Interplay of Efflux, Impermeability, and AmpC Activity Contributes to Cefuroxime Resistance in Clinical, Non-ESBL-Producing Isolates of Escherichia coli
Interplay of Efflux, Impermeability, and AmpC Activity Contributes to Cefuroxime Resistance in Clinical, Non-ESBL-Producing Isolates of Escherichia coli
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DOI：
10.1089/mdr.2009.0883
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发表时间：
2009-06-01
影响因子：
2.6
通讯作者：
Olsson-Liljequist, Barbro
中科院分区：
文献类型：
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作者：
Kallman, Owe;Giske, Christian G.;Olsson-Liljequist, Barbro
对超广谱头孢菌素敏感的大肠杆菌菌株对头孢呋辛的耐药并不少见，但其耐药机制至今尚未阐明。因此，14株临床非超广谱β-内酰胺酶E.大肠埃希菌中有11株对头孢呋辛耐药。使用定量RT-PCR检测基因acrA（编码AcrA，AcrAB-TolC外排泵系统的一部分）和ompF（编码孔蛋白OmpF）的转录水平。采用等电聚焦法检测β-内酰胺酶，分光光度法检测AmpC酶活性。在11株头孢呋肟耐药菌株中，7株acrA转录水平增加（从ATCC菌株的2.4倍增加到38倍），3株ompF转录水平非常低（
Cefuroxime resistance in Escherichia coli strains susceptible to extended-spectrum cephalosporins is not uncommon, but the resistance mechanisms have so far not been elucidated. Therefore, 14 clinical non-extended-spectrum beta-lactamase isolates of E. coli were examined, 11 of which were cefuroxime resistant. Quantitative RT-PCR was used to examine the transcription levels of the genes acrA (encoding AcrA, part of the AcrAB-TolC efflux pump system) and ompF (encoding the porin OmpF). Isoelectric focusing was used for detection of beta-lactamases, and a spectrophotometric assay was used to measure AmpC activity. Among the 11 cefuroxime-resistant isolates, 7 had increased acrA transcription (from 2.4 to 38 times the ATCC strain), 3 isolates had very low ompF transcription levels (