Emergence of KPC-2-producing Pseudomonas aeruginosa sequence type 463 isolates in Hangzhou, China

Area of Science:

• Microbiology
• Genetics
• Infectious Diseases

Background:

• Klebsiella pneumoniae carbapenemase (KPC)-producing Pseudomonas aeruginosa poses a significant threat due to high-level resistance to carbapenems and beta-lactam antibiotics.
• The emergence and spread of antimicrobial resistance in P. aeruginosa are critical global health challenges.

Purpose of the Study:

• To investigate the molecular epidemiology and genetic characteristics of KPC-producing P. aeruginosa isolates from Hangzhou, China.
• To understand the clonal expansion and transmission patterns of these resistant strains.

Main Methods:

• Isolation and identification of P. aeruginosa strains.
• Antimicrobial susceptibility testing, focusing on carbapenem and beta-lactam resistance.
• Molecular epidemiology using techniques such as multilocus sequence typing (MLST) to determine sequence types (STs).
• Genetic environment analysis to identify mobile genetic elements associated with resistance genes.

Main Results:

• Thirty-nine KPC-producing P. aeruginosa isolates were identified, all exhibiting high-level resistance.
• Molecular epidemiology revealed two dominant clones, designated A and B, both belonging to sequence type 463 (ST463).
• Genetic analysis showed that both clones harbor an ISKpn8 transposase, the bla(KPC-2) gene, and an ISKpn6-like transposase.

Conclusions:

• The findings demonstrate clonal expansion and transmission of KPC-2-producing P. aeruginosa strains in Hangzhou, China.
• ST463 appears to be a significant clone associated with the spread of carbapenem resistance in this region.
• The presence of specific genetic elements like ISKpn8 and ISKpn6-like transposases likely facilitates the dissemination of the bla(KPC-2) gene.