Principles of Anti-INfective Therapy

Question 1

Chemotherapeutic agents

Answer 1

any drug used to treat illness or disease, infectious disease generally refers to antibiotics

Question 2

Antimicrobial agent

Answer 2

substance that interferes with the proliferation of microorganisms

Question 3

Antibiotics agent

Answer 3

antimicrobial activity whose source is “natural” living organisms

Question 4

Antimicrobial spectrum - Bacteristatic

Answer 4

antimicrobial agent that inhibits growth when present, but does not kill; reversible; relies on immune system to eliminate pathogen

Question 5

Bactericidal

Answer 5

Agents that kill pathogen, but do not eliminate the dead cells/viruses; irreversible

Question 6

Narrow spectrum antibiotics

Answer 6

antibiotics that target a narrow range of microorganisms

Question 7

Broad spectrum antibiotics

Answer 7

antibiotics effective in killing both gram (+) and gram(-) bacteria, not preferred bc it wipes out NF and may lead to superinfections

Question 8

Resistant

Answer 8

microorganisms that are NOT inhibited

Question 9

Sensitive

Answer 9

microorganisms that are ARE inhibited

Question 10

Kirby-Bauer Disc diffusion Assay

Answer 10

antimicrobial sensitivity test to determine if the particular pathogen is sensitive or resistant to a specific antibiotic by measuring the zone of growth inhibition

Question 11

Kirby-Bauer Disc diffusion Assay down-side

Answer 11

cannot distinguish between bacteristatic and bactericidal, qualitative test

Question 12

Minimum Inhibitory Concentration (MIC) test

Answer 12

antimicrobial susceptibility test to measure the minimal concentration of antibodies necessary to inhibit the growth of microorganisms

Question 13

Minimum Inhibitory Concentration (MIC) test down-side

Answer 13

cannot distinguish between bacteristatic and bactericidal, quantitative test

Question 14

Minimum Bactericidal Concentration (MBC) test

Answer 14

antimicrobial susceptibility test to measure least amount of antibiotics to KILL 99.9% of the microorganism, MICs are grown on agar plates to determine if they were killed or inhibited by the antibiotics

Question 15

MBC =

Answer 15

most diluted MIC that did not have growth after plating on agar

Question 16

Dosage of antibiotics should ___________ the MBC and MIC

Answer 16

exceed

Question 17

Antimicrobial serumcidal concentrations

Answer 17

antimicrobial susceptibility test to measure the lowest concentration of antibiotics needed to kill microorganism in the presence of patient’s serum

Question 18

Antibiogram

Answer 18

detailed account of a hospitals trends of antibiotic usage, in comparison to resistance and susceptibility patterns

Question 19

Antibiogram can help prevent

Answer 19

antibiotic resistance by alleviating pressures

Question 20

Poor Selective Toxicity

Answer 20

target is more similar to self, drugs that target cell membrane exhibit poor selectivity - harmful to patient and microbe

Question 21

Good Selective Toxicity

Answer 21

target is less similar to self, drugs that target peptidoglycan cell walls exhibit good selectivity - harmful to microbe not to patient

Question 22

Why abscess formation is difficult to treat…

Answer 22

poor blood flow, difficult to deliver drugs/antibodies, multiply slower and are less effected by drugs, phagocytes do not reach site, tissue necrosis releases nutrients needed for bacterial growth, low pH at site effects drug effectiveness

Question 23

Treating an abscess

Answer 23

drainage and removal of necrotic tissue

Question 24

Why foreign bodies allow growth of microorganisms..

Answer 24

biofilms are allowed to grow on foreign objects, they should be removed ASAP

Question 25

Immunosuppression

Answer 25

even with antimicrobials, an intact immune system is necessary for removal of debris and effective treatment

Question 26

Superinfect

Answer 26

treat one disease and a new and different disease develops, generally as a result of overgrowth of NF

Question 27

Location of infection

Answer 27

antibiotics can penetrate tissues differently, must be considered when prescribing a medication

Question 28

Chemoprophylaxis

Answer 28

administering an antimicrobial to a patient who is not infected but at increased risk

Question 29

Justified prophylaxis

Answer 29

erythromycin eye drops to prevent opthalmia neonatorium, prophylaxis against malaria in travelers, rheumatic heart disease patients to prevent strep, bowel surgery, recurrent UTI, bite wound, exposure to meningococcal meningitis, MTB, HIV

Question 30

Unjustified prophylaxis

Answer 30

prevent secondary bacterial pneumonia in viral respiratory case, clean surgery, because patient insists

Question 31

Synergism (2 antimicrobials)

Answer 31

when used in conjunction with one another are much stronger (cidal) than separately

Question 32

Additive

Answer 32

when used in conjunction with one another they are additive in nature 1 + 1 = 2

Question 33

Antagonism

Answer 33

when used together, they reduce the effectiveness in comparison to being separate (drug/drug interaction or competition)

Question 34

Indifference

Answer 34

drugs used in conjunction has no effect on one another

Question 35

When to use combination therapy

Answer 35

polymicrobic infection, to lower dose of toxic drug, increase cidal effect, treat life-threatening illness, prevent emergence of resistance (TB, HIV)

Question 36

Drug resistance mechanisms - altering target

Answer 36

alter binding proteins, alter DNA gyrase, alter expression of dehydrofolate reductase

Question 37

Drug resistance mechanisms - inactivation of drug

Answer 37

ability to hydrolyze and breakdown drug, circumvent drug action by acquiring a different enzyme with same function (beta-lactamase)

Question 38

Drug resistance mechanisms - tolerance

Answer 38

evasion of killing by depression of bacterial growth rate