Blázquez Jesús
Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Campus Universidad Autonoma de Madrid, Spain.
Clin Infect Dis. 2003 Nov 1;37(9):1201-9. doi: 10.1086/378810. Epub 2003 Sep 30.
Contrary to what was thought previously, bacteria seem to be, not merely spectators to their own evolution, but, through a variety of mechanisms, able to increase the rate at which mutations occur and, consequently, to increase their chances of becoming resistant to antibiotics. Laboratory studies and mathematical models suggest that, under stressful conditions, such as antibiotic challenge, selective pressure favors mutator strains of bacteria over nonmutator strains. These hypermutable strains have been found in natural bacterial populations at higher frequencies than expected. The presence of mutator strains in the clinical setting may indicate an enhanced risk of acquiring antibiotic resistance through mutational and recombinational events. In addition, some antibiotics are inducers of mechanisms that transiently increase the mutation rate, and thus probably act, not only as mere selectors of antibiotic resistant clones, but also as resistance-promoters.
与之前的认知相反，细菌似乎不仅仅是自身进化的旁观者，而是通过多种机制能够提高突变发生的速率，从而增加其对抗生素产生耐药性的机会。实验室研究和数学模型表明，在诸如抗生素挑战等压力条件下，选择压力有利于细菌的突变菌株而非非突变菌株。已发现这些超突变菌株在自然细菌群体中的出现频率高于预期。临床环境中突变菌株的存在可能表明通过突变和重组事件获得抗生素耐药性的风险增加。此外，一些抗生素是可瞬时提高突变率的机制的诱导剂，因此可能不仅作为抗生素耐药克隆的单纯选择剂，还作为耐药性促进剂发挥作用。
