Infection and Drug Resistance (Jan 2020)
Characterization of blaNDM-1- and blaSHV-12-Positive IncX3 Plasmid in an Enterobacter Hormaechei New Sequence Type 1000 from China
Abstract
Peihan Li, 1, 2,* Yanfeng Lin, 1, 2,* Xiaofeng Hu, 2,* Yuqi Liu, 1, 2 Mei Xue, 3 Lang Yang, 1, 2 Jinhui Li, 2 Lei Zha, 2 Kaiying Wang, 1 Kezong Qi, 3 Shaofu Qiu, 2 Peng Li, 2 Hongbin Song 2 1Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, People’s Republic of China; 2Center for Disease Control and Prevention of PLA, Beijing, People’s Republic of China; 3Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Anhui, People’s Republic of China*These authors contributed equally to this workCorrespondence: Peng Li; Hongbin SongCenter for Disease Control and Prevention of PLA, 20 DongDa Street, Fengtai District, Beijing 100071, People’s Republic of ChinaTel/Fax +86-10-66948475Email [email protected]; [email protected]: Carbapenem-resistant Enterobacter cloacae complex has been reported worldwide and becomes a new challenge for clinical management. The present study was to characterize the IncX3 plasmid encoding blaNDM-1 and blaSHV-12 gene in E. hormaechei sequence.Materials and Methods: EcHK001 was recovered from the sputum sample of a patient. Species identification and antimicrobial susceptibility testing were performed using the VITEK 2 system, while further classification was carried out by hsp60 typing. The presence of NDM-1 was detected by PCR and sequencing. Conjugation experiments and southern blotting were carried out to determine the transferability of the NDM-1-carrying plasmid. Whole-genome sequencing and analysis were conducted to better understand the molecular characteristics of the multi-drug resistant isolate.Results: Strain EcHK001 was classified as E. hormaechei of new sequence type 1000. Multiple drug-resistant genes were detected. The blaNDM-1 and blaSHV-12 genes were located on a self-transferable IncX3 plasmid. Synonymous mutations were identified in the genes encoding TEM-1 and ACT-17. Phylogenetic analysis indicated that EcHK001 clustered into a different clade from domestic strains.Conclusion: The rapid spread of the recurrent IncX3 plasmid highlights the need for continuous surveillance of the NDM-1 dissemination. The presence of mutations in existing carbapenem-resistant genes may generate potential new variants and raise serious challenges for clinical treatment.Keywords: multidrug-resistant, NDM-1, SHV-12, enterobacter hormaechei
