尿液pH对常见泌尿系感染细菌抗生素敏感性的影响

目的 探讨尿液pH对常见泌尿系感染细菌抗生素敏感性的影响。方法 配制不同pH的人工尿液,以大肠杆菌、表皮葡萄球菌、金黄色葡萄球菌、产超广谱β-内酰胺酶(extended-spectrum β-lactamases,ESBL)的肺炎克雷伯菌和产ESBL的铜绿假单胞菌为研究菌种,环丙沙星、左氧氟沙星、磷霉素氨丁三醇和头孢呋辛为研究药物,采用药敏试验中的微量肉汤稀释法比较不同抗生素在不同pH的人工尿液培养基中的抗菌效力。结果 环丙沙星对大肠杆菌、表皮葡萄球菌和产ESBL的肺炎克雷伯菌的抗菌效果随着pH升高而升高;左氧氟沙星对大肠杆菌和表皮葡萄球菌的抗菌效果亦随着pH升高而升高;磷霉素对大肠杆菌、表皮葡萄球菌和金黄色葡萄球菌的抗菌效果随着pH的升高而降低;头孢呋辛对大肠杆菌和金黄色葡萄球菌的抗菌效果亦随着pH的升高而降低。结论 通过调节尿液pH能够改变致病菌对抗生素的敏感性,以期在临床上提高抗生素对泌尿系感染的治疗效果。

Influence of urinary pH on antibiotics efficacy against bacterial uropathogens

Objective To investigate the effect of urinary pH on bacterial antibiotics susceptibility to common urinary tract infections.Methods Artificial urine with different pH was prepared E.coli,Staphylococcus epidermidis,Staphylococcus aureus,ESBL-producing Klebsiella pneumoniae and ESBL-producing Pseudomonas aeruginosa were selected as the study species,while ciprofloxacin,levofloxacin,fosfomycin and cefuroxime were as the research antibiotics.The micro-broth dilution method in the susceptibility test was conducted to study the antibacterial efficacy of different antibiotics on the different bacteria in the artificial urine medium with different pH values.Results The antibacterial effects of ciprofloxacin on Escherichia coli,Staphylococcus epidermidis and ESBL-producing Klebsiella pneumoniae were enhanced with the increase of pH.The antibacterial effects of levofloxacin on Escherichia coli and Staphylococcus epidermidis were enhanced with the increase of pH too.Whereas when using fosfomycin in the treatment of E.coli,Staphylococcus epidermidis and Staphylococcus aureus,the lower the pH was,the higher the antibacterial activity was.And the antibacterial activity of cefuroxime on E.coli and Staphylococcus aureus decreased with the increase of pH.Conclusion The sensitivity of pathogenic bacteria to antibiotics can be changed by adjusting urinary pH,in order to improve the therapeutic effect of antibiotics on urinary tract infection in the clinic.