Lab 19 - Disinfectant Effectiveness

Question 1

what are antimicrobial agents?

Answer 1

chemical or physical agents that kill (cidal) or inhibit growth (static) of microbes

Question 2

what is sterilization?

Answer 2

killing all vegetative cells, viruses and endospores

Question 3

what is sterilization used for?

Answer 3

surgical instruments

Question 4

what is disinfection?

Answer 4

killing most or all vegetative cells and viruses

Question 5

what is a disinfectant?

Answer 5

for non-living things, example: for cleaning a lab bench

Question 6

what is an antiseptic?

Answer 6

for living things, example: mouth wash

Question 7

what is pasteurization?

Answer 7

reduces the number of spoilage microbes and kills pathogens. example: for milk

Question 8

what are the considerations when disinfecting?

Answer 8

-the type of microorganism
-the numbers present initially
-organic matter/biofilms
-time of exposure
-the risk of infection
-composition of the item
-toxicity
-cost and availability

Question 9

what do chemicals do to bacteria?

Answer 9

they disrupt cell membranes, proteins, or nucleic acids

Question 10

what are quaternary ammonium compounds?

Answer 10

quats are cationic detergents that punch holes in the bacterias membranes and denature cell’s proteins

Question 11

what does povidone iodine do?

Answer 11

it oxidizes proteins and nucleic acids

Question 12

what does DRT stand for?

Answer 12

decimal reduction time

Question 13

what is DRT?

Answer 13

the time required for 90% of a microbial population to be killed under specific conditions

Question 14

what is an example of DRT?

Answer 14

90% of 10,000 = 9000 killed and 1000 left in 5 mins.
Takes 20 mins to kill the whole population