Required Reading: Infection Control Flashcards
Members of the typical oral flora include
Streptococci
Actinomycetes
Anaerobic bacteria
Candidal species
Oral organisms are held in check by these 4 processes
- Rapid epithelial turnover/desquamation
- Salivary IgA/Host immune factors
- Dilution via salivary flow
- Competition b/w oral flora for resources
How does skin prevent entry of microbes
Keratinized tissue
Tight bonds between epithelial cells
This is the breakdown of living tissue by the action of microorganisms and is usually accompanied by inflammation
Sepsis
Does bacteremia automatically mean there is a septic state?
No
The attempt to keep patients, staff, and objects as free as possible of infectious agents
medical asepsis
The attempt to prevent microbes from gaining access to surgically created wounds
surgical apsepsis
the freedom from viable forms of microorganisms
sterility
the reduction of the number of viable microorganisms to levels judged safe by public health standards
sanitization
Similar to sanitization, but without the connection to public health standards
decontamination
What are the major chemical means of killing microbes of surfaces
- Antiseptics
- Disinfectants
- Ethylene oxide gas
The microorganisms most resistant to elimination
bacterial endospores
Any method capable of killing bacterial endospores can also kill….
Bacteria Viruses Mycobacteria Fungi Mold Parasites
Three methods generally available for instrument sterilization
- Dry heat
- Moist heat
- Ethylene oxide gas
How does dry heat differ from moist heat?
Moist heat works faster and at lower temps than dry heat
What endospore is used to monitor sterilization
Bacillus stearothermophilus
What items are best sterilized with dry heat
Bulky items that can withstand high temps, but are prone to rusting
Why does moist heat work at a lower temperature than dry heat
water is better at transferring heat
it take 7x more energy to turn boiling water to steam as it does to get water to boiling
Why does moist heat under pressure (Autoclaving) work even better?
Because the pressure increasing the boiling point of water, so the steam is that much hotter when it comes into contact with microbial cell proteins
What is ethylene oxide mixed with to make it safer to use
Carbon dioxide
Nitrogen
How long does it take to kill with ethylene oxide at 50 degrees C
3 hours
What is a downside to using ethylene oxide?
Equipment must aerate for 12 hours before use
How are chemical agents for instrument disinfection classified
High, intermediate, low biocidal activity
Why are quaternary ammonium compounds not recommended
they cannot kill Hep B Virus and become inactivated by soap and anionic agents
