Feng Jiao, Song Zhiwei, Dai Piaopiao, Chen Huimin, Hu Dakang, Yu Lianhua, Zhang Jin, Luo Xinhua
Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory of Medical Molecular Cell Biology, Shanxi University, Taiyuan, China.
Department of Clinical Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, China.
J Glob Antimicrob Resist. 2024 Dec;39:250-256. doi: 10.1016/j.jgar.2024.11.001. Epub 2024 Nov 14.
Carbapenem-resistant Enterobacter cloacae (CR-ECC) complex has posed significant challenges to the clinical treatment of infections, and Enterobacter hormaechei (E. hormaechei) is the most commonly identified nosocomial pathogen of CR-ECC.
Carbapenemases were detected by the immunocolloidal gold technique. The minimum inhibitory concentration (MIC) values were determined by VITEK2. The genome sequence of strain K432 was obtained and analysed.
We isolated the IMP-8-producing E. hormaechei strain K432 from a patient's urine specimen in a Chinese hospital, which exhibited resistance to multiple antibiotics, including ceftazidime, piperacillin/tazobactam, aztreonam, imipenem, meropenem, ciprofloxacin, levofloxacin, minocycline, and trimethoprim/sulfamethoxazole. The genome of strain K432 was composed of the chromosome cK432 (4863 kb) and 3 plasmids: pK432-IMP (45.8 kb), pK432-TEM (75.6 kb), and pK432-NR (4.8 kb). In K432, six drug-resistant genes were detected, including bla and fosA on cK432, bla, and qnrS1 on pK432-IMP, bla, and bla on pK432-TEM. The pK432-IMP belonged to a novel incompatibility group, and pK432-TEM was an incompatibility (Inc) R plasmid. Both of these two plasmids shared similar conserved backbone regions with their reference plasmids, respectively. However, the single accessory regions in these two plasmids were different from their reference plasmids, indicating that new recombination and integration events had occurred in K432.
This study provides a comprehensive understanding of the genomic characterization of K432 and identified a novel plasmid for IMP transmission. Further investigation and surveillance are warranted for pK432-IMP-type plasmid. While routine monitoring of MDR E. hormaechei strains is necessary in China.
耐碳青霉烯类阴沟肠杆菌（CR-ECC）复合体给感染的临床治疗带来了重大挑战，而霍氏肠杆菌（E. hormaechei）是CR-ECC中最常见的医院病原体。
采用免疫胶体金技术检测碳青霉烯酶。通过VITEK2测定最低抑菌浓度（MIC）值。获取并分析菌株K432的基因组序列。
我们从中国一家医院的患者尿液标本中分离出产IMP-8的霍氏肠杆菌菌株K432，该菌株对多种抗生素耐药，包括头孢他啶、哌拉西林/他唑巴坦、氨曲南、亚胺培南、美罗培南、环丙沙星、左氧氟沙星、米诺环素和甲氧苄啶/磺胺甲恶唑。菌株K432的基因组由染色体cK432（4863 kb）和3个质粒组成：pK432-IMP（45.8 kb）、pK432-TEM（75.6 kb）和pK432-NR（4.8 kb）。在K432中，检测到6个耐药基因，包括cK432上的bla和fosA，pK432-IMP上的bla和qnrS1，pK432-TEM上的bla和bla。pK432-IMP属于一个新的不相容群，pK432-TEM是一个不相容（Inc）R质粒。这两个质粒分别与其参考质粒共享相似的保守主干区域。然而，这两个质粒中的单个辅助区域与其参考质粒不同，表明K432中发生了新的重组和整合事件。
本研究全面了解了K432的基因组特征，并鉴定出一种用于IMP传播的新型质粒。有必要对pK432-IMP型质粒进行进一步研究和监测。同时，在中国对多重耐药霍氏肠杆菌菌株进行常规监测是必要的。
