Control Of Microbial Growth Flashcards
Examples of Bacteriostasis
Refrigeration
Freeze drying (lyphilization)
Rapid freezing through liquid nitrogen
Lowest temperature that will kill all organisms in a standardized culture with specified period of time
Thermal Death Point
Two methods of using heat
Moist Heat Sterilization
Dry Heat Sterilization
Destruction or removal kf pathigens from nonliving objects by physical kr chemical methods
Disinfection
Stop or inhibition of microbial growth or multiplication
Bacteriostasis
Ways of controlling sources of infections
Destruction of disease-causing microbes
Blocking source, vector and route of transmission of disease agents
Improvement of body defenses and host resistance
Common vector
Insects
Free or devoid of pathogens or the absence of significant contamination
Asepsis
The complete or total destruction of all organisms including cells, viable spores and viruses
Sterilization
Factors that influence effectiveness of antimicrobial procedures
Length of time applied Concentration Temperature Nature and number of microorganisms present Presence of organic matter
Organic matter
Urine
Stool
Blood
Sputum
Growth of pathogens in living tissues which indicates a disease process or contamination
Sepsis
Dry heat characteristics
Protein oxidation Slower Higher temperature More destructive Less efficient
Steam
70 degrees celsius
10 minutes
What are the physical agents of sterilization?
Mechanical methods
Use of heat
Other methods like Ultrasonics and radiation
Length of time necessary to kill a pure culture at a specified temperature
Thermal Death Time
Examples of Moist Heat Sterilization
Boiling Steam Pressurized steam Autoclave Pasteurization UHT HTST
What does HTST stands?
High Temperature Sterilization or High Temperature Slow Time
What does UHT stands?
Under high temperature
Practical, inexpensive and effective
Use of heat
Examples of filtration
Cellulose membrane Asbestos Unglazed porcelain Layer of sand Sintered glass HEPA Filters
Mechanical Methods
Filtration
Scrubbing
Sedimentation
Pressurized steam
Max 121 degrees celsius
Involves mild heating to destroy microbes found in milk, beer, wine and other dairy products without losing nutritional value
Pasteurization
HTST
72 degrees celsius- -15 seconds
UHT
140 degrees celsius- less than a second
Autoclave
121 degrees celsius- 15 pounds per square inches- 20 minutes
Ideal for cooking
Steam
Moist heat sterilization characteristics
Protein Coagulation Faster Low temperature Less destructive More efficient
Used together with a nonliving object or inanimate object
Disinfectant
Methods of dry heat sterilization
Flaming, burning or incineration
Hot air sterilization
Other term for hot air sterilization
Dry heat baking
Smell of protein oxidation
Burnt hair
Uses an oven or hot air sterilizer and used for glasswares, surgical instruments or any material destroyed in presence of water like oil or powder
Hot air sterilization or dry heat baking
Used in association with a living body or tissue
Antiseptic
Used for contaminated disposable materials like wire loop or needle
Flaming, burning or incineration
Common organic disinfectant
Phenol or Carbolic acid
Ideal boiling point
100 degrees celsius
Preserving the body
Cryogenics
