Department of Laboratory Medicine, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China.
Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China.
Int J Antimicrob Agents. 2023 Sep;62(3):106921. doi: 10.1016/j.ijantimicag.2023.106921. Epub 2023 Jul 9.
Carbapenem-resistant Klebsiella pneumoniae (CRKP) has widely disseminated globally, but its epidemiological characterization and clinical significance in paediatric patients are not well understood. In this study, we aimed to trace the dissemination dynamics of CRKP in the neonatal intensive care unit (NICU) of a tertiary hospital over a 10-y period.
We collected 67 non-duplicate K. pneumoniae species complex isolates from the NICU with patient metadata during 2009-2018. Antimicrobial susceptibility was determined by the agar or broth microdilution method. Risk factors for CRKP-positive patients were identified by univariate and multivariate analysis. Genetic characterization was dissected by whole-genome sequencing. Plasmid transmissibility, stability, and fitness were assessed.
Thirty-four of 67 isolates (50.75%) were identified as CRKP. Premature rupture of membranes, gestational age, and invasive procedures are independent risk factors for CRKP-positive patients. The annual isolation rate of CRKP varied between 0% and 88.9%, and multiple clonal replacements were observed during the study period, which could be largely due to the division of the NICU. All but one CRKP produced IMP-4 carbapenemase, which was encoded by an IncN-ST7 epidemic plasmid, suggesting that the IncN-ST7 plasmid mediated the CRKP dissemination in the NICU over 10 y. The same plasmid was found in several CRKP isolates from adult patients, of which two ST17 isolates from the neurosurgery department shared a high homology with the ST17 isolates from the NICU, indicating possible cross-departmental transmission.
Our study highlights the urgent need for infection control measures targeting high-risk plasmids like IncN-ST7.
耐碳青霉烯类肺炎克雷伯菌（CRKP）在全球广泛传播，但人们对其在儿科患者中的流行病学特征和临床意义了解甚少。在本研究中，我们旨在追踪 10 年间三级医院新生儿重症监护病房（NICU）中 CRKP 的传播动态。
我们收集了 2009 年至 2018 年期间来自 NICU 的 67 株非重复肺炎克雷伯菌属复合种分离株，并收集了患者的元数据。采用琼脂或肉汤微量稀释法测定抗菌药物敏感性。通过单因素和多因素分析确定 CRKP 阳性患者的危险因素。通过全基因组测序进行遗传特征分析。评估质粒的可传递性、稳定性和适应性。
67 株分离株中有 34 株（50.75%）鉴定为 CRKP。胎膜早破、胎龄和侵入性操作是 CRKP 阳性患者的独立危险因素。CRKP 的年分离率在 0%至 88.9%之间变化，研究期间观察到多次克隆替代，这主要是由于 NICU 的划分所致。除 1 株外，所有 CRKP 均产生 IMP-4 碳青霉烯酶，该酶由 IncN-ST7 流行质粒编码，提示 IncN-ST7 质粒介导了 10 年间 NICU 中 CRKP 的传播。成人患者中也发现了几株携带 CRKP 的菌株，其中来自神经外科的 2 株 ST17 分离株与 NICU 中的 ST17 分离株具有高度同源性，表明可能存在跨科室传播。
我们的研究强调了针对 IncN-ST7 等高危质粒采取感染控制措施的迫切需要。
