Microbial Growth and Antimicrobial Drugs

Question 1

definition of disinfectant

Answer 1

destroys 99.9% of harmful organisms

Question 2

definition of antiseptic

Answer 2

destroys harmful organisms from living tissue

Question 3

definition of sterilants

Answer 3

removing and destroying all microbial life

Question 4

definition of sepsis

Answer 4

bacterial contamination

Question 5

definition of asepsis

Answer 5

free of significant contamination

Question 6

biocide vs biostatic

Answer 6

kills microbes vs inhibits microbial growth

Question 7

define d-value

Answer 7

death curve; how long it takes to kill 90% of the microorganisms at a certain temp

Question 8

differentiate the various biological safety levels

Answer 8

BSL-1: not known to pose risk
BSL-2: associated with moderate disease risk
BSL-3: indigenous or exotic, potentially lethal
BSL-4: dangerous and exotic, fatal without treatment

Question 9

methods of dry heat

Answer 9

oxidation/flaming/incineration

Question 10

methods of moist heat

Answer 10

autoclave, pasteurization, boiling

Question 11

chemical methods

Answer 11

phenols, metals, halogens, alcohols

Question 12

examples of halogens used to control microbial growth

Answer 12

iodine (betadine wash), chlorine, fluorine

Question 13

how do heavy metals kills microbes?

Answer 13

binding to proteins and inhibiting enzymatic activity

Question 14

conditions that affect activity of an antimicrobial agent

Answer 14

population size/composition, concentration/intensity, duration of exposure, temperature, local environment

Question 15

define selective toxicity

Answer 15

destroying pathogens without damaging the host

Question 16

oral administration

Answer 16

more convenient but irritates GI system

Question 17

parenteral administration

Answer 17

short time to reach high concentration but only in heathcare settings

Question 18

define half life

Answer 18

rate at which 50% of the drug is eliminated from the plasma

Question 19

synergism

Answer 19

two drugs administered together to improve efficacy

Question 20

list mechanisms of action associated with drugs and effect on cells

Answer 20

prevents synthesis of peptidoglycan, targets bacterial translation, changes membrane permeability, interferes with replication and transcription, antimetabolites compete with normal substrates

Question 21

antiviral drugs

Answer 21

difficult to target, highly adaptive

Question 22

reasons for drug resistance

Answer 22

overuse, misuse, inappropriate use, patient noncompliance

Question 23

method of measuring effectiveness of antiseptics

Answer 23

disk diffusion and zone of inhibition