OPT 2222 Lesson 2 Flashcards
What is the most effective way to keep from spreading microorganisms?
Hand Washing!
What are undesirable microorganisms?
Bacteria Endospores Fungi Protozoa Worms Viruses Prions
Which undesirable microorganism likes dead tissue?
Fungi
What are Antiseptics?
Application of agents onto the body’s surfaces (skin, conjunctiva) to slow or destroy growth of microbes
What are Disinfectants
Application of agents onto objects (Inanimate)(Counters, instruments) to destroy or slow growing microbes
What is Sterilization
The complete removal and destruction of all microbes on an inanimate surface
What microbes have the highest resistance?
Non-living Prions
Dormant Bacterial Endospores
What microbes have a moderate resistance?
Pseudomonas
Mycobacterium Tuberculosis
Staphylococcus aureus
Protozoan Cysts
What microbes have the least resistance?
Bacterial Vegetative Cells
Fungal Spores, Hyphae, Yeast
Enveloped Viruses
Protozoan Trophozoites
How to kill microbes?
Sterilization Disinfection Antiseptics Sanitization Degermination
What is Microbial Death?
Permanent Loss of reproductive capability, even under optimum growth conditions hard to detect.
Factors that affect Death Rate
Number of Microbes Nature of Microbes Temperature pH Concentration of Agent Mode of Action of Agent Presents of Solvents Organic Matter Inhibitors
Antimicrobials act against what parts of cells?
Cell walls (they become fragile and lyse) Cell membrane (will lose integrity and flood the cell)
What acts on cell walls of microorganisms?
Drugs, Alcohols, and Detergents
What acts on cell membranes of microorganisms?
Detergent Surfactants
What inhibits protein synthesis?
Chloramphenicol
What does Ultra Violet (UV) Radiation do?
Inhibits DNA Transcription and Translation
What does Formaldehyde do?
Denatures proteins and inactivates nucleic acid
What does heat do to microorganisms?
Disrupts or denatures proteins
What types of heat are there?
Moist Heat
Dry Heat
What are the physical methods to disrupt proteins?
Heat (moist and dry) Cold Desiccation Radiation Filtration
What does Dry Heat / Incineration do?
They denature proteins and cause coagulation
What is Incineration?
Dry heat form of physical change that results in only carbon remaining
What is Thermal Death Time (TDT)?
The shortest time required to kill all the microbes at a given temperature.
What is Thermal Death Point (TDP)?
The lowest temperature required to kill all the microbes in 10 minutes.
What are the forms of moist heat sterilization?
Steam under pressure (Autoclave)
Steam non-pressurized (Boiling, Pasteurization, Tyndallization)
What must happen during Autoclaving
Steam must reach ALL surfaces
Temperature must be 121 C
Pressure must be 15 PSI
Time required is 10 to 40 minutes
What must NOT be Autoclaved
Items that are heat or moisture sensitive
What are the two types of Pasteurization
Batch Method
Flash Method
What is batch method pasteurization?
Heating to 63 - 66 C for 30 minutes
What is flash method pasteurization?
Heating to 71.6 C for 15 seconds