Principles of Antibiotics

Question 1

What is an antibiotic

Answer 1

Molecules that work by binding a target site on a bacteria

(Agents produced by micro-organisms that kill or inhibit the growth of other micro-organisms in high-dilution)

Question 2

Antimicrobials

Answer 2

Molecules that work by binding a target site on a microorganism (worm, virus, fungus, protozoan, bacterium)

Question 3

What groups of antibiotics impact cell wall synthesis?

Answer 3

Beta Lactams, Carbapenems, Monobactams

Question 4

Name some classes of Beta Lactams

Answer 4

Penicillins, Cephalosporins

Question 5

Beta Lactam antibiotics disrupt p_______ production

Answer 5

peptidoglycan

Question 6

Beta lactam antibiotics bind covalently and irreversibly to the p_______ b_____ p____

Answer 6

penicillin binding proteins

Question 7

Once the antibiotic has bound, the cell wall is disrupted and lysis occurs, resulting in a h________ or i_________ environment

Answer 7

hypo-osmotic or iso-osmotic

Question 9

Name some types of antibiotics impact nucleic acid synthesis?

Answer 9

DNA Gyrase. RNA Polymerase

Question 10

Name some types of antibiotics impacting protein synthesis

Answer 10

30S subunit, 50S subunit

Question 11

How do bactericidal antibiotics work?

Answer 11

The agent kills the bacteria

Question 12

How do bacteriostatic antibiotics work?

Answer 12

Prevent growth of bacteria .Ratio of Minimum Bactericidal Concentration to Minimum inhibitory Concentration of >4

Question 13

True or false: the antibiotic with the lowest MIC (minimum bactericidal conentration) is the best antibiotic

Answer 13

False

Question 14

What are the 2 major determinants of anti-bacterial effects?

Answer 14

Concentration and time that antibiotic remains on these binding sites

Question 15

What drug is used against staphylococcus aureus?

Answer 15

Flucloxacillin (if that doesn’t work then vancomycin)

Question 16

Bacteria can become resistant to antibiotics by changing the molecular configuration of antibiotic b_____ s___ or masks it

Answer 16

binding site

Question 17

Bacteria can become resistant to antibiotics by destroying or inactivating the ______

Answer 17

antibiotic

Question 18

Bacteria can become resistant to antibiotics by modifying the bacterial membrane p___ channel size, numbers and selectivity

Answer 18

porin

Question 19

Bacteria can become resistant to antibiotics by the proteins in bacterial membranes acting as an e____ or e____ pump so level of antibiotic is reduced

Answer 19

export or efflux

Question 21

Things to factor in about antibiotic safety when prescribing

Answer 21

Intolerance, allergy and anaphylaxis
Side effects
Age
Renal and Liver functioning
Pregnancy and breast feeding
Drug interactions
Risk of Clostridium difficile

Question 22

What can stop beta-lactam antibiotics working?

Answer 22

Beta-lactamases (giving antibiotic resistance)

Question 23

What was developed to combat beta-lactamases?

Answer 23

Beta lactamase inhibitor

Question 24

What antibiotic is good for those with penicillin allergy? (are also good for some resistant bacteria)

Answer 24

Cephalosporins

Question 25

What bacterias commonly causes cellulitis?

Answer 25

S. aureus, Group A,C,G streptococcus

Question 26

What antibiotic is used for cellulitis?

Answer 26

Flucloxacillin

Question 27

What antibiotic is used for s. pneumoniae?

Answer 27

PO amoxicillin, IV Benzylpenicillin

Question 28

Other than penicillin, what is a common antibiotic used for gram positive bacteria such as MRSA

Answer 28

Vancomycin and Teicoplanin

Question 29

Does Vancomycin easily cross the BBB?

Answer 29

No

Question 30

Name some macrolides (for gram positive bacteria and atypical pneumonia)

Answer 30

Clarithromycin and erythromycin

Question 31

What is a good antibiotic to use for cellulitis when the patient has a penicillin allergy?

Answer 31

Clindamycin (type of lincosamide)

Question 32

What are aminoglycosides used for?

Answer 32

Gram-negative rods
Often combined with other antibiotics
Needs to be closely monitored because it can be toxic (ears)
Good for UTIs

Question 33

Name a quinolone (for gram negative)

Answer 33

Ciprofloxacin, used for UTIs, has side-effects (aneurysms, intra-abdominal infections, lowers seizure threshold)

Question 34

Can beta-lactams be used for gram negatives?

Answer 34

Yes as gram negatives do still have peptidoglycan walls just not as effective.

Question 35

What are CPEs?

Answer 35

Carbapenemase producing Enterobacteriaceae
Most common cause of UTI, intra-abdominal infection

Question 36

What do carbapenemase do?

Answer 36

Enzyme which inactivates carbapenem antibiotics