ANTISEPTICS AND DISINFECTANTS Flashcards

Question

Which statement is TRUE regarding the action of glutaraldehyde on protozoa? A. The mechanism of action is well-defined B. It acts primarily on the protozoan nucleus C. It enhances the germination of protozoa D. The mechanism of action is unknown

Answer 1

D. The mechanism of action is unknown Rationale: The exact mechanism by which glutaraldehyde affects protozoa is not clearly understood.

Answer 2

D. Destruction of the semipermeable character of the cytoplasmic membrane Rationale: TCC acts by adsorbing to and destroying the semipermeable character of the cytoplasmic membrane, leading to bacterial cell death.

Answer 3

A. Gram-positive bacteria Rationale: TCC is particularly active against gram-positive bacteria and less so against gram-negative bacteria.

Answer 4

C. Soaps and deodorants Rationale: TCC is extensively used in consumer soaps and deodorants due to its antimicrobial properties.

Answer 5

C. Cytoplasmic membrane Rationale: TCC targets the cytoplasmic membrane, disrupting its semipermeable nature and leading to bacterial cell death.

Answer 6

B. Gram-negative bacteria Rationale: Gram-negative bacteria have an extra outer membrane that can act as a barrier to many antimicrobial agents.

Answer 7

B. Resistance in bacteria Rationale: Overuse of antimicrobial agents can lead to the development of resistant bacterial strains.

Answer 8

B. Appreciable substantivity (persistency) Rationale: TCC does not have a long-lasting or persistent effect on the skin.

Answer 9

C. By adsorbing to and destroying the semi-permeable character of the cytoplasmic membrane Rationale: TCC's mechanism of action involves adsorbing to the cytoplasmic membrane and compromising its semi-permeable nature, leading to cell death.

Answer 10

C. Sunscreens Rationale: The content provided does not mention sunscreens in relation to TCC, while it does refer to soaps and deodorants, and by extension, products like shampoos and hand sanitizers could potentially contain TCC.

Answer 11

b) Chlorhexidine Rationale: Chlorhexidine is mentioned as the most widely used biocide in antiseptic products.

Answer 12

a) Spores Rationale: It's specified that Chlorhexidine is not sporicidal.

Answer 13

a) Ethylhexyl end groups Rationale: Alexidine differs from Chlorhexidine due to its ethylhexyl terminal groups.

Answer 14

b) Alexidine Rationale: Alexidine is noted for its use in contact lens cleansing.

Answer 15

c) Elevated temperatures Rationale: Bisbiguanide has a marked sporicidal effect on Bacillus spores at elevated temperatures.

Answer 16

a) Mycobacteriostatic Rationale: Chlorhexidine is mycobacteriostatic, meaning it inhibits their growth but doesn't kill them.

Answer 17

c) Polymeric Biguanides Rationale: Polymeric Biguanides are noted for their use in swimming pool sanitation.

Answer 18

a) Chlorhexidine Rationale: Chlorhexidine is a membrane-active agent that causes protoplast and spheroplast lysis in non-sporulating bacteria.

Answer 19

d) Lipid-enveloped viruses Rationale: Chlorhexidine is mainly active against lipid-enveloped viruses.

Answer 20

b) Contact lens cleanser Rationale: Alexidine, not Chlorhexidine, is used as a contact lens cleanser.

Answer 21

b) Chlorhexidine at high concentrations Rationale: At high concentrations, Chlorhexidine causes intracellular coagulation in yeast.

Answer 22

a) Polyhexamethylene biguanides (PHMB) Rationale: Vantocil is a mixture of polyhexamethylene biguanides (PHMB).

Answer 23

b) Prevents spore development Rationale: Chlorhexidine inhibits spore development but doesn't kill them (not sporicidal).

Answer 24

b) Chlorhexidine Rationale: Chlorhexidine's activity is pH-dependent and is greatly reduced in the presence of organic matter.

Answer 25

c) Lipid-enveloped viruses Rationale: Chlorhexidine does not inactivate non-enveloped viruses like rotavirus and HAV, but is active against lipid-enveloped viruses.

Answer 26

c) Inhibits the growth of mycobacteria Rationale: A mycobacteriostatic agent inhibits the growth of mycobacteria without necessarily killing them.

Answer 27

a) Chlorhexidine Rationale: Chlorhexidine is a membrane-active agent that causes protoplast rupture and cellular leakage in yeast.

Answer 28

c) Viruses Rationale: Chlorhexidine's antiviral activity is described as variable.

Answer 29

c) Polymeric Biguanides Rationale: Polymeric Biguanides are used as disinfectants in the food industry.

Answer 30

b) Alexidine Rationale: Alexidine is described as having faster bactericidal activity.

Answer 31

b) Development Rationale: Chlorhexidine prevents the development of spores but doesn't inhibit germination.

Answer 32

d) Vantocil Rationale: Vantocil, which is a mixture of PHMB, is used in hospitals as a disinfectant.

Answer 33

b) Inactivates the viruses Rationale: Chlorhexidine is mainly active against lipid-enveloped viruses, implying it inactivates them.

Answer 34

a) Chlorhexidine Rationale: Chlorhexidine is described as a membrane-active agent for several microorganisms, including non-sporulating bacteria and yeast.

Answer 35

c) Polymeric Biguanides (PHMB) Rationale: The sequence of events for PHMB interaction with E. coli includes strong and specific adsorption to phosphate-containing compounds.

Answer 36

C) Sodium hypochlorite Rationale: Sodium hypochlorite is commonly used for hard surface disinfection and is a primary component in household bleach.

Answer 37

B) Sodium hypochlorite Rationale: Sodium hypochlorite is effective in disinfecting spills that may contain viruses like HIV or HBV.

Answer 38

B) N-chloro compound Rationale: Sodium dichloroisocyanurate is an N-chloro compound.

Answer 39

C) Oxidize cellular proteins Rationale: Chlorine-releasing agents are strong oxidizing agents that target and destroy the cellular activities of proteins.

Answer 40

C) Iodine Rationale: Both aqueous and alcoholic solutions (tinctures) of iodine have a long-standing history of use as antiseptics.

Answer 41

B) They are unstable. Rationale: Aqueous solutions of iodine are generally unstable.

Answer 42

C) Cysteine and methionine Rationale: Iodine particularly reacts with free-sulfur amino acids, namely cysteine and methionine.

Answer 43

C) Povidone-iodine Rationale: Povidone-iodine is an iodophor, not a chlorine-releasing agent.

Answer 44

B) Irritation and staining Rationale: Iodophors were designed to address issues like irritation and staining associated with direct iodine use.

Answer 45

B) Disrupts surface proteins Rationale: For enveloped viruses, iodine likely affects surface proteins, though it can also interfere with unsaturated bonds in membrane fatty acids.

Answer 46

B) Oxidizing agent Rationale: Chlorine dioxide is a chlorine-releasing agent, which are typically oxidizing agents.

Answer 47

D) The surface proteins Rationale: Iodine likely disrupts the surface proteins of enveloped viruses.

Answer 48

C) Povidone-iodine Rationale: While iodophors retain the germicidal activity of iodine, they are considered slightly less effective against specific fungi and spores compared to tinctures.

Answer 49

C) Iodine Rationale: Iodine is associated with irritation and excessive staining.

Answer 50

C) Iodophors Rationale: Iodophors, like povidone-iodine, were developed to address the limitations of direct iodine use.

Answer 51

B) Oxidizing Rationale: Iodine possesses : -bactericidal, -fungicidal, -tuberculocidal, -virucidal, -sporicidal properties but is not primarily described as an oxidizing agent in this context.

Answer 52

C) The spores lose refractivity and undergo lysis. Rationale: At elevated concentrations of chlorine-releasing agents, bacterial spores lose refractivity, their coats separate from the cortex, and they undergo lysis.

Answer 53

C) Both A and B Rationale: Both povidone-iodine and poloxamer-iodine are widely used iodophors for antiseptic and disinfectant purposes.

Answer 54

D) All of the above Rationale: Iodine rapidly penetrates into microorganisms, affecting key groups of proteins and reacting with nucleotides, fatty acids, and specific amino acids, leading to cell death.

Answer 55

c) Ag⁺ Rationale: Silver ions (Ag⁺) have a strong affinity for thiol groups in enzymes and proteins, leading to bacterial inactivation.

Answer 56

b) Warts Rationale: High concentrations of silver nitrate can act as a chemical cautery agent and treat warts.

Answer 57

b) Binding to key functional groups of fungal enzymes Rationale: Silver salts can bind to key functional groups in fungal enzymes, rendering them non-functional.

Answer 58

b) Ag⁺ and sulfadiazine (SD) Rationale: Silver sulfadiazine is a combination of silver ion (Ag⁺) and sulfadiazine (SD).

Answer 59

c) Pseudomonas aeruginosa Rationale: Ag⁺ acts to inhibit cell division and cause damage to the cell envelope and its contents of Pseudomonas aeruginosa.

Answer 60

c) Burns and wounds Rationale: Silver sulfadiazine is widely recognized for its effectiveness in preventing infections in burns and wounds.

Answer 61

c) Base pairs in the DNA helix Rationale: Bacterial inhibition occurs when Ag+ binds to a significant number of base pairs in the DNA helix.

Answer 62

d) Silver sulfadiazine Rationale: Silver sulfadiazine is commonly used in topical creams like Neosporin.

Answer 63

c) Its protein coagulation property Rationale: Silver nitrate can act as a chemical cautery agent due to its protein coagulation property.

Answer 64

c) Sprays Rationale: Silver nitrate is available in forms such as sprays and sticks.

Answer 65

c) Thiol groups Rationale: Silver ions (Ag⁺) have a strong affinity for thiol groups in enzymes and proteins.

Answer 66

c) Silver sulfadiazine Rationale: Silver sulfadiazine is recognized for its broad-spectrum antimicrobial activity.

Answer 67

c) Fungal infections Rationale: While silver nitrate can be used for cauterizing wounds and treating warts, it's not specifically known for treating fungal infections.

Answer 68

d) Silver sulfadiazine Rationale: Flamazine is a topical cream that contains silver sulfadiazine.

Answer 69

b) Surface and membrane bles Rationale: Silver sulfadiazine produces bles on the surface and membrane of susceptible bacteria.

Answer 70

c) Increasing bacterial replication Rationale: Silver compounds act to inhibit bacteria, not promote their replication.

Answer 71

c) Copper Rationale: Along with silver salts, copper binds to key functional groups of fungal enzymes.

Answer 72

b) Binds to base pairs inhibiting transcription Rationale: Bacterial inhibition

Answer 73

c. Ag+ interaction with thiol groups in enzymes Rationale: Silver ions have a strong affinity for thiol groups, which when disrupted leads to bacterial inactivation.

Answer 74

b. Warts Rationale: Silver nitrate's protein coagulation property allows it to act as a chemical cautery agent for warts.

Answer 75

c. Boosting immune response Rationale: Silver nitrate has antimicrobial properties but doesn't boost the immune response.

Answer 76

d. DNA Rationale: Silver sulfadiazine inhibits bacterial replication by binding to DNA base pairs, which inhibits transcription.

Answer 77

b. Silver Sulfadiazine Rationale: Silver sulfadiazine is a primary component in topical creams like Neosporin.

Answer 78

c. Binding to functional groups of fungal enzymes Rationale: Silver salts act on the functional groups of fungal enzymes, rendering them non-functional.

Answer 79

c. Silver Nitrate Rationale: Silver nitrate acts to inhibit cell division and damages the cell contents of Pseudomonas aeruginosa.

Answer 80

c. Sulfadiazine Rationale: Silver Sulfadiazine is a combination of Ag+ and Sulfadiazine (SD).

Answer 81

c. Protein coagulation Rationale: Due to its protein coagulation property, silver nitrate can act as a chemical cautery agent.

Answer 82

c. Copper Rationale: Both silver salts and other heavy metals like copper bind to key functional groups of fungal enzymes.

Answer 83

c. Preventing infections in burns and wounds Rationale: Flamazine contains silver sulfadiazine, which is primarily used for its effectiveness in preventing infections in burns and wounds.

Answer 84

b. Susceptible bacteria Rationale: Unlike silver nitrate, silver sulfadiazine produces bles on the surface and membrane of susceptible bacteria.

Answer 85

c. Thiol Rationale: Ag+ has a strong affinity for thiol groups in enzymes and proteins, leading to bacterial inactivation.

Answer 86

b. Chemical cautery Rationale: Silver nitrate can burn warts and treat sores due to its protein coagulation property.

Answer 87

a. Boosting immune response Rationale: Silver compounds have antimicrobial properties but they don't boost the immune response.

Answer 88

c. Pseudomonas aeruginosa Rationale: Silver nitrate acts to inhibit cell division and damages the cell contents of Pseudomonas aeruginosa.

Answer 89

c. Silver Sulfadiazine Rationale: Silver Sulfadiazine is known for its broad-spectrum antimicrobial activity.

Answer 90

c. Silver Nitrate Rationale: Silver nitrate is available in various forms, including sticks and sprays.

Answer 91

d. Inhibiting transcription by binding to DNA Rationale: Silver sulfadiazine binds to DNA base pairs, which in turn inhibits transcription and thus stops bacterial replication.

Answer 92

b) Binds to base pairs inhibiting transcription Rationale: Bacterial inhibition occurs when Ag+ binds to a significant number of base pairs in the DNA helix, which in turn inhibits transcription.

Answer 93

C. Hydrogen peroxide Rationale: The text mentions that hydrogen peroxide is widely used for disinfection, sterilization, and antisepsis.

Answer 94

C. 10-30% To achieve sporicidal activity, higher concentrations between 10-30% and prolonged contact times are needed. This efficacy is markedly amplified in its gaseous phase.

Answer 95

B. Producing hydroxyl free radicals Rationale: Hydrogen peroxide acts as an oxidant by producing hydroxyl free radicals that target essential cell structures.

Answer 96

C. Peracetic acid Rationale: The text mentions that peracetic acid is a stronger biocide compared to hydrogen peroxide.

Answer 97

C. Playgrounds Rationale: The text does not list playgrounds as a place where peracetic acid is used as a disinfectant.

Answer 98

B. Water and oxygen Rationale: The text mentions that hydrogen peroxide decomposes into water and oxygen.

Answer 99

B. Tetanus Rationale: Hydrogen peroxide is efficacious in preventing tetanus due to its sporicidal properties against Clostridium tetani.

Answer 100

B. Below 0.3% Rationale: The text mentions that peracetic acid is effective at concentrations below 0.3%.

Answer 101

B. Exposed sulfhydryl groups and double bonds Rationale: Research suggests that exposed sulfhydryl groups and double bonds are primary targets of hydrogen peroxide.

Answer 102

B. Phenol Rationale: The text mentions hydrogen peroxide as environmentally benign because it decomposes into water and oxygen. Phenol was not mentioned in this context.

Answer 103

C. Protozoa Rationale: Exhibits broad-spectrum effectiveness against a variety of microbes, including bacteria, bacterial spores, viruses, and yeasts. Particularly efficacious in preventing tetanus due to its sporicidal properties against Clostridium tetani.

Answer 104

C. Wastewater treatment Rationale: Peracetic acid has been recognized for its utility as a water purifier in wastewater treatments.

Answer 105

B. Producing hydroxyl free radicals Rationale: Phenols at high concentrations cause coagulation of cellular contents, leading to irreversible cellular harm. They don't produce hydroxyl free radicals.

Answer 106

D. Peracetic acid Rationale: Peracetic acid is used for low-temperature liquid sterilization of medical devices.

Answer 107

C. Clostridium tetani Rationale: Hydrogen peroxide is sporicidal against Clostridium tetani, which causes tetanus.

Answer 108

D. CH3COOOH Rationale: The chemical structure of peracetic acid is given as CH3COOOH.

Answer 109

D. Bacteria, bacterial spores, viruses, and yeasts Rationale: The text mentions that hydrogen peroxide has broad-spectrum effectiveness against a variety of microbes, including bacteria, bacterial spores, viruses, and yeasts.

Answer 110

C. Phenol Rationale: The text mentions peracetic acid as a sanitizing agent for food processing during processes like pasteurization.

Answer 111

D. Hydrogen peroxide Rationale: Hydrogen peroxide functions as an oxidant by producing hydroxyl free radicals that target essential cell structures.

Answer 112

D. Potassium (K+) Rationale: The text specifies that phenols induce the release of potassium (K+), indicating membrane damage.

Answer 113

C. Coagulation of cytoplasmic constituents Rationale: At elevated concentrations, phenols lead to the coagulation of cellular contents.

Answer 114

C. Irreversible cellular damage Rationale: The coagulation of cellular contents by phenols results in irreversible cellular harm.

Answer 115

c) 2,4,4'-trichloro-2'-hydroxydiphenyl ether Rationale: Triclosan is chemically known as 2,4,4'-trichloro-2'-hydroxydiphenyl ether.

Answer 116

b) Gram-positive bacteria Rationale: Triclosan is particularly active against gram-positive bacteria.

Answer 117

b) Triclosan and EDTA Rationale: When combined with EDTA, triclosan increases the permeability of bacterial outer membranes.

Answer 118

d) Electron transport chain Rationale: Hexachlorophene is known to inhibit the membrane-bound part of the electron transport chain.

Answer 119

c) Safeguard Rationale: Safeguard is a product known to contain Triclosan.

Answer 120

d) Cytoplasmic membrane Rationale: It's suggested that the primary effects of Triclosan are on the cytoplasmic

Answer 121

b) Causing hay fever Rationale: Triclosan has been associated with allergies and hay fever.

Answer 122

c) Neonates Rationale: There have been concerns about Hexachlorophene's toxicity, especially in neonates.

Answer 123

b) Stannous fluoride Rationale: Toothpaste without Triclosan often contains stannous fluoride as an antibacterial agent.

Answer 124

c) Promoting cell division Rationale: Hexachlorophene causes leakage, inhibits respiration, and leads to protoplast lysis but does not promote cell division.

Answer 125

d) Moisturizing lotions Rationale: Hexachlorophene is used in antibacterial soaps, pHisoHex, and shaving creams, but not typically in moisturizing lotions.

Answer 126

c) Essential nutrients Rationale: At subinhibitory concentrations, Triclosan has been found to inhibit the uptake of essential nutrients in E. coli.

Answer 127

c) Concerns about toxicity Rationale: Due to concerns about its potential toxicity, especially in neonates, Hexachlorophene's usage in antiseptic products is limited.

Answer 128

b) Increased antibacterial resistance Rationale: Using antibacterial toothpaste containing Triclosan can potentially increase the risk of developing antibacterial resistance.

Answer 129

d) Bacterial cells Rationale: Hexachlorophene induces leakage in bacterial cells.

Answer 130

c) Rapid release of cellular components and cell death Rationale: At bactericidal concentrations, Triclosan causes rapid release of cellular components, leading to cell death.

Answer 131

b) Allergies and hay fever Rationale: Triclosan has been associated with allergies and hay fever.

Answer 132

c) Respiration Rationale: Hexachlorophene inhibits respiration in bacteria.

Answer 133

b) Blood for an extended period Rationale: Triclosan has the potential to remain in the blood for extended periods.

Answer 134

c) Dove Rationale: Dove is not known to contain Triclosan.

Answer 135

B) Cationic detergents Rationale: QACs have a positive charge, thus they are termed as 'cationic'.

Answer 136

B) Disinfection of drinking water Rationale: QACs are mainly used for surface disinfection and not typically for disinfecting drinking water.

Answer 137

B) Hard-surface cleaning and deodorization Rationale: QACs are renowned for their hard-surface cleaning and deodorizing properties.

Answer 138

B) Opposite charge attraction Rationale: The positive charge of QACs allows them to bind with negatively charged microbial cell surfaces.

Answer 139

A) Oxidation of cellular proteins Rationale: QACs do not oxidize cellular proteins. They cause leakage, adsorption, and react with the membrane.

Answer 140

A) Broad-spectrum antimicrobials Rationale: QACs are effective against a wide range of microorganisms, hence termed broad-spectrum.

Answer 141

B) Their cationic nature Rationale: The cationic nature of QACs allows them to neutralize the negative charge on fibers, resulting in a softer feel.

Answer 142

A) Gram-negative bacteria Rationale: The outer membrane of Gram-negative bacteria can provide some protection against QACs.

Answer 143

C) Increased microbial resistance Rationale: Overuse of any antimicrobial can lead to increased resistance among microorganisms.

Answer 144

A) In the presence of organic matter Rationale: Organic matter can interfere with the activity of QACs, reducing their effectiveness.

Answer 145

C. Cationic (positive) Rationale: QACs are termed as cationic detergents, which means they possess a positive charge. This positive charge allows them to effectively bind to and interact with the negatively charged surfaces of many microbial cells.

Answer 146

B. Dehydration of organic materials Rationale: While QACs are known for disinfection, hard-surface cleaning, and deodorization, there's no mention in the provided information that they are used for the dehydration of organic materials.

Answer 147

B. Leakage of intracellular low-molecular-weight material Rationale: Once the QACs have penetrated and caused disorganization of the microbial cell membrane, the next step is the leakage of intracellular components, particularly those of low molecular weight. This leakage is indicative of the loss of cellular integrity, leading to the cell's eventual death.

Answer 148

C. Cytoplasmic membrane Rationale: QACs target the cytoplasmic membrane of the microbial cell. By reacting with the lipid or protein components of this membrane, they cause its disorganization. This is a crucial step in their antimicrobial action, leading to a cascade of events that culminate in the death of the microbial cell.

Answer 149

D. Chlorox (Clorox) Rationale: Chlorox (or Clorox) is a brand predominantly known for its bleach-based products. However, like many major cleaning product manufacturers, they have diversified their product range and could potentially produce cleaning agents with other active ingredients, such as QACs.

Answer 150

B. Ethylene oxide

Answer 151

B. Sterilizing heat-sensitive medical devices Rationale: Vapor-phase sterilants are ideal for heat-sensitive items that cannot withstand traditional heat sterilization.

Answer 152

D. Oxidation of metals Rationale: Alkylating agents attack organic compounds like DNA and proteins but do not typically oxidize metals.

Answer 153

D. It may leave toxic residues Rationale: Ethylene oxide can leave behind toxic residues if not properly aerated after sterilization.

Answer 154

C. It has potential health effects Rationale: Concerns related to health effects limit the widespread use of formaldehyde gas in healthcare settings.

Answer 155

C. PAA (peracetic acid) Rationale: PAA is considered more potent as an oxidizing agent in its vapor form than in its liquid form.

Answer 156

B. Hydrogen peroxide Rationale: Vapor-phase hydrogen peroxide is commonly used in combination with gas plasma in low-temperature sterilization systems.

Answer 157

C. Sulfhydryl Rationale: Alkylating agents are particularly reactive with sulfhydryl and other enzyme-reactive groups.

Answer 158

D. Operate at lower temperatures Rationale: Vapor-phase sterilants can effectively sterilize without the need for high temperatures, thus preserving heat-sensitive items.

Answer 159

B. Ethylene oxide Rationale: Ethylene oxide is explosive, which is one of its disadvantages as a sterilant.

Answer 160

C. Glutaraldehyde Rationale: Glutaraldehyde is a liquid sterilant used for disinfection and sterilization.

Answer 161

B. They have limited penetrability Rationale: Vapor-phase hydrogen peroxide and PAA, while effective, might not penetrate as deeply or as effectively in certain applications.

Answer 162

C. Formaldehyde Rationale: Formaldehyde is non-explosive, unlike ethylene oxide.

Answer 163

C. Ethylene oxide Rationale: Ethylene oxide is known to be mutagenic, posing risks if residues are not removed properly.

Answer 164

C. They don't damage heat-sensitive equipment Rationale: Vapor-phase sterilants can sterilize without the high temperatures that could damage heat-sensitive medical devices.

ANTISEPTICS AND DISINFECTANTS Flashcards

(190 cards)