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CONTROL OF                   MICROORGANISMS                               Lecture 5Thursday, September 15, 2011
LECTURE OUTLINE            Definition of Terms in Microbial Control            Pattern of Microbial Death          Conditi...
Thursday, September 15, 2011
The Control of          Microbial Growth               SEPSIS                microbial contamination              ASEPSIS ...
The Control of          Microbial Growth               SEPSIS                microbial contamination              ASEPSIS ...
The Control of           Microbial Growth              STERILIZATION               Removal of all microbial life          ...
The Control of           Microbial Growth              STERILIZATION               Removal of all microbial life          ...
The Control of           Microbial Growth            DISINFECTION              Removal of pathogens            ANTISEPSIS ...
The Control of           Microbial Growth            DISINFECTION              Removal of pathogens            ANTISEPSIS ...
The Control of          Microbial Growth              SANITATION                Lower microbial counts on eating          ...
The Control of          Microbial Growth              SANITATION                Lower microbial counts on eating          ...
PATTERN OF MICROBIAL         DEATH                                 Bacterial                               populations    ...
PATTERN OF MICROBIAL         DEATH                                 Bacterial                               populations    ...
The Control of         Microbial Growth                     HOW DO WE DECIDE                     WHETHER THEY ARE         ...
The Control of         Microbial Growth                     HOW DO WE DECIDE                     WHETHER THEY ARE         ...
The Control of         Microbial Growth                     HOW DO WE DECIDE                     WHETHER THEY ARE         ...
Conditions Influencing        Effectiveness of   Antimicrobial Agent Activity     1.     Population size              Larg...
Conditions Influencing        Effectiveness of   Antimicrobial Agent Activity     1.     Population size              Larg...
Conditions Influencing        Effectiveness of   Antimicrobial Agent Activity3. Concentration or Intensity of an Antimicro...
Conditions Influencing        Effectiveness of   Antimicrobial Agent Activity3. Concentration or Intensity of an Antimicro...
Conditions Influencing        Effectiveness of   Antimicrobial Agent Activity 5. Temperature             An increase in te...
Conditions Influencing        Effectiveness of   Antimicrobial Agent Activity 5. Temperature             An increase in te...
Thursday, September 15, 2011
PHYSICAL METHODS:              HEAT           Fire and boiling           Sufficient to destroy vegetative         cells (1...
PHYSICAL METHODS:              HEAT           Fire and boiling           Sufficient to destroy vegetative         cells (1...
PHYSICAL METHODS:              HEAT           Thermal Death Point (TDP)             The lowest temperature at which a     ...
PHYSICAL METHODS:              HEAT           Thermal Death Point (TDP)             The lowest temperature at which a     ...
However, such a destruction is    logarithmic and it is theoretically NOT      POSSIBLE to “completely destroy”           ...
However, such a destruction is    logarithmic and it is theoretically NOT      POSSIBLE to “completely destroy”           ...
However, such a destruction is    logarithmic and it is theoretically NOT      POSSIBLE to “completely destroy”           ...
PHYSICAL METHODS:              HEATThursday, September 15, 2011
PHYSICAL METHODS:              HEATThursday, September 15, 2011
PHYSICAL METHODS:              HEAT            z Value              The increase in temperature required to             re...
PHYSICAL METHODS:              HEAT            z Value              The increase in temperature required to             re...
APPLICATION: FOOD          INDUSTRYThursday, September 15, 2011
APPLICATION: FOOD          INDUSTRYThursday, September 15, 2011
APPLICATION: FOOD          INDUSTRY           After a food have been canned, it must be         heated to eliminate the ri...
APPLICATION: FOOD          INDUSTRY           After a food have been canned, it must be         heated to eliminate the ri...
APPLICATION: FOOD          INDUSTRYThursday, September 15, 2011
APPLICATION: FOOD          INDUSTRYThursday, September 15, 2011
APPLICATION: FOOD          INDUSTRY             If the z value for Clostridium spores is 10°CThursday, September 15, 2011
APPLICATION: FOOD          INDUSTRY           If the z value for Clostridium spores is 10°C           It takes a 10°C chan...
APPLICATION: FOOD          INDUSTRY           If the z value for Clostridium spores is 10°C           It takes a 10°C chan...
APPLICATION: FOOD          INDUSTRY           If the z value for Clostridium spores is 10°C           It takes a 10°C chan...
APPLICATION: FOOD          INDUSTRY           If the z value for Clostridium spores is 10°C           It takes a 10°C chan...
PHYSICAL METHODS: HEAT            (MOIST HEAT           STERILIZATION)Thursday, September 15, 2011
PHYSICAL METHODS: HEAT            (MOIST HEAT           STERILIZATION)Thursday, September 15, 2011
PHYSICAL METHODS: HEAT       (Dry Heat Sterlization)                               Hot-air       Autoclave Equivalent trea...
PHYSICAL METHODS: HEAT       (Dry Heat Sterlization)                               Hot-air       Autoclave Equivalent trea...
PHYSICAL METHODS: HEAT       (Dry Heat Sterlization)           Flaming                               Hot-air       Autocla...
PHYSICAL METHODS: HEAT       (Dry Heat Sterlization)           Flaming                               Hot-air       Autocla...
PHYSICAL METHODS: HEAT       (Dry Heat Sterlization)           Flaming           Incineration                             ...
PHYSICAL METHODS: HEAT       (Dry Heat Sterlization)           Flaming           Incineration                             ...
PHYSICAL METHODS: HEAT       (Dry Heat Sterlization)           Flaming           Incineration           Hot-air sterilizat...
HOW DOES HEAT KILL            MICROBESThursday, September 15, 2011
HOW DOES HEAT KILL            MICROBESThursday, September 15, 2011
HOW DOES HEAT KILL            MICROBES            MOIST HEAT              Kill effectively by degradation of nucleic      ...
HOW DOES HEAT KILL            MICROBES            MOIST HEAT              Kill effectively by degradation of nucleic      ...
HOW DOES HEAT KILL            MICROBES            MOIST HEAT              Kill effectively by degradation of nucleic      ...
PHYSICAL METHODS:     FILTRATION           Applicable for heat-sensitive materials that needs          sterilization      ...
PHYSICAL METHODS:     FILTRATION           Applicable for heat-sensitive materials that needs          sterilization      ...
PHYSICAL METHODS:     FILTRATION             Laminar flow hood versus          biological safety cabinets (HEPA          f...
PHYSICAL METHODS:     FILTRATION             Laminar flow hood versus          biological safety cabinets (HEPA          f...
BIOSAFETY                           CABINETS           Class1 (from room=outside)              protection: person and envi...
BIOSAFETY                           CABINETS           Class1 (from room=outside)              protection: person and envi...
PHYSICAL METHODS:         RADIATION            IONIZING RADIATION               X rays, gamma rays, electron beams        ...
PHYSICAL METHODS:         RADIATION            IONIZING RADIATION               X rays, gamma rays, electron beams        ...
Thursday, September 15, 2011
CHEMICAL                     AGENTSThursday, September 15, 2011
CHEMICAL                               METHODS              PHENOLICS              QUATERNARY                             ...
CHEMICAL                               METHODS              PHENOLICS              QUATERNARY                             ...
CHEMICAL                           METHODS  Chemical agent                Effectiveness against                           ...
CHEMICAL                           METHODS  Chemical agent                Effectiveness against                           ...
CHEMICAL     METHODS: Phenolics             First widely used antiseptic and disinfectant            Joseph Lister (1867):...
CHEMICAL     METHODS: Phenolics             First widely used antiseptic and disinfectant            Joseph Lister (1867):...
Disruption of                               Cell MembranesThursday, September 15, 2011
CHEMICAL     METHODS: Phenolics           ADVANTAGES: effective in the          presence of organic material and remain   ...
CHEMICAL     METHODS: Phenolics           ADVANTAGES: effective in the          presence of organic material and remain   ...
CHEMICAL        METHODS: Alcohols               Widely used disinfectant and antiseptics            Bactericidal and fungi...
CHEMICAL        METHODS: Alcohols               Widely used disinfectant and antiseptics            Bactericidal and fungi...
DENATURES                                PROTEINS,                               DISSOLVES                                ...
CHEMICAL        METHODS: Alcohols            Example: ethanol and isopropanol (70-80%           concentration)            ...
CHEMICAL        METHODS: Alcohols            Example: ethanol and isopropanol (70-80%           concentration)            ...
CHEMICAL METHODS:          Halogens              Iodine                Kills by oxidizing cell constituents               ...
CHEMICAL METHODS:          Halogens              Iodine                Kills by oxidizing cell constituents               ...
CHEMICAL METHODS:          Halogens           Chlorine             Usually for water supply                Kills by oxidat...
CHEMICAL METHODS:          Halogens           Chlorine             Usually for water supply                Kills by oxidat...
CHEMICAL METHODS:        Heavy Metals              Mercury, Arsenic, Zinc, Copper              Used as germicides         ...
CHEMICAL METHODS:        Heavy Metals              Mercury, Arsenic, Zinc, Copper              Used as germicides         ...
CHEMICAL METHODS:           Quats           DETERGENTS             Amphipathic (both polar and non-polar            ends) ...
CHEMICAL METHODS:           Quats           DETERGENTS             Amphipathic (both polar and non-polar            ends) ...
Soap                           Degerming             Surface-Active Agents or Surfactants Acid-anionic                    ...
CHEMICAL METHODS:         Aldehydes               FORMALDEHYDES                 Very reactive molecules that              ...
CHEMICAL METHODS:         Aldehydes               FORMALDEHYDES                 Very reactive molecules that              ...
EVALUATION OF                  ANTIMICROBIAL AGENT                    EFFECTIVENESS              PHENOL COEFFICIENT TEST  ...
EVALUATION OF                  ANTIMICROBIAL AGENT                    EFFECTIVENESS              PHENOL COEFFICIENT TEST  ...
CALCULATING PHENOL          COEFFICIENTS            The reciprocal of the appropriate test          disinfectant dilution ...
CALCULATING PHENOL          COEFFICIENTS            The reciprocal of the appropriate test          disinfectant dilution ...
CALCULATING PHENOL          COEFFICIENTS            The higher the phenol          coefficient value, the more          ef...
CALCULATING PHENOL          COEFFICIENTS            The higher the phenol          coefficient value, the more          ef...
DILUTION TESTS             Metal rings dipped in test bacteria are dried           Dried cultures placed in disinfectant f...
DILUTION TESTS             Metal rings dipped in test bacteria are dried           Dried cultures placed in disinfectant f...
DISK-DIFFUSION             METHODThursday, September 15, 2011
DISK-DIFFUSION             METHODThursday, September 15, 2011
CHEMOTHERAPEUTIC          AGENTSThursday, September 15, 2011
CHEMOTHERAPEUTIC          AGENTSThursday, September 15, 2011
CHEMOTHERAPEUTIC          AGENTS           Antibiotics are medicines used to treat infections          caused by bacteria ...
CHEMOTHERAPEUTIC          AGENTS           Antibiotics are medicines used to treat infections          caused by bacteria ...
Thursday, September 15, 2011
WHAT IF ANTIBIOTICS WERE         USED INCORRECTLY?           No healing effect - If antibiotics are used for          vira...
WHAT IF ANTIBIOTICS WERE         USED INCORRECTLY?           No healing effect - If antibiotics are used for          vira...
ANTIBIOTIC                      MECHANISMSThursday, September 15, 2011
ANTIBIOTIC                      MECHANISMSThursday, September 15, 2011
RESISTANCEThursday, September 15, 2011
RESISTANCEThursday, September 15, 2011
RESISTANCEThursday, September 15, 2011
RESISTANCEThursday, September 15, 2011
DO YOU CONTRIBUTE       TO RESISTANCE?Thursday, September 15, 2011
DO YOU CONTRIBUTE       TO RESISTANCE?Thursday, September 15, 2011
DO YOU CONTRIBUTE       TO RESISTANCE?Thursday, September 15, 2011
DO YOU CONTRIBUTE       TO RESISTANCE?Thursday, September 15, 2011
DO YOU CONTRIBUTE       TO RESISTANCE?           Another factor that contributes to resistance is          that when patie...
DO YOU CONTRIBUTE       TO RESISTANCE?Thursday, September 15, 2011
DO YOU CONTRIBUTE       TO RESISTANCE?Thursday, September 15, 2011
DO YOU CONTRIBUTE       TO RESISTANCE?           Also contributing to antibiotic resistance is the          widespread use...
ANY            QUESTIONS???Thursday, September 15, 2011
NEXT MEETING:          INTERACTIVE LECTURE/          QUIZ ON METABOLISMThursday, September 15, 2011
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Biology 120 lecture 5 2011 2012

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Transcript of "Biology 120 lecture 5 2011 2012"

  1. 1. CONTROL OF MICROORGANISMS Lecture 5Thursday, September 15, 2011
  2. 2. LECTURE OUTLINE Definition of Terms in Microbial Control Pattern of Microbial Death Conditions Influencing the Effectiveness of Antimicrobial Agents Use of Physical Agents Use of Chemical AgentsThursday, September 15, 2011
  3. 3. Thursday, September 15, 2011
  4. 4. The Control of Microbial Growth SEPSIS microbial contamination ASEPSIS absence of significant contaminationThursday, September 15, 2011
  5. 5. The Control of Microbial Growth SEPSIS microbial contamination ASEPSIS absence of significant contaminationThursday, September 15, 2011
  6. 6. The Control of Microbial Growth STERILIZATION Removal of all microbial life COMMERCIAL STERILIZATION Killing C. botulinum endosporesThursday, September 15, 2011
  7. 7. The Control of Microbial Growth STERILIZATION Removal of all microbial life COMMERCIAL STERILIZATION Killing C. botulinum endosporesThursday, September 15, 2011
  8. 8. The Control of Microbial Growth DISINFECTION Removal of pathogens ANTISEPSIS from living tissue DEGERMING from a limited areaThursday, September 15, 2011
  9. 9. The Control of Microbial Growth DISINFECTION Removal of pathogens ANTISEPSIS from living tissue DEGERMING from a limited areaThursday, September 15, 2011
  10. 10. The Control of Microbial Growth SANITATION Lower microbial counts on eating utensils BIOCIDE/GERMICIDE: Kills microbes BACTERIOSTATS: Inhibiting, not killing, microbesThursday, September 15, 2011
  11. 11. The Control of Microbial Growth SANITATION Lower microbial counts on eating utensils BIOCIDE/GERMICIDE: Kills microbes BACTERIOSTATS: Inhibiting, not killing, microbesThursday, September 15, 2011
  12. 12. PATTERN OF MICROBIAL DEATH Bacterial populations die at a constant logarithmic rateThursday, September 15, 2011
  13. 13. PATTERN OF MICROBIAL DEATH Bacterial populations die at a constant logarithmic rateThursday, September 15, 2011
  14. 14. The Control of Microbial Growth HOW DO WE DECIDE WHETHER THEY ARE ACTUALLY DEAD?Thursday, September 15, 2011
  15. 15. The Control of Microbial Growth HOW DO WE DECIDE WHETHER THEY ARE ACTUALLY DEAD?Thursday, September 15, 2011
  16. 16. The Control of Microbial Growth HOW DO WE DECIDE WHETHER THEY ARE ACTUALLY DEAD? “a microbe is defined DEAD if it does not grow when inoculated into culture medium that would normally support its growth”Thursday, September 15, 2011
  17. 17. Conditions Influencing Effectiveness of Antimicrobial Agent Activity 1. Population size Larger population requires a longer time to die 2. Population composition Microorganisms vary markedly on susceptibility Vegetative versus Spores Young versus Mature cellsThursday, September 15, 2011
  18. 18. Conditions Influencing Effectiveness of Antimicrobial Agent Activity 1. Population size Larger population requires a longer time to die 2. Population composition Microorganisms vary markedly on susceptibility Vegetative versus Spores Young versus Mature cellsThursday, September 15, 2011
  19. 19. Conditions Influencing Effectiveness of Antimicrobial Agent Activity3. Concentration or Intensity of an Antimicrobial Agent The more concentrated an agent the more rapidly microbes can be destroyed BUT sometimes an agent may be more effective at lower concentrations (e.g. 70% alcohol)4. Duration of Exposure The longer the exposure to an agent the more they will be killedThursday, September 15, 2011
  20. 20. Conditions Influencing Effectiveness of Antimicrobial Agent Activity3. Concentration or Intensity of an Antimicrobial Agent The more concentrated an agent the more rapidly microbes can be destroyed BUT sometimes an agent may be more effective at lower concentrations (e.g. 70% alcohol)4. Duration of Exposure The longer the exposure to an agent the more they will be killedThursday, September 15, 2011
  21. 21. Conditions Influencing Effectiveness of Antimicrobial Agent Activity 5. Temperature An increase in temperature at which a chemical acts often enhances it activity Example: acids used in high T = more effective 6. Local environment pH, organic matter, etc Controls or Protects the pathogenThursday, September 15, 2011
  22. 22. Conditions Influencing Effectiveness of Antimicrobial Agent Activity 5. Temperature An increase in temperature at which a chemical acts often enhances it activity Example: acids used in high T = more effective 6. Local environment pH, organic matter, etc Controls or Protects the pathogenThursday, September 15, 2011
  23. 23. Thursday, September 15, 2011
  24. 24. PHYSICAL METHODS: HEAT Fire and boiling Sufficient to destroy vegetative cells (10 minutes) Not high for killing endospores Disinfection but not sterilization!Thursday, September 15, 2011
  25. 25. PHYSICAL METHODS: HEAT Fire and boiling Sufficient to destroy vegetative cells (10 minutes) Not high for killing endospores Disinfection but not sterilization!Thursday, September 15, 2011
  26. 26. PHYSICAL METHODS: HEAT Thermal Death Point (TDP) The lowest temperature at which a microbial suspension in killed in 10 minutes Thermal Death Time (TDT) The shortest time needed to kill all organisms in a microbial suspension at a specific temperature and under defined conditionsThursday, September 15, 2011
  27. 27. PHYSICAL METHODS: HEAT Thermal Death Point (TDP) The lowest temperature at which a microbial suspension in killed in 10 minutes Thermal Death Time (TDT) The shortest time needed to kill all organisms in a microbial suspension at a specific temperature and under defined conditionsThursday, September 15, 2011
  28. 28. However, such a destruction is logarithmic and it is theoretically NOT POSSIBLE to “completely destroy” microbes in a sampleThursday, September 15, 2011
  29. 29. However, such a destruction is logarithmic and it is theoretically NOT POSSIBLE to “completely destroy” microbes in a sampleThursday, September 15, 2011
  30. 30. However, such a destruction is logarithmic and it is theoretically NOT POSSIBLE to “completely destroy” microbes in a sample Decimal Reduction Time or D value Time required to kill 90% of the microorganisms or spores in a sample at a specified temperature Time required for the line to drop by one log cycle or tenfold Used to estimate the relative resistance of a microbe to different temperaturesThursday, September 15, 2011
  31. 31. PHYSICAL METHODS: HEATThursday, September 15, 2011
  32. 32. PHYSICAL METHODS: HEATThursday, September 15, 2011
  33. 33. PHYSICAL METHODS: HEAT z Value The increase in temperature required to reduce D to 1/10 its value or to reduce it by one log cycleThursday, September 15, 2011
  34. 34. PHYSICAL METHODS: HEAT z Value The increase in temperature required to reduce D to 1/10 its value or to reduce it by one log cycle F value Time in minutes at a specific temperature needed to kill a population of cells or spores Usually 121°CThursday, September 15, 2011
  35. 35. APPLICATION: FOOD INDUSTRYThursday, September 15, 2011
  36. 36. APPLICATION: FOOD INDUSTRYThursday, September 15, 2011
  37. 37. APPLICATION: FOOD INDUSTRY After a food have been canned, it must be heated to eliminate the risk of botulism arising from the presence of Clostridium sporesThursday, September 15, 2011
  38. 38. APPLICATION: FOOD INDUSTRY After a food have been canned, it must be heated to eliminate the risk of botulism arising from the presence of Clostridium spores Example: (1012 to 100 spores) IF the D value = 0.204 minutes It would take 12D or 2.5 minutes to reduce the spore number by heating at the specified temperatureThursday, September 15, 2011
  39. 39. APPLICATION: FOOD INDUSTRYThursday, September 15, 2011
  40. 40. APPLICATION: FOOD INDUSTRYThursday, September 15, 2011
  41. 41. APPLICATION: FOOD INDUSTRY If the z value for Clostridium spores is 10°CThursday, September 15, 2011
  42. 42. APPLICATION: FOOD INDUSTRY If the z value for Clostridium spores is 10°C It takes a 10°C change in temperature to alter the D value tenfoldThursday, September 15, 2011
  43. 43. APPLICATION: FOOD INDUSTRY If the z value for Clostridium spores is 10°C It takes a 10°C change in temperature to alter the D value tenfoldThursday, September 15, 2011
  44. 44. APPLICATION: FOOD INDUSTRY If the z value for Clostridium spores is 10°C It takes a 10°C change in temperature to alter the D value tenfold THUS: if the cans are to be processed at 111°C rather than 121°C, the D value would increase by tenfold t 2.04 minutesThursday, September 15, 2011
  45. 45. APPLICATION: FOOD INDUSTRY If the z value for Clostridium spores is 10°C It takes a 10°C change in temperature to alter the D value tenfold THUS: if the cans are to be processed at 111°C rather than 121°C, the D value would increase by tenfold t 2.04 minutes The 12D value = 24.5 minutesThursday, September 15, 2011
  46. 46. PHYSICAL METHODS: HEAT (MOIST HEAT STERILIZATION)Thursday, September 15, 2011
  47. 47. PHYSICAL METHODS: HEAT (MOIST HEAT STERILIZATION)Thursday, September 15, 2011
  48. 48. PHYSICAL METHODS: HEAT (Dry Heat Sterlization) Hot-air Autoclave Equivalent treatments 170˚C, 2 hr 121˚C, 15 minThursday, September 15, 2011
  49. 49. PHYSICAL METHODS: HEAT (Dry Heat Sterlization) Hot-air Autoclave Equivalent treatments 170˚C, 2 hr 121˚C, 15 minThursday, September 15, 2011
  50. 50. PHYSICAL METHODS: HEAT (Dry Heat Sterlization) Flaming Hot-air Autoclave Equivalent treatments 170˚C, 2 hr 121˚C, 15 minThursday, September 15, 2011
  51. 51. PHYSICAL METHODS: HEAT (Dry Heat Sterlization) Flaming Hot-air Autoclave Equivalent treatments 170˚C, 2 hr 121˚C, 15 minThursday, September 15, 2011
  52. 52. PHYSICAL METHODS: HEAT (Dry Heat Sterlization) Flaming Incineration Hot-air Autoclave Equivalent treatments 170˚C, 2 hr 121˚C, 15 minThursday, September 15, 2011
  53. 53. PHYSICAL METHODS: HEAT (Dry Heat Sterlization) Flaming Incineration Hot-air Autoclave Equivalent treatments 170˚C, 2 hr 121˚C, 15 minThursday, September 15, 2011
  54. 54. PHYSICAL METHODS: HEAT (Dry Heat Sterlization) Flaming Incineration Hot-air sterilization Hot-air Autoclave Equivalent treatments 170˚C, 2 hr 121˚C, 15 minThursday, September 15, 2011
  55. 55. HOW DOES HEAT KILL MICROBESThursday, September 15, 2011
  56. 56. HOW DOES HEAT KILL MICROBESThursday, September 15, 2011
  57. 57. HOW DOES HEAT KILL MICROBES MOIST HEAT Kill effectively by degradation of nucleic acids and by denaturation of enzymes and other essential proteins May also disrupt cell membranesThursday, September 15, 2011
  58. 58. HOW DOES HEAT KILL MICROBES MOIST HEAT Kill effectively by degradation of nucleic acids and by denaturation of enzymes and other essential proteins May also disrupt cell membranesThursday, September 15, 2011
  59. 59. HOW DOES HEAT KILL MICROBES MOIST HEAT Kill effectively by degradation of nucleic acids and by denaturation of enzymes and other essential proteins May also disrupt cell membranes DRY HEAT Microbial death results from the oxidation of cell constituents and denaturation of proteinsThursday, September 15, 2011
  60. 60. PHYSICAL METHODS: FILTRATION Applicable for heat-sensitive materials that needs sterilization Types of filters Depth filters: consist of fibrous or granular materials that have been bonded into a thick layer filled with twisting channels of small diameter Membrane filters: porous membranes; 0.2 µm pore sizesThursday, September 15, 2011
  61. 61. PHYSICAL METHODS: FILTRATION Applicable for heat-sensitive materials that needs sterilization Types of filters Depth filters: consist of fibrous or granular materials that have been bonded into a thick layer filled with twisting channels of small diameter Membrane filters: porous membranes; 0.2 µm pore sizesThursday, September 15, 2011
  62. 62. PHYSICAL METHODS: FILTRATION Laminar flow hood versus biological safety cabinets (HEPA filters) High Efficiency Particulate Air Remove 99.97% particles 0.02 µm for sterilizing AIRThursday, September 15, 2011
  63. 63. PHYSICAL METHODS: FILTRATION Laminar flow hood versus biological safety cabinets (HEPA filters) High Efficiency Particulate Air Remove 99.97% particles 0.02 µm for sterilizing AIRThursday, September 15, 2011
  64. 64. BIOSAFETY CABINETS Class1 (from room=outside) protection: person and environment Class 2 (Type A and B) ) Type A and B: product, person and environment difference: type A air is recirculated back to room, type B exhausted outside the building Class 3: contained facility, higher level of protection and containmentThursday, September 15, 2011
  65. 65. BIOSAFETY CABINETS Class1 (from room=outside) protection: person and environment Class 2 (Type A and B) ) Type A and B: product, person and environment difference: type A air is recirculated back to room, type B exhausted outside the building Class 3: contained facility, higher level of protection and containmentThursday, September 15, 2011
  66. 66. PHYSICAL METHODS: RADIATION IONIZING RADIATION X rays, gamma rays, electron beams Excellent as a sterilizing agent and penetrates deep into objects NON-IONIZING RADIATION UV (about 260nm) Quite lethal but does not penetrate glass, dirt films, water and other substances very effectively Microwaves: kill by heat not usually antimicrobialThursday, September 15, 2011
  67. 67. PHYSICAL METHODS: RADIATION IONIZING RADIATION X rays, gamma rays, electron beams Excellent as a sterilizing agent and penetrates deep into objects NON-IONIZING RADIATION UV (about 260nm) Quite lethal but does not penetrate glass, dirt films, water and other substances very effectively Microwaves: kill by heat not usually antimicrobialThursday, September 15, 2011
  68. 68. Thursday, September 15, 2011
  69. 69. CHEMICAL AGENTSThursday, September 15, 2011
  70. 70. CHEMICAL METHODS PHENOLICS QUATERNARY AMMONIUM ALCOHOLS COMPOUNDS ALDEHYDES HALOGENS STERILIZING HEAVY METALS GASESThursday, September 15, 2011
  71. 71. CHEMICAL METHODS PHENOLICS QUATERNARY AMMONIUM ALCOHOLS COMPOUNDS ALDEHYDES HALOGENS STERILIZING HEAVY METALS GASESThursday, September 15, 2011
  72. 72. CHEMICAL METHODS Chemical agent Effectiveness against Endospores Mycobacteria Phenolics Poor Good Quats None None Chlorines Fair Fair Alcohols Poor Good Glutaraldehyde Fair GoodThursday, September 15, 2011
  73. 73. CHEMICAL METHODS Chemical agent Effectiveness against Endospores Mycobacteria Phenolics Poor Good Quats None None Chlorines Fair Fair Alcohols Poor Good Glutaraldehyde Fair GoodThursday, September 15, 2011
  74. 74. CHEMICAL METHODS: Phenolics First widely used antiseptic and disinfectant Joseph Lister (1867): reduced the risk of infection during operations Example: LYSOLR Act by denaturing proteins and disrupting cell membranesThursday, September 15, 2011
  75. 75. CHEMICAL METHODS: Phenolics First widely used antiseptic and disinfectant Joseph Lister (1867): reduced the risk of infection during operations Example: LYSOLR Act by denaturing proteins and disrupting cell membranesThursday, September 15, 2011
  76. 76. Disruption of Cell MembranesThursday, September 15, 2011
  77. 77. CHEMICAL METHODS: Phenolics ADVANTAGES: effective in the presence of organic material and remain active on surfaces long after application DISADVANTAGE: disagreeable odor and can cause skin irritation and in some instances brain damage (hexachlorophene)Thursday, September 15, 2011
  78. 78. CHEMICAL METHODS: Phenolics ADVANTAGES: effective in the presence of organic material and remain active on surfaces long after application DISADVANTAGE: disagreeable odor and can cause skin irritation and in some instances brain damage (hexachlorophene)Thursday, September 15, 2011
  79. 79. CHEMICAL METHODS: Alcohols Widely used disinfectant and antiseptics Bactericidal and fungicidal but not sporicidal May not destroy lipid-containing virusesThursday, September 15, 2011
  80. 80. CHEMICAL METHODS: Alcohols Widely used disinfectant and antiseptics Bactericidal and fungicidal but not sporicidal May not destroy lipid-containing virusesThursday, September 15, 2011
  81. 81. DENATURES PROTEINS, DISSOLVES LIPIDSThursday, September 15, 2011
  82. 82. CHEMICAL METHODS: Alcohols Example: ethanol and isopropanol (70-80% concentration) Act by denaturing proteins and possibly by dissolving membrane lipids 10-15 soaking in alcohol is sufficient to disinfect thermometers and small instrumentsThursday, September 15, 2011
  83. 83. CHEMICAL METHODS: Alcohols Example: ethanol and isopropanol (70-80% concentration) Act by denaturing proteins and possibly by dissolving membrane lipids 10-15 soaking in alcohol is sufficient to disinfect thermometers and small instrumentsThursday, September 15, 2011
  84. 84. CHEMICAL METHODS: Halogens Iodine Kills by oxidizing cell constituents and iodinating cell proteins Kill spores at high concentrations DISADVANTAGE: a stain may be left (answer = iodophor)Thursday, September 15, 2011
  85. 85. CHEMICAL METHODS: Halogens Iodine Kills by oxidizing cell constituents and iodinating cell proteins Kill spores at high concentrations DISADVANTAGE: a stain may be left (answer = iodophor)Thursday, September 15, 2011
  86. 86. CHEMICAL METHODS: Halogens Chlorine Usually for water supply Kills by oxidation of cellular materials and destruction of vegetative bacteria, fungi Will not kill spores Death within 30 minutesThursday, September 15, 2011
  87. 87. CHEMICAL METHODS: Halogens Chlorine Usually for water supply Kills by oxidation of cellular materials and destruction of vegetative bacteria, fungi Will not kill spores Death within 30 minutesThursday, September 15, 2011
  88. 88. CHEMICAL METHODS: Heavy Metals Mercury, Arsenic, Zinc, Copper Used as germicides How do they Kill: Heavy metals combine with proteins, often with their sulfhydryl groups and inactivate them May also precipitate cell proteinsThursday, September 15, 2011
  89. 89. CHEMICAL METHODS: Heavy Metals Mercury, Arsenic, Zinc, Copper Used as germicides How do they Kill: Heavy metals combine with proteins, often with their sulfhydryl groups and inactivate them May also precipitate cell proteinsThursday, September 15, 2011
  90. 90. CHEMICAL METHODS: Quats DETERGENTS Amphipathic (both polar and non-polar ends) Kill by disrupting microbial membranes and denature proteins ADVANTAGE: stable, non-toxic DISADVANTAGE: inactivated by hardThursday, September 15, 2011
  91. 91. CHEMICAL METHODS: Quats DETERGENTS Amphipathic (both polar and non-polar ends) Kill by disrupting microbial membranes and denature proteins ADVANTAGE: stable, non-toxic DISADVANTAGE: inactivated by hardThursday, September 15, 2011
  92. 92. Soap Degerming Surface-Active Agents or Surfactants Acid-anionic Sanitizing detergents Quarternary Bactericidal, Denature ammonium proteins, disrupt compounds plasma membrane Cationic detergentsThursday, September 15, 2011
  93. 93. CHEMICAL METHODS: Aldehydes FORMALDEHYDES Very reactive molecules that combine with proteins and inactivate them Sporicidal and can be used as sterilantsThursday, September 15, 2011
  94. 94. CHEMICAL METHODS: Aldehydes FORMALDEHYDES Very reactive molecules that combine with proteins and inactivate them Sporicidal and can be used as sterilantsThursday, September 15, 2011
  95. 95. EVALUATION OF ANTIMICROBIAL AGENT EFFECTIVENESS PHENOL COEFFICIENT TEST Best-known disinfectant screening test Potency of a disinfectant is compared with that of phenol The highest dilution that killed bacteria after a 10 minutes exposure are used to calculate phenol coefficientThursday, September 15, 2011
  96. 96. EVALUATION OF ANTIMICROBIAL AGENT EFFECTIVENESS PHENOL COEFFICIENT TEST Best-known disinfectant screening test Potency of a disinfectant is compared with that of phenol The highest dilution that killed bacteria after a 10 minutes exposure are used to calculate phenol coefficientThursday, September 15, 2011
  97. 97. CALCULATING PHENOL COEFFICIENTS The reciprocal of the appropriate test disinfectant dilution is divided by that for phenol to obtain the coefficient Example: phenol dilution = 1/90 and the maximum effective dilution for disinfectant X = 1/450 Phenol coefficient = 5Thursday, September 15, 2011
  98. 98. CALCULATING PHENOL COEFFICIENTS The reciprocal of the appropriate test disinfectant dilution is divided by that for phenol to obtain the coefficient Example: phenol dilution = 1/90 and the maximum effective dilution for disinfectant X = 1/450 Phenol coefficient = 5Thursday, September 15, 2011
  99. 99. CALCULATING PHENOL COEFFICIENTS The higher the phenol coefficient value, the more effective the disinfectant under this conditionsThursday, September 15, 2011
  100. 100. CALCULATING PHENOL COEFFICIENTS The higher the phenol coefficient value, the more effective the disinfectant under this conditionsThursday, September 15, 2011
  101. 101. DILUTION TESTS Metal rings dipped in test bacteria are dried Dried cultures placed in disinfectant for 10 min at 20°C Rings transferred to culture media to determine whether bacteria survived treatmentThursday, September 15, 2011
  102. 102. DILUTION TESTS Metal rings dipped in test bacteria are dried Dried cultures placed in disinfectant for 10 min at 20°C Rings transferred to culture media to determine whether bacteria survived treatmentThursday, September 15, 2011
  103. 103. DISK-DIFFUSION METHODThursday, September 15, 2011
  104. 104. DISK-DIFFUSION METHODThursday, September 15, 2011
  105. 105. CHEMOTHERAPEUTIC AGENTSThursday, September 15, 2011
  106. 106. CHEMOTHERAPEUTIC AGENTSThursday, September 15, 2011
  107. 107. CHEMOTHERAPEUTIC AGENTS Antibiotics are medicines used to treat infections caused by bacteria only Infections are usually caused by bacteria or viruses Antibiotics, therefore, do not cure all infections Many infections like the common cold, flu, mild sore throat or diarrhea are caused by virusesThursday, September 15, 2011
  108. 108. CHEMOTHERAPEUTIC AGENTS Antibiotics are medicines used to treat infections caused by bacteria only Infections are usually caused by bacteria or viruses Antibiotics, therefore, do not cure all infections Many infections like the common cold, flu, mild sore throat or diarrhea are caused by virusesThursday, September 15, 2011
  109. 109. Thursday, September 15, 2011
  110. 110. WHAT IF ANTIBIOTICS WERE USED INCORRECTLY? No healing effect - If antibiotics are used for viral infections, there will be no effect on the illness Antibiotic resistance - This occurs when one antibiotic no longer works on a specific type of bacteria A stronger antibiotic will be needed to treat the infection caused by this resistant strain of bacteriaThursday, September 15, 2011
  111. 111. WHAT IF ANTIBIOTICS WERE USED INCORRECTLY? No healing effect - If antibiotics are used for viral infections, there will be no effect on the illness Antibiotic resistance - This occurs when one antibiotic no longer works on a specific type of bacteria A stronger antibiotic will be needed to treat the infection caused by this resistant strain of bacteriaThursday, September 15, 2011
  112. 112. ANTIBIOTIC MECHANISMSThursday, September 15, 2011
  113. 113. ANTIBIOTIC MECHANISMSThursday, September 15, 2011
  114. 114. RESISTANCEThursday, September 15, 2011
  115. 115. RESISTANCEThursday, September 15, 2011
  116. 116. RESISTANCEThursday, September 15, 2011
  117. 117. RESISTANCEThursday, September 15, 2011
  118. 118. DO YOU CONTRIBUTE TO RESISTANCE?Thursday, September 15, 2011
  119. 119. DO YOU CONTRIBUTE TO RESISTANCE?Thursday, September 15, 2011
  120. 120. DO YOU CONTRIBUTE TO RESISTANCE?Thursday, September 15, 2011
  121. 121. DO YOU CONTRIBUTE TO RESISTANCE?Thursday, September 15, 2011
  122. 122. DO YOU CONTRIBUTE TO RESISTANCE? Another factor that contributes to resistance is that when patients are prescribed antibiotics for a just cause, many do not finish their medication This allows resistant bacteria to survive more easily The practice of saving unused medication to treat themselves or others at a later date can also lead to resistant strainsThursday, September 15, 2011
  123. 123. DO YOU CONTRIBUTE TO RESISTANCE?Thursday, September 15, 2011
  124. 124. DO YOU CONTRIBUTE TO RESISTANCE?Thursday, September 15, 2011
  125. 125. DO YOU CONTRIBUTE TO RESISTANCE? Also contributing to antibiotic resistance is the widespread use of antibiotics to promote weight gain and to control disease in cattle, pigs, and chickens Forty to fifty percent of antibiotics produced are used in livestock feed This leads to an increase of resistant bacteria in these animals, which is then spread to humansThursday, September 15, 2011
  126. 126. ANY QUESTIONS???Thursday, September 15, 2011
  127. 127. NEXT MEETING: INTERACTIVE LECTURE/ QUIZ ON METABOLISMThursday, September 15, 2011
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