National Medicines Institute, Warsaw, Poland.
Międzyleski Specialist Hospital, Warsaw, Poland.
J Antimicrob Chemother. 2022 May 29;77(6):1561-1569. doi: 10.1093/jac/dkac076.
Consecutive Polish regions have become endemic for NDM-1-producing Klebsiella pneumoniae ST11, followed by K. pneumoniae ST147. Since 2017 a significant increase in NDM-positive Enterobacter hormaechei cases has been observed.
To investigate the origin and character of this increase in NDM-positive E. hormaechei.
The analysis included 160 NDM-producing Enterobacter cloacae complex isolates, recovered in 2015-20 in 37 centres of 9/16 regions. These were typed by PFGE and MLST, and screened by PCR-mapping for NDM-1-encoding Tn125-like elements. Forty-four isolates were sequenced by MiSeq. Species identification was based on whole-genome average nucleotide identity; clonality and phylogeny were inferred by SNP approaches. The structural plasmid analysis was done for 12 isolates sequenced by MinION.
The isolates belonged to 11 STs, predominantly ST89 (65.6%), followed by ST146 (15.6%), ST198 (7.5%) and ST1303 (3.7%), representing different E. hormaechei subspecies. Most of the isolates contained the Tn125A variant of the K. pneumoniae ST11 lineage, and several had Tn125F of the ST147. Individual E. hormaechei genotypes represented various epidemiological situations, from sporadic cases to single-hospital, city and regional outbreaks, including one caused by ST89 organisms with 82 cases in 17 centres. Acquisitions of the Tn125A/Tn125F determinants by the E. hormaechei strains occurred around 10 times and were plasmid-mediated, with a significant plasmid rearrangement in case of Tn125F.
The increase in E. hormaechei NDM-1 cases in Poland is a consequence of the uncontrolled spread of NDM-1-producing K. pneumoniae genotypes. Several E. hormaechei lineages have acquired NDM-encoding plasmids in different locales which started 'secondary' progressive outbreaks.
连续的波兰地区已成为 NDM-1 产肺炎克雷伯菌 ST11 的地方病，随后是 K. pneumoniae ST147。自 2017 年以来，观察到 NDM 阳性肠杆菌属霍氏菌病例显著增加。
研究 NDM 阳性 E. hormaechei 增加的起源和特征。
分析包括 2015-20 年在 9/16 个地区的 37 个中心回收的 160 株 NDM 产阴沟肠杆菌复合菌株。通过 PFGE 和 MLST 对这些菌株进行分型，并通过 PCR 图谱筛选 NDM-1 编码的 Tn125 样元件。对 44 株分离物进行 MiSeq 测序。种属鉴定基于全基因组平均核苷酸同一性；通过 SNP 方法推断克隆性和系统发育。对 12 株经 MinION 测序的分离株进行结构质粒分析。
分离株属于 11 个 ST，主要是 ST89（65.6%），其次是 ST146（15.6%）、ST198（7.5%）和 ST1303（3.7%），代表不同的 E. hormaechei 亚种。大多数分离株含有肺炎克雷伯菌 ST11 谱系的 Tn125A 变体，少数分离株含有 ST147 的 Tn125F。个别 E. hormaechei 基因型代表不同的流行病学情况，从散发病例到单医院、城市和区域暴发，包括由 ST89 引起的 17 个中心 82 例的暴发。E. hormaechei 菌株获得 Tn125A/Tn125F 决定因素的次数约为 10 次，并且是质粒介导的，在 Tn125F 的情况下发生了显著的质粒重排。
波兰 E. hormaechei NDM-1 病例的增加是 NDM-1 产肺炎克雷伯菌基因型不受控制传播的结果。几个 E. hormaechei 谱系在不同地点获得了编码 NDM 的质粒，这些质粒引发了“继发性”渐进性暴发。
