Genomic Insights into the First Emergence of blaNDM-5-Carrying Carbapenem-Resistant Salmonella enterica Serovar London Strain in China

Shaohua Tan,1,* Xiangchen Li,2,* Bing Lu,1,3 Yibin Lin,3 Yunxiang Cai,1 Jie He,4 Sisi Chen,2 Junli Gao,2 Junshun Gao,2 Xinhua Qiang1 1Department of Clinical Laboratory, The First People’s Hospital of Huzhou, Huzhou, Zhejiang, 313000, People’s Republic of China; 2Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, Zhejiang, 310020, People’s Republic of China; 3School of Medicine, Huzhou University, Huzhou, Zhejiang, 313000, People’s Republic of China; 4Department of Infectious Diseases, The First People’s Hospital of Huzhou, Huzhou, Zhejiang, 313000, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xinhua Qiang, Department of Clinical Laboratory, The First People’s Hospital of Huzhou, No. 158 Back Square Road, Wuxing District, Huzhou, Zhejiang, 313000, People’s Republic of China, Email qiangxinhua@zjhu.edu.cnAbstract: Carbapenem-resistant Salmonella enterica (S. enterica) pose a significant threat to public health, causing gastroenteritis and invasive infections. We report the first emergence of a carbapenem-resistant S. enterica serovar London strain, A132, carrying the blaNDM-5 gene in China. Whole-genome sequencing and bioinformatics analysis assigned A132 to be ST155, a multidrug-resistant clone frequently reported in China. The strain A132 exhibited resistance to multiple antibiotics, with 20 acquired antibiotic resistance genes (ARGs) identified, predominantly located on the IncFIB plasmid (pA132-1-NDM). Notably, the blaNDM-5 gene was located within an IS 26 flanked-class 1 integron-ISCR1 complex, comprising two genetic cassettes. One cassette is the class 1 integron, which may facilitate the transmission of the entire complex, while the other is the blaNDM-5-containing ISCR1-IS 26-flanked cassette, carrying multiple other ARGs. Genbank database search based on the blaNDM-5-carrying cassette identified a similar genetic context found in transmissible IncFIA plasmids from ...