Sterilization, Disinfection, and Containment - Kozel Flashcards
What is sterilization?
use of physical or chemical agents to destroy all microbial forms, INCLUDING SPORES
What is the difference between sterilization and disinfection?
Disinfection doesn’t kill microbial spores
What is antisepsis? Are spores killed?
chemical agents on the skin or other living tissue to inhibit OR eliminate microbes; NO SPORICIDAL ACTION IMPLIED
WTF is a biocide?
general term describing a broad spectrum chemical agent that inactivates microbes
There is an inverse relationship between disinfectant (blank) and time required to kill
concentration
What are the factors that play into disinfectant potency?
- concentration
- time
- pH–DRAMATIC EFFECTS
- temerpature
- presence of extraneous materials (can bind or inactivate disinfectant)
- the bug itself
As temp increases, killing time (blank)
decreases
Try to list out the relative resistances to antiseptics?
Prions>crytposporidium (coccidia)>mycobacteria (TB)>cysts (giardia)>small non-enveloped viruses (polio)>trophozoites>gram neg>fungi>large non enveloped viruses>gram pos >lipid enveloped viruses (HIV/HBV)
List the relative disinfectant resistance of viruses?
small non enveloped> large non enveloped > lipid enveloped
Ethylene oxide and aldehydes have what MOA?
alkylate and cross-link macromolecules (protein, DNA, or RNA)
Formaldehyde, glutaraldehyde and ethylene oxide are what class of agent?
etheylene oxide and aldehydes
What is used in chemical sterilization of equipment?
glutaraldehyde
What is used in environmental decon in gasseous form or disolved in water?
formaldehyde
What is used as gaseous sterilization of HEAT SENSITIVE materials?
ethylene oxide
What is the MOA of oxidizing agents?
oxidize proteins and DNA breakage
Ozone, hydrogen peroxide, and peracetic acid are what class of agentz?
oxidizing agents
What is used in the disinfection of air systems?
ozone!
What is used to clean wounds, disinfect implants and prostheses?
H2O2
What the fuck do you use peracetic acid for?
its a chemical sterilant for hard surfaces
How do halogens work?
oxidize proteins
Is iodine or chlorine a skin disinfectant? and the other?
iodine is for skin, chlorine is chemical decon
How do phenolic compounds work?
disrupt lipid membranes and denature proteins
Which is in soap and which is a skin disinfectant? Chlorhexidine and Triclosan
Chlorhexidine for skin and Triclosan in soap
Quaternary ammonium compounts act as (blank) due to the their amphoteric properties that disrupt membranes
surfactants
The actual name of lysol is (blank), a type of quaternary ammonium compound
benzalkonium
What do alcohols do?
denature proteins
what physiological adaptation gives bugs better resistance to disinfectants?
biofilms!
Inactivation of chlorhexidine, formaldehyde, and mercurials can be acquired via (blank)
plasmids or mutation
what chemicals are susceptible to efflux?
quaternary ammoniums and chlorhexidine
Silver compounds are liable to (blank) form of resistance
reduced uptake
At what temp do most pathogenic bacteria die?
60C
At what temp do vegetative forms of all bacteria and fugi die?
80C
At what temp do spores of pathogens die?
100C
At what temp do all bacterial spores die?
120C
At what temp does pasteurization happen?
72C
At what temp does boiling happen?
100C
At what temp does the autoclave run?
120C
At what temp is dry heat used to kill microbes?
180C
T/F: incineration is always a fun alternative to autoclave
truth
UV irradiation is used to control (blank) or surface contamination as it has little penetration of solids
airborne
Ionizing radiation like X rays or gamma rays is used to sterilize (blank)
small HEAT SENSITIVE articles
Filtration of heat-labile liquids does not remove what?
viruses
Does HEPA air filtration catch viruses?
yes
How would you sterilize packages of surgical dressing?
autoclave on dry cycle
How would you decon liquids from research lab that have live viruses in them?
mix with 10% bleach if small volume or autoclave if large volume
How would you decon a thermometer in a peds clinic?
alcohol
How would you sterilize 50 glass flasks containing bacterial culture media?
autoclave on slow exhaust cycle
How would you sterilize plastic pipettes in their plastic wrappers (heat sensitive)?
ionizing radiation
How would you dispose of a large quantity of lab glassware that has been contaminated with pathogenic fungi?
autoclave
How would you sterilize 200ml of tissue culture media (heat labile)?
filter sterilization
How would you decon a biosafety hood prior to changing HEPA filters?
formaldehyde gas for an “environmental” decon
How would you disinfect the skin at a lumbar puncture?
iodine–need it STERILE
How would you disinfect the skin at a venipuncture?
alcohol - don’t need it sterile, just cleansed
How would you process raw milk?
pasteurization
How would you decon a lab bench top after routine bacterial culture?
amphyl phenolic based disinfectant
What is the only BSL that is not separated from general traffic?
BSL 1
What BSL does not rely on primary or secondary barriers?
bSL1
T/F: lab personnel must have specific training and supervision of a micro scientist at all BSL levels
true
HBV, HIV, and slamonellae are what BSL?
BSL 2
hazard associated with percutaneous exposure, ingestion, or mucous membrane exposure is BSL what?
BSL 2
Extreme precautions are taken with sharps at BSL what>?
BSL 2
When do you use a bio safety cabinet in BSL 2?
procedures that generate splashes or aerosols
T/F: all procedures in BSL 3 are done in a bio safety cabinet
true
T/F: BSL 3 have the potential for aerosol transmission
true
T/F: BSL 4 work is contained to BSL 3 safety cabinets
true
what other measures are needed for BSL 4?
if not in fully self contained BSL 3 cabinet, can use BSL 2 with positive pressure suits ventilated by life support
