Genomic Characterization of Infrequent and Under-Detected VIM-Producing Pseudomonas putida Complex Isolates in Greek Hospitalized Patients

Authors:
Preprint
Publisher website
Google Scholar
  • 13 November 2026
    • DOI:10.20944/preprints202611.1495.v1
Abstract
Pseudomonas putida (P. putida) is a strictly aerobic, non-fermenting Gram-negative bacillus ubiquitously present in soil and aquatic environments. However, emerging evidence identifies P. putida as an increasingly important opportunistic pathogen responsible for severe nosocomial infections, particularly bacteremia and sepsis in immunocompromised and critically ill patients. Central Public Health Laboratory (CPHL) routinely receives carbapenem-resistant Pseudomonas spp isolates from the Greek hospitals. Five isolates (3 from 2023 and 2 from 2025) were sent to the laboratory as P. aeruginosa, P. putida and P. fluores. The isolates were subjected to phenotypical and molecular methods for the detection of the Metallo-Beta-Lactamases (MBL) genes [EDTA test, conventional PCR and Whole-genome sequencing (WGS) respectively]. The isolates were confirmed as VIM-producing isolates, while WGS reassigned them to four distinct species within the P. putida complex (P. soli, P. kurunegalensis, P. juntendi, and P. ceruminis). The isolates carried variations of the blaVIM (VIM-2, VIM-4 and VIM-72) and were diverted into 5 different Sequence types (STs;3, 12, 13, 104, 125). VIM variants were distributed across phylogenetically distinct lineages, suggesting independent acquisition of events rather than clonal dissemination. Genome annotation and virulence screening confirmed the absence of the exotoxin A gene in all isolates. Although Pseudomonas putida isolates causing bacteremia have previously been reported in Greek hospitals, to our knowledge, this is the first study to assign the initially Pseudomonas spp isolates to new species of the P. putida complex and to characterize their genetic profile, at the level of resistance genes and phylogeny.