Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK.
J Appl Microbiol. 2013 Nov;115(5):1117-26. doi: 10.1111/jam.12320. Epub 2013 Sep 3.
The extensive use of microbicides in a wide range of applications has been questioned with regard to their role in the development of bacterial resistance to antimicrobials. This study aims to measure the phenotypic and genotypic changes in Burkholderia lata strain 383 exposed to chlorhexidine gluconate (CHG) and benzalkonium chloride (BZC), two commonly used cationic microbicides.
The susceptibility of B. lata strain 383 to CHG and BZC and a range of antibiotics was determined using standardized MIC, MBC and antibiotic susceptibility testing protocols before and after short-term exposure to a low microbicide concentration. Measurements were performed on four separate occasions over a 1-year period. Changes in gene expression were investigated using quantitative real-time PCR. Although the susceptibility profile to CHG and BZC was not altered, a change in antibiotic susceptibility profile was observed for ceftazidime, and for imipenem and ciprofloxacin in 2/4 repeats. An outer membrane protein and ABC transporter were found to be significantly upregulated following treatment with BZC and CHG, respectively.
The comparison of MIC and MBC results following microbicide exposure with baseline data offered a prospective protocol to quantify any change in bacterial susceptibility profile. However, the use of a standardized antibiotic susceptibility protocol with B. lata strain 383 showed some inconsistencies in results between repeats.
With ever-increasing interest in the impact of microbicides on emerging antimicrobial resistance in bacteria growing, this study demonstrated that comparing susceptibility profile obtained after exposure to microbicides with baseline susceptibility values could play a role in establishing the potential risk of microbicide resistance and cross-resistance development and also in the development of a protocol that allows the prediction of microbicide resistance.
由于广泛应用于多种用途的杀菌剂，人们对其在导致细菌对抗微生物药物产生耐药性方面的作用产生了质疑。本研究旨在测量经葡萄糖酸氯己定（CHG）和苯扎氯铵（BZC）处理的伯克霍尔德菌 383 菌株的表型和基因型变化，这两种杀菌剂是常用的阳离子杀菌剂。
使用标准化的 MIC、MBC 和抗生素药敏试验方案，在短期接触低浓度杀菌剂后，测定伯克霍尔德菌 383 菌株对 CHG 和 BZC 以及一系列抗生素的敏感性，在一年的时间内进行了四次独立的测量。使用定量实时 PCR 研究基因表达的变化。尽管 CHG 和 BZC 的药敏谱没有改变，但在 4 次重复中有 2 次观察到头孢他啶、亚胺培南和环丙沙星的抗生素药敏谱发生了变化。在分别用 BZC 和 CHG 处理后，发现外膜蛋白和 ABC 转运蛋白的表达显著上调。
将暴露于杀菌剂后的 MIC 和 MBC 结果与基线数据进行比较，提供了一种定量细菌药敏谱变化的前瞻性方案。然而，使用标准化的抗生素药敏试验方案对伯克霍尔德菌 383 进行测试，结果在重复之间存在一些不一致。
随着人们对杀菌剂对细菌新兴抗药性的影响的兴趣日益增加，本研究表明，将暴露于杀菌剂后获得的药敏谱与基线药敏值进行比较，可以在确定杀菌剂耐药性和交叉耐药性发展的潜在风险方面发挥作用，并有助于制定一种可以预测杀菌剂耐药性的方案。
