Microbiology Lecture II minor - Sheet1.csv

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  1. Physical Means of Control
    Filtration. Ultra violet radiation. Autoclaving and using Dry Ovens (heat. steam. and dessication). Removal using flushing and adherence/absorption
  2. When is filtration used
    1. The material we are trying to remove the bacteria is from is heat sensitive. (Ex. Trying to remove bacteria from urine).2. When we are usuing small volumes of solution.
  3. Filtration mechanism
    Are a filter material with various pore sizes. Can range from 0.22microns to 0.45microns diameter. We pass a fluid through this filter and microoganisms will get caught in the filters and microbe free bacteria fluid is created. When the the fluid is hard to pass through the filter it is probably clogged with microoganism and continued force will tear the filter.
  4. Radiation
    Many different types of radiation. UV (ultraviolet) radiation is the most common used in a micro sense. Is good for surface sterilization. UV does not penetrate deeply is blocked by many things even a piece of paper.
  5. Mode of action for UV.
    Causes thymine dimer. Causes DNA damage specifically to the thymine (pyrminidine). Two adjacent Thymines will fuse together and will cause a shift in the reading of codons (FRAMESHIFT)
  6. Factors effecting the effectivness of UV
    1. Exposure Time the ultraviolet radiation. 2. The species of bacteria (bacterial species). Bacteria that can form spores are more resistant to the effects of UV radiation vs its vegetative form.
  7. Repair mechanism for UV
    Photolyases are used by bacteria to repair the DNA damage caused by UV radiation. Will remove the thymine dimer. These repair mechanism can be overwhelmed with continued exposure.
  8. Autoclaves 
    They are costly and need pumping. electricity. and can be dangerous. Is a large metal jacket and in the metal is holes where water will come in. The water will come in and turn to steam and the sealed container increases atmospheric pressure. Uses both steam and pressure will DESTROY SPORES. Temp 121 degrees C and 15 PSI for about 15 minutes. Total time for autoclaving about 45 minutes.
  9. Dry Ovens
    Good but not as good as autoclaves but take a long time to work. You can not use a liquid in a dry oven. We use a dry oven when we want things not to get moist. It takes many hours and works on the principle of dehydration. Long dehydration.
  10. Boiling
    Is very effective but must be done for a long period of time.
  11. Chilling
    Very good at inhibiting growth (bacteriostatic) prevents bacteria from growing.
  12. Bacteriostatic
    Just inhibiting growth. Not killing. Preventing them from growing. ex. refrigeration. Viristatic (used to inhibit viruses) Fungistatic (inhabited fungus).
  13. Bacteriocidal
    Used to actually kill bacteria. Destroys them. The term cidal can be applied to viruses and fungus. Viricidal and fungicidal.
  14. Flushing
    Use water to physically blow them away.
  15. Hand washing
    Is a combination of chemical and physical means of control. The soap is a chemical and physical. the soap will adhere the microbes and makes them easier to slide off your hands. The water is the physical flush to remove the microbes.
  16. Disinfectant
    "An agent such as heat
  17. Hypochlorites
    Bleaches the most widely used type of chemical control. About 53%
  18. Alcohols
    Used for about 26% for chemical control
  19. Quatenary compounds
    Ammonia used in lab very effective but cost alot of money.
  20. Antiseptic
    A substance that inhibits the growth and reproduction of disease-causing microorganisms designed for living entities.
  21. Sanitize
    To make acceptable by removing unpleasant or offensive features and may include disinfection.
  22. Fomite
    "An inanimate object or substance that is capable of transmitting infectious organisms from one individual to another. Ex. Mouse pad
  23. Vectors
    Living things that transfer pathogens
  24. Carries
    Are vectors that carry the illness but dont demonstrate the illness
  25. Reservoir
    A large collection of pathogens in one place. Storage place. Ex. biohazard bag
  26. Disinfectant effectivenss depends on
    1. Type of contaminating microorganism. 2. Degree of contamination. 3. Amount of protein containing material. 4. Acitvity. 5. Type of chemical. 6. Concentration and quantity of chemicals. 7. Contact time and temperature* 8. Residual acity 9. Toxicity 10. Cost
  27. Hypochlorites
    "Bleaches. Usually used in about a 5% concentration
  28. Iodine and Iodophor Disinfectants
    Provide wide germicidal activity and are relatively nontoxic. Limited activity when in the presence of organic matter. Usually found in surgical scrubs (Triclosin). Does foster resistance to microbes. Fair effectiveness as sporicidal agents.
  29. Chlorohexidine
    Same as Iodine and Iodophor
  30. Alcohols
    Very good at bacteria and viruses. Not good at killing spores. Irritating to the tissue. Excellent when used at 70-95 percent concentration for disinfecting instruments. 70% alcohol is better than higher concentration because water helps it penetrate into the cells and does not evaporate fast.
  31. Oxidizing Agents
    "Peroxides. Moderate to wide germicidal activity
  32. Phenolic Disinfectants
    Not good for skin. Wide germicidal range. Very effective in the presence of organic matter. Poor to limited to residual activity. Not sporicidal.
  33. Quatenary Ammonium compounds
    Broad spectrum. Normally used in hospitals.
  34. Chemical Control mechansims
    Dehydrate or denature proteins.
  35. Aldehydes
    Are carcinogenic. Broad spectrum. Kill spores and fungus. Formaldehyde
  36. Important factor when choosing a disinfectant (summary)
    The choice of disinfectant or cleaning agent along with the optimum concentration and the item of action is very important when destroying microbes. It is also important that the resistance of microbes to different disinfectants and cleaning agents be taken into account when planning the cleaning process.
  37. Detergents and surfactants
    Depends on water you have. Hard water (contains an appreiatable aquantity of disolved material). Soft water is treated water which teh only cation (positively charged ions) in sodium. Long hydrocarbon chains but water soluble.
  38. Soaps
    Fats and lye. Work well physically. Chemically work only on lipids for long period of time.
  39. Bile Salts
    Work likes soaps. Likes dissolve like. Destroys lipids
  40. Ozone and ozonolysis
    An ozonide is also the unstable compound formed by teh addition of ozone to the C=C bond in alkenes. Ozone is alos very strong oxidizing agent. normally used for medial implants.
  41. Phenol
    Is the disinfectant standard which all other disinfectans are compared.
  42. Phenol coefficient
    highest dilution that causes kill after 10 minutes of exposrue but not after 5 minutes. You make a dilution of the chemical and a dilution of phenol. You find the concentration at which the microbe will grow at 5 minutes but not at 10 minutes. They you make a ration of Chemical Tested Concentration/Phenol Concentration. If PC =1 same as phenol. PC <1 less effective. PC>1 better than phenol.
  43. Probiotics
    Beneficial Gut Bateeria
  44. Prebiotics
    """Foods"" that foster benefical functions of Probiotics. Ex. onions. cerals. fiber"
  45. Echnaccea
  46. Garlic
    Alllicin works to inhibit bacteria growth. Anitmicrobial
  47. Cranberry
    Inhibit fimbriae
  48. Hot peppers
    Capsaicin and capsicum indirectly promote substance P from pain causes inflammation. Inflammation increases cytokine productions which leads to increased phagocytosis and decreased inflammation.
  49. Porphyria
    "Genetic disorder has anemia
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Microbiology Lecture II minor - Sheet1.csv
2012-02-27 08:30:43
Microbiology Physcial chemical means control

Chemical and physical mean of microbial control
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