Emergence of Aeromonas veronii strain co-harboring bla KPC-2 , mcr-3.17 , and tmexC3.2-tmexD3.3-toprJ1b cluster from hospital sewage in China

• Published in: Frontiers in microbiology 2023, Vol.14, p.1115740
• Main Authors: Zhu, Zhichen, Wu, Shuhua, Zhu, Jie, Wang, Tao, Wen, Yicheng, Yang, Chengcheng, Lv, Jinnan, Zhang, Haifang, Chen, Liang, Du, Hong
• Format: Article
• Language: English
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2023.1115740

The raise of multi-drug resistant bacteria involving carbapenem, colistin, or tigecycline resistance constitutes a threat to public health, which partly results from the transmission of corresponding mobile resistance genes, such as and for carbapenem, for colistin, and gene cluster for tigecycline. Herein, we described the emergence of an strain HD6454 co-harboring , , and gene cluster from hospital sewage. Whole genome sequencing (WGS) was used to determine the genome sequence of HD6454, and the detailed genomic analysis of genetic elements or regions carrying key antimicrobial resistance genes (ARGs) from HD6454 were performed. Cloning experiment was conducted to confirm the function of key ARGs in mediating antimicrobial resistance. Conjugation experiment was conducted to determine the mobility of the plasmid. The results showed that this strain belonged to a novel sequence type (ST) variant ST1016, and carried 18 important ARGs. Among them, the was carried by non-self-transmissible IncP-6 plasmid, while gene cluster and were carried by integrative and mobilizable element (IME) or IME-related region in chromosome. The , , and genes were further inferred to originate from IMEs of species. Additionally, for the first time, the was confirmed to confer low-level resistance to colistin under inducible expression, while gene cluster was confirmed to confer low-level resistance to tigecycline. This is the first report of a strain co-harboring , , and gene cluster. Although the resistance and/or mobility of these ARGs are limited in this strain, the emergence of this multiple important ARGs-carrying strain deserves further attention.