As the name implies 50s subunit protein synthesis inhibitors such as erythromycin inhibit protein synthesis by binding to the 50S subunit of the 23S rRNA molecule of the bacterial ribosome. This ultimately acts to block the exit of the growing peptide chain. It should be noted that gram+ bacteria more effectively accumulate erythromycin than gram negative bacteria thereby making it more effective in this group of bacteria. Erythromycin is used to treat syphilis, group b strep, respiratory tract and skin infections. Resistance to erythromycin can evolve when gram+ bacteria develop pumps which export the drug thereby protecting the bacteria from the drug’s effects.
A second potential target of antibiotics is the bacterial cell membrane. Targeting of the bacterial cell membrane by polymyxins is specific for gram negative bacteria due to their specificity for lipopolysaccharide which is common in gram negative bacteria. Polymyxins are used to treat MDR strains of Pseudomonas aeruginosa. Polymyxins (which feature a cyclic peptide with a long hydrophobic tail) work by disrupting the structure of the bacterial cell membrane via their interaction with the cell membrane’s …show more content…
A number of naturally derived compounds have shown promise when used as a combination therapy. The ultimate goal of these therapies would be in decreasing the amount of traditional drug needed for treatment and/or providing the best overall treatment outcome. Furthermore, synergy has been shown to exist for some of the drugs used in these combination therapies. Combination therapies/cocktails are often used in the treatment of cancer where a multipronged approach is usually the best treatment plan for avoiding