Co-Production of NDM-1 and OXA-10 β-Lactamase in Citrobacter braakii Strain Causing Urinary Tract Infection

Huiming Han,1,* Zhi Zhao,2,* Yan Lin,1 Baihui Lin,1 Hao Xu,3 Beiwen Zheng3 1School of Basic Medical Sciences, Beihua University, Jilin, Jilin Province, People’s Republic of China; 2Department of Neonatology, Shaanxi Province People’s Hospital, Xi’an, Shaanxi Province, People’s Republic of China; 3Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Beiwen Zheng, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, No. 79 Qingchun Road, Hangzhou, Zhejiang Province, 310003, People’s Republic of China, Tel +86 571 872 364 23, Fax +86 571 872 364 21, Email zhengbw@zju.edu.cnAbstract: In this study, we describe, for the first time, the co-existence of blaNDM-1and blaOXA-10 in a carbapenem-resistant Citrobacter braakii strain DY2019 isolated from a patient with urinary tract infection in China. We aimed to investigate the genomic context of two β-lactamase-producing plasmids and characterize the transmission mechanism of the carbapenemase-encoding gene. Whole-genome sequencing of strain DY2019 was performed with Nanopore and Illumina platforms, which revealed a chromosome sequence with the length of 4,830,928 bp, an IncC group plasmid pDY2019-OXA (size of 178,134 bp), and a novel IncHI2 group plasmid pDY2019-NDM (length 348,495 bp). A total of 16 antimicrobial resistance genes (ARGs) that confer resistance to nine different antibiotic groups were identified in strain DY2019, and 11 of them were carried by plasmid pDY2019-OXA. These data and analyses suggest that the carbapenem-resistant C. braakii strains may serve as potential reservoir of carbapenemase and highlight the need for further close surveillance of this species in clinical settings.Keywords: Citrobacter braakii, carbapenem-resistant, NDM-1, OXA-10, whole-genome sequencing, urinary tract infection