It has been hypothesized that long term application of new generation antibiotics could result in bacterial species which are susceptible to old generation antibiotics. However, there are several factors which make such a hypothesis questionable. Resistance could be reversible but bacteria will die due to the presence of the antibiotic in the bacterial population. Furthermore, if a microorganism becomes resistant to a second generation of antimicrobial agents it will also be resistant to the first generation of that class. In addition, the turnover time for cycling is unknown, the use of new generation antimicrobial agents is expensive, producing a new generation of an antimicrobial class may not be straightforward, and there are different administrations for different generations of a class of an antibiotic. Antimicrobial resistance in bacterial populations is an example of Darwinian evolution. Is it possible that a species with a ‘superior’ phenotype resulting in natural selection of that species over others would lose that phenotype in the future? Considering the aforementioned points, we suggest that cycling antibiotic resistance does not occur, and that it would be extremely unlikely to do so.
展开▼
