Genome analysis of extensively drug-resistant Pseudomonas aeruginosa ST1971 from a patient in China hospitalized for severe pneumonia

The emergence and outbreak of carbapenem-resistant Pseudomonas aeruginosa (CRPA) are a major global public threat. we aimed to characterize the genome of drug-resistant and virulent genes in an extremely drug-resistant Pseudomonas aeruginosa strain to understand its antimicrobial resistance trends and pathogenicity. An XDR Pseudomonas aeruginosa strain was isolated in China from a patient with severe pneumonia. Antimicrobial susceptibility testing, genome sequencing and phylogenetic analysis was performed. Predictions were fulfilled using curated bioinformatics tools. The assembly of the strain (CRPA190) comprised 76 contigs with a total length of 7 009 318 bp. CRPA190 belongs to sequence type 1791 (ST1791) and the O11 serogroup. Nine prophage regions, three CRISPR arrays, and two Cas clusters were identified. However, no plasmids were predicted. Antibiotic susceptibility tests showed that CRPA190 was resistant to all the tested antibiotics, including carbapenem, polymyxin B and ceftazidime-avibactam. Forty antimicrobial resistance genes were predicted in CRPA190, including several carbapenemase genes such as blaPDC-142, blaPME-1, blaNDM-1 and blaOXA-902. The isolate was predicted to be pathogenic and possess strong biofilm-forming ability. It harbors virulence genes that are associated with an arsenal of virulence determinants involved in adherence, motility, exotoxins, exoenzymes, immune modulation, biofilms, nutritional/metabolic factors and effector delivery systems. These findings enhance our understanding of the resistance and pathogenicity of the ST1791 Pseudomonas aeruginosa strain which is unique in China and provide a broader perspective on the global epidemiological landscape, suggesting the emergence of P. aeruginosa ST1971, which requires control measures to limit its dissemination.