Exam 1: Sterilization, Disinfection, Decontamination

Question 1

What is sterilization?

Answer 1

The removing or killing of all microbes on an object or in any material (killing spores)

Question 2

What does killing mean?

Answer 2

Making microbes unable to grow or reproduce even under the most favorable growth conditions

Question 3

What does sterile mean?

Answer 3

Totally devoid of life, all cells are dead

Question 4

What is the limiting requirement of sterilization?

Answer 4

Destruction of bacterial endospores, the most resistant form of life

Question 5

What is disinfection?

Answer 5

The process of reduction or elimination of pathogenic microbes in or on materials so they are no longer a hazard
Some living microbes may persist

Question 6

Is disinfection sterilization?

Answer 6

No

Question 7

What are disinfections?

Answer 7

Chemical agents used on inanimate objects

Question 8

What are antiseptics?

Answer 8

Relatively nontoxic chemical agents used on animals or people

Question 9

What is decontamination?

Answer 9

The same as disinfection but implies a broader role including inactivation or removal of microbial toxins and pathogens

Question 10

What does germicide/germicidal refer to?

Answer 10

An agent capable of killing most microbes rapidly

Question 11

What may be an agent that is germicidal?

Answer 11

Bactericidal, sporicidal, fungicidal, or viricidal

Question 12

What do bacteriostatic and fungistatic indicate?

Answer 12

That the antimicrobial agents is primarily inhibitory in its action; they prevent growth without killing

Question 13

What is preservation?

Answer 13

The prevention of multiplication of microorganisms in formulated products, including pharmaceuticals and foods

Question 14

What are simple methods for preventing exposure to undesirable microbes?

Answer 14

Mechanical removal- washing and scrubbing
Cooking food
Maintain normal flora

Question 15

Is boiling sterilization? Why?

Answer 15

No. It does not kill spores

Question 16

What are physical methods to control microbes?

Answer 16

Heat
Radiation
Filtration

Question 17

What are the 4 ways that heat is used to destroy microbes?

Answer 17

Boiling water or steam at 100 degrees C
Dry heat at 160-170 degrees C for 1 hr or 145 degrees C for 4 hrs.
Autoclaving
Pasteurization

Question 18

Is dry heat sterilization?

Answer 18

Yes

Question 19

What is the most effective and commonly used method to achieve sterilization?

Answer 19

Autoclaving

Question 20

Describe autoclaving

Answer 20

A temperature of 121 degrees C is attained when steam is at 15 psi pressure
15 minutes is effective for instrument sterilization, but longer times may be needed for media or other liquids

Question 21

Is pasteurization sterilization?

Answer 21

No

Question 22

What is UV light used to do?

Answer 22

Combat air-borne infections and contaminants

It is effective against vegetative cells, but some spores are resistant

Question 23

What is ionizing radiation commonly used to do?

Answer 23

Sterilize many items, including foods and almost all disposable medical devices

Question 24

What is filtration used to do?

Answer 24

Sterilize bacteriologic media, serum, injection fluids, and solutions or other heat sensitive

Question 25

What filter should be used in filtration?

Answer 25

One with a pore size of 0.45 μm or less to remove all bacteria (except mucoplasmas) from solutions

Question 26

Do filters remove viruses?

Answer 26

No, but they are used to separate bacterial from viruses for viral culture

Question 27

List bacteria that are resistant to disinfectants and antiseptics from most resistant to least

Answer 27

Spores Mycobateria (acid-fast gram-positives) Gram negative bacteria Gram positive bacteria

Question 28

How do antiseptics and disinfectant differ from antibiotics?

Answer 28

Have a broader spectrum of activity | May have multiple targets in or on the bacterial cell

Question 29

What are the major groups of chemical disinfectants?

Answer 29

``` Alcohols Ethylene oxide gas Aldehydes Halogens Phenolic compounds Quarternary ammonium compounds Biguanide compounds Peroxygens Silver compounds Mercurials Soaps or anionic detergents ```

Question 30

Describe alcohols

Answer 30

Rapidly bactericidal, including many acid-fast organisms, but are not sporicidal Widely used for hard-surface decontamination and skin antisepsis Antimicrobial activity is optimal in the 60-90% range

Question 31

Describe ethylene oxide gas

Answer 31

Sporicidal It is mutagenic and explosive Requires a long aeration time

Question 32

What are the different types of aldehydes?

Answer 32

Glutaraldehyde | Formaldehyde

Question 33

What is glutaraldehyde?

Answer 33

The most bactericidal compound available

Question 34

Describe glutaraldehyde

Answer 34

Broad spectrum activity against bacteria, spores, fungi, and viruses Has good mycobactericidal activity Used for low-temperature disinfection of endoscopes and surgical instruments

Question 35

Describe formaldehyde

Answer 35

Sporicidal, but require long exposure time | Mixed with alcohols it is the most effective instrument soak available

Question 36

What are the different halogens?

Answer 36

``` Sodium hypochlorite (bleach) Aqueous or alcoholic solutions of iodine (tincture) Iodophors (povidone-iodine) ```

Question 37

What is sodium hypochlorite used for?

Answer 37

Hard surface decontamination

Question 38

What are aqueous or alcoholic solutions of iodine?

Answer 38

Rapidly bactericidal, sporicidal, and fungicidal, but they are unstable and associated with irritation and excessive staining

Question 39

What are iodophors?

Answer 39

Complexes of iodine with a solubilizing agent | They are more stable, but considered less active against spores and fungi

Question 40

What are phenolic compounds used as?

Answer 40

Antiseptics Disinfectants Preservatives

Question 41

What is highly resistant to phenolic compounds?

Answer 41

Mycobacterium

Question 42

What is the oldest known disinfectant?

Answer 42

Phenol

Question 43

What are examples of phenolic compounds?

Answer 43

Chloroxylenol | Triclosan

Question 44

What is chloroxylenol?

Answer 44

A broad spectrum antimicrobial effective against bacteria, fungi, and viruses

Question 45

What is triclosan?

Answer 45

Widely used in antiseptic soaps and hand rinses | Especially effective against gram-positives

Question 46

What are quarternary ammonium compounds?

Answer 46

Nitrogenous cationic surface active agents used for preoperative disinfections of unbroken skin, application to mucosal membranes, and disinfection of non-critical surfaces Also used for cleaning and deodorization Not sporicidal or mycobactericidal

Question 47

When do quarternary ammonium compounds not work?

Answer 47

When they come into contact with organic material

Question 48

What is the most widely used thing in antiseptic products, in particular in handwashing and oral products?

Answer 48

The biguanide, chlorhexidine

Question 49

Describe biguanide compounds

Answer 49

Bactericidal with broad-spectrum efficacy | Not mycobactericidal or sporicidal

Question 50

Describe peroxygens

Answer 50

Widely used for disinfection and antisepsis Has broad-spectrum activity Bacterial expression of catalase or other peroxidases can increase tolerance Higher concentrations and longer exposure times are required for sporicidal activity

Question 51

What are silver compounds used to do?

Answer 51

Prevent infection of burns and some eye infections

Question 52

What are the types of acquired resistance to antiseptics and disinfectants?

Answer 52

Mutation Gene acquisition Physiologic adaptation

Question 53

What has increased resistance to antiseptics and disinfectants? What is this an examples of?

Answer 53

Bacteria in biofilms | Physiologic adaptation