WorksheetsChapter 5 and 20 Controlling Microbial Growth
Total questions: 44
Worksheet time: 22mins
Which of these are NOT physical processes of control?
Heat
Antimicrobial chemicals
Irradation
Mechanical
What is sterilization?
Removing or destroying ALL microbes on or in a product
Eliminating most or all pathogens
Reducing the number of pathogens to a safe level
Delaying spoilage of perishable products
What is disinfection?
The removal or destruction of all microbes on or in a product
Delaying spoilage of perishable products
Elimination of most or all pathogens on or in a product
Reducing the number of pathogens to a safe level
What is preservation?
Delaying spoilage of perishable products
Elimination of most or all pathogens on or in a product
Removal or destruction of all microbes on or in a product
Reduction of the number of pathogens to a safe level
What is decontamination?
Delaying spoilage of perishable products
Elimination of most or all pathogens on or in a product
Removal or destruction of all microbes on or in a product
Reducing the number of pathogens to a safe level
Which of these is NOT a type of highly resistant microbes?
Endospores
Enveloped Viruses
Protozoan Cysts and Oocysts
Mycobacterium Species
Pseudomonas species
In daily life...
You should use chlorine in your water
You should irradiate your food before you eat it
You should sterilize your dishes once a day
You should wash with soap and water, which aids in mechanical removal of microbes
It is important to consider situations when deciding how to address microbial control. This is because in daily life, mechanical washing of dishes is enough, but in a hospital, during surgery, sterilization may be needed.
True
False
It takes more time to kill a small population of microorganisms than it does to kill a large population.
True
False
What is the D value?
The disinfectant time (or time it takes to kill 50% of the organism's population)
The decimal reduction time (or time required to kill 90% of bacteria)
A value from a direct count
A value comparing dead bacteria to the direct count
Which of these are reasons that a disinfectant may be more or less effective at killing bacteria? (SELECT ALL THAT APPLY)
Dirt, grease, and blood
Biofilms
Temperature
pH
color of disinfectant used
Environmental Conditions do not alter the effectiveness of disinfectants and sterilization techniques.
True
False
Critical instruments...
Come into direct contact with body tissues and MUST be sterile
Come into contact with mucous membranes, but do not penetrate the body tissues and must be free of viruses and vegetative bacteria
Only contact unbroken skin and there is very little risk of infection
Semi-critical Instruments...
Come into direct contact with body tissues and MUST be sterile
Come into contact with mucous membranes, but do not penetrate the body tissues and must be free of viruses and vegetative bacteria
Only contact unbroken skin and there is very little risk of infection
Non-critical Instruments...
Come into direct contact with body tissues and MUST be sterile
Come into contact with mucous membranes, but do not penetrate the body tissues and must be free of viruses and vegetative bacteria
Only contact unbroken skin and there is very little risk of infection
Why does the composition of the item to be sterilized matter?
It doesn't! Anything can be sterilized with any method
The material can dictate the sterilization methods that is needed. For example, not all plastics can be used in an autoclave.
Everything can be autoclaved, however, not everything can be sterilized using dry heat.
Boiling...
Brief heat that prevents spoilage without significantly changing the quality of foods and drinks.
A commercial process of sterilization using an industrialized autoclave.
A process of using pressurized stream (at 15psi) and heat (of 121 degrees C)
Easily destroys most microbes, takes about 5 minutes and is a form of moist heat. However, endospores can survive.
Commercial canning is...
Brief heat that prevents spoilage without significantly changing the quality of foods and drinks.
A commercial process of sterilization using an industrialized autoclave.
A process of using pressurized stream (at 15psi) and heat (of 121 degrees C)
Easily destroys most microbes, takes about 5 minutes and is a form of moist heat. However, endospores can survive.
Sterilization is...
Brief heat that prevents spoilage without significantly changing the quality of foods and drinks.
A commercial process of sterilization using an industrialized autoclave.
A process of using pressurized stream (at 15psi) and heat (of 121 degrees C)
Easily destroys most microbes, takes about 5 minutes and is a form of moist heat. However, endospores can survive.
Pasteurization is...
Brief heat that prevents spoilage without significantly changing the quality of foods and drinks.
A commercial process of sterilization using an industrialized autoclave.
A process of using pressurized stream (at 15psi) and heat (of 121 degrees C)
Easily destroys most microbes, takes about 5 minutes and is a form of moist heat. However, endospores can survive.
Dry heat kills bacteria better than moist heat
True
False
Filtration can be of both air and fluid and is used to remove microorganism
True
False
Radiation does NOT include...
Ionization
Ultraviolet light
Heat
Microwaves
What does UV light do to cells?
UV light causes the cell wall to burst and kills the cell (so endopsores are resilient because they have a thick cell wall)
UV light damages the DNA in actively dividing organisms (making endospores resilient)
UV light creates heat that is lethal to the organisms, but heats unevenly, so some microbes are uneffected
Causes the cells to go radioactive because UV is a form of radiation
Why is microwaving raw foods ineffective in killing all bacteria in the food and, therefore, not a good method for preparing food?
Microwaves directly harm cell DNA in actively dividing cells, so endospores can survive.
Microwaves have poor penetration and can be filtered out by glass or oils, allowing some bacteria to survive
Microwaves create radiation that, when used to cook food, can cause bacteria to mutate.
Microwaves do not heat evenly, which allows some heat-sensitive cells survive
How does pressure kill bacteria?
By denaturing proteins and altering the permeability of membranes
By causing thymine on the DNA to stick together creating thymine dimers, preventing the cell from replicating or carrying out cellular metabolism
By targeting specific membrane molecules and destroying the cell through apotosis
Pressure slows the growth of many pathogens, but does not kill or reduce their number
Which of these are important to take into account when choosing a chemical to destroy bacterial agents? (SELECT ALL THAT APPLY)
Potentcy
Toxicity
Residue
Cost and availability
Temperature
Freezing kills bacteria.
True -- proteins are denatured at a low temperature, which prevents them from ever growing again
False -- freezing stops microbial growth, and can even kill some cells, but most grow once they thaw
Lyophilization is..
A type of radiation used to kill bacteria
Freeze-drying
A process of canning where a giant autoclave is used
The process of adding sugar or salt to something to reduce water availability in a cell.
Which of these will NOT cause bacteria to evolve and become resistant to antibiotics?
Overmedicating
Following directions and finishing antibiotics completely (not stopping them once you feel better)
Using antibiotics anytime you don't feel well
Taking antibiotics for viruses -- it does the same thing!
What is the therapeutic index?
The index used to decide which medication or therapy to use for a particular issue
The time it takes for a medication to take effect
An index on how an antibiotic interferes with mechanisms or structures specific to bacteria
The safe amount of a medication calculated by the lowest dose toxic to a patient divided by dose typically used
Why would you use a broth dilution test?
To discover how well a certain bacteria grows on a plate
To find the lowest dose of an antibiotic needed needed
To see if you are using proper antiseptic technique
To discover if bacteria can grow in different concentrations of TSB
Bacteriostatic chemicals kill bacteria
True -- they often target cell walls causing the bacteria to die
False -- they inhibit bacterial growth, allowing the bacteria to be eliminated safely
Bactericidal chemicals kill bacteria
True -- they target specific features of the bacteria and cause cell death
False -- they inhibit bacterial growth, allowing the bacteria to be eliminated safely
If you know the bacteria you are trying to kill you would use a...
Broad-Spectrum antibiotic to affect a wide range of bacteria
Narrow-Spectrum antibiotic that is specific to that type of bacteria
Broad-Spectrum Antibiotics
Have few side effects and are the best choice for most people, covering a broad range of people
Are used on all people and do not depend on genetics to determine how effective they will be on a specific person
Affects a limited range of bacteria
Affects a wide range of bacteria including the normal microbiota which puts the patient at risk for other infections.
Antagonistic Drugs
Enhance each other and increases their effectiveness
Counteract each other when in combination
Do not work together or against each other.
Antagonistic Drugs
Do not work together or against each other
Counteract each other when in combination
Enhance each other and increases their effectiveness
Additive drugs
Do not work together or against each other (are not antagonistic or synergistic)
Counteract each other when in combination
Enhance each other and increases their effectiveness
Which of these are NOT adverse or side effects of antibiotics?
Allergic reactions
Suppression of normal microbiota -- could allow some unwanted microbes to establish themselves
Toxic effects -- usually at high concentrations
Overgrowth of normal microbiota
Which of these is an example of innate/intrinsic resistance??
Horizontal gene transfer
A type of developed resistance in a previously sensitive organism
Spontaneous mutation
A bacteria lacks a cell wall naturally, so it is not targeted by bacteria
Which of these is an example of acquired resistance?
Gram negative and having a lipid bilayer that prevents some molecules from entering
Through spontaneous gene mutation or horizontal gene transfer
Bacteria lacks a cell wall and, therefore, is resistant to penicillin
Through a process of metabolizing the antibiotic and creating a cure
Which of these are mechanisms of bacterial resistance to antibiotics (SELECT ALL THAT APPLY)
Alteration in target molecules
Increased elimination of medication
Antibiotic-inactivating enzymes
Decreased uptake of medications
Gene transfer is where a bacteria shares and R plasmid, which carries several resistance genes to another bacteria.
True
False
