Mechanisms of Antibiotics - Quick Review

Penicillin
Binds to PCP's which inhibits cell wall synthesis...autolytic enzyme activation leads to bactericidal activity on dividing bacteria

Cephalosporins
B-lactam Bactericidal...Binds to PCP's and inhibits murein synthesis and cell wall production


Erythromycin
Inhibits protein synthesis by binding reversibly to 50s ribosomal subunits ...specifically inhibits translocation step of protein synthesis, where tRNA/amino acid complex moves from the acceptor site to the peptidyl site on the ribososmes

Gentamicin
Aminoglycoside bactericidal...enters by oxygen dependent active transport, binds to 30s and inhibits protein synthesis...interferes with initiation complex, induces misreading of mRNA, and breaks up polysomes...synergistics with B-lactams

Quinolones
Inhibits DNA topoisomerase II (DNA gyrase)...bactericidal

Sulfa
Bactriostatic, structural analog of PABA and a competetive antagonist for dihydropteroate synthetase

Thrombolysis and Angioplasty

Causes of Haematemesis

Aminoglycosides' Sources

Aminoglycosides obtained from Micromonospora Spp.
Gentamicin
Sisomicin
Netilmicin

Aminoglycosides obtained from Streptomyces Spp.
Streptomycin
Neomycin
Kanamycin
Tobramycin
Framycetin