体外诱导人型支原体对氟喹诺酮类药物耐药的实验研究

Study on drug resistance of mycoplasma hominis induced by fluoroquinolones in vitro

目的探讨体外短期和长期诱导后人型支原体(Mh)对氟喹诺酮类药物的耐药和交叉耐药情况。方法将Mh标准株PG21在分别含有次抑菌浓度环丙沙星、氧氟沙星、司帕沙星和加替沙星的液体培养基中传代培养3代和12代后,筛选诱导株并分别检测其对4种药物的MIC值。结果经体外诱导后,分别筛选出4株短期诱导株(传3代)和4株长期诱导株(传12代)。4株短期诱导株对诱导药物和非诱导药物均产生耐药和交叉耐药,但耐药程度较低;4株长期诱导株的耐药和交叉耐药程度大大提高;且这种体外获得性耐药具有较好的稳定性。结论体外长时间、次抑菌浓度的氟喹诺酮类药物刺激将诱导Mh产生稳定的耐药和交叉耐药;短期诱导产生低度耐药,长期诱导产生高度耐药。

Objective To explore the drug resistance or cross-resistance of mycoplasma hominis after 3-passage and 12-passage induction by fluoroquinolones in vitro. Methods The mycoplasma hominis standard strain PG21 were cultured stepwise for 3 and 12 passages respectively with ciprofloxacin,ofloxacin, sparfloxacin and gatifloxacin at subinhibitory concentrations and the minimum inhibition concentrations（MICs） to these drugs were detected before and after induction. Results Four 3-passage and four 12-passage resistant strains were selected respectively after induced by fluoroquinolones in vitro. Four 3-passage selected strains exhibited low-lever resistance or cross-resistance and another four 12-passage selected strains exhibited high lever resistance or cross resistance to these fluoroquinolones. The resistance or cross-resistance of mycoplasma hominis induced by fluoroquinolones in vitro were stable. Conclusion The resistance and cross-resistance of mycopiasma hominis to fluoroquinolones can be induced after long time and subinhibitory concentration stimulation with the fluoroquinolones in vitro. Low-lever and high lever resistance or cross-resistance were selected after 3-passage and 12 passage induction respectively.