氟苯尼考对鲁氏耶尔森氏菌体外药效研究

本文研究了氟苯尼考对鲁氏耶尔森氏菌(Yersinia ruckeri)体外药效学,测定了最小抑菌浓度(MIC)、最小杀菌浓度(MBC)、生长动力学曲线和杀菌动力学曲线和抗菌后效应(PAE)及四种培养因子对氟苯尼考体外抑制鲁氏菌活性的影响。结果表明:MIC、MBC和MBC/MIC分别为0.5μg.mL-1、1μg.mL-1和2;鲁氏菌在液体培养基中1h后进入对数生长,大约持续7h;在用药4～6 h达到最大药效。由杀菌曲线可知,氟苯尼考的杀菌功效具有浓度依赖性;在2 MIC、4 MIC和8 MIC时,PAE分别为3.71±0.11、4.54±0.27和5.52±0.23;氟苯尼考对鲁氏菌作用最适pH值为6～8,且二价阳离子(Mg2+)、血清含量及细菌数量小于108时对药效无显著影响。因此,保证药物浓度和作用时间,并配合最适培养条件,是氟苯尼考发挥最高药效的前提条件。

Pharmacodynamics of Florfenicol on Bacterium Yersinia ruckeri in vitro

The pharmacodynamics of florfenicol on bacterium Yersinia ruckeri were studied in vitro including minimal inhibitory concentration（MIC）;minimal bactericidal concentration（MBC ）; the growth curve of the bacterium; the bacteriocidal curve of the florfenicol and post-antibiotic effect（PAE）. The results showed thatthe florfenicol had MIC of 0.5 μg·mL^-1, MBC of 1μg·mL^-1 and MBC/MIC of 2. The logarithmic growth phase was observed in the bacterium cultured in fluid medium for 1 hour and lasted about 7 hours. The florfenicol showed the maximum activity 4-6 hours after administration and was a dose-dependence by the bacteriocidal curve. The value of PAE were found to be 3.71±0.11 in 2 MIC,4.54± 0.27 in 4 MIC, and 5.52± 0.23 in 8 MIC. Florfenicol had the most effective inhibition of Y. ruckeri at pH 6-8. There was no significant impact of Mg2＋, serum content, and less than 108 of bacteria quantity on bactericidal activity of the florfenicol. Therefore, the maximal efficacy of florfenicol depends on dose, administration period and the optimal environmental factors.