Micro 22 Unit 3 Chapter 7

Front 1

Sepsis (Greek for decay or putrid)

Back 1

Bacterial Contamination as in (septic tank)

Front 2

Asepsis

Back 2

the absence of significant contamination

Front 3

Sterilization

Back 3

- the removal or destruction of al lliving microorganisms, including endospores but with the possible exceptions of prions

- steam autoclave

Front 4

Sterilant

Back 4

- a sterilizing agent

Front 5

sterile

Back 5

a characteristic of being free of all living things

Front 6

Commercial Sterilization

Back 6

- limited heat treatment to food, just enough to kill endospores of that produce a deadly toxin

Front 7

Disinfection

Back 7

Destruction of vegetative pathogens on inanimate objects

- may use chemical, ultraviolet radiation, boiling water, or steam

- cavicide

Front 8

a disinfectant

Back 8

a chemical used to treat an inert surface or substance in order to destroy vegetative pathogens

Front 9

Antisepsis

Back 9

Destruction of vegetative pathogens on living tissues

- treatment is almost always by chemical antimicrobials

Front 10

an antiseptic

Back 10

a chemical used to treat living tissue in order to destroy vegetative pathogens

- betadine

Front 11

Degerming

Back 11

Removal of microbes from a limited area, such as the skin around an injection site.

- mostly a mechanical removal by an alcohol-soaked swab

Front 12

Sanitization

Back 12

Treatment is intended to lower microbial counts on eating and drinking utensiles to safe public health levels

- may be done with high-temp washing or dipping into a chemical disinfectant

Front 13

- cide

Back 13

- suffix of treatments that cause the outright death of microbes

-ie. virucide: inactivates viruses

germicide/biocide: kills microorganisms

fungicide: kills fungi

Front 14

- stasis

Back 14

- suffix of treatments that inhibit the growth and multiplication of microbes

- many important control methods are static rather than cidal

- fungistatic

-bacteriostatic

Front 15

Describe the patterns of microbial death caused by treatments with microbial control agents

Back 15

- Bacterial populations usually die at a constant rate when heated or when treated with antimicrobial agents, microbes die at a logarithmic rate, not all the same time

- it is necessary to use logarithmic numbers to graph baceterial populations effecetively

Front 16

Explain what is meant by the statement: Bacterial populations usually die at a constant rate

Back 16

This means that the same percentage of survivors dies during each equal time period (they do not all die at the same time)

Front 17

Describe the generalized effects of microbial control agents on cellular structures

Back 17

1. Alteration of Membrane Permeability: damage to lipids or proteins of the plasma membrane causes cellular contents to leak into the surrounding medium and interferes with growth of the cell

Front 18

Describe the generalized effects of microbial control agents on cellular structures

Back 18

2. Damage to Proteins of Nucleic Acids: the breaking of hydrogen bonds by heating or chemicals causes denaturation of proteins. Damage to the nucleic acids prevents cells from replication or creating enzymes.

Front 19

Moist Heat

Back 19

- moist heat kills microbes by coagulating proteins (denaturation) by breaking hydrogen bonds.

Front 20

Moist Heat: Boiling at 100° C

Back 20

- disinfection (cannot be relied upon to kill spores)

Front 21

Moist Heat: Flowing Steam at 100° C

Back 21

- disinfection (cannot be relied upon to kill spores)

Front 22

Moist Heat: Steam Under Pressure

Back 22

- the function of pressure is to raise boiling point of water

- sterilization: should kill spores, viruses, etc

- 15psi = 121° C for 15mins.

Front 23

Moist Heat: Pasteurization

Back 23

- eliminate microbes that cause spoilage and pathogenic microbes by heating.

Invented by Louis Pasteur.

Front 24

HTST Pasteurization of Milk

Back 24

High Temp Short Time:

minimum of 72° for 15 seconds (75° if sugar in product). Milk keeps well under refrigeration.

Front 25

UHT Treatments of Milk

Back 25

Ultra-High Tempetraure Treatments:

Sterilization of milk which allows for storage for several months without refrigeration

- 140° C for 4 seconds, packed in a presterilized containerie. used for coffee creamers in US

Front 26

Dry Heat (kills by oxidation effects)

Back 26

1. Direct Flaming: Sterilization

2. Incineration: Sterilization

3. Hot air oven: Sterilization (common run 170° for about 2 hrs)

- dry heat requires longer times because for same temp, it carries less heat.

Front 27

Filtration (separation of bacteria from suspending liquid)

Back 27

- passage of a liquid or gas through a screenlike material with pores small enough to retain microbes

- can get filters with specific pore sizes, most filters pass viruses

-ie. HEPA filters (High-efficiency particulate air)

Front 28

Cold: Low Temperatures (Static)

Back 28

- static for most organisms

- metabolic rate of most microbes so reduced that they cannot reproduce or synthesize toxins

Front 29

Refrigeration (Static)

Back 29

optimum remp is just above freezing (0-7° C)

- except for microbes that thrive in cold

Front 30

Freezing (Static)

Back 30

optimum temp for home freezer is 0° F or (-17°C)

Front 31

Drying (Dessication): Static

Back 31

- static for most organisms

- denies cell of moisture needed for growth

ie. clothing, bedding and fressing may contain infectious microbes in dried mucus, urine, pus and feces

Front 32

Listeria

Back 32

- one important exception of Pathogenic bacteria that can grow in refrigerator temperatures

Front 33

High Pressures (Disinfection)

Back 33

- disinfection

- alters molecular structures of proteins/carbohydrates results rapid inactivation of vegetative cells.

- a treatment that preserves flavors, colors and nutrient values of products

Front 34

Osmotic Pressure (Static)

Back 34

- high concentrations of salt or sugars which creates a hypertonic environment that causes water to leave the microbial cell.

- denies the cell moisture needed for growth

-ie. curing meats/preserving fruits

Front 35

Ionizing Radiation (Sterilization)

Back 35

- ionization of water, forms highly reactive hydroxyl radicals that kill organisms by reacting with DNA and damaging them

- destruction of DNA

X-rays: produced by beam of high voltage electrons

Gamma Rays: produced by decaying isotopes

- both have great penetration ability

Front 36

Nonionizing Radation (Ulra-Violet Light)

Back 36

- damages DNA

- optimum wave length: 260 nm

- poor penetrating ability

- used to disinfect vaccines/air

Front 37

MIcrowaves

Back 37

- do not have much direct effect

Front 38

DRAW OUT TABLE 7.5 (pg. 186)

Back 38

This is basically the whole fuckign chapter lol wtfcuk.

Front 39

Lyophilization

Back 39

- Decreases chemical reactions/changes in proteins

- Most effective method for long-term preservation; Process of water removal by a high vacuum at low temperatures

Front 40

tincture

Back 40

a solution with an alcohol solvent

ie. iodine tincture

Front 41

oligodynamic action

Back 41

- the ability of very small amounts of heavy metals to exert antimicrobial activity

- ie. silver, copper, zinc, and mercury

Front 42

List five factors related to effective disinfection

Back 42

1. kills all pathogens including spores and viruses

2. harmless to human or animal tissues

3. harmless to instruments and matericals (non corrosive/non staining)

4. good penetrating ability

5. works well at cool temperatures

6. nonflammable

7. has cleaning ability

8. has deodorizing ability

9. not inactivated by organic matter

10. good shelf life

11. low cost

Front 43

Contast -cidal vs. -static action of antimicrobial agents

Back 43

-cidal: kills microbes at a logarithmic rate

ie. cavicide

-static: prevents the growth of microbes

ie. freezing can prevent growth of bacteria, but if returned to normal temps then it will grow again

Front 44

Disinfectant vs. Antiseptic

Back 44

A disinfectant: is used to destroy vegetative pathogens on inanimate objects

An antiseptic: is used to destroy vegetative pathogens on living tissue

-both are usually chemicals

Front 45

Remember:

Gram-Negative bacteria are generally more resistant than Gram-Positive Bacteria to disinfectants and antispects. Prions, endospores of bacteria, mycobacteria and protozoan cysts and oocytes are very resistant. Organic matter (vomit and feces) frequently affectst the actions of chemical control agents, so the environment matters too.

Back 45

Gram-negative are more resistant

Front 46

Write/Draw out Table 7.8 for a summary of Chemica lConrol Methods covered in Lecture

Back 46

LOL OKAY.

Front 47

Phenol and Phenolics

Back 47

phenol = carbolic acid

- the first disinfectant/antiseptic, introduced by Joseph Lister

1. Phenol

2. Phenolics

3. Biphenols

- disruption of plasma membrane/denaturation of enzymes

Front 48

Biguanides (Chlorhexidine)

Back 48

- disruption of plasma membrane

- for skin and mucuous membranes (hand soaps and lotions)

Front 49

Halogens (Iodine)

Back 49

- Iodine inhibits protein function

Iodine: 3 forms

1. Aqueous

2. Tincture

3. Organics

Front 50

Halogens (chlorine)

Back 50

- chlorine alters cellular componencts

- bleach = sodium hypochlorite 5.25%

- used for water treatment

Front 51

Alcohols

Back 51

- protein denaturation and dissolves lipids

- ethanol (better)

- isopropanol (best)

- optimum concentration at 70%; higher concentration is less effection, action requires presence of some water

- do not kill bacterial spores or most viruses

Front 52

Heavy Metals

Back 52

- denaturation of enzymes and proteins

- oligodynamic action: Toxic effect of metal ions on microbes

- mercury, inactivated by organic matter

- silver nitrate - used on infant's eyes to prevent gonorrheal infection

- copper, zinc

Front 53

Surface-Active Agents

Back 53

1. Soaps and Detergents

2. Acid anionic sanitizers

3. Quaternary ammonium compouds (cationic detergents) - combine cleaning/disinfectant ability = good for gram + bacteria, fungi, protozoa but weak against gram - or spores

Surfactants decreases the surface tension of liquids, makes the mwetter and improves penetration and cleaning ability

Front 54

Oxidizing Agents (Peroxygens and Other Forms of OXygen)

Back 54

- various chemicals that release free oxygen (0)

hydrogen peroxide: H2O2 --> H2O + O

- effectively disinfects inanimate objects

peracetic acid: effective liquid sporicide and sterilant

ozone: O3 --> O2 + O

- Benzoyl peroxide

- used for Deep Wounds

Front 55

Dyes

Back 55

Crystal Violet

- more effective against Gram + than Gram - (used to treat candida albicans)

Front 56

Chemical Food Preservatives

Back 56

1. Organic Acids widely used to control molds and bacteria in food or cosmetics

2. Nitrates prevents growth of Clostridium botulinum in food; imparts red color.

Front 57

Aldehydes

Back 57

- Protein denaturation, verry effective antimicrobial for disinfecting medical equipment.

Front 58

Chemical Sterilization

Back 58

- Inhibits vital cellular functions (sterilization of materials that would be damaged by heat)

Front 59

Evaluation of Disinfectnats

Back 59

Disk-Diffusion Method

1. Inoculate agar plate with pathogen

2. Place paper discs dipped in different disinfectants on surface of agar

3. Incubate

4. Compare zones of inhibition