Carbapenem-resistant <i>Morganella morganii</i> carrying <i>bla</i> <sub>KPC-2</sub> or <i>bla</i> <sub>NDM-1</sub> in the clinic: one-decade genomic epidemiology analysis
Jiayao Yao, Yueyue Hu, Xinru Wang, Jie Sheng, Ying Zhang, Xiaofei Zhao, Jiaqing Wang, Xiufang Xu, Xi Li
Abstract
ABSTRACT Carbapenem-resistant Morganella morganii (CRMM) isolates, particularly those producing Klebsiella pneumoniae carbapenemase-2 (KPC-2) or New Delhi metallo-β-lactamase-1 (NDM-1), are increasingly being recognized as causative agents of nosocomial infections. However, systematic phylogeography and genetic characterization of these isolates worldwide are still lacking. Here, through seven years of surveillance of CRMM in a tertiary hospital, we analyzed the genomic characteristics of bla KPC-2 - or bla NDM-1 -positive CRMM isolates. Furthermore, we conducted a global genomic epidemiological study of Morganella spp. harboring bla KPC or bla NDM using the NCBI database over the past decade. By combining the timeline of isolate collection with the structural analysis of the plasmids, we traced the evolution of the IncL/M plasmid, which acquired the bla KPC-2 gene. Our findings indicate that horizontal transfer of Tn 6296 based on IS 26 is crucial for the transmission of bla KPC in CRMM isolates. Additionally, the Tn 125 transposon appears to have played an important role in early plasmid-mediated dissemination of bla NDM ; however, it has been surpassed in recent years by other elements, including IS 26 and IS CR . In summary, through phylogeographic analysis of Morganella spp. globally, we elucidated their spatial–temporal distribution and revealed the evolutionary characteristics of KPC- or NDM-producing CRMM isolates as the predominant "epidemic" clone. IMPORTANCE Currently, infections attributable to carbapenem-resistant Morganella morganii (CRMM) isolates harboring bla KPC or bla NDM are on the rise, highlighting the increasing severity of acquired antimicrobial resistance. However, systematic phylogeographic and genetic characterization of these isolates worldwide is still lacking. In this study, we elucidated the spatial–temporal distribution and evolutionary trajectory of bla KPC and bla NDM genes within their core genetic environments. We emphasize the necessity of strengthening surveillance and controlling these organisms in clinical settings to prevent the generation of so-called "superbug" isolates.