Antiseptics and disinfectants

Question 1

Cleansers, antiseptics, and disinfectants
They play critical roles in preventing infectious disease transmission in veterinary medicine

➢ Ignaz Semmelweis demonstrated as early as the 1840s the efficacy of ______ washing → following Pasteur’s identification of infective agents as the ______ of disease

➢ Joseph Lister (1827-1912), a pioneer of antiseptic ________ and ________ medicine, suggested the use of antiseptics in the field of surgery
→ treatment of the hands with ___:___ carbolic lotion
→ methods for chemical sterilization of _______, _______, and surgical _______
His principle: “that bacteria must never gain entry into an operation wound”

Answer 1

Cleansers, antiseptics, and disinfectants
They play critical roles in preventing infectious disease transmission in veterinary medicine

➢ Ignaz Semmelweis demonstrated as early as the 1840s the efficacy of hand washing → following Pasteur’s identification of infective agents as the cause of disease

➢ Joseph Lister (1827-1912), a pioneer of antiseptic surgery and preventative medicine, suggested the use of antiseptics in the field of surgery
→ treatment of the hands with 1:20 carbolic lotion
→ methods for chemical sterilization of bandages, dressings, and surgical instruments
His principle: “that bacteria must never gain entry into an operation wound”

Question 2

Cleansers, antiseptics, and disinfectants are differentiated by their intended ____ and characteristic _______, not by their chemical ______.

Answer 2

Cleansers, antiseptics, and disinfectants are differentiated by their intended use and characteristic properties, not by their chemical content

Question 3

➢ A cleanser aids in _______ removal of ______ material
→ It is not necessarily a ________
➢ An antiseptic is a _____ applied to ____ tissue
➢ A disinfectant is a ______ applied to ________ objects

Answer 3

➢ A cleanser aids in physical removal of foreign material
→ It is not necessarily a germicide
➢ An antiseptic is a biocide applied to living tissue
➢ A disinfectant is a biocide applied to inanimate objects

Question 4

Antiseptics and Disinfectants
Because certain antiseptics may be __________ on inanimate surfaces and because certain disinfectants are _________ to living tissue
They should not be used __________!!

Disinfectants (sanitizers or sterilants) –> Are regulated by the ____

Antiseptics —> Must be registered with the _____

Answer 4

Antiseptics and Disinfectants
Because certain antiseptics may be inactivated on inanimate surfaces and because certain disinfectants are hazardous to living tissue
They should not be used interchangeably!!
Disinfectants (sanitizers or sterilants) –> Are regulated by the Environmental Protection Agency (EPA)
Antiseptics —> Must be registered with the Food
and Drug Administration (FDA)

Question 5

Cleansers contain __________ or _______ that remove dirt and contaminating organisms
by _________ and __________ means
➢ Cleansers can be classified into three types based on the ______ and ______ of the hydrophilic portion: ?

Answer 5

Cleansers contain surfactants or detergents remove dirt and contaminating organisms
by solubilization and physical means
➢ Cleansers can be classified into three types based on the presence and charge of the hydrophilic portion:
* Anionic
* Cationic
* Nonionic

Question 6

Cleansers
Anionic cleansers: ______ (anionic surfactants)
- R-COO-Na+

Dissociation in water to ________ liberates a molecule with both a _______ and _________
portion, which can emulsify and solubilize hydrophobic _____, ____, and _________ membranes
→ they can be inactivated in the presence of ______ detergents or certain ______ ions
such as free ____ in hard water

Answer 6

Cleansers
Anionic cleansers: Soaps (anionic surfactants)
- R-COO-Na+

Dissociation in water to R-COO-liberates a molecule with both a hydrophilic and hydrophobic
portion, which can emulsify and solubilize hydrophobic dirt, fat, and protoplasmic
membranes
→ they can be inactivated in the presence of cationic detergents or certain positive ions
such as free Ca++ in hard water

Question 7

Cleansers
Cationic cleansers: ________
- are cationic surfactants with _______ activity
→ they combine readily with _____, ____, and _____
The mixture of soaps and QACs forms a _______, which _______ the activity of both compounds

Answer 7

Cleansers
Cationic cleansers: quaternary ammonium compounds (QACs)
QACs are cationic surfactants with germicidal activity
→ they combine readily with proteins, fats, and phosphates
The mixture of soaps and QACs forms a precipitate, which terminates the activity of both compounds

Question 8

Antiseptics
An antiseptic __________ the microbial population on skin and other living tissues
Its MOA involves (in most cases) ________ disruption of cellular ________ or _______
An ideal antiseptic
* ________ spectrum of activity
* ____ toxicity
* _____ penetrability
* Maintain activity in the presence of ___ and _____ tissue
* Little skin _______ or _______ with the normal healing process

Answer 8

Antiseptics
An antiseptic reduces the microbial population on skin and other living tissues
Its MOA involves (in most cases) nonspecific disruption of cellular membranes or
enzymes
An ideal antiseptic
* Broad spectrum of activity
* Low toxicity
* High penetrability
* Maintain activity in the presence of pus and necrotic tissue
* Little skin irritation or interference with the normal healing process

Question 9

Antiseptics
The use of antiseptics is recommended in situations which require ________ reduction of bacterial contamination
* _______ surgery
* During __________
* Insertion of ________ implants

Answer 9

Antiseptics
The use of antiseptics is recommended in situations which require maximal reduction of bacterial contamination
* After surgery
* During catheterization
* Insertion of invasive implants

Question 10

Disinfection and Sterilization
Sometimes disinfection is confused with sterilization
→ True chemical sterilization requires the use of an _____-registered agent capable of
killing _____ infective organisms → including ____ and _______ spores (within __ h)

Disinfection is a process that eliminates _____, if not ___, pathogenic organisms, excluding _____ forms, from an inanimate object.

Sterilization is a process that eliminates ____ microbial forms by a ______ or _______ means.

Answer 10

Disinfection and Sterilization
Sometimes disinfection is confused with sterilization
→ True chemical sterilization requires the use of an EPA-registered agent capable of
killing all infective organisms → including fungal and bacterial spores (within 10 h)
Disinfection is a process that eliminates most, if not all, pathogenic organisms,
excluding spore forms, from an inanimate object
Sterilization is a process that eliminates all microbial forms by a physical or
chemical means

Question 11

Disinfectants
* Surface disinfection: The treatment of objects that are too _____ to soak in
disinfectant (cabinets, exam tables, chairs, lights and cages)
* Immersion disinfection: Immersion of _____ objects in disinfectants for sufficient
time to kill the ______ of contaminating pathogenic organisms

Answer 11

Disinfectants
* Surface disinfection: The treatment of objects that are too large to soak in
disinfectant (cabinets, exam tables, chairs, lights and cages)
* Immersion disinfection: Immersion of small objects in disinfectants for sufficient
time to kill the majority of contaminating pathogenic organisms

Question 12

Disinfectants
The ideal characteristics of a disinfectant:
* _______ spectrum
* ______ action
* Activity in the presence of ______ material (_____, _____, and ______)
* Compatibility with _________
* ____ toxicity
* _________
* __________
* They should not _________ instruments or metallic surfaces or disintegrate _______, _______, or other materials

Answer 12

Disinfectants
The ideal characteristics of a disinfectant:
* Broad spectrum
* Fast action
* Activity in the presence of organic material (blood, sputum, and feces)
* Compatibility with detergents
* Low toxicity
* Odorless
* Economical
* They should not corrode instruments or metallic surfaces or disintegrate rubber, plastic, or other materials

Question 13

Disinfectants
According to the ability of disinfectants to kill different classes of microorganisms they
can be grouped into:
High, intermediate, and low levels → first classification system
* High-level disinfection destroys ____ microorganisms except high concentrations
of bacterial ______
* Intermediate-level disinfection __________ acid-fast microorganisms
→ Mycobacterium _________, most _____ and _____, but not necessarily ________ spores
* Low-level disinfection kills ____ bacteria, some ______, and some ____, but not ________ bacilli or bacterial _____ → It occurs in less than 10 min

Answer 13

Disinfectants
According to the ability of disinfectants to kill different classes of microorganisms they
can be grouped into:
High, intermediate, and low levels → first classification system
* High-level disinfection destroys all microorganisms except high concentrations
of bacterial spores
* Intermediate-level disinfection inactivate acid-fast microorganisms
→ Mycobacterium tuberculosis, most viruses and fungi, but not necessarily
bacterial spores
* Low-level disinfection kills most bacteria, some viruses, and some fungi, but
not tubercle bacilli or bacterial spores → It occurs in less than 10 min

Question 14

Disinfectants
A second classification system divides instruments and patient-care items into
three categories based on risk of infection involved in their use
* Critical: those that _____ or _____ skin or ________ ___________, usually at a sterile site
* Semicritical: those that touch _______ mucous membranes
* Noncritical: those that do _____ touch mucous membranes but may contact ____ skin

Critical items should be _______
Semicritical items require ____ level disinfection
Noncritical items require ____ to _______ level of disinfection

Answer 14

Disinfectants
A second classification system divides instruments and patient-care items into
three categories based on risk of infection involved in their use
* Critical: those that enter or penetrate skin or mucous membranes, usually at a
sterile site
* Semicritical: those that touch intact mucous membranes
* Noncritical: those that do not touch mucous membranes but may contact intact skin

Critical items should be sterilized
Semicritical items require high level disinfection
Noncritical items require low to intermediate level of disinfection

Question 15

Popular Antiseptic and Disinfecting Agents
Alcohol
* Alcohols are the most ________ antiseptic and disinfecting products
* ________ and ________ alcohol are the most used
* They are ______ solvents and ___ denaturants
→ They kill organisms by _________ the lipid cell membrane and ________ membrane cellular proteins
* Alcohols are most effective when diluted with ________
Ethyl alcohol → ____%
Isopropyl alcohol → ____%

Answer 15

Popular Antiseptic and Disinfecting Agents
Alcohol
* Alcohols are the most popular antiseptic and disinfecting products
* Ethyl and isopropyl alcohol are the most used
* They are lipid solvents and protein denaturants
→ They kill organisms by solubilizing the lipid cell membrane
and denaturing membrane cellular proteins
* Alcohols are most effective when diluted with water
Ethyl alcohol → 70%
Isopropyl alcohol → 50%

Question 16

Popular Antiseptic and Disinfecting Agents
Alcohol
Alcohols have excellent ________ activity against most vegetative gram-_____,
gram-______, and _________ bacillus organisms
They do not inactivate bacterial ________
They are active against many _____ and _______ (principally __________ viruses)

Answer 16

Popular Antiseptic and Disinfecting Agents
Alcohol
Alcohols have excellent antibacterial activity against most vegetative gram-positive,
gram-negative, and tubercle bacillus organisms
They do not inactivate bacterial spores
They are active against many fungi and viruses (principally enveloped viruses)

Question 17

Popular Antiseptic and Disinfecting Agents
Alcohol
* The alcohols are not recommended for _____-level disinfection or chemical __________
→ inactivity against bacterial _______
→ reduced efficacy in the presence of _______ or _______
➢ ______ proteins are denatured by alcohol and will ________ to instruments being disinfected

Answer 17

Popular Antiseptic and Disinfecting Agents
Alcohol
* The alcohols are not recommended for high-level disinfection or chemical sterilization
→ inactivity against bacterial spores
→ reduced efficacy in the presence of protein or bioburden
➢ Blood proteins are denatured by alcohol and will adhere to instruments
being disinfected

Question 18

Popular Antiseptic and Disinfecting Agents
Alcohol
➢ After repeated and prolonged use alcohol can:
* Damage the _______ mounting of lensed instruments
* ____ or _____ rubber and certain plastic tubing
* Be ________ to metal surfaces

Answer 18

Popular Antiseptic and Disinfecting Agents
Alcohol
➢ After repeated and prolonged use alcohol can:
* Damage the shellac mounting of lensed instruments
* Swell or harden rubber and certain plastic tubing
* Be corrosive to metal surfaces

Question 19

Popular Antiseptic and Disinfecting Agents
Alcohol
The effectiveness is drastically reduced by organic matter such as ____, ______, and ____ → they are most effective on ____ skin
They produce ____ reduction in bacterial counts (contact times of __-__ minutes) resulting in elimination of almost ___% of organisms. Rapid evaporation _____ contact time
Although alcohols are among the safest antiseptics, toxic reaction have been reported in ____ → alcohol can be _____ to the skin and cause ____ irritation

Answer 19

Popular Antiseptic and Disinfecting Agents
Alcohol
The effectiveness is drastically reduced by organic matter such as feces, mucus, and
blood → they are most effective on clean skin
They produce rapid reduction in bacterial counts (contact times of 1-3 minutes) resulting
in elimination of almost 80% of organisms. Rapid evaporation limits contact time
Although alcohols are among the safest antiseptics, toxic reaction have been reported in
children → alcohol can be drying to the skin and cause local irritation

Question 20

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
* Iodine has _______ activity against:
* Gram-_______ and gram-______ bacteria
* Bacterial _____
* ______
* Most _____
* Iodine exerts its effects by diffusing into the cell and interfering with ________ reactions
and by disrupting ________ and ________ acid structure

Answer 20

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
* Iodine has germicidal activity against:
* Gram-positive and gram-negative bacteria
* Bacterial spores
* Fungi
* Most viruses
* Iodine exerts its effects by diffusing into the cell and interfering with metabolic reactions
and by disrupting protein and nucleic acid structure

Question 21

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
* It is ________ in water
→ Iodine is prepared in _______ (tincture)
* Tincture of iodine is most effectively formulated as a __-__% iodine solution in ____% ethyl alcohol
→ in this form, most bacteria are killed within ___ minutes of application
* The antibacterial activity of this combination is _______ than that of the alcohol alone

Answer 21

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
* It is insoluble in water
→ Iodine is prepared in alcohol (tincture)
* Tincture of iodine is most effectively formulated as a 1-2% iodine solution in 70%
ethyl alcohol
→ in this form, most bacteria are killed within 3 minutes of application
* The antibacterial activity of this combination is greater than that of the alcohol alone

Question 22

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
Disadvantage of tincture of iodine:
_______ and ______
__________ metals
Stains _____ and ________

Answer 22

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
Disadvantage of tincture of iodine:
Irritating and allergic
Corrodes metals
Stains skin and clothing

Question 23

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
Trying to reduce the undesirable aspects of tinctures led to prepare it with solubilizing surfactants → _________
* Have similar spectrum of activity to ______ solutions
→ they are ______ irritating, allergenic, staining and corrosive
* They have ________ activity (___-__ h): Common solubilizing carrier polyvinylpyrrolidone (PVP-iodine) or commonly called ?

Answer 23

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
Trying to reduce the undesirable aspects of tinctures led to prepare it with
solubilizing surfactants → Iodophors
* The iodophors have similar spectrum of activity to aqueous solutions
→ they are less irritating, allergenic, staining and corrosive
* They have prolonged activity (4-6 h)

Common solubilizing carrier polyvinylpyrrolidone
(PVP-iodine) or commonly called povidone-iodine

Question 24

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
* Iodophors are excellent _______ agents as well as _________ and _________
* They retain their activity in presence of ________ matter
* It is necessary a proper dilution to __% iodine. More concentrated are _____ efficacious
Iodophors are quickly ________ but may require prolonged contact times to kill certain _____ and ______ spores
Iodine can be systemically absorbed through the _____ and ?

Answer 24

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Iodine
* Iodophors are excellent cleansing agents as well as antiseptics and disinfectants
* They retain their activity in presence of organic matter
* It is necessary a proper dilution to 1% iodine. More concentrated are less
efficacious
Iodophors are quickly bactericidal but may require prolonged
contact times to kill certain fungi and bacterial spores
Iodine can be systemically absorbed through the skin and mucous membranes

Question 25

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Chloride
Chlorine-containing solutions were first introduced in the early 1900s in chemical
form of _________ __________
* They are effective _______, _______, ________ and _________ agents
* The chemical form most used today include the _________ (sodium and calcium) and _______ chlorides (chloramine-T)

MOA: inhibition of cellular _______ reactions, protein _________ and ________ of nucleic acids

Answer 25

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Chloride
Chlorine-containing solutions were first introduced in the early 1900s in chemical
form of sodium hypochlorite
* They are effective bactericidal, fungicidal, virucidal and protozoacidal agents
* The chemical form most used today include the hypochlorites (sodium and
calcium) and organic chlorides (chloramine-T)
MOA: inhibition of cellular enzymatic reactions, protein denaturation and inactivation
of nucleic acids

Question 26

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Chloride
The use of hypochlorites as disinfectants is ______
→ chloride solutions are ______ and destroy many _____
They are commonly used as ____-level disinfectants on _____ equipment, animal _____ quarters, hospital ____, and other _____ items
The hypochlorites are not recommended for routine use as ________
→ Very _______ to the skin and they ____ healing

Answer 26

Popular Antiseptic and Disinfecting Agents
Halogens: Iodine and chloride
Chloride
The use of hypochlorites as disinfectants is limited
→ chloride solutions are corrosive and destroy many fabrics
They are commonly used as low-level disinfectants on dairy equipment, animal housing
quarters, hospital floor, and other noncritical items
The hypochlorites are not recommended for routine use as antiseptics
→ Very irritating to the skin and they delay healing

Question 27

Biguanides: Chlorhexidine (Chx)
Chx is a synthetic ______ antiseptic compound with better activity against gram-______ than against gram-_____ organisms. It _____ sporicidal activity

Mode of action
Chx kills ______ by disrupting the cell _________ and precipitating cell contents
A 0.1% aqueous solution shows significant killing actions after only ____ seconds. Chx
solutions have the _____ residual activity (5-6 h)
Chlorhexidine retains its activity in the presence of ______ and other ________ material

Answer 27

Biguanides: Chlorhexidine (Chx)
Chx is a synthetic cationic antiseptic compound with better activity against gram-positive
than against gram-negative organisms. It lacks sporicidal activity
Mode of action
Chx kills bacteria by disrupting the cell membrane and precipitating cell contents
A 0.1% aqueous solution shows significant killing actions after only 15 seconds. Chx
solutions have the longest residual activity (5-6 h)
Chlorhexidine retains its activity in the presence of blood and other organic material

Question 28

Biguanides: Chlorhexidine (Chx)
Chx has extremely ____ toxicity even when used on intact skin of ________.
* Chx is available in a detergent base as a __% solution or as a ___% liquid foam
* It has been widely used as a ________ antiseptic, wound _____, and ____ dip

Polyhexamethylene biguanide (PHMB)
PHMB is a polymeric biguanide with activity against gram-_________ and gram-________
bacteria including methicillin-resistant: ?

Answer 28

Biguanides: Chlorhexidine (Chx)
Chx has extremely low toxicity even when used on intact skin of newborns
* Chx is available in a detergent base as a 4% solution or as a 2% liquid foam
* It has been widely used as a presurgical antiseptic, wound flush, and teat dip
Polyhexamethylene biguanide (PHMB)
PHMB is a polymeric biguanide with activity against gram-positive and gram-negative
bacteria including methicillin-resistant:
Staphylococcus aureus
Pseudomonas aeruginosa
Streptococcus equi

Question 29

PHMB has been used to treat infections in the _____, ______, and ______ and has been formulated in contact lens disinfectants and mouth rinses.
Nontoxic as a component of an _____ flush for dogs

Answer 29

PHMB has been used to treat infections in the eye, mouth, and vagina and has been formulated in contact lens disinfectants and mouth rinses.
Nontoxic as a component of an ear flush for dogs

Question 30

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* Formaldehyde has ___________ activity both as a gas and in liquid form. Formalin, the
_________ form, is 37% formaldehyde by weight
* Formaldehyde is an effective but slow ?
→ it requires __ - ___ hours contact time
* It is effective against ________ ______, bacterial _____, and most animal viruses, including ____ disease virus
* It inactivates microorganisms by ________ the amino and sulfhydryl groups of
proteins and ring nitrogen atoms of purine bases

Answer 30

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* Formaldehyde has antimicrobial activity both as a gas and in liquid form. Formalin, the
aqueous form, is 37% formaldehyde by weight
* Formaldehyde is an effective but slow bactericide, virucide, and fungicide
→ it requires 6 - 12 hours contact time
* It is effective against M. tuberculosis, bacterial spores, and most animal viruses,
including foot-and-mouth disease virus
* It inactivates microorganisms by alkylating the amino and sulfhydryl groups of
proteins and ring nitrogen atoms of purine bases

Question 31

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* Its action is not affected by _______ matter
* Formaldehyde is relatively noncorrosive to ?
* Formaldehyde alone is considered a ____-level disinfectant and in combination with alcohol can be used as a chemical _________ for surgical instruments

National Institute for Occupational Safety and Health requires it to be handled as a potential _________, thereby limiting worker exposure time.

Answer 31

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* Its action is not affected by organic matter
* Formaldehyde is relatively noncorrosive to metals, paint, and fabric
* Formaldehyde alone is considered a high-level disinfectant and in combination with alcohol
can be used as a chemical sterilant for surgical instruments
National Institute for Occupational Safety and Health requires it to be
handled as a potential carcinogen, thereby limiting worker exposure time

Question 32

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* Glutaraldehyde has better bactericidal, virucidal and sporicidal activity than _________
* Its biocidal activity is related to its ability to alkylate ________, _______, _________ and _________ groups affecting RNA, DNA, and protein synthesis
* GLT has high-level disinfection and chemical sterilization
→ ________ spectrum of activity
→ It retains its biocidal activity in the presence of _______ matter
→ It is ___________ to metal, rubber, and plastic
→ It does not damage ________ instruments

Answer 32

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* Glutaraldehyde has better bactericidal, virucidal and sporicidal activity than formaldehyde
* Its biocidal activity is related to its ability to alkylate sulfhydryl, hydroxyl, carboxyl, and amino
groups affecting RNA, DNA, and protein synthesis
* GLT has high-level disinfection and chemical sterilization
→ Wide spectrum of activity
→ It retains its biocidal activity in the presence of organic matter
→ It is noncorrosive to metal, rubber, and plastic
→ It does not damaged lensed instruments

Question 33

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* GLT solutions must be used in _____-ventilated areas
→ air concentrations of 0.2 ppm are irritating to the ____ and ____ passages
Using a 2% aqueous alkaline GLT solution the contact time needed was:
→ Less than __ minutes for vegetative bacteria
→ 10 minutes for _____
→ 3 hours for bacterial _______
The caustic nature of both formaldehyde and GLT makes them inappropriate as
_________ → protective gloves should be worn when using ________ disinfectants

Answer 33

Aldehydes: formaldehyde and glutaraldehyde (GLT)
* GLT solutions must be used in well-ventilated areas
→ air concentrations of 0.2 ppm are irritating to the eyes
and nasal passages
Using a 2% aqueous alkaline GLT solution the contact time needed was:
→ Less than 2 minutes for vegetative bacteria
→ 10 minutes for fungi
→ 3 hours for bacterial spores
The caustic nature of both formaldehyde and GLT makes them inappropriate as
antiseptics → protective gloves should be worn when using aldehyde disinfectants

Question 34

Oxidizing Compounds: hydrogen peroxide and potassium peroxymonosulfate
* Hydrogen peroxide has been reported to have ________, _________, and ___________
activity
* 3% hydrogen peroxide has been shown to be _________ to tissues (fibroblast)
→ not suitable for _________ wound care
* Hydrogen peroxide is considered a stable and effective ________ (soft contact lenses)
* Hydrogen peroxide have been formulated to contain a _______ and ________
→ improve antimicrobial activity

Answer 34

Oxidizing Compounds: hydrogen peroxide and potassium peroxymonosulfate
* Hydrogen peroxide has been reported to have bactericidal, virucidal, and fungicidal
activity
* 3% hydrogen peroxide has been shown to be damaging to tissues (fibroblast)
→ not suitable for routine wound care
* Hydrogen peroxide is considered a stable and effective disinfectant (soft contact lenses)
* Hydrogen peroxide have been formulated to contain a surfactant and stabilizer
→ improve antimicrobial activity

Question 35

Oxidizing Compounds: hydrogen peroxide and potassium peroxymonosulfate (PPMS)

• PPMS is used in disinfection systems of ____ and ____ _____
• It has been formulated with ______ _____ and organic ___ and ____
  → effective against over 580 infectious agents including:
  _______
  Gram-______ and gram-_______ bacteria
  Fungi (______ and ______)
  ________ (EPA Master label)
• It is marketed as a powder → It is stable in solution for approx. one week
• It is widely used as a ______-level disinfectant for surfaces in laboratories, dental care facilities, and hospitals

Answer 35

Oxidizing Compounds: hydrogen peroxide and potassium peroxymonosulfate (PPMS)

• PPMS is used in disinfection systems of pools and hot tubs
• It has been formulated with potassium chloride and organic acids and salts
  → effective against over 580 infectious agents including:
  Viruses
  Gram-positive and gram-negative bacteria
  Fungi (mold and yeast)
  Mycoplasma (EPA Master label)
• It is marketed as a powder → It is stable in solution for approx. one week
• It is widely used as a high-level disinfectant for surfaces in laboratories, dental care facilities, and hospitals

Question 36

Factors Affecting Efficacy of Antiseptics and Disinfectants
* Organic material has an especially profound effect on the _________ efficacy
* Physical cleaning ________ disinfection is the most important step
→ e.g., ________ and _______-based disinfectants and ______
* Organic matter such as blood, pus, feces, soil, food, and milk, are believed to directly reduce the activity of _______ compounds via a
➢ Chemical reaction → _______ amount of compound available for killing
➢ Spatial nonreaction → _______ to get to the organism

Answer 36

Factors Affecting Efficacy of Antiseptics and Disinfectants
The amount of organic material
* Organic material has an especially profound effect on the biocidal efficacy
* Physical cleaning before disinfection is the most important step
→ e.g., chlorine and iodine-based disinfectants and QACs
* Organic matter such as blood, pus, feces, soil, food, and milk, are believed to
directly reduce the activity of antimicrobial compounds via a
➢ Chemical reaction → smaller amount of compound available for killing
➢ Spatial nonreaction → inability to get to the organism

Question 37

Factors Affecting Efficacy of Antiseptics and Disinfectants
* ____________ is less affected by organic contamination than other compounds
→ it is useful for instruments whose _______ or ________ makes it impossible to be thoroughly cleaned

Answer 37

Factors Affecting Efficacy of Antiseptics and Disinfectants
* Glutaraldehyde is less affected by organic contamination than other compounds
→ it is useful for instruments whose surface or design makes it
impossible to be thoroughly cleaned

Question 38

Factors Affecting Efficacy of Antiseptics and Disinfectants
The number and organism type present
* The higher the level of microbial contamination, the ______ must be the exposure to the chemical biocide
* Gram-positive bacteria are in general ____ resistant to disinfectant and antiseptic
compounds than gram-negative organisms due to a less ____-rich cell wall

Answer 38

Factors Affecting Efficacy of Antiseptics and Disinfectants
The number and organism type present
* The higher the level of microbial contamination, the longer must be the exposure to the chemical biocide
* Gram-positive bacteria are in general less resistant to disinfectant and antiseptic
compounds than gram-negative organisms due to a less lipid-rich cell wall

Question 39

Factors Affecting Efficacy of Antiseptics and Disinfectants
The number and organism type present
* Of the gram-negative bacteria, Pseudomonas aeruginosa has been identified as _______ resistant to antimicrobial agents
* Mycobacteria, due to _____ and _______ nature of their cell wall, are _____ resistant to many compounds
* The efficacy of most germicides against bacterial spores increases with ______
→ the most effective method against bacterial spores is ______ _____ (115◦C autoclaving)

Answer 39

Factors Affecting Efficacy of Antiseptics and Disinfectants
The number and organism type present
* Of the gram-negative bacteria, Pseudomonas aeruginosa has been identified as more
resistant to antimicrobial agents
* Mycobacteria, due to unusual and hydrophobic nature of their cell wall, are highly resistant to many compounds
* The efficacy of most germicides against bacterial spores increases with temperature
→ the most effective method against bacterial spores is moist heat (115◦C autoclaving)

Question 40

Formation of biofilms
* Bacteria present on metal or other surfaces may form a ______
→ slimy layer consisting of an organic ______ matrix in which ______ are embedded.
The intercellular matrix contains products of cellular ________ including ions, nutrients, and enzymes such as ?
* Bacteria in biofilm are _____ sensitive to disinfectant inactivation
→ ________ diffusion through polymer matrix

Answer 40

Formation of biofilms
* Bacteria present on metal or other surfaces may form a biofilm
→ slimy layer consisting of an organic polymer matrix in which microbes are embedded
The intercellular matrix contains products of cellular metabolism including ions, nutrients, and enzymes such as polysaccharases, proteases, and β-lactamases
* Bacteria in biofilm are less sensitive to disinfectant inactivation
→ decreased diffusion through polymer matrix

Question 41

Resistance to antiseptics and disinfectants
* Like resistance towards traditional antibiotics, bacteria can ______ genes that are associated with resistance towards antiseptic and disinfectant compounds
* Concentrations of disinfectants are generally much ______ than the cidal
concentration required to kill bacteria
➢ Staphylococcus aureus has been shown to be resistant to ____ and __________
➢ Pseudomonas species show a _____-level resistance (_______)

Answer 41

Resistance to antiseptics and disinfectants
* Like resistance towards traditional antibiotics, bacteria can acquire genes that are associated with resistance towards antiseptic and disinfectant compounds
* Concentrations of disinfectants are generally much higher than the cidal
concentration required to kill bacteria
➢ Staphylococcus aureus has been shown to be resistant to QACs and chlorhexidine
➢ Pseudomonas species show a low-level resistance (unstable)

Question 42

Resistance to antiseptics and disinfectants
* The mechanisms of resistance developed against a ________ or _______ could confer resistance to an _________
* The MOA of antibiotics are well known
➢ Single specific target → e.g., inhibitors protein, nucleic acid synthesis inhibitors of RNA polymerase, DNA gyrase

Mechanisms of disinfectants and antiseptics are less well understood and often involve more general and multiple cellular targets

Answer 42

Resistance to antiseptics and disinfectants
* The mechanisms of resistance developed against a disinfectant or antiseptic could confer resistance to an antibiotic
* The MOA of antibiotics are well known
➢ Single specific target → e.g., inhibitors protein, nucleic acid synthesis inhibitors of RNA polymerase, DNA gyrase

Mechanisms of disinfectants and antiseptics are less well understood and often involve more general and multiple cellular targets

Question 43

Resistance to antiseptics and disinfectants
MOA of disinfectants and antiseptics includes:
* Interaction with cell ____ or _____
* Disruption of membrane ________
* Inhibition of membrane _______
* _________ agents

Answer 43

Resistance to antiseptics and disinfectants
MOA of disinfectants and antiseptics includes:
* Interaction with cell wall or envelope
* Disruption of membrane integrity
* Inhibition of membrane enzymes
* Alkylating agents

Question 44

Expense
* Cost may be a factor in the selection of disinfectants and antiseptics
➢ Dilution of biocide used → overdilution may significantly _______ biocidal potency
The __________ recommendations should be followed when diluting a biocide
* The selection of biocides should be based primarily on _______ and ______, not cost

Answer 44

Expense
* Cost may be a factor in the selection of disinfectants and antiseptics
➢ Dilution of biocide used → overdilution may significantly reduce biocidal potency
The manufacture’s recommendations should be followed when diluting a biocide
* The selection of biocides should be based primarily on efficacy and safety, not cost

Question 45

Surgical antisepsis
* The application of antimicrobial chemicals to skin, mucosa, and wounds to reduce the risk of infection
* It is important to distinguish between antiseptic use on ___ skin and that on _____ membranes or in __________
→ different formulations and concentration of antiseptics are indicated
* Preparations containing ______ or ______ (scrubs) are to be used only on intact skin
* The concentration of antiseptic used in wounds is less, in general than that of
preparations applied to intact skin

Answer 45

Surgical antisepsis
* The application of antimicrobial chemicals to skin, mucosa, and wounds to reduce the risk of infection
* It is important to distinguish between antiseptic use on intact skin and that on mucous membranes or in wounds
→ different formulations and concentration of antiseptics are indicated
* Preparations containing alcohol or detergents (scrubs) are to be used only on
intact skin
* The concentration of antiseptic used in wounds is less, in general than that of
preparations applied to intact skin

Question 46

Surgical antisepsis
Surgical preparation of the skin →surgical hand scrub or alcohol-base hand rub
The purpose is to remove _______ flora and ______ resistant flora for the duration of surgery (glove tears)
The primary problem –> ______

• Nails should be ______
• _______ nails and nail ______ are discouraged!
• ______ should be removed from under the fingernails
  The _________ area has higher microbial counts. Contamination of the hands can
  increase when gloves create a ______, _____ environment

Answer 46

Surgical antisepsis
Surgical preparation of the skin →surgical hand scrub or alcohol-base hand rub
The purpose is to remove transient flora and reduce resistant flora for the duration of surgery (glove tears)
The primary problem –> negligence

• Nails should be short
• Artificial nails and nail polish are discouraged!
• Debris should be removed from under the fingernails
  The subungual area has higher microbial counts. Contamination of the hands can
  increase when gloves create a warm, moist environment

Question 47

Examples of Antiseptic Use In Veterinary Medicine
Surgical antisepsis
Duration of washing
→ for the __________ action
→ to allow antimicrobial products sufficient contact _____
* The American College of Surgeons suggests that a surgical scrub of _____ s., including
brushing of the _____ and ______ areas, is adequate
→ longer scrub may be performed by veterinary _______
Two alternatives
1. Initial water-and ____ cleansing followed by use of an ____-based rub for at least __ minutes
2. 5-minutes _______ or _______ hand scrub

Answer 47

Examples of Antiseptic Use In Veterinary Medicine
Surgical antisepsis
Duration of washing
→ for the mechanical action
→ to allow antimicrobial products sufficient contact time
* The American College of Surgeons suggests that a surgical scrub of 120 s., including
brushing of the nails and fingertip areas, is adequate
→ longer scrub may be performed by veterinary surgeons
Two alternatives
1. Initial water-and soap cleansing followed by use of an alcohol-based rub for at least 5 minutes
2. 5-minutes chlorhexidine or iodophor hand scrub

Question 48

Surgical antisepsis
Chlorhexidine techniques
→ the active agents have residual _________ activity (under surgical _____)
➢ It has been shown that Chx has negative effects on the skin of health care workers, resulting in:
→ tissue ________
→ elimination of beneficial deeper _________
→ predisposition to colonization with ______ bacteria

Answer 48

Surgical antisepsis
Chlorhexidine techniques
→ the active agents have residual bactericidal activity (under surgical gloves)
➢ It has been shown that Chx has negative effects on the skin of health care workers, resulting in:
→ tissue disruption
→ elimination of beneficial deeper microflora
→ predisposition to colonization with pathogenic bacteria

Question 49

Surgical antisepsis
Preoperative preparation of the veterinary patients
* Clipping and/or shaving
* Removal of gross contamination and dirt
* Gentle antiseptic scrubbing should begin at the incision site and move outward
over the entire surgical area
* Proper antiseptic contact time should be made. A final antiseptic spray is often
applied and left to dry on the surgical site

Question 50

Surgical antisepsis
Surgical preparation of mucous membranes
* Antisepsis of mucous membranes (oral) presents problems
→ Bacterial colonization is very high
→ The efficacy of oral antiseptics is affected by dilution effects
→ Inactivation due to salivary proteins
* An increase in antiseptic concentration is limited by local irritation
* Only a few solutions are useful as oral antiseptics: povidone-iodine, chlorhexidine,
and hexetidine
➢ Povidone-iodine solution reduces inflammation, the progression of periodontal disease
and bacteremia after dental extraction
➢ Chx can adsorb to negatively charged surfaces in the mouth such as the tooth and
mucosa

Question 51

Treatment of open wounds
How to properly treat a wound?
* Patient age
* General health status
* Cause
* Size and extent of contamination

The opinion is divided concerning the utility of antiseptics in routine wound care
* Some authors affirm this practice reduces the incidence of infections as a
complication
* Many reports in the literature discuss potential toxic and harmful effects of
antiseptics on fragile healing tissues
* Surface colonization of wounds does not imped healing

Any agent chosen should not
impede the healing process

Question 52

Treatment of open wounds
* Chlorhexidine diacetate solution (0.05%) has a wide spectrum of antimicrobial
activity and minimal deleterious effects on wound healing
* Saline or hypertonic saline have been proposed to be effective means of eliminating
debris and lowering bacterial counts
* A maximum of 1% of povidone iodine has been recommended as the most effective
and least tissue-toxic dilution
* A dilute Dakin’s solution (0.005% sodium hypochlorite) has been shown to be both
bactericidal and not damaging to fibroblasts
* Sodium hypochlorite solutions has been proposed for the treatment of atopic
dermatitis and recurrent pyoderma in dogs

Question 53

Disinfectants are widely used on:
* Floor
* Tables
* Walls
* Surgical equipment
* Instruments before storage
* Animal housing facilities
Manufacturer recommendation regarding → contact time, dilution, and useful life

Question 54

Salmonella
* There are many Salmonella serotypes. An important foodborne pathogen
* The control of Salmonella on production animal facilities is important for public
health even when animals are asymptomatic
* Salmonella outbreaks have caused interruptions in services at veterinary teaching
hospitals
To prevent loss of income and public confidence the most important is to decontaminate a
veterinary hospital quickly, efficiently, and effectively
➢ Disinfectant footbaths → Peroxygen compounds (75%) > QACs

Question 55

Salmonella
* Glutaraldehyde was found to be the most effective compound in reducing Salmonella
enteritis and S. senftenberg bacterial load in poultry houses
* Formaldehyde was also found to be effective even at low temperatures
* In a study that investigated disinfection of poultry transport containers, halogen compounds
and QAC were effective against artificially contaminated surfaces. Only sodium hypochlorite
or an iodine-containing disinfectant was able to achieve 100% reduction

Question 56

Avian influenza (Orthomyxoviridae)→ highly pathogenic avian influenza, HPAI
* As an envelope virus is sensitive to most detergents and disinfectants. The US Environmental
Protection Agency reports approx. 200 products registered for disinfection (included alcohols,
phenolics, oxidating agents)
* Infectious viruses can be recovered from manure for up to 105 days → removal of all organic
material. Contaminated litter and manure should be composted or buried