A novel transposon Tn7540 carrying blaNDM-9 and fosA3 in chromosome of a pathogenic multidrug-resistant Salmonella enterica serovar Indiana isolated from human faeces

Yao Sun; Yijia Han; Changrui Qian; Qi Zhang; Zhuocheng Yao; Weiliang Zeng; Tieli Zhou; Zhongyong Wang

doi:10.1016/j.jgar.2023.01.013

A novel transposon Tn7540 carrying bla_NDM-9 and fosA3 in chromosome of a pathogenic multidrug-resistant Salmonella enterica serovar Indiana isolated from human faeces

J Glob Antimicrob Resist. 2023 Jun:33:72-77. doi: 10.1016/j.jgar.2023.01.013. Epub 2023 Feb 26.

Authors

Yao Sun¹, Yijia Han², Changrui Qian³, Qi Zhang⁴, Zhuocheng Yao², Weiliang Zeng¹, Tieli Zhou⁵, Zhongyong Wang⁶

Affiliations

¹ Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, China.
² Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China.
³ School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China.
⁴ Department of Clinical Laboratory, Yongjia Hospital of Traditional Chinese Medicine, Wenzhou, China.
⁵ Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, China. Electronic address: wyztli@163.com.
⁶ Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University; Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, China. Electronic address: wangforever2000@163.com.

PMID: 36854357
DOI: 10.1016/j.jgar.2023.01.013

Abstract

Objectives: Emergence of multidrug-resistant (MDR) Salmonella enterica serovar Indiana has raised global concern. Mobile genetic elements (MGEs) play vital roles in accelerating the dissemination of resistance genes in bacteria communities. The study aims to improve our understanding of the underlying resistance mechanisms and characterize the MGEs in a MDR S. Indiana isolate.

Methods: Here, we report the characteristics of a MDR pathogenic S. Indiana isolate. The antimicrobial susceptibility pattern of S. Indiana QT6365 was determined. The genomic structure of the chromosome and the plasmid, serotype, and multi-locus sequence type were analysed by whole genome sequencing. The circular form derived from IS26-flanked transposon was confirmed by reverse polymerase chain reaction and sequencing.

Results: S. Indiana QT6365 exhibited resistance to all tested antimicrobials except for aztreonam, amikacin, polymyxin, and tigecycline, was defined as MDR, and belonged to ST17. S. Indiana QT6365 was closely related with food resource S. Indiana C629 with similar resistance gene profiles. Multiple resistance genes are mainly carried by a novel transposon Tn7540 located on the chromosome and an IncHI2/HI2A/N plasmid. Sequence analysis and the formed circular intermediate suggested Tn7540 might be generated through homologous recombination by IS26-bounded translocatable units (IS26-fosA-IS26-intI1-dfrA12-aadA2-sul1-ISCR1-bla_NDM-9-IS26).

Conclusions: To the best of our knowledge, this is the first report of the novel chromosomal transposon possessing bla_NDM-9 and fosA3 in S. Indiana isolated from human specimen, which might facilitate the dissemination of resistance genes and should arouse serious awareness.

Keywords: Chromosome; Multidrug-resistant; Salmonella enterica serovar Indiana; Transposon; Whole genome sequencing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents* / pharmacology
Chromosomes
Drug Resistance, Multiple, Bacterial / genetics
Feces
Humans
Salmonella
Salmonella enterica*
Serogroup

Substances

Anti-Bacterial Agents