Polymorphic Variation in Susceptibility and Metabolism of Triclosan-Resistant Mutants of Escherichia coli and Klebsiella pneumoniae Clinical Strains Obtained after Exposure to Biocides and Antibiotics
Polymorphic Variation in Susceptibility and Metabolism of Triclosan-Resistant Mutants of Escherichia coli and Klebsiella pneumoniae Clinical Strains Obtained after Exposure to Biocides and Antibiotics
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DOI：
10.1128/aac.00187-15
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发表时间：
2015-06-01
影响因子：
4.9
通讯作者：
Coquea, Teresa M.
中科院分区：
文献类型：
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作者：
Curiao, Tania;Marchi, Emmanuela;Coquea, Teresa M.
接触杀菌剂可能导致对其他抗菌剂产生交叉抗性。本文研究了选择杀菌剂的大肠埃希菌和肺炎克雷伯菌突变体中杀菌剂和抗生素敏感性、代谢和适应成本的变化。暴露于三氯生（TRI）、苯扎氯铵（BKC）、氯己定（CHX）或次氯酸钠（SHC）、氨苄西林或环丙沙星后，获得不同程度三氯生敏感性的大肠杆菌和肺炎克雷伯菌突变体。使用表型微阵列检测突变体的抗微生物敏感性和代谢变化。通过定量逆转录pcr （qRT-PCR）检测AcrAB泵和全局调控因子（SoxR、MarA和RamA）的表达，并对fabI基因的中心部分进行测序。通过比较相对生长速率来评估抗性的适应度成本。用杀菌剂和/或抗生素筛选后，获得了大肠杆菌和肺炎克雷伯菌的三氯生耐药（TRIr）和三氯生超敏感（TRIhs）突变体。大肠杆菌TRIr突变体，包括fabI基因突变或acrB、acrF和marA表达突变，表现出对TRI、CHX和抗生素的易感性变化。TRI MIC较高的TRIr突变体表现出羧酸、氨基酸和碳水化合物代谢的改善。在TRIr突变体中，对一种抗菌素的耐药性引起对另一种抗菌素的超敏感。TRIr突变体具有适应度成本，特别是过表达ara（大肠杆菌）或过表达rama（肺炎克雷伯菌）突变体。TRI、BKC和CIP暴露经常产生TRIr突变体，表现出arac样全球调节因子（MarA、SoxR和RamA）、AcrAB-TolC和/或FabI的改变，并影响抗菌敏感性、适应性和代谢。这些不同的表型表明，不同的选择过程形成了对抗生素/杀菌剂抗性的进化，并影响了其他适应性性状。
Exposure to biocides may result in cross-resistance to other antimicrobials. Changes in biocide and antibiotic susceptibilities, metabolism, and fitness costs were studied here in biocide-selected Escherichia coli and Klebsiella pneumoniae mutants. E.coli and K. pneumoniae mutants with various degrees of triclosan susceptibility were obtained after exposure to triclosan (TRI), benzalkonium chloride (BKC), chlorhexidine (CHX) or sodium hypochlorite (SHC), and ampicillin or ciprofloxacin. Alterations in antimicrobial susceptibility and metabolism in mutants were tested using Phenotype MicroArrays. The expression of AcrAB pump and global regulators (SoxR, MarA, and RamA) was measured by quantitative reverse transcription-PCR (qRT-PCR), and the central part of the fabI gene was sequenced. The fitness costs of resistance were assessed by a comparison of relative growth rates. Triclosan-resistant (TRIr) and triclosan-hypersusceptible (TRIhs) mutants of E. coli and K. pneumoniae were obtained after selection with biocides and/or antibiotics. E. coli TRIr mutants, including those with mutations in the fabI gene or in the expression of acrB, acrF, and marA, exhibited changes in susceptibility to TRI, CHX, and antibiotics. TRIr mutants for which the TRI MIC was high presented improved metabolism of carboxylic acids, amino acids, and carbohydrates. In TRIr mutants, resistance to one antimicrobial provoked hypersusceptibility to another one(s). TRIr mutants had fitness costs, particularly marA-overexpressing (E. coli) or ramA-overexpressing (K. pneumoniae) mutants. TRI, BKC, and CIP exposure frequently yielded TRIr mutants exhibiting alterations in AraC-like global regulators (MarA, SoxR, and RamA), AcrAB-TolC, and/or FabI, and influencing antimicrobial susceptibility, fitness, and metabolism. These various phenotypes suggest a trade-off of different selective processes shaping the evolution toward antibiotic/biocide resistance and influencing other adaptive traits.