Control of Microbial Growth (Lab)

Question 1

A process of destroying all forms of microbial life including the endospores.

Answer 1

Sterilization

Question 2

most resistant forms of life

Answer 2

endospores

Question 3

What is the apparatus used, time needed, temperature required, and examples of materials used in steam under pressure?

Answer 3

Autoclave
15-20 minutes
121 degrees Celsius
Bacteriologic media

Question 4

What is the apparatus used, time needed, temperature required, and examples of materials used in free flowing steam/Tyndallization/intermittent?

Answer 4

Arnold sterilizer
30 minutes for 3 consecutive days with incubation period in between sterilization
100 degrees Celsius
Culture media that cannot withstand autoclave temp.

Question 5

What is the apparatus used, time needed, temperature required, and examples of materials used in boiling?

Answer 5

Boiler
10 minutes
100 degrees Celsius
Water, food, and utensils, dental supplies

Question 6

What is the apparatus used, time needed, temperature required, and examples of materials used in inspissation?

Answer 6

Inspissator
2 hours for 3 successive days
75-80 degrees Celsius
High protein media

Question 7

What is the apparatus used, time needed, temperature required, and examples of materials used in pasteurization?

Answer 7

Pasteurizer
30 minutes, 15 seconds, less than a second
63 degrees Celsius, 72 degrees Celsius, 141 degrees Celsius
Alcoholic beverages, milk, food

Question 8

heat that kills microbes by coagulation of proteins by the breakage of hydrogen bonds that hold the proteins in three dimensional structures

Answer 8

moist heat

Question 9

heat that kills by oxidation effects

Answer 9

dry heat

Question 10

What are the 3 types of Dry heat?

Answer 10

Direct flaming
incineration
hot air sterilization

Question 11

What is the apparatus used, time needed, temperature required, and examples of materials used in direct flaming?

Answer 11

Bunsen burner
until red glow/hot
N/A
inoculation instruments, tip of forceps

Question 12

What is the apparatus used, time needed, temperature required, and examples of materials used in incineration?

Answer 12

Incinerator
N/A
870-980 degrees Celsius
Hazardous materials (paper cups, animal carcasses)

Question 13

What is the apparatus used, time needed, temperature required, and examples of materials used in hot air sterilization?

Answer 13

Oven
2 hours
160-180 degrees Celsius
petri dishes

Question 14

Give 3 examples of heat sensitive materials

Answer 14

culture media, enzymes, serum, vaccines, antibiotics

Question 15

It is the passage of liquid or gas through a screen-like material, pores are small enough to retain microorganisms. It is also used to sterilize heat sensitive materials.

Answer 15

Filtration

Question 16

What are the 4 types of filter and their composition?

Answer 16

Berkefeld - diatomaceous earth
Seitz - asbestos pad
Chamberland Pasteur - unglazed porcelain
Morton - sintered glass

Question 17

This is a system of laminar flow filter which is used extensively to provide dust-free and bacteria-free air

Answer 17

High efficiency particulate air (HEPA)

Question 18

What is the principal effect of ionizing radiation? and Why?

Answer 18

Ionization of water because it forms highly reactive hydroxyl radicals

Question 19

Give an example of a non-ionizing radiation

Answer 19

UV light

Question 20

What type of radiation is used to disinfect vaccines and other medical products?

Answer 20

Non-ionizing radiation

Question 21

What is the most important precaution in preventing nosocomial infections?

Answer 21

Handwashing

Question 22

How long should we handwash to remove most transient organisms?

Answer 22

30 seconds