OCTC-Micro-Chapter 9 – Flashcards

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Antisepsis
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Reduction in the number of microorganisms and viruses, particularly potential pathogens on living tissue.
EX: iodine, alchool
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Antiseptics are frequently_________ whose strength has been ________ to make them safe for living tissues.
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disinfectants, reduced
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Aspetic refers to an environment or procedure free of ______.
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pathogenic contaminants.
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Examples of aseptic
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prep of surgical field, hand washing, flame sterilization of laboratory equipment.
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Scientists, laboratory technicians and health care workers routinely follow standardized _______ techniques
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aseptic
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-cide
-cidal
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suffixes indicating destruction of a type of microbe.
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Example of
-cide
-cidal
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Bactericide, fungicide, germicide, virucide
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Germicides include_____ oxide, ____oxide &_____.
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ethylene, propylene, aldehydes
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Degerming is the
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removal of microbes by mechanical means
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Examples of degerming
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Hand washing, alcohol swabbing at site of infection and skin scrubbing
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Disinfection
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Destruction of most microorganims and viruses on nonliving tissue
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Examples of disinfectants
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Phenolics, alcohols, aldehydes and soaps
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The term disinfection is primarily used in relation to _____.
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pathogens
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Pasturization
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use of heat to destroy pathogens and reduce the number of spoilage microorganisms in food and beverages
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Examples of Pasturization
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milk, fruit juices, wine, and beer
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in pasteurization, heat treatment is _____ to reduce alteration of taste and nutrients.
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brief
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in pasteurization,______ microbes still remain and eventually cause _______.
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non pathogenic, spoilage
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Sanitization
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removal of pathogen from objects to meet public health standards.
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Washing tableware in scalding hot water in restaurants is an example of?
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Sanitization
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Standards of _____vary among governmental jurisdictions.
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Sanitization
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What is the only difference of disinfecting dishes at home and sanitizing dishes at a restaurant?
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public (sanitization) vs. private (disinfection).
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-statis
-static
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suffixes indicating inhibition, but not complete destruction of a type of microbe
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What are some examples of -statis &
-static?
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Bacteriostatic, fungistatic, virustatc
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______ agents include some chemicals, refrigeration and freezing.
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Germistatic
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Sterilization
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Destruction (complete removal) of ALL microorganims and viruses in or on an object
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Preparation of microbial culture media and canned food is an example of what?
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Sterilization
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How is sterilization typically achieved?
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by steam, under pressure, incineration,or ethylene oxide gas.
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Sterilization does not apply to _____.
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prions(infectious proteins that cause mad cow disease)
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Only _____ destroys prions.
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incineration
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Commercial Sterilizationis defined as?
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sufficient heat treatment to kill endospores of Clostridium botulinum in canned food.
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Vegetables are available in _____ packaging
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aseptic
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What is the use of chemical methods for eliminating or reducing microbes and viruses (particularly pathogens) on the skin or living tissue?
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Antisepsis
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Antisepsis is a modification of _____?
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disinfection
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Disinfectants destroy vegetative pathogens but not ______?
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all viruses and bacterial endospores.
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Unlike sterilization, disinfection suggests that
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some viable microbes may persist.
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Disinfectants are_____concentrated and left on the surface of _______ longer.
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more inanimate objects
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Antiseptic are disinfectants whose strength is ______ to make them _______?
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reduced, safe for living tissue
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Examples of disinfection:
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1.applying a 5% solution of bleach to examining table
2.boiling eating utensils used by a sick person
3.immersing thermometers in iodine solution between use
4.combs soaked in ammonia solutions at barber shop.
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What is the term that refers to microbial contamination and growth of microorganisms in blood and tissues (think septic tank)?
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Sepsis
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Decontamination:
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Process of rendering an object, person, or area free of a substance
Such as:Bacteria, poison gas, radioactive substance
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Cide and cidal: Virucides
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inactivate viruses
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Cide and cidal: Bactericides
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kill bacteria
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Cide and cidal: Fungicides
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kill fungal hyphae, spores, yeast.
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Cide and cidal: Germicides
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are chemical agents kill pathogens in general.
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What is Microbial death?
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permanent loss of Reproductive ability of microbes under ideal environmental conditions.
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What is one way to evaluate the efficiency of an antimicrobial agent (chemical or physical)?
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calculate the microbial death RATE.
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What is Microbial Death Rate?
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the time it takes for heat or chemicals to kill a population of microorganism under certain conditions.
Ex. Boil (212 ?F) water 10 minutes
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Microbial death rate is usually ____ over time for a _____ pathogen under a ______ set of conditions.
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constant, particular, particular
For example: 90% of a population of microbes is killed per minute.
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In the death phase of cell population growth curve The cells die at a _____ rate. They die ______.
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constant, exponentially.
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The Viral envelop surrounds a _____
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viral protein.
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Viral Envelop is made up of proteins and phospholipids that are
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Responsible for attachment of virus to target cell.
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Damage to the viral envelop does what? Why?
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Fatally interrupts viral replication Because the enveloped virus is now unable to attach to the host cell.
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Non-enveloped viruses have _____tolerance of harsh conditions and antimicrobial agents because they do not _____ on the envelop to attach to the target cell.
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greater, depend
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Protein function depends on it specific _____ shape.
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3-D
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Microbial life depends on continuous supply of _____ to function as _____ and structural molecules.
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proteins, enzymes
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A perfect antimicrobial agent or method would be
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1.Inexpensive and fast-acting
2.Stable during storage
3.Control all microbial growth while being harmless to humans, animals, and objects
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Factors affecting Efficacy of Antimicobial methods
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1.What area is to be treated?
2.How susceptible or resistant is the microbe?
3.What are the Environmental conditions?
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1.What area is to be treated?
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Harsh chemicals and extreme heat cannot be used on humans, animals and fragile objects.
Needles and scalpels carry a greater potential for infection so they must be sterilized.
Items that contact the skin may be disinfected
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2.How susceptible or resistant is the microbe?
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Select a method to kill the hardiest microbes present and Assume that more fragile microbes are killed as well.
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The three most resistant microbes are:
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1.Bacterial endosproes
2.Species of Mycobacterium
3.Cysts of protozoa
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The Hardest Microbes to Treat (1)
1. Bacterial Endospores
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Endospores of Bacillus and Clostridium are the most resistant life forms
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Bacillus and Clostridium can survive in _______of temperature, chemicals, and acidity
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extremes
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The Hardest Microbes to Treat (2)
2.Mycobacterium
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cell walls have a waxy coat that prevents:
1.The entrance of water based chemical
2.Dehydration
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The Hardest Microbes to Treat (3)
3. Protozoal cysts wall prevents entry of:
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Most disinfectants
Protects protozoa against drying
Shields protozoa against heat, and radiation
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The effectiveness of germicides can be classified as _____ or ______.
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high or low
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_____ level germicides kill all pathogens, including bacterial endospores.
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high
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3.Environmental Conditions affect ______ of antimicrobials
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efficacy
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High temperatures and extremely low or high pH usually ____ the effectiveness of antimicrobial agents.
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increases
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Biofilms, and fat, feces, emesis, and blood usually _______ the effectiveness of antimicrobial agents. Therefore, It is very important to ______ objects before using disinfectants or sterilization.
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decrease, clean
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What are the four Methods for Testing or Evaluating the Effectiveness Disinfectants and Antiseptics?
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1.Phenol Coefficient
2.Use-Dilution Test
3.Disk-Diffusion Method
4.In-Use Test.
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1. Phenol Coefficient Test (Carbolic acid)
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Phenol (carbolic acid or benzene) was used by Lister in late 1850s
Phenol was the standard to test all other disinfectants and antiseptics.
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1.Phenol Coefficient Test (Carbolic acid)
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Researchers evaluated the efficiency of disinfectants and antiseptics when compared to phenol (carbolic acid).
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Phenol Coefficient Test has been replaced by newer methods because we
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no longer extensively use phenol as a antiseptic.
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2. Use-Dilution Test
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Use-dilution test is another method of evaluating efficacy of disinfectants and antiseptics.
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What is the first step used in the Use-dilution test?
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1.Metal rings dipped into broth cultures of bacteria are dried at 37C.
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What is the 2nd step used in the Use-dilution test?
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2. Rings with dried cultures are placed in different dilutions of a disinfectant:
Example: control (distilled water), 2%, 5%, 15% of Clorox solution.
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What is the 3rd step used in the Use-dilution test?
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3. Rings stay in solution for 10 min at 20°C (68F) and rinsed.
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What is the 4th step used in the Use-dilution test?
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4. Rings are transferred to nutrient agar and incubated to determine whether bacteria survived disinfectant treatment
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What is the 5th step used in the Use-dilution test?
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5. Look for growth on agar plate. The most effective agent is the one that entirely prevents microbial growth at the highest dilution.
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3.Kelsey-Sykes Capacity Test
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is the standard alernative assessment approved by the European Union to determine the capacity of a given chemical to inhibit bacterial growth.
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3.Kelsey-Sykes Capacity Test step 1
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1. Researchers add a suspension P. aeruginosa or S. aureus to different concentrations of chemical being tested
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3.Kelsey-Sykes Capacity Test step 2
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2.After predetermined time, move the mixture into broth with a disinfectant deactivator
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3.Kelsey-Sykes Capacity Test step 3
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3.Incubate for 48 hours
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3.Kelsey-Sykes Capacity Test step 4
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4.Measure turbidity
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3.Kelsey-Sykes Capacity Test step 5
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5.Lack of turbidity indicates lack of bacterial reproduction
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3. Disk-Diffusion Method aka Kirby-Bauer Method
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demonstrates the effectiveness of disinfectants and antiseptics on pathogens.
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Procedure for Disk-Diffusion Method
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A disk of filter paper is soaked in different chemical agents and then placed on an agar plate just previously inoculated with bacteria.
Bacteria are incubated and then observed.
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Disk-Diffusion Method results
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A clear zone around the disk indicates inhibition called zone of inhibition.
The visible area around disk is where bacteria did not grow.
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In Disk-Diffusion Method the ______
are measured to determine the microorganism’s sensitivity to the disinfectants, antiseptic or antibiotic.
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zones of inhibition
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The disk with the _____ zone of inhibition is the best agent to use against that particular pathogen.
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largest
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4.In-Use Test
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The In-Use Test is a more realistic method for determining the effectiveness of a disinfectant or antiseptic.
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In The In-Use Test Swabs are taken from ______before and after application of disinfectant or antiseptic.
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actual objects (operating room equipment)
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Describe what happens in the In-Use Test
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The swabs are inoculated onto nutrient agar plates and incubated.
The plates are monitored for growth before and after the disinfectant was used.
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List the 10 types of Physical Methods of Microbial Control (Table 9.4 pg. 270)
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1.Moist Heat = Boiling, Autoclaving (pressure cooking), Pasteurization and Ultrahigh-temperature sterilization.
2.Dry Heat = Hot air and Incineration
3.Refrigeration
4.Freezing
5.Desiccation (drying)
6.Lyophilization (freeze drying)
7.Filtration
8.Osmotic Pressure
9.Ionizing radiation (electron beams, gamma rays, X rays)
10.Nonionizing radiation (ultraviolet light)
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Heat = one of the older and more common means of _______.
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microbial control
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High Temperatures = ______ proteins, interfere with cell walls and cytoplasmic membranes, and disrupt function and structure of ______.
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denature, nucleic acids
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Thermal death point is
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lowest temperature required to kill bacteria in a broth in 10 minutes.
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Thermal death time is
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the time required to kill all bacteria in a broth at a given temperature.
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Decimal reduction time (D time) is the
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time required to kill 90% of the population of bacteria in a sample at a given temperature
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Researchers measure the effectiveness of heat sterilization by calculating the
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decimal reduction time.
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Thermal death time is the time it takes to completely _____ a particular volume of liquid at a set_______.
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sterilize, temperature
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How does high temperature control microbes in the environment?
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High temperatures denatures proteins, interferes with the integrity of cytoplasmic cell walls and disrupts the function and structure of nucleic acids.
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List 6 heat-related methods used in microbial control.
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1.Moist heat
2.Boiling
3.Autoclaving
4.Pasteurization
5.Ultrahigh-temperature sterilization
6.Dry heat
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Moist Heat is used to do what 4 things?
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disinfect, sanitize, sterilize, pasteurize.
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4 Types of Moist heat
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Boiling
Autoclaving
Pasteurization
Ultrahigh-Temperature Sterilization
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Boiling (100?C) kills _______ cells of bacteria and fungi, protozoan trophozoites, and most viruses within
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vegetative, 10 minutes at sea level.
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Boiling does not kill which 3 things and why?
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endospores, protozoan cysts, and some viruses. because they can survive boiling for 10 minutes at sea level
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Will it require longer boiling time in Denver or Los Angeles?
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It takes a longer boiling time in Denver.
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Why does it require longer boiling time in Denver or Los Angeles?
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Water boils at lower temperatures at higher elevations because there is less air pressure and steam escapes more quickly and pulls of excess heat.
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When is an autoclave required?
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An autoclave is used when sterilization is required.
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Autoclaving does not let the ____escape and water will boil at a ____temperature.
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steam , higher
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Autoclaves are used to sterilize ____?
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medical and laboratory supplies that can tolerate heat and moisture.
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The Autoclave conditions are?
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121?C, 15 psi, 15 minutes.
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what are used to check for sterility of the items being autoclaved.
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Bacillus stearothermophilus endospores
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Pasteurization is a method of _____ & ______Without altering the quality of the food
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Heating foods to kill pathogens
Control spoilage organisms
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Pasteurization is used for:
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Milk
Ice cream
Yogurt
Fruit juices
Beer and Wine
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Pasteurization is not
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sterilization.
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Dairy industry and other food processors use:Ultrahigh-temperature sterilization
To rid liquids of
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all living microbes.
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Liquids are passed through super heated steam at 140?C (284?F) for 1-3 second, then rapidly cooled. What is this?
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Ultrahigh-temperature sterilization
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milk and other liquid products passed through Ultrahigh-temperature sterilization can be
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stored indefinitely at room temperature.
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What is a better conductor of heat… water or air?
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water
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What is more effective in controlling microbes in the environment… moist heat or dry heat?
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Moist heat is more effective than dry heat because water is better conductor of heat than air.
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At sea level, what does boiling at 100C kill? What does it not kill?
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Boiling (100?C) kills vegetative cells of bacteria and fungi, protozoan trophozoites, and most viruses not kill endospores, protozoan cysts, and some viruses
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In Denver, will water boil at a greater than 100C or less than 100C?
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less then because Water boils at lower temperatures at higher elevations because there is less air pressure and steam escapes more quickly and pulls of excess heat.
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Will it take longer or less time to boil water for 10 minutes to kill microbes in Los Angeles as compared to Denver?
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less time because there is more pressure
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Autoclaving:
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device that uses steam heat under pressure to sterilize chemicals and objects that can tolerate moist heat.
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Autoclaving needs less than _____to sterilize an object at _______.
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15 mins, 121 C
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Autoclaving denatures______ and destroys______.
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proteins, membranes
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Pasteurization
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the use of heat to kill pathogens and reduce the number of spoilage microorganisms in dairy products, fruit juices, beer, and wine
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4 types of pasteurization of milk:
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1.Historical (batch) pasteurization
2.Flash pasteurization
3.Ultrahigh-temperature pasteurization
4.Ultrahigh- temperature sterilization:
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