CH 8 INFECTION CONTROL Flashcards
Explain the difference between antisepsis, disinfection, sanitization, and sterilization
- Antisepsis: using physical/chemical means to remove microorganisms from living tissue.
- Disinfection: Removal of vegetative bacteria from tissue or an object.
- Sanitization: Reduction of microorganisms from an object through cleansing.
- Sterilization: Removing all infectious particles, including spores.
What is the term for slowing of the rate of microbial growth?
Microbistasis
Name an infectious agent that has high resistance.
Bacterial endospores
Name some infectious agents with moderate resistance.
- Tuberculosis
- Staph aureus
- Pseudomonas
- Protozoans
- Unenveloped viruses
Name some infectious agents with low resistance
- Most vegetative bacteria
- Fungal spores/hyphae
- Enveloped viruses
- Yeasts
- Trophozoites
What does HEPA stand for?
High efficiency particulate air
What is a common example of a filtrative device?
Masks
Does filtration produce sterile liquids?
No
Why would you use filtration rather than heat?
For liquids sensitive to heat like drugs.
What is another term for incineration?
Dry heating
What temperature is pasteurization done at?
About 69-72 degrees celsius
At what temperature is dry heating/incineration done?
800-6500 degrees
What temperature are most household freezers kept at, and what temperature is more longer term microbistasis done at?
-20 degrees and -80 degrees
What does radiation do to bacteria?
Disrupts DNA
What are two examples of ionizing radiation?
Gamma rays and x-rays
What does ionizing radiation do to bacteria?
Displaces electrons, forming reactive ions in cells which disrupt their structure
What is an example of non ionizing radiation, and what is it used for?
UV light, used for municipal water, food, and sterilizing rooms in hospitals
What are two alcohols that are used as disinfectants?
Ethanol and isopropanol
What can alcohol not kill?
Spores, viruses
What two halogens are used as disinfectants?
Chlorine and iodine
What are two examples of chlorine based disinfectants?
Hypochlorite solution (bleach), and chloramine
What is an example of an iodine based product?
Iodophors
What are two examples of heavy metals used as disinfectants?
Silver and mercury
What is the term for the characteristic of heavy metals that make them microbicidal?
Oligodynamic
What are two examples of phenol based disinfectants?
Carbolic acid, and chlorhexadine
How does hydrogen peroxide destroy microbes?
Oxidant, creates free radicals
Why would ozone be used to disinfect municipal water as opposed to UV light?
When water contains organic material and UV cannot penetrate it
How does soap work to reduce microbial load?
Emulsifying agent
How do detergents work to reduce microbial load?
Amphipathic molecules work as surfactants, meaning they break up surface tension of lipid based membranes
Name one example of a detergent used to clean floors and surfaces
Quaternary ammonium
Name two examples of aldehydes used as disinfectants
Formaldehyde, glutaraldehyde
How do aldehydes work to decrease microbial load?
Cause protein cross linking, disrupting bacterial cell structure
Name 4 reasons microorganisms are becoming resistant to antibiotics
- Antibiotics have been used indiscriminately
- They are used in animals that serve as food
- Antibacterial residues are now present in the environment
- Lack of new antibiotics
Name some examples of drug-resistant microorganisms
- Carbapenem resistant Acinetobacter
- Candida auris
- C. diff
- Carbapenem resistant Enterobacter
- Drug resistant N. gonorrhea
Name 4 mechanisms of drug resistance
- Drug inactivation e.g. penicilllinases
- Decreased cell permeability due to cell receptor changes
- Increased elimination due to presence of membrane protein “drug pumps”
- Alternate metabolic pathways
What is the term for the smallest concentration that visibly inhibits growth of infection?
Minimum inhibitory concentration (MIC)
What is the term for the ratio of dose that is effective vs. Dose that is toxic to humans?
Therapeutic index
