Cleaning and Disinfection Flashcards
Clean to dirty workflow
Vacuum protection.
A - Suction flask
B - Overflow
C - HEPA filter to protect vacuum system (D) for aerosolized microorganisms
Bag-in/Bag-out system
Allows for removal of contaminated filters when gas or vapor decontamination are prevented or when chemicals or radionucleotides have been used.
Needs to be installed with BSC as it is expensive to retrofit later.
A - Filters
B - Bag
C - Safety straps
D - Cinching
E - Shock cord located in the mouth of the PVC bag restricts the bag around the second rib of the housing lip.
Define cleaning.
Removal of gross contamination from a surface to the extent necessary for further processing for intended use.
Physical, no antimicrobial activity. Pre-req to disinfection or sterilizations, especially for biofilms.
Define disinfection.
Process that eliminates nearly all recognized pathogenic microorganisms, but not necessarily all microbial forms (bacterial spores) present on inanimate objects.
Generally less lethal than sterilization
How does the FDA categorize disinfectants?
Low, intermediate, and sterilant/high level.
By definition, how does chemical disinfection differ from chemical sterilization?
Lack of sporocidal power of disinfectants.
Most labs should select a disinfectant product that has a claim for efficacy against what agent?
Tuberculocidal/mycobactericidal
Compare the kill level and margins of safety between disinfection and sterilization?
Disinfection does not have the kill level nor the margin of safety of sterilization.
What factors affect disinfection? (5)
- Nature and number of contaminating microorganisms, especially spores
- Amount of organic matter present
- Type and condition of surfaces, instruments, devices, and materials to be disinfected
- Temperature
- Contact time
Define sterilization.
A process that renders an item, device, or solution completely free of all forms of living microorganisms, including spores and viruses.
Categorical absolute but, the procedure is defined as a process, after which the probability of a microorganism surviving on an item subjected to treatment is less than one in a million. Referred to as a sterility assurance level of 10^-6.
Define decontamination.
A process that renders an area, device, item, or material safe to handle in the context of being reasonably free from a risk of disease transmission. Can involve cleaning, disinfection, and/or sterilization.
Primary objective is to reduce level of contamination so that transmission of infection is prevented.
What is the descending order of relative resistance to disinfectant chemicals?
How are Pseudomonas spp. an exception to the general order of relative resistance to chemical disinfectants?
Pseudomonas are sensitive to high-level disinfectants, but are protected in biofilms and free-living amoeba.
Which agents are resistant to glutaraldehyde?
Some nontuberculous mycobacteria, some fungal ascospores of Microascuc cinereus and Chaetomium globosum, and the pink-pigmented Methylobacteria.
How are prions resistant to decontamination?
Resistant to conventional uses of heat and/or chemical germicides. Dispose and incinerate.
When are Select Agents no longer subject to the Select Agent Regulations?
Once inactivated.
What is the difference between inactivation and disinfection?
Inactivation typically leaves cell components intact that can be used as reagents for assay development or other studies. Purpose of disinfection is to kill and damage pathogens with no attention to preserving cell components.
What does the Select Agent Regulations require?
Inactivation process to be validated. Risk of sending/using incompletely inactivated agents.
