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94 Cards in this Set

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_____ refers to the removal or destruction of all microbes includeing viruses and bacterial endospores, in or on an object.
sterilization
True or False

Sterilization destroys prions.
False. Prions (infections proteins) is not destroyed by standard sterilization techniques.
True or False

Sterilization can leave behind some innocuous microbes.
True- as in commercial sterilization does not kill all hyperthermophilic microbes
____ describes an environt or procedure that is free of contamination by pathogens.
aspetic
____ refers to the use of physical or chemical agents knowns as disinections.

Give some examples.
disinfections

examples: UV light, heat, alcohol
What is the difference between disinfection and antisepsis?
Disinfection refers to treatment of inanimate objects whereas as antisepsis is used when referring to the chemical application on tissues.
____ is the removal of microbes from a surface by scrubbing.
degerming
____ is the process of disinfecting places and utensils used by the public to reduce the number of pathogenic microbes to meet accepted public health standards.
sanitization.
___ is the use of heat to kill pathogens and reduce the number of spoilage microorgansims in food and beverages.
Pasteurization
What suffices indicate the inhibition, but not complete destruction of a type of microbe?
-stasis
-static
Define microbial death.
The permamnent loss of reproductive ability under ideal environemental conditions.
How can the efficact of an antimicrobial agent be evaluated?
By calculating the microbial death rate
What is the term used for removing microbes by mechanincal means?
degerming
True or False

The microbial death rate is usually found to be constant over over time.
True
What are the two classifiucations of the actions of antimicrobial agents?
1. Alteration of cell walls and membranes

2. Damage to proteins and nucleic acids
What portion of the ribosome is responsible for catalyzing the synthesis of proteins?
Ribozyme
What are the three factors that affect the efficacy of antimicrobial methods?
1. Site to be treated
2. Relative susceptibility of microoganisms
3. Environmental conditions
List microbes in order of those most susceptible to those most resistant
Enveloped viruses
Gram-positive viruses
Fungi
Gram-negative bacteria
Active stage protozoa
(which are aka trophozoites)
cysts of protozoa
Mycobacteria
Bacterial Endospores
List 3 of the MOST hardiest organisms from lesser to greater.
Cysts of protozoa- cell wall prevents disinfectant entry and protects against drying, radiation, and heat.

Mycobacterial (such as mycobacterium tuberculosis) has large amounts of waxy lipids that protect against drying and most water-bassed chemicals

Bacterial endospores- (such as bacillus and clostridium) and can survive harsh environmental extremes of temperature and acidity as well as chemical disinfectants
The effectiveness of ____ can be measured as high, intermediate, and low.
Germicides
What does an intermediate level germicide kill?
fungal spores, protozoan cysts, viruses, and pathogenic bacteria, but NOT endospres.
True or False

Warm disinfectants work better than cool ones
True
True or false

Antimicrobial effect of heat is decreased by an acididc environment.
False, it is enhanced by an acidic environment.
___ is the use of heat to kill pathogens and reduce the number of spoilage microorgansims in food and beverages.
Pasteurization
What suffices indicate the inhibition, but not complete destruction of a type of microbe?
-stasis
-static
Define microbial death.
The permamnent loss of reproductive ability under ideal environemental conditions.
How can the efficact of an antimicrobial agent be evaluated?
By calculating the microbial death rate
What is the term used for removing microbes by mechanincal means?
degerming
True or False

The microbial death rate is usually found to be constant over over time.
True
What are the two classifiucations of the actions of antimicrobial agents?
1. Alteration of cell walls and membranes

2. Damage to proteins and nucleic acids
What portion of the ribosome is responsible for catalyzing the synthesis of proteins?
Ribozyme
What are the three factors that affect the efficacy of antimicrobial methods?
1. Site to be treated
2. Relative susceptibility of microoganisms
3. Environmental conditions
List microbes in order of those most susceptible to those most resistant
Enveloped viruses
Gram-positive viruses
Fungi
Gram-negative bacteria
Active stage protozoa
(which are aka trophozoites)
cysts of protozoa
Mycobacteria
Bacterial Endospores
List 3 of the MOST hardiest organisms from lesser to greater.
Cysts of protozoa- cell wall prevents disinfectant entry and protects against drying, radiation, and heat.

Mycobacterial (such as mycobacterium tuberculosis) has large amounts of waxy lipids that protect against drying and most water-bassed chemicals

Bacterial endospores- (such as bacillus and clostridium) and can survive harsh environmental extremes of temperature and acidity as well as chemical disinfectants
The effectiveness of ____ can be measured as high, intermediate, and low.
Germicides
What does an intermediate level germicide kill?
fungal spores, protozoan cysts, viruses, and pathogenic bacteria, but NOT endospres.
True or False

Warm disinfectants work better than cool ones
True
True or false

Antimicrobial effect of heat is decreased by an acididc environment.
False, it is enhanced by an acidic environment.
What are the three methods for evaluating disinfectants?
1. Phenol coefficient
2. use dilution test
3. in-use test
Define phenol coefficient
a ratio that compares an antimicrobial agent's efficacy against a microbe to that of phenol's
A phenol coefficient greater than ___ indicates that an antimicrobial agent is more effective than phenol
1.0
Which of the following bacteria is not used in a use-dilution test?

a. Salmonella cholerasuis
b. Salmonella enterica
c. Staphylococcus aureus
d. Psuedomonas aeruginosa
b. Salmonella enterica
Which of the following tests is used as a current standard test for evaluating disinfectants and antispetics?

a. phenol coefficient
b. in-use test
c. use-dilution test
d. all of the above
c. use-dilution test
Which of the following test applies to more real life situations and why?
a. phenol coefficient
b. in-use test
c. use-dilution test
d. none of the above
b. in-use test because the antimicrobial agent is compared to a range of microbes found in biofilms as opposed to just one or a few microbes used in the other tests.
What are the 5 physical methods of microbial control?
Exposure to the microbes to extremes of heat and cold, dessication, filtration, osmotic pressure, and radiation
______ is the lowest temperature that kills all cells in a broth in 10 minutes.
Thermal death point
_____ is the time it takes to completely sterilize a particular volume of liquid at a set temperature
Thermal death time
Define decimal reduction time.
It is the time required to destroy 90% of the microbes in a sample
Which endospore is used as a reference for heat sterilization in foods?
clostridium botulinum
Which is more effective at killing microbes: moist or dry heat? Why?
Moist heat is more effective because water is a better conductor then heat.
Boiling kills vegetative cells of bacteria and fungi, the trophozoites of protozoa, and most viruses within ____ minutes at sea level.
10
Autoclaves use ___ in conjunction with steam to achieve sterilization.
Pressure
In autoclaving, temperature, pressure, and time for sterilization are:
121 degrees celsius, 15 lbs of pressure, 10 minutes
What is a biological indicator used to assess sterilization in autoclaving?
Bacillus stearothermophilus
Which of the following are controlled in pasteurization?

a. Brucella melitensis
b. Mycobacterium Bovis
c. Escherichia coli
d. All of the above
d. all of the above
True or False

Pasteurization = sterilization
False, Thermoduric (heat tolernt) and thermophilic (heat loving) survive
Milk used to be pasteurized using the ____ method for 30 minutes at 63 degrees celsius.
batch
List two types of pasteurization used today.
Flash pasteurization-milk flows through tubes heated to 72 for 15 minutes

Ultrahigh-temperature pasteurization- milk is heated to 140 degrees celsius for 1-3 seconds
Dry heat sterilization occurs at ___ degrees celsius for 1 hour or ___ degrees celsius for 2 hours.
170
160
Refigeration halts the growht of most pathogens that are predominately ____ with the exceptions of ___ and ___.
mesophiles
listeria
yersinia
____ us an antimicrobial technique which combines freezing and drying.
lyophilization
Give some examples where filtration is used.
opthalamic solution, antibiotics, vaccines, liquid vitamins, enzymes, and culture media.
What does HEPA stand for?
High efficiency particulate air
____ pressure inhibits microbial growth in foods by utilizing high concentrations of salt and sugar in foods.
Osmotic
What are the two types of radiation used?
particulate radiation and electromagnetic radiation
What symbol is used to show that foods in the US are irradiated?
radura
Wavelengths shorter than 1 nm are ____ forms of radiation.
ionizing
wavelengths greater than 1 nm in length are ____ forms of radiaiont.
nonionizing
True or False

UV light is a form of ionizing radiation
False

UV light is a form of non-ionizing radiation
List some chemcial methods of microbial control
phenol and phenolics, halogens, oxidizing agents, surfactants, heavy metals,aldehydes, gaseous agents
What are two examples of bisphenolics?
orthophenylphenol and triclosan
True or False

Phenolics are intermediate to low-level disinfectants that denature proteins and disrupt cell membranes in a wide variety of pathogens
True
List some positives and negatives of phenol
Positives: effective in the presence of contaminating organic material and are active on surfaces for long time

Negative: smelly and possible side effects
Alcohols are not effective against which of the following?

a. fungal spores
b. bacterial endospores
c viruses
d. a and b
d. a and b
Alcohols are considered ___ level disinfectants
intermediate
Alcohols function in what way?
Denature proteins and disrupt cytoplasmic membranes
____ are solutions of other antimicrobial chemcials in alcohols.
tinctures
Give an example of a halogen disinfectant
iodine
How do oxidizing agents work and give some examples?
Oxidizing agents such as peroxides, ozone, and peracetic acid work by oxidizng microbial enzymes which prevent metabolism.
Oxidizing agents are ___ level disinfectants
high
How do surfactants work?
They reduce surface tension which allows the solvent to become more effective at dissolving solute materials.
What are two common surfactants used?
Soap and detergens
What are the most popular detergents for microbial control?
Quaternary ammonioum compounds or quatas

-NH4, hydrogen atoms replaces by other functional groups or hydrocarbon chains. Examples: Zephiran and Cepacol
How do quats function?
They disrupt cellular membrans and cause a loss of essential internal ions
Which of the following are Quats effective against?

a. enveloped viruses
b. non enveloped viruses
c. mycobacteria
d. nonenveloped viruses
a. enveloped viruses
What heavy metal is effective against Neisseria gonorhoeae?
1% silver nitrate
Aldehydes are compounds containing a termal ___ group
CHO
How do aldehydes function?
They cross link amin, hydroxyl, sulfhydryl, and carboxyl organic functional groups thus causing the denaturization of proteins
List two low level forms of microbial control?
surfactants and metal (possibly phenol and phenolics as well)
3 examples of high level microbial control includes:
oxidizing agents, aldehydes, and gaseous agents
Give some examples of gaseous agents used for microbial control.
ethylene oxide, propylene oxide, and beta-propiolactone
How do gaseous agents work?
Denature proteins
Which of the following microbial controls only denatures proteins and does not disrupt the cell wall?

a. phenolics
b. alcohols
c. aldehydes
d. gaseous agents
c and d (trick question!) the latter two ONLY denature protein whereas the upper two also disrupts cell membranes
When a scientist chemically modifies an antibiotic it is called a ____?
semisynthetic