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What is the definition of the term Sterilization?
What is the definition of the term Sterilization?
Sterilization is the removal of all microorganisms.
What is the definition of the term Disinfection?
What is the definition of the term Disinfection?
Disinfection is the elimination of most or all pathogens.
What is the definition of the term Decontamination?
What is the definition of the term Decontamination?
Decontamination involves reducing pathogens to levels that are considered safe to handle.
What is the definition of the term Sanitized?
What is the definition of the term Sanitized?
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What is the definition of the term Preservation?
What is the definition of the term Preservation?
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Heat treatment is often used to sterilize or disinfect.
Heat treatment is often used to sterilize or disinfect.
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Which of the following is the most common and reliable mechanism for food preservation?
Which of the following is the most common and reliable mechanism for food preservation?
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What is the name of the industrial-sized autoclave used in the commercial canning process?
What is the name of the industrial-sized autoclave used in the commercial canning process?
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Which of these factors can potentially interfere with the effectiveness of heat penetration and the action of chemicals during sterilization?
Which of these factors can potentially interfere with the effectiveness of heat penetration and the action of chemicals during sterilization?
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Which of the following factors can influence the effectiveness of sterilization methods?
Which of the following factors can influence the effectiveness of sterilization methods?
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What is the term for the time required to kill 90% of a microbial population under specific conditions?
What is the term for the time required to kill 90% of a microbial population under specific conditions?
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Most medical instruments categorized as critical items should be sterilized.
Most medical instruments categorized as critical items should be sterilized.
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Which type of medical instrument falls under the category of semicritical?
Which type of medical instrument falls under the category of semicritical?
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Non-critical medical instruments are those that only come into contact with unbroken skin.
Non-critical medical instruments are those that only come into contact with unbroken skin.
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Which of the following methods is generally considered inappropriate for sterilizing plastics and other sensitive items due to potential damage?
Which of the following methods is generally considered inappropriate for sterilizing plastics and other sensitive items due to potential damage?
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Boiling water can effectively sterilize materials.
Boiling water can effectively sterilize materials.
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What is the term for the high-temperature, short-time heat treatment often used for pasteurizing milk products?
What is the term for the high-temperature, short-time heat treatment often used for pasteurizing milk products?
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What is the term for the extremely high-temperature heat treatment often used for pasteurizing milk products, which produces shelf-stable products?
What is the term for the extremely high-temperature heat treatment often used for pasteurizing milk products, which produces shelf-stable products?
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The process of using pressurized steam to sterilize materials is commonly done in an autoclave.
The process of using pressurized steam to sterilize materials is commonly done in an autoclave.
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Dry heat sterilization is generally considered less effective than moist heat sterilization.
Dry heat sterilization is generally considered less effective than moist heat sterilization.
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Incineration is a method of dry heat sterilization.
Incineration is a method of dry heat sterilization.
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Which of the following methods is commonly used to sterilize heat-sensitive materials and is often employed for packaging medical supplies and instruments?
Which of the following methods is commonly used to sterilize heat-sensitive materials and is often employed for packaging medical supplies and instruments?
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Ultraviolet radiation is generally considered an effective method for sterilizing objects in turbid liquids.
Ultraviolet radiation is generally considered an effective method for sterilizing objects in turbid liquids.
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High-pressure processing is a method used for pasteurizing commercial foods like guacamole, and it is usually employed at pressures up to 130,000 psi.
High-pressure processing is a method used for pasteurizing commercial foods like guacamole, and it is usually employed at pressures up to 130,000 psi.
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Sterilants are designed to destroy all microorganisms, including viruses and endospores.
Sterilants are designed to destroy all microorganisms, including viruses and endospores.
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High-level disinfectants are effective against viruses and vegetative cells, but they are typically not effective against endospores.
High-level disinfectants are effective against viruses and vegetative cells, but they are typically not effective against endospores.
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Intermediate-level disinfectants are effective against bacteria and fungi, but they aren't typically effective against mycobacteria. They are commonly used for non-critical instruments.
Intermediate-level disinfectants are effective against bacteria and fungi, but they aren't typically effective against mycobacteria. They are commonly used for non-critical instruments.
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Low-level disinfectants are effective against fungi and most vegetative bacteria, but they are typically not effective against mycobacteria, endospores, or naked viruses.
Low-level disinfectants are effective against fungi and most vegetative bacteria, but they are typically not effective against mycobacteria, endospores, or naked viruses.
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Alcohols are generally considered to be both readily biodegradable and relatively inexpensive.
Alcohols are generally considered to be both readily biodegradable and relatively inexpensive.
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Aldehydes are more effective against a wider range of microorganisms compared to alcohols.
Aldehydes are more effective against a wider range of microorganisms compared to alcohols.
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Chlorhexidine is commonly used as an antiseptic in soaps, lotions, and mouthwashes.
Chlorhexidine is commonly used as an antiseptic in soaps, lotions, and mouthwashes.
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Ethylene oxide is commonly used to sterilize medical devices because it's very effective in destroying endospores.
Ethylene oxide is commonly used to sterilize medical devices because it's very effective in destroying endospores.
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Halogens are reliable in destroying all types of bacteria, including endospores.
Halogens are reliable in destroying all types of bacteria, including endospores.
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Metal compounds, such as mercury and tin, are still widely used as preservatives due to their effectiveness and safety profile.
Metal compounds, such as mercury and tin, are still widely used as preservatives due to their effectiveness and safety profile.
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Ozone is a powerful oxidizing agent that is known for its effectiveness in disinfecting drinking water and wastewater, and is often used as an alternative to chlorine.
Ozone is a powerful oxidizing agent that is known for its effectiveness in disinfecting drinking water and wastewater, and is often used as an alternative to chlorine.
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Hydrogen peroxide is a highly effective sterilant that's often used to sterilize medical instruments and equipment.
Hydrogen peroxide is a highly effective sterilant that's often used to sterilize medical instruments and equipment.
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Peracetic acid is a strong oxidizer that's considered more potent than hydrogen peroxide.
Peracetic acid is a strong oxidizer that's considered more potent than hydrogen peroxide.
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Phenolic compounds are known for their wide range of activity and their effectiveness in the presence of detergents and organic contaminants.
Phenolic compounds are known for their wide range of activity and their effectiveness in the presence of detergents and organic contaminants.
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Quaternary ammonium compounds (quats) are cationic detergents that are typically used to disinfect food preparation surfaces.
Quaternary ammonium compounds (quats) are cationic detergents that are typically used to disinfect food preparation surfaces.
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Weak organic acids, such as benzoic, sorbic, and propionic acid, are commonly used as food preservatives to inhibit microbial growth.
Weak organic acids, such as benzoic, sorbic, and propionic acid, are commonly used as food preservatives to inhibit microbial growth.
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Nitrate and nitrite are commonly used in processed meats to prevent the growth of Clostridium botulinum, which can cause deadly botulism.
Nitrate and nitrite are commonly used in processed meats to prevent the growth of Clostridium botulinum, which can cause deadly botulism.
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Refrigeration effectively inhibits the growth of all microorganisms.
Refrigeration effectively inhibits the growth of all microorganisms.
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Freezing food is considered a highly effective method for eliminating all microorganisms.
Freezing food is considered a highly effective method for eliminating all microorganisms.
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Adding salt or sugar to food can effectively prevent microbial growth by reducing the available water for microorganism activity.
Adding salt or sugar to food can effectively prevent microbial growth by reducing the available water for microorganism activity.
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Lyophilization, also known as freeze drying, is a method commonly used to preserve food products like coffee, milk, meats, fruits, and vegetables.
Lyophilization, also known as freeze drying, is a method commonly used to preserve food products like coffee, milk, meats, fruits, and vegetables.
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Drying food, while effective in inhibiting microbial growth, does not reliably kill all microorganisms, and there have been cases of illnesses like salmonellosis from dried eggs.
Drying food, while effective in inhibiting microbial growth, does not reliably kill all microorganisms, and there have been cases of illnesses like salmonellosis from dried eggs.
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Study Notes
Chapter 5: Control of Microbial Growth
- Microbial control methods vary depending on the situation and desired level of control.
- Joseph Lister's work revolutionized surgery by introducing methods to prevent wound infections.
- Lister utilized carbolic acid (phenol) and sterilized instruments to prevent infections.
- Modern hospitals utilize strict procedures to prevent microbial contamination.
Principles of Control
- Sterilization: Eliminates all microorganisms, including endospores and viruses (but not prions).
- Disinfection: Eliminates most or all pathogens; some viable microbes may remain.
- Disinfectants: Used on inanimate objects.
- Antiseptics: Used on living tissues.
- Pasteurization: Brief heating to reduce spoilage organisms and pathogens.
Approaches to Control (continued)
- Decontamination: Reduces pathogens to safe levels.
- Sanitization: Reduces microbial population to meet health standards.
- Preservation: Delays spoilage of perishable food and other products.
- Add bacteriostatic (growth inhibiting) preservatives.
Daily Life
- Washing and scrubbing with soaps and detergents is a common method to reduce microbial populations.
- Soap mechanically removes organisms.
- Beneficial skin microbiota reside deeper, so regular handwashing is not adversely affected.
Hospitals
- Minimizing microbial populations is crucial for preventing healthcare-associated infections.
- Patients undergoing invasive procedures are more susceptible to infections.
- Hospital settings frequently contain pathogens like fecal, urine, respiratory droplets and bodily secretions.
- Instruments must be sterilized to prevent introducing infections to deep tissues.
- Prions are a new concern because they are difficult to destroy.
Food and Food Production Facilities
- Perishables retain quality longer when microbes are removed, destroyed, or inhibited.
- Heat treatment is a common method.
- Irradiation is used to control certain foods.
- Chemical additives can control spoilage.
- Facilities must maintain clean surfaces to minimize microbes.
Water Treatment Facilities
- Ensuring safe drinking water involves removing pathogens.
- Chlorine is traditionally used to disinfect water, although it can react with naturally occurring chemicals to create disinfection by-products (DBPs).
- Some DBPs are linked to long-term health risks.
- Some organisms, like Cryptosporidium parvum, are resistant to chemical disinfectants.
- Regulations require minimization of DBPs and C. parvum in treated water.
Selection of an Antimicrobial Procedure
- Selecting effective procedures can be challenging due to the existence of various factors involved in the process.
- Factors like the type and number of microbes, environmental conditions, risk of infection, and the composition of the infected item are important considerations.
- Multiple highly resistant microbes, like bacterial endospores and protozoan cysts, require extreme conditions to completely destroy them.
- The time needed for heat or chemicals to kill microbes depends on microbial population size.
- Environmental conditions like dirt, grease, body fluids can interfere with effective microbial control, and factors like pH and temperature influence chemical effectiveness.
Composition of Item
- Certain sterilization and disinfection methods are inappropriate for certain items like plastics.
- Irradiation provides a viable alternative to heat for moisture-sensitive materials.
Using Heat to Destroy Microorganisms and Viruses
- Heat treatment is a safe and relatively fast method.
- Moist heat, a reliable method for denaturing proteins and destroying microorganisms, includes boiling, pasteurization, and sterilization using pressurized steam (autoclaving) and flash sterilization.
- Dry heat is less effective than moist heat, but can be used for sterilization in hot air ovens.
Using Other Physical Methods to Remove or Destroy Microbes
- Filtration methods remove microbes from fluids and is extensively used in both liquids and air.
- Membrane filters with small pore sizes are frequently used.
- HEPA (high-efficiency particulate air) filters remove nearly all microbes from air.
- Radiation, including ultraviolet light and gamma rays, can be used to destroy microbes, but have limitations pertaining to penetrating power.
Chemical Methods to Remove or Destroy Microbes
- Sterilants destroy all microorganisms, whereas high-level disinfectants typically destroy viruses, vegetative cells, and some fungi.
- Intermediate and low-level disinfectants target different microorganisms.
- Chemical disinfectants have limitations based on the nature of the material being sanitized, organic matter, or the chemical residue left behind after use.
Preservation of Perishable Products
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Chemical preservatives must be non-toxic for safe consumption.
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Weak organic acids and nitrites are commonly used as preservatives.
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Nitrates and nitrites inhibit microbial growth, particularly in processed meats.
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They preserve the color and increase the safety of processed meats but are known carcinogens.
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Low-temperature storage of perishable products slows or stops enzyme reactions. Avoiding microbial growth is crucial to preserving the quality and safety of perishable products.
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Reducing available water through salting, adding sugar, and drying food reduces microbial growth based on the removal of water from bacterial cells.
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Description
Explore the key concepts of microbial control methods covered in Chapter 5. Learn about sterilization, disinfection, and the historical impact of Joseph Lister’s contributions to surgery. This quiz will test your understanding of how various techniques are applied in modern healthcare settings.
