Antimicrobials - Cell Wall Inhibitors - Cephalosporins

Question 1

What is the prefix for cephalosporins?

Answer 1

Cef or Cep

Question 2

How do penicillins block cell wall synthesis?

Answer 2

They bind to the penicillin-binding protein (PBS) which inhibits the transpeptidase enzyme

Question 3

How do penicillins degrade peptidoglycan?

Answer 3

The drugs contain autolysins and murein hydrolases which destroy the bacterial cell wall (peptidalglycan)

Question 4

What are the 7 cephalosporins?

Answer 4

Cefazolin/Cephalexin
Cefuroxime/Cefotetan
Ceftriaxone/Cefotaxime/Ceftazidime
Cefepime
Ceftaroline

Question 5

What is the effect of cephalosporins?

Answer 5

Bactericidal if they use mechanism (binding to PBP –> inhibit transpeptidase, and degrade the peptidoglycan with murein hydrolase/autolysis). Bacterial static if they only use one.

Question 6

What is the effect of penicillins?

Answer 6

Bactericidal if they use mechanism (binding to PBP –> inhibit transpeptidase, and degrade the peptidoglycan with murein hydrolase/autolysis). Bacterial static if they only use one.

Question 7

What is the bactericidal effect dependent on?

Answer 7

The drug is time-dependent and must be at the Minimum Bactericidal Concentration (MBC). Killing power does not increase with concentration but killing power will continue as long as the drug is above the MBC.