Conceptual Evaluation of Antibiotics

CONCEPTUAL EVALUATION OF ANTIBIOTICS

There is a great deal of discussion about the development of future antibiotics and whether this is the correct direction to follow. It is noteworthy that every antibiotic on the market has been derived or modified from natural products produced by microbial life forms. It is also interesting to note that these life forms continue to synthesize antibiotics. If they had lost efficacy in nature one would expect that these organisms would have evolved to stop wasting energy on their synthesis, suggesting that in nature antibiotics continue to have efficacy. The question is then, what disconnect is there between how antibiotics function in nature and how they are used in medicine?

For one thing, in the production of antibiotics an active compound is purified from the fermentation liquor and tested as an antibiotic against a planktonic target population of bacteria. This approach assumes that the planktonic population is a relevant target for antibiotic selection. It also assumes that other components of the liquor are not important components in the activity of the antibiotic. It is very possible that these discarded components may define activity against the biofilms found in nature. It is more difficult, if not impossible, to bring complex mixtures of active ingredients through regulatory process; however, this may be the active form of antibiotics in nature that are able to function against biofilms.