Genetic characteristics of blaNDM-1-positive plasmid in Citrobacterfreundii isolate separated from a clinical infectious patient Du, Xiao-Xing and Wang, Jian-Feng and Fu, Ying and Zhao, Feng and Chen, Yan and Wang, Hai-Ping and Yu, Yun-Song,, 62, 1332-1337 (2013), doi = https://doi.org/10.1099/jmm.0.057091-0, publicationName = Microbiology Society, issn = 0022-2615, abstract= This study reports an infectious case involving an NDM-1-producing Citrobacter freundii and further explored the potential threat of the bla NDM-1 gene by analysing the characteristics of the NDM-1-encoding plasmid sequence. A bla NDM-1-positive C. freundii with high resistance to carbapenems was separated from a clinical patient suffering from a urinary tract infection. S1 nuclease-based plasmid analysis followed by Southern blot hybridization, a conjugation experiment and electrotransformation confirmed that the bla NDM-1 gene was located on a plasmid. High-throughput sequencing of the bla NDM-1-postive plasmid (pCFNDM-CN) showed that it was a 54 kb IncX-type plasmid and contained a backbone region and a variable region with two β-lactamase genes (bla NDM-1 and bla SHV-12). The NDM-1 composite transposon in the variable region was surrounded by IS26 and IS5-truncated ISAba125, and shared a high sequence similarity to the bla NDM-1 surrounding structure in Acinetobacter spp. Our research suggested that the NDM-1 composite transposon might play an essential role in mobilization of the bla NDM-1 gene from Acinetobacter spp. to Enterobacteriaceae., language=, type=