Zhanel G G, Crampton J, Kim S, Nicolle L E, Davidson R J, Hoban D J
Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada.
Chemotherapy. 1992;38(6):388-94. doi: 10.1159/000239032.
This investigation used the postantibiotic effect (PAE) and killing curves to examine the antimicrobial activity of subinhibitory (1/8x, 1/4x and 1/2x MIC) and inhibitory (1x MIC) concentrations of ciprofloxacin against mucoid (M) and nonmucoid (NM) urinary isolates of Pseudomonas aeruginosa. Subinhibitory concentrations (1/8x, 1/4x and 1/2x MIC) of ciprofloxacin produced PAEs with no difference between M and NM strains. For NM strains, those with low MICs (< or = 1.0 mg/l) to ciprofloxacin produced significantly longer PAEs than isolates with high MICs (> 1 mg/l). Killing curve studies demonstrated that subinhibitory concentrations of ciprofloxacin produce little effect (1/8x MIC) or stasis (1/4x and 1/2x MIC) of growth for several hours. Only 1x MIC was bactericidal for several strains. At 1/2x and 1x MIC, bacterial inhibition was greater against NM versus M isolates. The M phenotype of P. aeruginosa reduces killing by ciprofloxacin but not the PAE.
本研究采用抗生素后效应（PAE）和杀菌曲线，来检测环丙沙星对黏液型（M）和非黏液型（NM）铜绿假单胞菌尿液分离株的亚抑菌浓度（1/8倍、1/4倍和1/2倍MIC）及抑菌浓度（1倍MIC）的抗菌活性。环丙沙星的亚抑菌浓度（1/8倍、1/4倍和1/2倍MIC）产生的PAE在M型和NM型菌株之间无差异。对于NM型菌株，对环丙沙星MIC较低（≤1.0mg/L）的菌株产生的PAE明显长于MIC较高（>1mg/L）的分离株。杀菌曲线研究表明，环丙沙星的亚抑菌浓度在数小时内对生长几乎没有影响（1/8倍MIC）或产生生长停滞（1/4倍和1/2倍MIC）。只有1倍MIC对几种菌株具有杀菌作用。在1/2倍和1倍MIC时，对NM型分离株的细菌抑制作用强于M型分离株。铜绿假单胞菌的M表型可降低环丙沙星的杀菌作用，但不影响PAE。
