{
  "abstract": "Background\n\nMultidrug-resistant Klebsiella pneumoniae (MDR-KP) is a global health threat with limited treatment options. Comparative in vitro data for imipenem-relebactam (I/R) and ceftolozane-tazobactam (C/T) across diverse MDR-KP clinical populations remain limited.Methods\n\nSusceptibility to I/R and C/T was determined by Etest. Whole-genome sequencing was used to identify sequence types, resistance genes, and virulence genes, with hypervirulent K. pneumoniae (hvKP) defined by genomic criteria.Results\n\nA total of 312 nonduplicate MDR-KP clinical isolates, including 70.8% carbapenem-resistant K. pneumoniae (CR-KP), 56.7% difficult-to-treat resistant K. pneumoniae (DTR-KP), and 28.2% carbapenem-resistant hvKP (CR-hvKP), were retrospectively analyzed. I/R resistance was low across all subgroups (overall 3.8%, CR-KP 5.0%, DTR-KP 6.2%, CR-hvKP 2.3%) and across specimen types (0-9.6%; blood 3.8%). In contrast, C/T resistance was higher (overall 57.7%, CR-KP 79.2%, DTR-KP 91.0%, CR-hvKP 84.1%), with the highest rate in respiratory isolates (63.0%), followed by blood (57.7%) and urine (50.0%). Among extended-spectrum β-lactamase (ESBL)-producing isolates, I/R and C/T resistance rates were 2.1% and 12.4%, respectively. Although C/T resistance was higher in hvKP than in classic K. pneumoniae in unadjusted analysis, hvKP was not independently associated with increased C/T resistance after adjustment. Instead, ST11, ST15, ST307, blaKPC-2, and blaNDM-1 were independently associated with C/T resistance. For I/R, blaNDM-1 was associated with resistance.Conclusions\n\nI/R was active across MDR-KP subgroups including CR-hvKP and DTR-KP. C/T worked mainly against ESBL-producers. These findings highlight the importance of resistance genotyping when interpreting susceptibility to these agents.",
  "abstract_shown": true,
  "affiliations": [
    "Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China.",
    "Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing 100191, China.",
    "Department of Infectious Disease, Peking University Third Hospital, Beijing 100191, China.",
    "Department of Laboratory Medicine, Peking University Third Hospital, Beijing 100191, China.",
    "Department of Respiratory and Critical Care Medicine, Peking University Third Hospital, Beijing 100191, China."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Juan Yi"
    },
    {
      "affs": [
        2
      ],
      "name": "Chao Liu"
    },
    {
      "affs": [
        1
      ],
      "name": "Ping Yang"
    },
    {
      "affs": [
        2
      ],
      "name": "Bowen Wang"
    },
    {
      "affs": [
        3
      ],
      "name": "Jiajia Zheng"
    },
    {
      "affs": [
        0,
        1,
        4
      ],
      "name": "Ning Shen"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d68h6hxt8ne1r.bib",
  "cited_by": 0,
  "doi": "10.3390/antibiotics15100947",
  "fulltext_url": "https://europepmc.org/articles/PMC13700561",
  "id": "d68h6hxt8ne1r",
  "issns": [
    "2079-6382"
  ],
  "landing_url": "https://europepmc.org/article/MED/42938688",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1313|Antibiotic Resistance in Bacteria"
    ]
  ],
  "openalex": "W7214069395",
  "pdf_url": "https://europepmc.org/articles/PMC13700561?pdf=render",
  "pmcid": "PMC13700561",
  "pmid": "42938688",
  "published": "2026-09-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/d68h6hxt8ne1r.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:24Z",
      "native_id": "MED:42938688",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42938688"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:1313|Antibiotic Resistance in Bacteria",
      "subfield": "general"
    }
  ],
  "title": "In Vitro Activity of Imipenem/Relebactam and Ceftolozane/Tazobactam Against Multidrug-Resistant Klebsiella pneumoniae: A Retrospective Single-Center Study in China.",
  "title_text": "In Vitro Activity of Imipenem/Relebactam and Ceftolozane/Tazobactam Against Multidrug-Resistant Klebsiella pneumoniae: A Retrospective Single-Center Study in China.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:22:24Z",
  "url": "https://research.draconitic.com/paper/d68h6hxt8ne1r",
  "venue": "Antibiotics (Basel, Switzerland)",
  "versions": []
}