Effects of chronic triclosan exposure upon the antimicrobial susceptibility of 40 ex-situ environmental and human isolates
Effects of chronic triclosan exposure upon the antimicrobial susceptibility of 40 ex-situ environmental and human isolates
复制标题
DOI：
10.1111/j.1365-2672.2006.02811.x
复制
发表时间：
2006-05-01
影响因子：
4
通讯作者：
McBain, A. J.
中科院分区：
文献类型：
--
作者：
Ledder, R. G.;Gilbert, P.;McBain, A. J.
背景：三氯生(TCS)暴露在大肠杆菌中，选择耐受性克隆，其Enoyl-acyl载体蛋白还原酶(Fabi)发生突变。据推测，这种现象在细菌属中普遍存在，可能与对第三方药物的耐药性有关。方法：采用梯度平板技术，将肠道、人腋窝、人类口腔来源的低传代分离物和从家庭下水道分离的细菌，以及选定的类型培养物，在10代中暴露于TCS浓度不断上升的环境中。其中包括一株新鲜的粪便分离的大肠杆菌作为阳性对照。结果：肠道菌对洗必泰、四环素、氯霉素、那利地酸和环丙沙星的敏感性增加，口腔菌株对洗必泰、四环素和甲硝唑的敏感性降低。对催产克雷伯菌、蛋白水解菌和嗜麦芽窄食单胞菌的TCS敏感性也有所下降。其余35株菌株对TCS和其他测试药物的敏感性没有变化。结论：这些数据表明，TCS暴露对高水平耐药性的选择并不普遍，似乎仅限于某些肠道细菌，尤其是大肠杆菌。TCS敏感性的改变不会影响对化学上无关的抗菌药的敏感性。意义和影响：获得性高水平的TCS耐药性并不是一个普遍的现象。
Background: Triclosan (TCS) exposure of Escherichia coli selects for tolerant clones, mutated in their enoyl-acyl carrier protein reductase (FabI). It has been inferred that this phenomenon is widespread amongst bacterial genera and might be associated with resistance to third party agents.Methods: Ex-situ, low passage isolates of enteric, human axilla., human oral origin and bacteria isolated from a domestic drain, together with selected type cultures were exposed to escalating concentrations of TCS over 10 passages using a gradient plate technique. One fresh faecal isolate of E. coli was included as a positive control. TCS susceptibility was determined for all strains before and after exposure, whilst enteric isolates were additionally assessed for susceptibility towards chlorhexidine, tetracycline, chloramphenicol, nalidixic acid and ciprofloxacin, and the oral isolates towards chlorhexidine, tetracycline and metronidazole.Results: Triclosan exposure of E. coli markedly decreased TCS susceptibility. TCS susceptibility also decreased for Klebsiella oxytoca, Aranicola proteolyticus and Stenotrophomonas maltophilia. Susceptibility of the remaining 35 strains to TCS and the other test agents remained unchanged.Conclusions: These data suggest that selection for high level resistance by TCS exposure is not widespread and appears to be confined to certain enteric bacteria, especially E. coli. Change in TCS susceptibility did not affect susceptibility towards chemically unrelated antimicrobials. Significance and impact: Acquired high-level TCS resistance is not a widespread phenomenon.