Abstract：
The global transmission of carbapenem-resistant Acinetobacter baumannii (CRAB) poses a significant and grave threat to human health. To investigate the potential relationship between hospital sewage and the transmission of CRAB within healthcare facilities, isolates of Acinetobacter spp. obtained from untreated hospital sewage samples were subjected to antimicrobial susceptibility tests, genome sequencing, and bioinformatic and phylogenetic tree analysis, and that data were matched with those of the clinical isolates. Among the 70 Acinetobacter spp. sewage isolates tested, A. baumannii was the most prevalent and detectable in 5 hospitals, followed by A. nosocomialis and A. gerneri. Worryingly, 57.14 % (40/70) of the isolates were MDR, with 25.71 % (18/70) being resistant to carbapenem. When utilizing the Pasteur scheme, ST2 was the predominant type among these CRAB isolates, with Tn2006 (ΔISAba1-blaOXA-23-ATPase-yeeB-yeeA-ΔISAba1) and Tn2009 (ΔISAba1-blaOXA-23-ATPase-hp-parA-yeeC-hp-yeeB-ΔISAba1) being the key mobile genetic elements that encode carbapenem resistance. Seven A. gerneri isolates which harbored Tn2008 (ISAba1-blaOXA-23 -ATPase) and the blaPER-1 gene were also identified. Besides, an A. soil isolate was found to exhibit high-level of meropenem resistance (MIC ≥128 mg/L) and harbor a blaNDM-1 gene located in a core genetic structure of ISAba125-blaNDM-1-ble-trpF-dsbC-cutA. To investigate the genetic relatedness between isolates recovered from hospital sewage and those collected from ICUs, a phylogenetic tree was constructed for 242 clinical isolates and 9 sewage isolates. The results revealed the presence of two evolutionary clades, each containing isolates from both ICU and sewage water, suggesting that CRAB isolates in untreated sewage water were also the transmission clones or closely related evolutionary isolates recoverable in hospital settings. Findings in this work confirm that hospital sewage is a potential reservoir of CRAB.
摘要：
耐碳青霉烯鲍曼不动杆菌（CRAB）在全球范围内的传播对人类健康构成了重大而严重的威胁。调查医院污水与医疗机构内CRAB传播之间的潜在关系，不动杆菌属的分离株。从未经处理的医院污水中获得的样品进行了抗菌敏感性测试，基因组测序，以及生物信息学和系统发育树分析，并且该数据与临床分离株的数据相匹配。在70种不动杆菌属中。测试污水隔离物，鲍曼不动杆菌在5家医院中最普遍和可检测到，其次是A.noconomeialis和A.gerneri。令人担忧的是,57.14%(40/70)的菌株为MDR,25.71％（18/70）对碳青霉烯耐药。当利用巴斯德计划时，ST2是这些CRAB分离株中的主要类型，Tn2006（ΔISAba1-blaOXA-23-ATPase-yeeB-yeeA-ΔISAba1）和Tn2009（ΔISAba1-blaOXA-23-ATPase-hp-parA-yeeC-hp-yeeB-ΔISa1）是编码碳青霉烯抗性的关键移动遗传元件。还鉴定了七个携带Tn2008(ISAba1-blaOXA-23-ATPase)和blaPER-1基因的gerneri分离株。此外,发现一种土壤分离物表现出高水平的美罗培南抗性（MIC≥128mg/L），并且具有位于ISAba125-blaNDM-1-ble-trpF-dsbC-cutA核心遗传结构中的blaNDM-1基因。为了调查从医院污水中回收的分离株与从ICU收集的分离株之间的遗传相关性，构建了242个临床分离株和9个污水分离株的系统发育树。结果显示存在两个进化枝，每个都含有来自ICU和污水的分离物，表明未经处理的污水中的CRAB分离株也是在医院环境中可回收的传播克隆或密切相关的进化分离株。这项工作的结果证实，医院污水是CRAB的潜在水库。
