Infection and Drug Resistance (Apr 2022)
Genetic Characterization of blaNDM-1-Carrying Citrobacter portucalensis Sequence Type 328 and Citrobacter freundii Sequence Type 98
Abstract
Lijun Wang,1 Ziyao Li,2 Nan Xiao,1 Jie Tang,1 Yu He,3 Jun Guo,4 Xiuying Zhao1 1Department of Clinical Laboratory, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, 102218, People’s Republic of China; 2Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, 100029, People’s Republic of China; 3Qitan Technology Ltd., Chengdu, Sichuan Province, 610044, People’s Republic of China; 4Department of Geriatrics, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, 102218, People’s Republic of ChinaCorrespondence: Jun Guo, Department of Geriatrics, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, 102218, People’s Republic of China, Email [email protected] Xiuying Zhao, Department of Clinical Laboratory, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, 102218, People’s Republic of China, Email [email protected]: NDM-1-producing Citrobacter portucalensis and Citrobacter freundii simultaneously occurred in a hospital. This study aims to characterize the blaNDM-1-carrying plasmids in these Citrobacter strains.Methods: Cf7303, Cf7308, and Cf7313 were recovered from three patients in a teaching hospital from September 24 to October 1, 2021. Bacteria were identified by MALDI-TOF mass spectrometry, and antibiotics susceptibility tests were determined by VITEK® 2 compact system. Whole-genome sequencing (WGS) was performed using the HiSeq Illumina and QNome platform to characterize the genomes.Results: Cf7303 was identified as C. portucalensis Sequence Type 328 by WGS, and harbored two plasmids, namely pCf7303 and a novel IncFIB pNDM-Cf7303 on which antibiotic-resistant genes (blaTEM-1, blaCTX-M-14, blaNDM-1, aac (3)-IId, aadA2, fosA3, sul1, sul2, catA2, tetD, dfrA12, qacEdelta1, mph(A), and bleMBL) are located. C. freundii strain Cf7308 and Cf7313 belonged to the same Sequence Type 98. Cf7308 contained two plasmids, pCf7308, and an IncN1 pNDM-Cf7308 with homology to pNDM-BTR in E. coli and pNDM-CWH001 in C. freundii.Conclusion: We characterized a putatively novel IncFIB plasmid carrying blaNDM-1 in C. portucalensis. In addition, the closely related blaNDM-1-carrying IncN1 plasmids in E. coli and C. freundii suggest that interspecies or intraspecies horizontal transfer occurs in China.Keywords: NDM-1, Citrobacter portucalensis, Citrobacter freundii, whole-genome sequencing
