Unidad de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena, Seville, Spain.
Instituto de Biomedicina de Sevilla IBIS, Hospital Universitario Virgen Macarena, CSIC, Universidad de Sevilla, Seville, Spain.
Antimicrob Agents Chemother. 2018 Dec 21;63(1). doi: 10.1128/AAC.01396-18. Print 2019 Jan.
The aim of this study was to characterize the population structure of 56 OXA-48-like-producing isolates, as well as extended-spectrum β-lactamase (ESBL) and carbapenemase genes, recovered in 2014 and 2015 from 16 hospitals in southern Spain. XbaI pulsed-field gel electrophoresis and multilocus sequence typing were performed to assess clonal relatedness. Representative isolates belonging to OXA-48-like-producing and CTX-M-15-coproducing pulsotypes were selected for characterization of - and -carrying plasmids by PCR-based replicon typing, IncF subtyping, whole-genome sequencing analysis, and typing of Tn structures. Forty-three OXA-48-producing isolates (77%) were recovered from clinical samples and 13 from rectal swabs. All isolates showed ertapenem MIC values of ≥1 mg/liter, although 70% remained susceptible to imipenem and meropenem. Forty-nine isolates (88%) produced OXA-48, 5 produced OXA-245, and 2 produced OXA-181. Twenty-eight different pulsotypes (5 detected in more than 1 hospital) and 16 sequence types (STs) were found. The most prevalent clones were ST15 (29 isolates [52%]) and ST11 (7 isolates [13%]). Forty-five (80%) isolates were also carriers. The gene was mostly (82%) located on IncR plasmids, although ST15 and ST11 isolates also carried this gene on IncF plasmids. The composite transposon variant Tn-like was the most frequent. Among ST15 and ST11 isolates, different transposon variants were observed. The gene was mainly located on IncL plasmids, although IncM plasmids were also observed. The spread of OXA-48-like-producing in southern Spain is mainly due to ST15 and ST11 clones. Variation within clonal lineages could indicate different acquisition events for both ESBL and carbapenemase traits.
这项研究的目的是对 2014 年至 2015 年从西班牙南部 16 家医院分离的 56 株产 OXA-48 样碳青霉烯酶的分离株，以及产超广谱β-内酰胺酶（ESBL）和碳青霉烯酶基因的种群结构进行特征描述。使用 XbaI 脉冲场凝胶电泳和多位点序列分型来评估克隆相关性。选择属于 OXA-48 样和 CTX-M-15 共产生脉冲型的代表性分离株，通过 PCR 基于复制子分型、IncF 亚型、全基因组测序分析和 Tn 结构分型来对 - 和 - 携带质粒进行特征描述。从临床样本中分离出 43 株产 OXA-48 的分离株（77%），从直肠拭子中分离出 13 株。所有分离株均表现出厄他培南 MIC 值≥1 毫克/升，尽管 70%对亚胺培南和美罗培南仍保持敏感。49 株分离株（88%）产生 OXA-48，5 株分离株产生 OXA-245，2 株分离株产生 OXA-181。发现 28 种不同的脉冲型（5 种在超过 1 家医院中发现）和 16 种序列型（ST）。最流行的克隆是 ST15（29 株[52%]）和 ST11（7 株[13%]）。45 株（80%）分离株也是 携带者。基因主要位于 IncR 质粒上（82%），尽管 ST15 和 ST11 分离株也将此基因携带在 IncF 质粒上。复合转座子变体 Tn 样是最常见的。在 ST15 和 ST11 分离株中，观察到不同的转座子变体。基因主要位于 IncL 质粒上，尽管也观察到 IncM 质粒。OXA-48 样产 在西班牙南部的传播主要是由于 ST15 和 ST11 克隆。克隆谱系内的变异可能表明 ESBL 和碳青霉烯酶特性的不同获得事件。
