Adler Amos, Ayala-Montaño Stefany, Assous Mark V, Geffen Yuval, Reuter Sandra
Clinical Microbiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
Department of Epidemiology and Preventive Medicine, School of Public Health, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Ann Clin Microbiol Antimicrob. 2025 Aug 20;24(1):45. doi: 10.1186/s12941-025-00814-7.
The mcr-9 allele is typically located on IncHI2 type plasmids, but there are only few reports describing the co-occurrence of the bla gene on the same plasmid. Our aims were to describe the spread of an IncHI2A plasmid harboring both the mcr-9 and the bla genes in a multicenter study in Israel. All New-Delhi Metallo-β-lactamase-producing Enterobacterales (NDME) isolated from three medical centres in Israel between January 2018 and July 2019 were included. The mcr-9.1 gene was identified in 37/212 (17.4%) of the isolates, mostly in Enterobacter cloacae (34/37, 92%). The mcr-9.1 gene was also identified in Klebsiella pneumoniae sequence types (ST)-76 (n = 2) and Escherichia coli ST-69 (n = 1). In one hospital, out of 32 E. cloacae isolates, 19 (51.35%) were clustered into five transmission clusters of the ST-511, ST-1261 and ST-1750. Four subtypes of a ~ 290 kb IncHI2A type plasmid were identified in all isolates that co-harbored the mcr-9.1 and the bla genes. This plasmid was identified in all isolates, with four sub-communities (sc), with sc-4 identified in all three species. The resistance genes were surrounded by the IS26 (mcr-9.1) or by the ISAba125 and the IS300 (bla) mobile elements. The dissemination of the mcr-9.1 and the bla genes was accelerated via clonal spread and the dual carriage on a single plasmid.
mcr-9等位基因通常位于IncHI2型质粒上，但仅有少数报告描述了bla基因与mcr-9基因在同一质粒上同时出现的情况。我们的目的是在以色列的一项多中心研究中描述携带mcr-9和bla基因的IncHI2A质粒的传播情况。纳入了2018年1月至2019年7月间从以色列三个医疗中心分离出的所有产新德里金属β-内酰胺酶的肠杆菌科细菌（NDME）。在212株分离菌中的37株（17.4%）中鉴定出mcr-9.1基因，主要存在于阴沟肠杆菌中（34/37，92%）。在肺炎克雷伯菌序列型（ST）-76（n = 2）和大肠埃希菌ST-69（n = 1）中也鉴定出了mcr-9.1基因。在一家医院的32株阴沟肠杆菌分离菌中，有19株（51.35%）聚集形成了ST-511、ST-1261和ST-1750的五个传播簇。在所有同时携带mcr-9.1和bla基因的分离菌中鉴定出了约290 kb的IncHI2A型质粒的四种亚型。在所有分离菌中都鉴定出了这种质粒，分为四个亚群（sc），在所有三个菌种中都鉴定出了sc-4。抗性基因被IS26（mcr-9.1）或ISAba125和IS300（bla）移动元件包围。mcr-9.1和bla基因通过克隆传播和在单个质粒上的双重携带而加速传播。
