIGH temperature 140*C for <1 sec. (sterilization of milk)
Thermoduric
Non-disease causing organisms that survive pasteurization.
Autoclave
Steam under pressure.
15psi 121*C for 15 minutes or more depending on a volume.
Steam in autoclave
Displaces air and penetrates. It is CRITICAL to package autoclave properly.

Trapped (airlocks) air is not replaced by steam and reduces the effectiveness of temp and pressure.
Moist heat denatures _____
Proteins
Dry heat sterilization kills by ____
oxidation

(Flaming, Incineration, Hot-air sterilization (oven is most desired))

Hot air 170*C for 2 hours.
Filtration removes _______
Microbes
Low temperature inhibit microbial ______
growth
Example of low temperature treatments.
Refrigeration
Deep Freezing
Lyophilization
High pressure denatures ___.
proteins
Desiccation prevents_____.
metabolism
Drying out is called _____
Desiccation
Osmotic pressure cause ______.
Plasmolysis
Plasmolysis
Breakdown inside a microbe
HEPA filters
High efficiency Particle Air Filters remove airborn microbes and filter particles that are >0.3 micrometars.

Used in operating and clean rooms.

Used in rooms of burn and immunocompromised patients.
Membrane filters are made of ________________ and have _________ ________ pore size.
cellulose nitrate or synthetic polymers and have very small pore size
Viruses are ______ of all "microorganisms".
smallest
Filter sterilization can be use to sterilize _____ or energy _______ materials such as __________ and _______.
heat
bacterial media (agar)
drug solutions.

(Agar is put through the filter first t make sure that all microorganisms are out.)
POINT MUTATIONS
involve changes in only one of few nucleotides (component of nucleic acid)
UV and Ionizing radiation
is what we are most interested in.
Gama Ray ionizing radiation steralization is used to sterilize_____ and _____.
Food and plastics.
Electron Beam steralization by ionizing radiation is uzed for __________.
Pharmaceuticals.
*****Ionizing radiation can_______*********
break down DNA/RNA
Creates free radicals
Ionizing Radiation
Gamma rays, X-rays and electron beams
Cause break in two DNA strands and result in delentions (nucleotide) and translocation (movement of nucliotide to different spot)
Free radicals
are high energy radiation in which energy can be:

Absorbed by atoms
added to electrons

or
electrons are ejected from atoms which leaves ionized atoms and unpaired electrons.
(T) Can break both phosphodiester bonds of DNA helix.
Free radicals
Ultraviolet light
Blueish light used to kill off some circulation bacteria.
It has poor penetration (table/bench tops and small samples of liquid)
Pyrimidine dimers
caused by ultraviolet light are part of the nucleotide and cause errors during DNA repair.
Intense exposure to UV light causes
Direct molecular damage.
Radiation damages _____
DNA
Ionizing radiation includes:
X rays, Gamma rays and Electron beams)
Non-ionizing radiation includes:
UV light
Microwaves kill by:
Heat, but are not especially antimicrobial.
Principles of effective disinfection include:
Concentration of disinfectant
Organic matter
pH
Time
In order to evaluate disinfectant use:
Dilution test
Dilution test
1. Metal rings are dipped in test bacteria and dried.
2. Dried cultures are placed in disinfectant for 10 min at 20*C
3. Rings are transferred to culture media to determine weather bacteria survived treatment.
Pseudomonos
Very important in nosocomial infections.
Types of disinfectants:
Phenols
Phenolics (Lysol)
Bisphenols
Hexachlorophone
Triclosan
Phenolics (Lysol)
injures lipid plasma membrane and results in leakage of cell.
Bisphenols
Hexachlorophone and Triclosan
Disrupt plasma membranes
Bigunides (Chlorhexidine)
(A lot of disinfectant soaps) Have broad spectrum activiti. Used for microbial control on skin and mucus membranes.
Disrupt plasma membranes by blocking lipid synthesis
Biguanides (Chlorohexidine)
Halogens (Iodine and Chlorine)
Oxidizing agents (disinfectant)
Iodine (I2) impairs protein synthesis and alters plasma membrane.
Idophore
Variation of Iodine. Halogen, +organic molecule from which iodine is released slowly, thus non-staining and non-irritating.
Bleach
Hypochlorous acid (HOCl)

(Halogen (Chlorine))
Alcohol, Ethanol and Isopropanol
Disinfectants that denature proteins and dissolve lipids.
Hevy Metals (Ag, Hg and Cu)
Disinfectants with oligodynamic action. They denature proteins by combining with protein SH groups.

Silver nitrate: used to treat eyes of newborns
Mercuric chloride: bacteriostatic
Chemical food preservatives
Organic acids
Nitrates
Antibiotics
Organic acids
Food preservatives that inhibit metabolism or integrity of microbial plasma membrane.

Controls molds and bacteria in food and cosmetics.
Organic acids include
Sorbic acid
Benzoic acid
Calcium propionate
Nitrates
Prevent endospore germination
Antibiotics
Nisin and natamycin prevent spoilage of cheese.
Nisin And Natamycin
Prevent spoilage of cheese.
Aldehyde
very effective antimicrobials that inactivate proteins by cross-linking them with functional groups.

Eg.(Glutaraldehyde (cold liqid steralizing agent) and formaldehyde)
Gaseous Sterilants
Used to sterilize closed chambers without heat by denaturing proteins.

Eg. Ethylene oxide
Ethyline oxide
Gaseous sterilant that denatures proteins, used to sterilize closed chambers WITHOUT heat.
Peroxygens
Oxidizing agents (O3 or ozone),
H2O2 (ammonium) is
Peroxygen that is effective disinfectant for inanimate objects like contact lenses.
Peracetic acid
Peroxygen that is very effective liquid chemical sporicide (considered STERILANT)

It leaves NO TOXIC RESIDUE and is NOT affected by organic matter.
Most resistant infectious proteins
Prions
Mycobacteria
have thick waxy wall
Phenolics are good for treatment of
Mycobacteria
Alchocols are good for treatment of
Mycobacteria
Glutaraldehyde is fair in treating _______ and good in treating ________.
Endospores
Mycobacteria.
Modes of sterilization (review)
Dry heat
Moist heat
Chemicals (Gases, Liqids)
Radiation
Filtration
Boiling
100*C for 10 minutes will kill most pathogenic microbes and is the MOST RELIABLE METHOD OF DISINFECTING (not sterilizing) instruments and apparatus.
Halogens-Iodine in 70% alcohol
is most effective skin germicide but may cause severe reaction and stainin
Iodophors
Iodine and non-ionic detergents- less toxic and irritating disinfectant.

Eg. Betadine
Chlorine
Used in disinfecting drinking water, swimming pools and bedpans.
Phenolic Compounds
Disinfects instruments, utensils, sinks, toilets, floors.
Excrata-chlorinated phenolic-hexachlorophane (T)
Phenolic compound used as a protective hand wash in O.R.
Alcohol-Isopropyl Alcohol 70% is
effective skin germicide
Oxidizing agent disinfectant
hydrogen peroxide
Hydrogen Peroxide
an antiseptic which liberates oxygen bubbles when in contact with organic material.

It helps MECHANICALLY loosen slough and pus in a wound.
Heavy metal disinfectant/antiseptic
Silver Nitrate
Silver nitrate
Heavy metal used on burns but may cause indelible staining of linen.

Previously used in newborns
Drying
many microbes are killed by drying but spores can withstand drying process.
UV light
may kill some airborne microbes in O.R.
Formeldehyde
terminal room fumigation, also means of disinfecting mechanical apparatus such as patient ventilators.
Iodophors
Iodine and non-ionic detergents that are less toxic and irritating.
Eg. Betadine
Filtration (review)
pharmaceutical fluids and lab media (agar) are passed through a filter removing microbes.

Air in O.R. is filtered

Face mask filters out microbes but a WET mask ALLOWS MICROBES to pass through.