Objective To understand the drug resistance and genome characteristics of clinical isolates of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in Jiangsu province.

Methods Clinical CRPA isolates from sentinel hospitals in Jiangsu from 2016 to 2023 were collected. The susceptibility test to 19 antibiotics in 10 classes was conducted by broth dilution method. Whole genome sequencing, multi-site sequence typing and serotype prediction were conducted for the isolates, and their drug resistance genes, transposons and mobile elements were analyzed.

Results A total of 68 strains of CRPA isolated from patients were collected. The results of drug susceptibility test showed that all the strains were resistant to 9 antibiotics in 7 classes, i.e. chloramphenicol, cotrimoxazole, cefotaxime, cefazolin, tetracycline, ampicillin, ampicillin/sulbactam and amoxicillin-clavulanate, and 33 drug-resistance phenotypes were found. Two of the strains were pan-drug-resistant to all 19 antibiotics tested. Forty-three sequence types (STs) were identified in all the isolates, ST235 was predominant. The clustering diagram showed that ST241 was in the central of all STs. A total of 8 serotypes were identified, mainly O6, O11 and O3 in 67.65% of all the strains. A total of 23 antibiotic resistance genes to 8 classes of antibiotics were found. In the 68 strains, 54.41% had integrated and conjugate elements, 39.71% had integrated and mobile elements, and no strains were found to carry plasmid.

Conclusion In this study, the characteristics of the drug resistance, high risk ST and high resistance/serotype of carbapenem-resistant P. aeruginosa in Jiangsu were described at genome level, providing scientific evidence for effective treatment and prevention of infection caused by P. aeruginosa.