Antimicrobials

Question 1

What do bactericidals do?

Answer 1

Kill bacteria

Question 2

What do bacteriostatics do?

Answer 2

Inhibit/arrest growth of bacteria

Question 3

What part of bacteria do most antibiotics target?

Answer 3

The cell wall

Question 4

Which antibiotics act on PG biosynthesis?

Answer 4

Penicillin’s
Cephalosporin’s
Carbapenem’s
Beta lactam antibiotics

Question 5

What are beta lactam antibiotics effective against?

Answer 5

Growing and dividing cells. They kill bacteria by autolysis.

Question 6

Why are some bacteria resistant to beta lactam antibiotics?

Answer 6

Because they produce betalactamase, an enzyme that breaks down the beta lactam ring.

Question 7

How do beta lactam antibiotics work?

Answer 7

Inhibit the enzymes involved in the transpeptidase cross-linking reaction
Interfere with linking the individual chains together
Disrupt PG synthesis leading to autolysis

Question 8

What type of bacteria are penicillins most effective against?

Answer 8

Very effective against gram positive

Question 9

What kind of bacteria are cephalosporins effective against?

Answer 9

Gram positive
Anaerobes
Gram negative
Pseudomonas

Question 10

Carbapenems are effective against most bacteria except which 2?

Answer 10

MRSA and VRE

Question 11

What drug is used to treat MRSA?

Answer 11

Vancomycin

Question 12

How do drugs like tetracycline, doxycycline and aminoglycosides work?

Answer 12

Inhibit protein synthesis in the 30s unit of the ribosome to prevent bacteria multiplying

Question 13

Name an aminoglycoside

Answer 13

Gentamycin, streptomycin and tobramycin

Question 14

How do drugs like chloramphenicol and macrolides work?

Answer 14

Inhibit protein synthesis in the 50s unit of the ribosome to prevent bacteria multiplying

Question 15

Name a macrolide

Answer 15

Erythromycin and clarithromycin

Question 16

What are the antibiotics that inhibit DNA biosynthesis?

Answer 16

Fluoroquinolones (ciprofloxacin, norfloxacin, levofloxacin and moxifloxacin)

Question 17

What do the names of fluoroquinolones end in?

Answer 17

“floxacin”

Question 18

Antibiotics inhibiting RNA biosynthesis

Answer 18

Rifampicin,

Question 19

What is rifampicin mostly used to treat? How does it work?

Answer 19

Tuberculosis.

It inhibits bacterial RNA polymerases

Question 20

What is required for biosynthesis of nucleotides?

Answer 20

Folic acid

Question 21

How does trimethoprim work?

Answer 21

Inhibits dihydrofolate reductase to inhibit the synthesis of nucleotides, DNA and RNA.

Question 22

How does sulphonamide work?

Answer 22

Inhibits dihydropteroate synthase to inhibit synthesis of nucleotides, DNA and RNA.