antibiotic that inhibit cell wall synthesis

2. Background
Background

3. What is β-lactam???
 A four-membered lactam These antibiotics inhibiting the
(A lactam is a cell walls of bacteria
cyclic amide),nitrogen atom Cause lethal effect on bacteria
is attached to the β-carbon
relative to the carbonyl.
 The β-lactam ring is part of
the core structure of
several antibiotic families(β-
lactam antibiotics), such as:
•

4. Structure of Cephalosporins
Cephalosporins (red in colour is structure of β-lactam )

5. Mechanism of action
Cephalosporins are  All bacterial cells have a cell
bactericidal (which means wall that protects them
that they kill bacteria) have  Structure of β-lactam can
the same mode of action as detect enzymes which involve
other β-lactam antibiotics as in cell wall synthesis.
penicillins  Then it can inactivating the
enzymes thus inhibit
formation of cell wall which
causes the walls to break
down and eventually the
bacteria die.

6. Uses
 Used to treat a wide variety of bacterial infections, such as
respiratory tract infections (pneumonia, strep throat, tonsillitis,
bronchitis), skin infections and urinary tract infections

7. Commonly used for surgical
prophylaxis - prevention of
bacterial infection before,
during, and after surgery

8. Classifications of Cephalosporins
 Grouped into “generations” based on their spectrum of
microbial activity, such as:
• 1st generation
• 2nd generation
• 3rd generation
• 4th generation
 First Chepalosporins designated first generation while
later, more advanced cephalosporins were classified as
2nd generation and so on.
 Each newer generation of cephalosporins has
significantly greater gram-negative antimicrobial
properties than previous one.

9. 1st generation 2nd generation
 Moderate  Greater gram-negative
 Treating staphylococcal spectrum while retaining
and streptococcal some activity against
infections and therefore gram-positive bacteria
are alternatives for skin  More resistant to β-
and soft-tissue infections. lactam, treating upper
 Example: and lower respiratory
 Cephaloridine tract infections, sinusitis
and otitis media.
 Cephalothin  Active against E. coli,
 Cephapirin Klebsiella and Proteus
 Example :
 Cefaclor
 Cefoxitin

10. 3rd generation 4th generation
 Further increased activity  Greater resistance to β-
against gram-negative lactam than the 3rd
organisms generation.
 Excellent activity against  Can cross blood brain
most strains of barrier and are effective
Streptococcus in meningitis
pneumoniae including  Example :
that have high level  Cefepime
resistance to penicillin  Cefluprenam
and N. gonorrhoeae
 Cefozopran
 Example:
 Cefdinir
 Cefixime