Antimicrobials- L2

Question 1

What are antimicrobials?

Answer 1

Drugs that destroy microbes, prevent their multiplication or growth, or prevent their pathogenic effect.

Question 2

What needs to be known to treat a bacterial infection?

Answer 2

location, likely pathogens involved, which antimicrobials are likely to be effective for the pathogen at the particular site.

Question 3

What other factors need to be considered for antimicrobial therapy?

Answer 3

Cost, safety, ease of use, and possible resistance

Question 4

Who and when was penicillin discovered

Answer 4

Alexander Fleming 1928

Question 5

What is an Antibiotic?

Answer 5

A chemical substance produced by a microorganism that inhibits the growth of or kills other microorganisms.

Question 6

What is an Antimicrobial agent?

Answer 6

a chemical substance derived from a biological source or produced by chemical synthesis that kills or inhibits the growth of microorganisms.

Question 7

These antimicrobials are produced by bacteria or fungus.

streptomycin, penicillin, tetracycline

Answer 7

Natural (true Antibiotic)

Question 8

Semi-Synthetic antimicrobials are what?

Answer 8

Chemically-altered natural compound

ampicillin, amikacin

Question 9

What are synthetic antimicrobials?

Answer 9

Chemically designed in the lab

sulfonamides, enrofloxacin, marbofloxacin

Question 10

What are the classifications of Antimicrobial agents?

Answer 10

Chemical Family Structure
Mode of Action
Type of Antimicrobial activity
Spectrum of Antibacterial Activity

Question 11

What does the clinician need to know to treat with antimicrobials?

Answer 11

The drugs,
The microbiology
The Patient

Question 12

What are the modes of action?

Answer 12

inhibitors of cell wall synthesis
inhibitors of protein synthesis
inhibitors of membrane function
inhibitors of nucleic acid synthesis
(Anti-metabolites)

Question 13

What are the two types of Antibacterial Susceptibility Testing?

Answer 13

1 Dilution (Broth/Agar)
2 Diffusion (Disk)

Question 14

What is a susceptibility break point?

Answer 14

a drug concentration above which an organism is considered resistant and at or below this value organism is susceptible to that drug.

Question 15

what are the three break point values?

Answer 15

Susceptible, Intermediate, and Resistant

Question 16

What is Minimum inhibitory concentration (MIC)?

Answer 16

Minimum amount of drug required to inhibit bacterial growth.

Question 17

Drugs with _____ MIC values are better choices to use.

Answer 17

Lower

Question 18

What is the likelihood of therapeutic success with a susceptible rating?

Answer 18

High

Question 19

what is the likelihood of therapeutic success with an Intermediate rating?

Answer 19

UNCERTAIN

Question 20

what is the likelihood of therapeutic success with a resistant rating?

Answer 20

none, High likelihood of therapeutic failure

Question 21

what is kirby bauer disk diffusion?

Answer 21

A bacterial isolate from pure culture spread on agar plate. single concentration Antimicrobial disks are added to the plate and the diameter of growth inhibition is measured.

Question 22

Is kirby Bauer disk diffusion accurate for MIC?

Answer 22

NO

Question 23

What is Broth dilution?

Answer 23

Multiple dilutions of antimicrobial agents, measure and report growth inhibition endpoint (MIC).

Question 24

Gradient Diffusion or E-test

Answer 24

Agar plate with strips of Antimicrobial agents with varying concentrations ranging from high to low from outside of plate to the middle of the plate.

Question 25

What are broad spectrum antibiotics?

Answer 25

Antibiotics that are active against a wide range of bacteria

Question 26

what are narrow spectrum antibiotics?

Answer 26

Antibiotics which are only effective against a narrow range of bacteria.

Question 27

What are some things to consider when selecting antimicrobial drugs for treatment?

Answer 27

``` Time dependent killing Concentration dependent killing AUC Pharmacokinetics Pharmacodynamics ```

Question 28

Why would one use Antimicrobial combinations?

Answer 28

Mixed infections Prevention of Antimicrobial resistance Increase effectiveness in treating some infections

Question 29

What are the two types of resistance?

Answer 29

Innate | Acquired

Question 30

What is innate resistance?

Answer 30

preexisting genomic property

Question 31

What is acquired resistance?

Answer 31

New genetically encoded trait not representative of the species. (acquired by mutation or horizontal gene transfer)

Question 32

What are some mechanisms of resistance?

Answer 32

Enzymatic destruction or inactivation of drug prevention of penetration to target sites within microbe alteration of drugs target site Rapid efflux of antibiotics

Question 33

why is there an emergence of antimicrobial resistance?

Answer 33

``` Widespread antimicrobial use Microbial adaptation and change changes in demographics Medical advances Changes in ecosystems Cutbacks in public health systems ```

Question 34

What is the potential impact of antimicrobial resistance

Answer 34

``` Increased mortality to infectious disease Veterinarian revisits High treatment costs Productivity loss and Economic Impact Zoonotic spread of resistant Microbes Increased nosocomial infections ```

Question 35

What are some problematic bacterial organisms?

Answer 35

Vancomycin resistant Enterococcus (VRE) Methicillin resistant Staphylococcus aureus (MRSA) Extened spectrum Beta Lactamase (ESBL) producing E. coli and Klebsiella sp. Fluoroquinolone resistant Campylobacter jejuni Multiple drug resistant (MDR) E. coli and Salmonella Organisms with innate resistance (Enterococcus, Enterobacter, Pseudomonas, Acinetobacter) MDR and XDR Mycobacterium tuberculosis

Question 36

How are Antimicrobials missused?

Answer 36

Providers- Over prescription use Patients/clients- compliance, stockpiling, OTC Industry- over promotion, competition between brands

Question 37

Strategies to Reduce antimicrobial Resistance. | What does prudent Drug use mean?

Answer 37

Maximize efficacy of therapeutic regimens Restrict extra-labe use to high risk patients observe withdrawal period Use antimicrobials of limited human health concern use alternative therapies

Question 38

strategies to reduce antimicrobial Resistance. | what is pathogen control?

Answer 38

Animal waste management Reduce contamination in slaughter and processing maintain herd health and infection control

Question 39

Strategies to reduce antimicrobial Resistance | What does Policy mean?

Answer 39

control of drug use in food animals National antimicrobial resistance monitoring system educational efforts

Question 40

Polyene Antifungal drugs what are they and what is their mechanism of action?

Answer 40

Amphotericin, Nystatin, and pimaricin | interact with sterols in the cell membrane

Question 41

Azole antifungal drugs what are they and what is their mechanism of action?

Answer 41

Fluconazole, itraconazole, and Ketoconazole | inhibits cytochrome P450- dependent enzymes involved in the biosynthesis of ergosterol

Question 42

Allylamine and Morpholine antifungal drugs what are they and what is their mechanism of action?

Answer 42

allylamines (naftifine, terbinafine) inhibit ergosterol biosynthesis

Question 43

Antimetabolite antifungal drugs what are they and what is their mechanism of action?

Answer 43

5-Fluorocystosine, acts as an inhibitor of both DNA and RNA synthesis