Question 1

Your friend Joe recently visited the doctor for steroid injections into his knee to reduce swelling due to a previous knee injury.Within a couple of days,he had an infection caused by Pseudomonas,a very pathogenic and drug resistant bacterium.Luckily,Joe went to the doctor immediately and received antibiotics.The doctor tells him that the same problem has occurred to many other people across the United States.Predict the most likely cause of this situation.

Accepted Answer

A)   The steroid was contaminated at the production plant, so all batches of that drug made at that plant were contaminated with the bacterium.
B)   The bacterium is normally on the skin of people, so can easily access the patient's blood during the needle stick.
C)   The staff giving the steroid injections did not use proper aseptic technique.
D)   The needles were re-used and already contaminated before being used on the patients.E) C) and D)
F) B) and D)

Question 2

Which of the following is an advantage to using phenolics as antimicrobial agents?

Accepted Answer

A)   The presence of organic matter does not limit its antimicrobial qualities.
B)   They are not susceptible to resistance by organisms.
C)   They have low toxicity.
D)   They are effective sterilants against all microbial forms.E) B) and C)
F) A) and B)

Question 3

You have some old plastic Petri dishes that you would like to use for pouring bacteriological agar plates.The only method of physical sterilization is ultraviolet radiation sterilization with your UV light (you cannot use the autoclave because it will disfigure and melt the plastic) .After sterilizing the plates,pouring the sterilized agar medium,and then leaving the plates out at room temperature for a day or two to let them solidify and dry,you find contaminating bacterial colonies growing on the agar.Predict what has happened in this situation.

Accepted Answer

A)   The room temperature enhanced the growth of normal biota of the agar.
B)   Air got into the poured agar plates, contaminating them.
C)   The lids of the Petri dishes were inadvertently left on while being sterilized.
D)   The agar had bacteria in it, even after sterilization in the autoclave.E) B) and C)
F) C) and D)

Question 4

Endospores can be inactivated by

Accepted Answer

A)   dry heat at 170°C for 2 hours.
B)   incineration.
C)   glutaraldehyde for 3 or more hours.
D)   ethylene oxide for 3 or more hours.
E)   All of the choices are correct.F) B) and D)
G) C) and D)

Question 5

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state,the three-dimensional configuration of the proteins.

Accepted Answer

A)   mutate
B)   bind
C)   dissolve
D)   denatureE) None of the above
F) A) and B)

Question 6

Your aim is to sterilize prosthetic devices like heart valves and artificial joint structures before being used in the patient.Considering where they will be placed and the probable composition of the devices,what would be the best chemical to use?

Accepted Answer

A)   Crystal violet dye
B)   Iodine
C)   Quaternary ammonium compounds
D)   BleachE) A) and C)
F) B) and C)

Question 7

What instrument is most effective for pressure-temperature sterilization?

Accepted Answer

A)   Water-bath
B)   Autoclave
C)   Incubator
D)   Oven
E)   Bunsen burnerF) B) and E)
G) A) and E)

Question 8

The compound that is an organic base containing chlorine and two phenolic rings,and is used increasingly for wound degerming,neonatal washes,hand scrubbing,and prepping surgical skin sites is ______.

Accepted Answer

A)   a quaternary ammonium compound
B)   carbolic acid
C)   triclosan
D)   formalin
E)   chlorhexidineF) A) and B)
G) A) and E)

Question 9

Which of the following germicides is/are also sporicidal?

Accepted Answer

A)   Betadine
B)   Chlorine
C)   Phenolics
D)   Chlorhexidine
E)   All of these except phenolics.F) A) and E)
G) A) and C)

Question 10

Which of the following is not used as an antiseptic?

Accepted Answer

A)   Iodophor
B)   Aqueous glutaraldehyde
C)   3% hydrogen peroxide
D)   Chlorhexidine
E)   MerthiolateF) A) and B)
G) B) and C)

Question 11

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

Accepted Answer

A)   Ultraviolet (germicidal)  light
B)   Gamma rays
C)   121°C at 15 psi for 15 minutes
D)   160°C for 2 hours
E)   All of the choices are correct.F) B) and C)
G) C) and D)

Question 12

Hydrogen peroxide is

Accepted Answer

A)   sporicidal.
B)   fungicidal.
C)   bactericidal.
D)   virucidal.
E)   All of the choices are correct.F) All of the above
G) C) and D)

Question 13

Soaps and detergents are very effective as sterilants.

Accepted Answer

A) True 
 B)False

Question 14

Antimicrobial agents can target the cell wall by

Accepted Answer

A)   blocking its synthesis.
B)   digesting it.
C)   denaturing proteins.
D)   All of the choices are correct.E) B) and C)
F) All of the above

Question 15

All of the following are phenols or phenolics except ______.

Accepted Answer

A)   hexachlorophene
B)   Zephiran
C)   cresols
D)   triclosan
E)   LysolF) A) and B)
G) B) and C)

Question 16

In lab,inoculating loops are sterilized using ______.

Accepted Answer

A)   chemicals
B)   incineration
C)   filtration
D)   moist heat
E)   gas sterilizationF) A) and D)
G) None of the above

Question 17

The shortest time required to kill or inactivate all the microbes in a sample at a specified temperature is called the

Accepted Answer

A)   thermal death point (TDP) .
B)   thermal death time (TDT) .
C)   sporicidal time.
D)   death phase point.E) B) and C)
F) C) and D)

Question 18

All microbicidal agents are sterilants.

Accepted Answer

A) True 
 B)False

Question 19

_____ heat is more rapidly effective and efficient compared to _____ heat.

Accepted Answer

A)   High; dry
B)   High; moist
C)   Dry; moist
D)   Moist; dry
E)   Moist; highF) D) and E)
G) A) and E)

Question 20

Which of the following is true regarding the use of osmotic pressure as an antimicrobial agent?

Accepted Answer

A)   Salts and sugars external to a microbe create a hypotonic environment, which causes lysis of the cell.
B)   Salt is an effective solute to create an osmotic pressure gradient outside of a cell; however, the use of sugar, such as in jams and jellies, works via a different mechanism.
C)   Exposing a microbe to a hypertonic environment draws water out of the cell, causing plasmolysis.
D)   Exposing organisms to the air on a benchtop so they completely dry out is an example of using osmotic pressure as a means of microbial control.E) All of the above
F) B) and D)

Exam 11: Physical and Chemical Control of Microbes

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state,the three-dimensional configuration of the proteins.

Correct Answer
verified

The shortest time required to kill or inactivate all the microbes in a sample at a specified temperature is called the

Correct Answer
verified

Antimicrobial agents can target the cell wall by

Correct Answer
verified

Your aim is to sterilize prosthetic devices like heart valves and artificial joint structures before being used in the patient.Considering where they will be placed and the probable composition of the devices,what would be the best chemical to use?

Correct Answer
verified

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

Correct Answer
verified

Correct Answer
verified

Which of the following is not used as an antiseptic?

Correct Answer
verified

Which of the following germicides is/are also sporicidal?

Correct Answer
verified

The compound that is an organic base containing chlorine and two phenolic rings,and is used increasingly for wound degerming,neonatal washes,hand scrubbing,and prepping surgical skin sites is ______.

Correct Answer
verified

Which of the following is true regarding the use of osmotic pressure as an antimicrobial agent?

Correct Answer
verified

Soaps and detergents are very effective as sterilants.

Correct Answer
verified

Correct Answer
verified

_ heat is more rapidly effective and efficient compared to _ heat.

Correct Answer
verified

What instrument is most effective for pressure-temperature sterilization?

Correct Answer
verified

All microbicidal agents are sterilants.

Correct Answer
verified

Hydrogen peroxide is

Correct Answer
verified

Which of the following is an advantage to using phenolics as antimicrobial agents?

Correct Answer
verified

In lab,inoculating loops are sterilized using ______.

Correct Answer
verified

Endospores can be inactivated by

Correct Answer
verified

All of the following are phenols or phenolics except ______.

Correct Answer
verified

Exam 11: Physical and Chemical Control of Microbes

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state,the three-dimensional configuration of the proteins.

Correct AnswerverifiedShow Answer

The shortest time required to kill or inactivate all the microbes in a sample at a specified temperature is called the

Correct AnswerverifiedShow Answer

Antimicrobial agents can target the cell wall by

Correct AnswerverifiedShow Answer

Your aim is to sterilize prosthetic devices like heart valves and artificial joint structures before being used in the patient.Considering where they will be placed and the probable composition of the devices,what would be the best chemical to use?

Correct AnswerverifiedShow Answer

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following is not used as an antiseptic?

Correct AnswerverifiedShow Answer

Which of the following germicides is/are also sporicidal?

Correct AnswerverifiedShow Answer

The compound that is an organic base containing chlorine and two phenolic rings,and is used increasingly for wound degerming,neonatal washes,hand scrubbing,and prepping surgical skin sites is ______.

Correct AnswerverifiedShow Answer

Which of the following is true regarding the use of osmotic pressure as an antimicrobial agent?

Correct AnswerverifiedShow Answer

Soaps and detergents are very effective as sterilants.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

_____ heat is more rapidly effective and efficient compared to _____ heat.

Correct AnswerverifiedShow Answer

What instrument is most effective for pressure-temperature sterilization?

Correct AnswerverifiedShow Answer

All microbicidal agents are sterilants.

Correct AnswerverifiedShow Answer

Hydrogen peroxide is

Correct AnswerverifiedShow Answer

Which of the following is an advantage to using phenolics as antimicrobial agents?

Correct AnswerverifiedShow Answer

In lab,inoculating loops are sterilized using ______.

Correct AnswerverifiedShow Answer

Endospores can be inactivated by

Correct AnswerverifiedShow Answer

All of the following are phenols or phenolics except ______.

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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_ heat is more rapidly effective and efficient compared to _ heat.

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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