DOI: 10.1128/spectrum.02390-26 ISSN: 2165-0497
Chromosomal
bla
NDM-1
embedded within mosaic genomic islands in
Pseudomonas aeruginosa
ST235 co-producing VIM-2 or KPC-2
Daiana Cristina Silva Rodrigues, Orlando Carlos da Conceição-Neto, Joanderson Cadena da Silva, Ivson Cassiano de Oliveira Santos, Bruna Ribeiro Sued-Karam, Melise Chaves Silveira, Ana Paula D'Alincourt Carvalho-Assef, Cláudio Marcos Rocha-de-Souza ABSTRACT
Chromosomal integration of carbapenemase genes in
Pseudomonas aeruginosa
remains rare and poorly characterized. We report the genomic resolution of two extensively drug-resistant (XDR)
Pseudomonas aeruginosa
ST235 clinical isolates from Southern Brazil co-producing multiple carbapenemases. Hybrid Illumina-Nanopore sequencing revealed the rare chromosomal integration of
bla
NDM-1
within large mosaic genomic islands in both strains. Additionally, CCBH33512 harbored a chromosomal tandem duplication of
bla
VIM-2
, while CCBH33606 carried a 149-kb IncU-type plasmid bearing
bla
KPC-2
. These atypical architectures demonstrate structural adaptations that favor the stable persistence of extreme resistance determinants in clinical settings.
IMPORTANCE
The persistent threat of
Pseudomonas aeruginosa
lies in its structural adaptability. By sequencing extensively resistant clinical isolates, we revealed that extreme resistance genes are embedded within massive, complex genomic islands. These major structural rearrangements permanently lock resistance traits into the bacterial chromosome. Understanding this architectural evolution is vital, as it highlights how hospital pathogens use complex genetic strategies to ensure stable, long-term survival against last-resort antibiotics.