2.13: Effectiveness of chemical germicides

Question 1

Chemical germicides are substances designed to:

Answer 1

-reduce the number of pathogens on a surface, in a liquid, or on/in living tissue.

Question 2

Disinfectants:

Answer 2

-germicides designed for use on surfaces or in liquids (nonliving objects)

Question 3

Antiseptics:

Answer 3

-germicides designed for use on/in living tissue

Question 4

Use-dilution test:

Answer 4

-a standard procedure used to measure the effectiveness of disinfectants specifically against pathogenic bacteria

Question 5

Describe the use dilution test that was done in lab:

Answer 5

-glass beads were coated with living bacteria
-then they were exposed to varying concentrations of test germicides and then transferred to a growth medium
-after some time in the incubation, the medium is examined for growth.

Question 6

If a solution is sufficient to prevent microbial growth at least ??% of the time is considered a useable dilution of that germicide for a specific population

Answer 6

-95%

Question 7

What germicides were used?

Answer 7

-bleach
-hydrogen peroxide
-simple green
-isopropyl alcohol

Question 8

What media was used?

Answer 8

-nutrient broth

Question 9

What bacteria’s were used?

Answer 9

-E.coli
-Staphylococcus epidermidis

Question 10

At what temp. and for how long are the test tubes incubated?

Answer 10

-35+2C for 48 hours

Question 11

what test is used as a standard procedure to measure the effectiveness of disinfectants specifically against pathogenic bacteria:

Answer 11

-use dilution test

Question 12

What is the difference between a disinfectant and an antiseptic?

Answer 12

-Antiseptics are used on people whereas disinfectants are used on objects

Question 13

Germicides designed for use on or in living tissue are specifically called:

Answer 13

-antiseptics

Question 14

TRUE OR FALSE:
If 75% Bleach is effective reducing the number of Staphylococcus aureus you can assume it must also be effective reducing the number of Pseudomonas aeruginosa.

Answer 14

-false

Question 15

TRUE OR FALSE:
The Use-Dilution Test, glass beads or stainless steel cylinders coated with dead bacteria are exposed to varying concentrations of germicides and then transferred to a growth medium

Answer 15

-FALSE
-bacteria is ALIVE

Question 16

In the chemical germicides: disinfectant and antiseptics experiment, what is the purpose of control #4?

Answer 16

-To demonstrate that the beads being used were sterile.

Question 17

Substance used on surfaces (floors, tables, sinks, countertops, surgical instruments, etc.) or in liquids is a:

Answer 17

-disinfectant

Question 18

Control #1 purpose was:

Answer 18

-to show that broth was sterile

Question 19

Control #2 was to show that:

Answer 19

-broth was alive

Question 20

CLEAR BROTH=
TURITY BROTH=

Answer 20

-germicide was strong enough to prevent growth
-germicide was not strong enough to kill microbes, there is growth