title: Genetic characteristics of blaNDM-1-positive plasmid in Citrobacter freundii isolate separated from a clinical infectious patient.
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)-positive 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.
authors.affiliation: Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Xiao-Xing
authors.initials: XX
authors.lastname: Du
authors.affiliation: Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Wang
authors.affiliation: Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Wang
authors.affiliation: Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Yun-Song
authors.initials: YS
authors.lastname: Yu
mesh_terms: D000150:Acinetobacter / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D016971:Citrobacter freundii / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D004756:Enterobacteriaceae Infections / Q000175:diagnosis; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010957:Plasmids / Q000235:genetics* / Q000378:metabolism; D014552:Urinary Tract Infections / Q000382:microbiology; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1