First description of NDM-1 and IMP-1 producing carbapenem-resistant Pseudomonas mendocina

Abstract

Abstract Objective: To describe NDM-1 and IMP-1 producing carbapenem-resistant Pseudomonas mendocina. Methods: Antimicrobial susceptibility test was performed on carbapenemase-producing P.mendocinaclinical isolate. Whole genome sequencing data were analyzed using comparative genomics. The virulence of P. mendocina strain was analyzed by string test, serum killing assay and biofilm formation assay. Conjugation experiment and whole genome sequencing (WGS) was used to determine the transferability of plasmid co-producing NDM-1 and IMP-1 genes. Case presentation: A middle-aged woman's urine culture sample confirmed Pseudomonas Mendoza infection. Piperacillin/tazobactam was discontinued based on the drug susceptibility results. Biapenem in combination with etimicin was used as an anti-infection therapy for a week. Results: The P. mendocina strain had intrinsic resistance to most clinical antibiotics, including aminoglycosides, beta-lactams,sulfonamides, tetracyclines, aztreonam and fosfomycin. Serum resistance and biofilm array had indicated moderate virulence. The conjugation assay showed that the NDM-1 gene was located on a conjugable plasmid. WGS revealed that the P. mendocina strain had a 5.62832Mb chromosome (62.47% GC content) and a 172.851 Kb plasmid (56.83% GC content). Additionally, it showed that the isolates carried the NDM-1 and IMP-1 resistance genes. Conclusion: This is the first descriptive study of a P. mendocina strain producing NDM-1 and IMP-1 carbapenemases.The findings of this study suggest that medical staff in clinical and laboratory departments should pay close attention to the isolation, identification, and pathogenecity of the rare bacteria during routine examinations, and immediately adopt infection control measures to prevent its spread.