适应度代价对大肠杆菌药物敏感性恢复的作用

Effect of the Fitness Cost on Drug-resistanc Reversal of Escherichia coli

通过测定野生型大肠杆菌对氟喹诺酮类药物敏感的、耐药的以及从耐药诱导恢复敏感的3种菌株的生长曲线,探讨适应度代价对细菌耐药性变化的影响。结果表明:对氟喹诺酮类药物耐药的大肠杆菌C02的生长速率远低于敏感菌株C01和恢复敏感性后菌株C03;而敏感菌株C01和敏感性恢复菌株C03的细菌生长曲线相近,说明在无药物选择压力环境中,适应度代价高的耐药菌生存竞争力低于适应度代价低的敏感菌,敏感菌逐渐取代耐药菌,使菌群对药物的敏感性得以恢复。

To discuss the effect of the fitness cost on drug-resistanc reversal of Escherichia coli, the growth curves of three strains E.coli, which E. coli C01 was sensitivity to fluoroquinolones, E. coli C02 was resistance to fluoroquinolones and E. coli C03 was restored sensitivity to fluoroquinolones, were determined. The result showed that the growth velocity of E. coli C02 resistented to fluoroquinolones was far lower than E. coli C01 or E. coli C03, and the growth velocities of E. coli C01 or E. coli C03 were quit similar. It demonstated that the survival competitiveness of drug-resistant bacteria possessed the high fitness cost was lower than sensitive one armied low fitness cost in the environment of no drug selection pressure. The drug-resistant bacteria was gradually replaced by ensitive bacteria and the drug sensitivity of microbiome was restored.