摘要:
To compare the postantibiotic effects (PAE) of some common antibiotics in aquaculture on Aeromonas hydrophila (A.hydrophila),The broth macrodilution method was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the selected 5 kinds of typical antimicrobial agents against A.hydrophila,and PAE induced the drugs at the concentration of 0,1/2 MIC,1 MIC,2 MIC and 4 MIC.Then the growth curves of bacteria were measured and recorded by viable counting method and the PAE value were calculated.The results showed that the MIC and MBC of the antibacterials were 0.016 and 0.023 μg/mL for enrofloxcin,0.250 and 0.500 μg/mL for doxycycline,0.250 and 0.500 μg/mL for norfloxacin,1 and 4 μg/mL for florfenico 1,2 and 4 μg/mL for thiamphenicol,respectively,and the 5 kinds of antibacterials had a certain PAE value at different concentrations,among which the PAE of doxycycline could up to 2.84 h.It was described that each of antibiotics had its own PAE value against A.hydrophila and the PAE value presented a certain concentration dependence (1/2 MIC-4 MIC).Therefore,it should consider to extend the dosing interval and make the therapeutic regimen more scientific on treatment of fish diseases for the particular features of PAE.%为比较研究水产养殖中几种常见抗菌药物对嗜水气单胞菌(A.hydrophila)的体外抗菌后效应(PAE),本研究选取5种典型的抗菌药物(恩诺沙星、盐酸多西环素、诺氟沙星、氟苯尼考以及甲砜霉素),采用常量肉汤稀释法测定它们对A.hydrophila的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),并在0、1/2 MIC、1 MIC、2 MIC和4 MIC药物浓度下进行PAE诱导,再用活菌计数法测定并记录细菌生长曲线,计算PAE值.结果显示,5种抗菌药物的MIC和MBC分别为0.016和0.023μg/mL(恩诺沙星),0.250和0.500 μg/mL(盐酸多西环素),0.250和0.500 μg/mL(诺氟沙星),1和4μg/mL(氟苯尼考)以及2和4μg/mL(甲砜霉素);5种抗菌药物在不同浓度下均有一定的PAE,其中盐酸多西环素最长可达2.84 h.本研究结果表明,这5种抗菌药物对A.hydrophila均有相当的PAE,并且在一定范围内呈浓度依赖性.提示在治疗鱼病及临床给药时,可以考虑PAE的独有特性,延长给药间隔,科学用药.