{
  "abstract": "Background: Pseudomonas aeruginosa is a ubiquitous opportunistic bacterial pathogen associated with nosocomial infections and is a leading cause of infection in persons with cystic fibrosis (pwCF). The front-line treatment for multidrug-resistant P. aeruginosa infections is ceftolozane-tazobactam (C/T). While previous research has characterized clinical P. aeruginosa isolates that evolved resistance to C/T, the collateral effect of evolved resistance on susceptibility to bacteriophages has not been explored. Methods: We collected paired P. aeruginosa clinical isolates from 10 pwCF and 18 non-pwCF who developed treatment-emergent C/T resistance. We compared genetic relatedness, acute and chronic virulence phenotypes, and antibiotic and phage susceptibilities between each pair of susceptible baseline and treatment-emergent C/T-resistant isolates. Results: Treatment-emergent C/T-resistant isolates were genetically closely related to baseline isolates in all patients. Virulence phenotypes did not differ between pre- and post-C/T exposure isolates, but isolates from pwCF demonstrated differences in protease production, twitching motility, and amino acid auxotrophy compared to isolates from non-pwCF. Treatment-emergent C/T resistance was associated with increased resistance to ceftazidime and ceftazidime/avibactam, but no other trends in antibiotic or phage susceptibility were detected. Conclusions: Treatment-emergent resistance to C/T does not cause predictable alterations in phage susceptibility across genotypically and phenotypically diverse multidrug-resistant P. aeruginosa clinical isolates.",
  "abstract_shown": true,
  "affiliations": [
    "University of Pittsburgh"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "N. R. Wallace"
    },
    {
      "name": "R. L. DiDonato"
    },
    {
      "name": "B. A. Jackson"
    },
    {
      "name": "E. G. Kline"
    },
    {
      "name": "K. M. Squires"
    },
    {
      "name": "A. J. Dorazio"
    },
    {
      "name": "R. K. Shields"
    },
    {
      "affs": [
        0
      ],
      "name": "D. Van Tyne"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/aa2yz9rztc1x0.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.03.749285",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.03.749285v1.full",
  "id": "aa2yz9rztc1x0",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.03.749285v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "microbiology"
    ],
    [
      "openalex",
      "1313|Antibiotic Resistance in Bacteria"
    ]
  ],
  "openalex": "W7211977204",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.03.749285v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/aa2yz9rztc1x0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:03Z",
      "native_id": "10.64898/2026.09.03.749285",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.03.749285v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:microbiology",
      "subfield": "microbiology"
    }
  ],
  "title": "Variable phage susceptibility of Pseudomonas aeruginosa from patients with and without cystic fibrosis following treatment-emergent resistance to ceftolozane-tazobactam",
  "title_text": "Variable phage susceptibility of Pseudomonas aeruginosa from patients with and without cystic fibrosis following treatment-emergent resistance to ceftolozane-tazobactam",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:03Z",
  "url": "https://research.draconitic.com/paper/aa2yz9rztc1x0",
  "venue": "bioRxiv",
  "versions": []
}