Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 18, 1700, Fribourg, Switzerland.
Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), University of Fribourg, Fribourg, Switzerland.
Eur J Clin Microbiol Infect Dis. 2019 May;38(5):945-949. doi: 10.1007/s10096-019-03531-0. Epub 2019 Mar 15.
Our aim was to evaluate the prevalence of fosfomycin-resistant strains among ESBL-producing Escherichia coli isolates recovered from community patients in Switzerland. A total of 1225 ESBL-producing E. coli isolates were collected between 2012 and 2013 from a private and community laboratory. Fosfomycin resistance was assessed by using the novel rapid fosfomycin/E. coli NP test and agar dilution method. Resistant isolates were further investigated for acquired resistance genes fosA1-7 by PCR and sequencing. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were performed to evaluate the clonal relationship among fosA3-carrying isolates. Out of the 1225 ESBL-producing E. coli isolates analyzed in this study, 1208 were fosfomycin susceptible while 17 were fosfomycin resistant. No discrepancy was observed between the rapid fosfomycin/E. coli NP test and the agar dilution method taken as the gold standard. Five out of the 17 resistant isolates carried a fosA-like gene. No clonal relationship was observed among those isolates. Here, the prevalence of fosfomycin resistance among ESBL-producing E. coli isolates in the community is reported for the first time in Switzerland, being ca. 1.4%. Among the five isolates carrying a fosA gene, four encoded the FosA3 enzyme, being the most prevalent fosfomycin-resistant determinant. An excellent correlation was observed between minimum inhibitory concentration-based susceptibility categorization and results of the rapid fosfomycin/E. coli NP test, further indicating the excellent sensitivity and specificity of this recently developed rapid test whose results are obtained in less than 2 h.
我们的目的是评估瑞士社区患者分离的产 ESBL 大肠杆菌中耐福沙霉素菌株的流行率。在 2012 年至 2013 年期间，从一家私人和社区实验室共收集了 1225 株产 ESBL 的大肠杆菌。采用新型快速福沙霉素/大肠杆菌 NP 试验和琼脂稀释法评估福沙霉素耐药性。通过 PCR 和测序进一步研究耐福沙霉素的获得性耐药基因 fosA1-7。脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）用于评估携带 fosA3 的分离株之间的克隆关系。在本研究中分析的 1225 株产 ESBL 的大肠杆菌中，1208 株对福沙霉素敏感，17 株对福沙霉素耐药。快速福沙霉素/大肠杆菌 NP 试验与作为金标准的琼脂稀释法之间没有差异。17 株耐药株中有 5 株携带 fosA 样基因。这些分离株之间没有观察到克隆关系。在这里，首次在瑞士报告了社区中产 ESBL 的大肠杆菌中福沙霉素耐药的流行率，约为 1.4%。在携带 fosA 基因的 5 株分离株中，有 4 株编码 FosA3 酶，是最常见的福沙霉素耐药决定因素。最小抑菌浓度分类与快速福沙霉素/大肠杆菌 NP 试验结果之间存在极好的相关性，进一步表明该新开发的快速试验具有极好的敏感性和特异性，其结果在不到 2 小时内即可获得。
