Novel KPC-2 Plasmid in a Clinical Salmonella Rissen Selected by Antibiotic Pressure

Area of Science:

• Microbiology
• Genomics
• Antimicrobial Resistance

Background:

• The emergence of antibiotic-resistant bacteria poses a significant global health threat.
• Carbapenemase-producing Enterobacterales (CPE) are a major concern, often carrying resistance genes on mobile genetic elements like plasmids.
• Salmonella enterica serovar Rissen is an important foodborne pathogen.

Purpose of the Study:

• To characterize the genomic features of a clinical Salmonella Rissen isolate.
• To identify and analyze the novel IncN2 plasmid harboring the blaKPC-2 gene.
• To understand the role of this plasmid in antimicrobial resistance.

Main Methods:

• Whole-genome sequencing of the Salmonella Rissen isolate.
• Plasmid identification and characterization using bioinformatic tools.
• Antimicrobial susceptibility testing.

Main Results:

• Genomic characterization revealed a novel IncN2 plasmid, designated pSEay-KPC.
• The pSEay-KPC plasmid carried the blaKPC-2 gene, conferring resistance to carbapenems, along with blaACC-1, blaTEM-1, and qnrB genes.
• The isolate exhibited broad-spectrum resistance, surviving ceftriaxone and ciprofloxacin treatments, but was susceptible to meropenem-vaborbactam.

Conclusions:

• IncN2 plasmids are significant vectors for the dissemination of clinically important resistance genes, including blaKPC-2.
• The presence of such plasmids in Salmonella Rissen complicates treatment strategies for infections.
• Effective management of infections caused by MDR strains requires understanding plasmid-mediated resistance mechanisms and utilizing last-resort antibiotics.