Antibiotics-modes of action, resistance mechanisms and the search for new compounds

According to their mechanism of action antibiotics can be divided into 4 groups. 1. Antibiotics inhibiting bacterial cell wall biosynthesis. 2. Antibiotics inhibiting DNA synthesis. 3. Antibiotics inhibiting RNA synthesis and 4. Antibiotics inhibiting protein synthesis. Basic mechanisms of antibiotic resistance include cell impermeability, modification of target site, modification or degradation of the antibiotic and increased efflux of the antibiotic. The following can be used in the search for new compounds: 1. Microorganisms isolated from extreme life conditions 2. Environmental DNA (eDNA) in which genes coding for secondary metabolites are looked for. 3. Streptomyces genomics yielding information about genes coding biosynthesis of new compounds. 4. Combinatorial biosynthesis for the production of hybrid antibiotics