Wang Yugang, Sun Xicai, Wang Honggang
1Department of Laboratory Science, Shandong Second Medical University, Weifang, Shandong, China.
2Clinical Laboratory, Weifang Hanting Dist People's Hospital, Weifang, Shandong, China.
Acta Microbiol Immunol Hung. 2025 May 22;72(2):113-118. doi: 10.1556/030.2025.02604. Print 2025 Jun 20.
To identify antibiotic resistant genes and assess the clonality of carbapenem-resistant Enterobacter cloacae (CRECL) isolates from a hospital setting, altogether fifty-two clinical CRECL isolates were collected from 2012 to 2023. Antibiotic resistance genes including blaNDM, blaVIM, blaIMP, blaOXA-48, blaCTX-M-1 and blaTEM, were analyzed by PCR and nucleic acid sequencing. Sequence data were compared with those in the National Center for Biotechnology Information database. Clonality analysis was performed by ERIC-PCR. Among the 52 isolates, urine samples (23.1%) were the most common source, followed by puncture fluid (13.5%). The isolates were predominately obtained from urology (15.4%), followed by hepatobiliary surgery (11.5%). All isolates exhibited carbapenem resistance, with resistance rates of 88.5%, 84.6%, and 94.2% to imipenem, meropenem, and ertapenem, respectively. This was frequently accompanied by co-resistance to fluoroquinolones (67.2% to ciprofloxacin) and aminoglycosides (61.5% to tobramycin), likely due to the co-existence of multiple resistance genes on mobile genetic elements such as plasmids. However, all isolates remained sensitive to polymyxins, 67.2% to tigecycline and 50% to amikacin. Several carbapenem resistance genes were detected in isolates, with blaNDM-1 being the most abundant (40.4%), followed by blaNDM-5 (21.2%). Additionally, blaOXA-48 (3.8%), blaIMP-6 (1.9%) and blaVIM-1 gene (1.9%) have also been found in a few isolates. Among β-lactam resistance genes, blaTEM-1 (42.3%) is the most prevalent, followed by blaCTX-M-1 gene (23.1%). Clonality analysis classified the isolates into five clusters (A-E). Multiple strains exhibited >86% similarity, indicating clonal spread. In conclusion, CRECL isolates demonstrated extensive antimicrobial resistance, primarily mediated by blaNDM-1 and blaTEM. Clonality analysis revealed the presence of clonally related strains across different hospital departments, suggesting potential nosocomial transmission. Enhanced surveillance, strict disinfection and isolation measures are necessary to prevent the spread of CRECL and mitigate nosocomial infections and dissemination of epidemics.
为了鉴定抗生素耐药基因并评估医院环境中耐碳青霉烯类阴沟肠杆菌（CRECL）分离株的克隆性，2012年至2023年共收集了52株临床CRECL分离株。通过聚合酶链反应（PCR）和核酸测序分析了包括blaNDM、blaVIM、blaIMP、blaOXA - 48、blaCTX - M - 1和blaTEM在内的抗生素耐药基因。将序列数据与美国国立生物技术信息中心数据库中的数据进行比较。通过肠杆菌基因间重复共有序列PCR（ERIC - PCR）进行克隆性分析。在这52株分离株中，尿液样本（23.1%）是最常见的来源，其次是穿刺液（13.5%）。分离株主要来自泌尿外科（15.4%），其次是肝胆外科（11.5%）。所有分离株均表现出对碳青霉烯类的耐药性，对亚胺培南、美罗培南和厄他培南的耐药率分别为88.5%、84.6%和94.2%。这常常伴随着对氟喹诺酮类（对环丙沙星耐药率为67.2%）和氨基糖苷类（对妥布霉素耐药率为61.5%）的共同耐药，这可能是由于质粒等可移动遗传元件上存在多个耐药基因。然而，所有分离株对多粘菌素仍敏感，对替加环素敏感率为67.2%，对阿米卡星敏感率为50%。在分离株中检测到几种碳青霉烯类耐药基因，其中blaNDM - 1最为常见（40.4%），其次是blaNDM - 5（21.2%）。此外，在少数分离株中还发现了blaOXA - 48（3.8%）、blaIMP - 6（1.9%）和blaVIM - 1基因（1.9%）。在β - 内酰胺类耐药基因中，blaTEM - 1（42.3%）最为普遍，其次是blaCTX - M - 1基因（23.1%）。克隆性分析将分离株分为五个簇（A - E）。多个菌株表现出>86%的相似性，表明存在克隆传播。总之，CRECL分离株表现出广泛的抗菌药物耐药性，主要由blaNDM - 1和blaTEM介导。克隆性分析揭示了不同医院科室中存在克隆相关菌株，提示可能存在医院内传播。加强监测、严格的消毒和隔离措施对于预防CRECL的传播以及减轻医院感染和疫情传播是必要的。
