Antibacterial protocols 7.2 Disinfectants

Question 1

With disinfection, what is destroyed and what survives?

Answer 1

Microbes are destroyed but more resilient organisms survive

Question 2

Effectiveness of disinfection is influenced by what 5 things?

Answer 2

1. the nature of item to be disinfected
2. number and resilience of the contaminating organisms
3. amount of organic material present (which inactivates disinfectant)
4. type and concentration of disinfectant
5. duration and temperature of exposure

Question 3

High-level disinfectants are used for items for invasive procedures that cannot withstand? Ex?

Answer 3

sterilization procedures
Ex: certain types of endoscopes and surgical instruments with plastic or other
components that cannot be autoclaved

Question 4

High-level disinfectants are most effective if?

Answer 4

if the surface is cleaning or organic material removed before disinfecting it

Question 5

examples of High-level disinfectants?

Answer 5

moist heat, glutaraldehyde, hydrogen peroxide, peracetic acid, and chlorine compounds

Question 6

examples of Intermediate-level disinfectants?

Answer 6

alcohols, iodophor compounds, phenolic compounds

Question 7

Intermediate-level disinfectants are used for surfaces or instruments where? Examples?

Answer 7

with semicritical instruments or where contamination with spores and highly resilient organisms is unlikely
* flexible fiberoptic endoscopes, laryngoscopes, vaginal specula, anesthesia breathing circuits

Question 8

examples of Low-level disinfectants

Answer 8

quaternary ammonium compounds

Question 9

Low-level disinfectants are used to treat? Examples

Answer 9

noncritical instruments and devices

* blood pressure cuffs, electrocardiogram electrodes, and stethoscopes

Question 10

Low-level disinfectanted items are non-critical, this means?

Answer 10

they do not penetrate through mucosal surfaces or into sterile tissues

Question 11

Moist Heat attempts to sterilize items using? Inefficient because? What is killed and what survives?

Answer 11

boiling water

• inefficient because only a temperature (100° C) can be maintained
• kills vegetative organisms, spores survive

Question 12

How does moist heat kill?

Answer 12

causes denaturation of microbial proteins

Question 13

do NOT confuse moist heat with?

Answer 13

autoclave. Whihc is steam under pressure and VERY effective, kills spores

Question 14

What color is Ethylene Oxide?
soluble in?
sterilizes?
aeration period?

Answer 14

1) colorless gas
2) soluble in water and common organic solvents
3) sterilize heat-sensitive items
4) 16 hours or longer

Question 15

Ethylene Oxide sporicidal activity is through?

Answer 15

alkylation of terminal hydroxyl, carboxyl, amino, and sulfhydryl groups

Question 16

Why must Ethylene Oxide be dissipated before the item can be used?

Answer 16

Because ethylene oxide can damage viable tissues

Question 17

Aldehydes exert their effect through?
vapors are?
Used how often?
toxic to?

Answer 17

effect through alkylation
Vapors may be carcinogenic
rarely used in health care settings
toxic to exposed kin/mucous membranes

Question 18

Best known Aldehydes?
Which one is less toxic?
Which one can be toxic to skin?

Answer 18

formaldehyde and glutaraldehyde

• *glutaraldehyde is less toxic
• *formaldehyde can be toxic to skin and mucous membranes

Question 19

Examples of Oxidizing Agents?

Answer 19

ozone, peracetic acid, and hydrogen

peroxide

Question 20

Hydrogen peroxide effectively kills most bacteria and spores at what % conc.?

Answer 20

bacteria= 3% to 6%
spore= 10% to 25%

Question 21

The active oxidant form is not hydrogen peroxide but rather the?

Answer 21

free hydroxyl radical formed by the decomposition of hydrogen peroxide

Question 22

Hydrogen peroxide is used to disinfect?

Answer 22

plastic implants, contact lenses, and surgical prostheses

Question 23

Disinfecting halogen compounds contain? Used how often?

Answer 23

iodine or chlorine, are used extensively

Question 24

What are the most effective halogens? why?

Answer 24

iodine

*It is a highly reactive element that precipitates proteins and oxidizes essential enzymes

Question 25

Iodine is microbial against?

Answer 25

virtually all organisms, including spore-forming bacteria and mycobacteria

Question 26

What is the most commonly and used iodine? why?

Answer 26

Povidone iodine (iodine complexed with polyvinylpyrrolidone)
*relatively stable and nontoxic to tissues and metal surfaces

Question 27

What are the 3 forms of chlorine that may be present in water?

Answer 27

1. elemental chlorine (Cl2), which is a very strong oxidizing agent
2. hypochlorous acid (HOCl)
3. 3 hypochlorite ion (OCl2)

Question 28

Chlorine can exert its effect by the irreversible oxidation of?

Answer 28

sulfhydryl (SH) groups of essential enzymes

Question 29

Hypochlorites interact with cytoplasmic components to form?

Answer 29

toxic Nchloro compounds, which interfere with cellular metabolism

Question 30

Chlorine compounds demonstrate good germicidal activity, although spore forming organisms are 10- to 1000-fold more resistant?

Answer 30

than vegetative bacteria

Question 31

Phenolic Compounds

1) are rarely used as?
2) is not sporical at?
3) bisphenols are what?

Answer 31

1) raraly used as disinfectants
2) not sporicidal at room temperature
3) teo phenol compounds linked together

Question 32

Phenol is believed to act by disrupting?

Answer 32

lipid-containing membranes, resulting in leakage of cellular contents

Question 33

An example of halogenated bisphenol? What does it do?

Answer 33

hexachlorophene

*an antiseptic with activity against gram-positive bacteria

Question 34

Quaternary Ammonium Compounds

1) Made up of?
2) Act by denaturing?

Answer 34

1) 4 organic groups covalently linked to nitrogen

2) denaturing cell membranes to release the intracellular components

Question 35

Examples of Quaternary Ammonium Compounds?

Answer 35

benzalkonium chloride and cetylpyridinium chloride

Question 36

What is resistant to Quaternary Ammonium Compounds?

Answer 36

Many viruses and all bacterial spores are resistant.

*Pseudomonas, Mycobacterium, and the fungus Trichophyton are resistant

Question 37

What are the two most commonly used alcohols for disinfection?

Answer 37

ethanol and isopropanol

Question 38

alcohol is rapidly bactericidal against?

Answer 38

vegetative bacteria, mycobacteria, some fungi, and lipid-containing viruses

Question 39

alcohol has NO activity against?

Answer 39

bacterial spores! and have poor activity against some fungi and non–lipid containing viruses

Question 40

alcohol germicidal activity increases with?

Answer 40

Germicidal activity increases with increasing chain length (maximum of five to eight carbons)

Question 41

alcohol acivity is great in the presense of?

Answer 41

water

*Thus 70% alcohol is more active than 95% alcohol

Question 42

alcohol is common disinfectant for?

Answer 42

skin surfaces (thermometers
*when followed by treatment with an iodophor, it is extremely effective for cleansing skin