表征抗菌药物抑菌动力学的等效线药敏试验方法  

Antibiotic Susceptibility Test to Characterize the Antimicrobial Dynamics of Antibiotic Concentration by Isobiologram

作　　者：刘玉庆[1,2] 胡明[1,2] 刘焕奇[3] 王进文[1,2] 赵敏[1,2] 李靖冉[1,3] 付晓杰[1,3] 骆延波[1,2] 齐静[1,2] 李璐璐[1,2] 高培基[2] 

机构地区：[1]山东省农业科学院畜牧兽医研究所山东省动物疫病防治与繁育重点实验室,济南250101 [2]山东大学生命科学学院、微生物技术国家重点实验室,济南250100 [3]青岛农业大学动物科技学院,青岛266000

出　　处：《中国科学：生命科学》2015年第6期614-622,共9页Scientia Sinica(Vitae)

基　　金：国家自然科学基金(批准号:81271886);国家科技重大专项(批准号:2013ZX10004217003);公益性行业(农业)科研专项(批准号:201203040)资助

摘　　要：以抗菌药物作用浓度与时间对抑菌率的协同作用，改进通行的药敏试验方法．采用Bioscreen全自动生长曲线分析仪，在线测定连续时间、连续固定浓度抗菌药物作用下禽致病性大肠杆菌BBZ6-3g在MHB中生长量（A600），建立了抑菌动力学检测体系．用Sigmaplot构建以相对抑菌率RBR=1—At-i／At_0对抗菌药物浓度和作用时间的等效线图．等效线图全面地反映了药物浓度和时间对抑菌量的影响过程及趋势，兼具二维曲线的量化和三维曲面的直观特点，而且RBR通过归一化处理，消除了细菌群体的自然增殖的本底、不同接种量、不同抗菌药物的差异影响，可以直接比较不同抗菌药物的抑菌率，专门比较浓度和时间对抑菌率的影响．抑菌作用本质上是抗菌药物抑制细菌对营养物质的利用效率和程度，与细菌死亡是不同但是相关的过程。0．5RBR为传统的目测最低抑菌浓度（MIC），以此为界，等效线图可以直观地分为3部分：分化区（O．5纵向等效线以左，全部浓度）、生长区（0．5以上的等效线）、抑菌区（0．5纵向等效线以右延伸且0．5以下的等效线）．分化区边界时间在100～300min，因此传统的药敏试验以8—12h的终态来判断抑菌率，确定MIC是可靠的；抑菌区和生长区之间的等效线疏密，实际上是浓度依赖性和时间依赖性的依据．抑菌动力学检测体系和反映RBR的等效线图，改良了传统药敏试验方法，有望分析不同接种量对抑菌率和菌群变异的影响、不同浓度的抗菌药物后效应（PAE），比较不同菌种或不同抗药性水平菌株的抑菌动力学．The antibiotic susceptibility test （AST） method was improved by evaluating the synergy of antimicrobial concentration and time to antimicrobial rate. The concentration of E. coli BBZ6-3 suspension in the MHB was detected with turbidity （A600） by automatic growth curve analyzer （Bioscreen） in continuous time while exposed to various concentrations of antibiotics. Based on this testing system of antibacterial dynamics, isobiologram was built by Sigma plot through relative bacteriostatic rate （RBR=I-At-i/At_o） to antibiotic concentration and treating time. It could perfectly suggest that the process and trend of bacteriostatic action was affected with the two factors, which possessed compatible advantage of both quantitative character of two-dimensional curve and visual character of three-dimensional curve： With the normalized processing, RBR could eliminate the influence of some factors, such as the background effect of bacteria growth, inoculums concentration and variety of antibiotics. So the bacteriostatic rate of different antibiotics, specially the effect of concentration and time, could directly be compared through it. The essence of bacteriostaticaction was that the nutriment utilization efficiency and degree were inhibited by antibiotics when bacteria grew in media, which was different form direct sterilization but was a correlative course. Isobiologram was divided into three parts by 0.5 RBR （traditional visual MIC by the naked eye）： differentiation area （left area of lengthways isobiologram 0.5 RBR, all concentrations）, growth area （above isobiologram 0.5 RBR）, bacteriostasis area （right area of lengthways isobiologram 0.5 RBR and below isobiologram 0.5 RBR）. The periphery of differentiation area was 100-300 rain, so it was credible to determine the MIC at 8-12 h in traditional AST. In fact, the isobiologram density of growth area and bacteriostasis area was the evidence of concentration dependence and time dependence. Bacteriostatic dynamics testing system and RBR isob

关 键 词：相对抑菌率(RBR) 等效线 抑菌区 浓度 时间 

分 类 号：S859.7[农业科学—临床兽医学]