Epidemiological characteristics of and -producing carbapenem-resistant based on whole genome sequences in Jiangsu, China.

Carbapenem-resistant (CRKP), particularly those with high virulence, cause invasive disease in clinical settings. An epidemiological investigation was conducted on the evolution, virulence, and antimicrobial resistance of CRKP isolates in two tertiary teaching hospitals in Jiangsu, China from November 2020 to December 2021. There were 31 different CRKP strains discovered. We performed whole genome sequencing (WGS) on 13 and -producing CRKP to reveal molecular characteristics. Five ST15/ST11 isolates had CRISPR-Cas systems. By conjugation tests, can be transmitted horizontally to . A conjugative pHN7A8-related multi-resistance plasmid (, , , , , and ) was first discovered in CRKP clinical isolates. Using bacteriological testing, a serum killing assay, and an infection model with , three ST11-K64 generating carbapenem-resistant hypervirulent (CR-hvKP) were identified. These strains harbored a virulent plasmid and an IncFII-family pKPC/pHN7A8 conjugative plasmid, which led to hypervirulence and resistance. One of these CR-hvKPs, which co-harbored , , , and genes, was first discovered. Importantly, this CR-hvKP strain also produced biofilm and had non-inferior fitness. The widespread use of ceftazidime/avibactam might provide this CR-hvKP with a selective advantage; hence, immediate action is required to stop its dissemination. Another important finding is the novel ST6136 in . Finally, the sterilization efficiency rates of FeC nanoparticles in CRKP were more than 98%. Furthermore, our novel antibacterial FeC nanoparticles may also provide a therapeutic strategy for infections.