Retrospective analysis of the transmission of difficult-to-treat resistant Pseudomonas aeruginosa - genotype beats phenotype.
- 1Department for Infection Prevention and Control, Institute for Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany. [email protected].
- 2Department for Infection Prevention and Control, Institute for Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
- 3Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
Abstract
Background
Difficult-to-treat resistant Pseudomonas aeruginosa (DTRPA) represents a challenging resistance phenotype with carbapenem-resistant P. aeruginosa playing a major role. However, carbapenemase-negative DTRPA (CN-DTRPA) are more susceptible to reserve antibiotics and rarely reported in outbreaks, differing from frequently outbreak-associated carbapenemase-producing DTRPA (CP-DTRPA) with limited therapeutic options. Despite, international guidelines recommend equal infection prevention and control (IPC) measures. Here, we analysed the transmission of CP-DTRPA and CN-DTRPA using epidemiology and whole-genome sequencing (WGS).Methods
Clinical DTRPA isolates collected between 2019 and 2024 were subjected to WGS. Genetic clusters were defined using cgMLST thresholds of ≤ 11 and ≤ 3 allelic differences. Epidemiological relatedness was estimated on hospital stay, interpatient contact and environmental exposures. For possibly epidemiologically linked cases, precolonisation with carbapenem-susceptible P. aeruginosa (CSPA) and antibiotic exposure during hospitalisation were assessed.Results
Among 190 DTRPA isolates, CN-DTRPA (79.5%) was predominant compared to 20.5% CP-DTRPA, mainly carrying blaVIM-2. Twelve genetic clusters involving 39 patients were identified. Seven clusters (CP-DTRPA n = 4; CN-DTRPA n = 2, CP-DTRPA/CN-DTRPA-mixed n = 1) showed possible epidemiological relatedness. CP-DTRPA isolates were frequently associated with clusters (OR 17.47, 95% CI 7.43-41.08) and environmental transmission. Diverse CN-DTRPA were rather linked to interpatient CSPA-transmission following CN-DTRPA emergence after prolonged antibiotic exposure.Conclusion
CN-DTRPA predominated and displayed high diversity, consistent with possible antibiotic-driven resistance development in precolonised patients. In contrast, less frequent and less diverse CP-DTRPA were associated to outbreaks. These findings highlight the need to evaluate differentiated IPC strategies, including targeted screening and environmental interventions for CP-DTRPA, while further investigating the potential role of antimicrobial stewardship in preventing the emergence of CN-DTRPA. Multicentre studies are required for evidence-based IPC strategies.
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BibTeX
@article{jasuja2026retrospective,
title = {{Retrospective analysis of the transmission of difficult-to-treat resistant Pseudomonas aeruginosa - genotype beats phenotype.}},
author = {Jasmin Kaur Jasuja and Philipp Maximilian Maurer and Laura Carlsen and Eva-Maria Theresia Klupp and Cristina Elena Belmar Campos and Holger Rohde and Martin Aepfelbacher and Johannes Karl-Mark Knobloch},
journal = {Antimicrobial resistance and infection control},
year = {2026},
month = oct,
doi = {10.1186/s13756-026-01851-3},
url = {https://europepmc.org/article/MED/42963799},
note = {CC BY},
}
RIS
TY - JOUR
TI - Retrospective analysis of the transmission of difficult-to-treat resistant Pseudomonas aeruginosa - genotype beats phenotype.
AU - Jasmin Kaur Jasuja
AU - Philipp Maximilian Maurer
AU - Laura Carlsen
AU - Eva-Maria Theresia Klupp
AU - Cristina Elena Belmar Campos
AU - Holger Rohde
AU - Martin Aepfelbacher
AU - Johannes Karl-Mark Knobloch
PY - 2026
DA - 2026/10/30
JO - Antimicrobial resistance and infection control
DO - 10.1186/s13756-026-01851-3
UR - https://europepmc.org/article/MED/42963799
AB - Background Difficult-to-treat resistant Pseudomonas aeruginosa (DTRPA) represents a challenging resistance phenotype with carbapenem-resistant P. aeruginosa playing a major role. However, carbapenemase-negative DTRPA (CN-DTRPA) are more susceptible to reserve antibiotics and rarely reported in outbreaks, differing from frequently outbreak-associated carbapenemase-producing DTRPA (CP-DTRPA) with limited therapeutic options. Despite, international guidelines recommend equal infection prevention and control (IPC) measures. Here, we analysed the transmission of CP-DTRPA and CN-DTRPA using epidemiology and whole-genome sequencing (WGS).Methods Clinical DTRPA isolates collected between 2019 and 2024 were subjected to WGS. Genetic clusters were defined using cgMLST thresholds of ≤ 11 and ≤ 3 allelic differences. Epidemiological relatedness was estimated on hospital stay, interpatient contact and environmental exposures. For possibly epidemiologically linked cases, precolonisation with carbapenem-susceptible P. aeruginosa (CSPA) and antibiotic exposure during hospitalisation were assessed.Results Among 190 DTRPA isolates, CN-DTRPA (79.5%) was predominant compared to 20.5% CP-DTRPA, mainly carrying blaVIM-2. Twelve genetic clusters involving 39 patients were identified. Seven clusters (CP-DTRPA n = 4; CN-DTRPA n = 2, CP-DTRPA/CN-DTRPA-mixed n = 1) showed possible epidemiological relatedness. CP-DTRPA isolates were frequently associated with clusters (OR 17.47, 95% CI 7.43-41.08) and environmental transmission. Diverse CN-DTRPA were rather linked to interpatient CSPA-transmission following CN-DTRPA emergence after prolonged antibiotic exposure.Conclusion CN-DTRPA predominated and displayed high diversity, consistent with possible antibiotic-driven resistance development in precolonised patients. In contrast, less frequent and less diverse CP-DTRPA were associated to outbreaks. These findings highlight the need to evaluate differentiated IPC strategies, including targeted screening and environmental interventions for CP-DTRPA, while further investigating the potential role of antimicrobial stewardship in preventing the emergence of CN-DTRPA. Multicentre studies are required for evidence-based IPC strategies.
SN - 2047-2994
ER -