{
  "abstract": "The increasing prevalence of multidrug-resistant (MDR) bacteria isolated from dogs with external otitis presents a major therapeutic challenge in veterinary medicine, and antimicrobial photodynamic therapy has emerged as a promising alternative. Meso-tetra-pyridyl porphyrins bearing peripheral platinum(II) (3-PtTPyP) and palladium(II) (3-PdTPyP) complexes have shown activity against clinically relevant Gram-positive bacteria and may represent effective photosensitizers for otitis-associated MDR pathogens. Therefore, this study evaluated the antimicrobial activity and effects on bacterial morphology and adhesive properties of 3-PtTPyP and 3-PdTPyP on MDR isolates of Corynebacterium auriscanis, Enterococcus faecalis, Staphylococcus epidermidis, and Streptococcus canis obtained from dogs with otitis. Antibacterial activity was investigated by determining the minimum inhibitory and bactericidal concentrations (MBC) and by bacterial time-kill assay under white-light irradiation for 120 min. Alterations in bacterial morphology and nanomechanical properties were investigated using atomic force microscopy (AFM). Both porphyrins promoted a marked reduction in bacterial concentrations under white-light irradiation using MBC, although their bactericidal effects varied depending on the bacterial species and porphyrin. The 3-PtTPyP exhibited a more consistent photodynamic response against E. faecalis e C. auricanis, whereas 3-PdTPyP displayed greater effected against S. canis e S. epidermidis. AFM revealed pronounced changes in surface topography and nanomechanical properties after treatment with both porphyrins. Overall, these results demonstrate that 3-PtTPyP and 3-PdTPyP are promising photosensitizers for the inactivation of MDR Gram-positive bacteria associated with canine otitis externa, and the performance against the MDR Gram-positive bacteria was dependent of species.",
  "abstract_shown": true,
  "affiliations": [
    "Center for Rural Sciences, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul Brasil",
    "Laboratory Surfaces and Macromolecules, Department of Physics, Center for Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul Brasil",
    "Chemistry Department, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina Brasil",
    "Department of Preventive Veterinary Medicine, Center for Rural Sciences, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul Brasil",
    "Laboratory of Veterinary Microbiology and Immunology, Federal Institute Farroupilha, Campus Frederico Westphalen, Frederico Westphalen, Rio Grande do Sul Brasil"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Tauana Fernanda Jantsch Voigt"
    },
    {
      "affs": [
        0
      ],
      "name": "Eduarda Martins"
    },
    {
      "affs": [
        0
      ],
      "name": "Junior Navarini"
    },
    {
      "affs": [
        1
      ],
      "name": "Matheus Gass Lopes"
    },
    {
      "affs": [
        1
      ],
      "name": "Paulo Ricardo de Souza"
    },
    {
      "affs": [
        2
      ],
      "name": "Bernardo Almeida Iglesias"
    },
    {
      "affs": [
        3
      ],
      "name": "Fernanda Silveira Flores Vogel"
    },
    {
      "affs": [
        4
      ],
      "name": "Letícia Trevisan Gressler"
    },
    {
      "affs": [
        3
      ],
      "name": "Juliana Felipetto Cargnelutti",
      "orcid": "0000-0002-3160-3643"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cfthspt9b1djz.bib",
  "cited_by": 0,
  "doi": "10.1007/s00284-026-05202-8",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13736366/",
  "id": "cfthspt9b1djz",
  "issns": [
    "0343-8651",
    "1432-0991"
  ],
  "landing_url": "https://doi.org/10.1007/s00284-026-05202-8",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Article"
    ],
    [
      "openalex",
      "1306|Photodynamic Therapy Research Studies"
    ]
  ],
  "openalex": "W7225259112",
  "pdf_url": "https://link.springer.com/content/pdf/10.1007/s00284-026-05202-8.pdf",
  "pmcid": "PMC13736366",
  "pmid": "42980665",
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cfthspt9b1djz.ris",
  "sources": [
    {
      "first_seen": "2026-11-09T12:21:49Z",
      "native_id": "PMC13736366",
      "source": "pmc",
      "url": "https://doi.org/10.1007/s00284-026-05202-8"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:1306|Photodynamic Therapy Research Studies",
      "subfield": "oncology"
    }
  ],
  "title": "Photoinactivation of multidrug-resistant Gram-positive bacteria isolated from dogs with otitis using tetra-cationic porphyrins bearing peripheral platinum(II) (3-PtTPyP) and palladium(II) (3-PdTPyP) complexes",
  "title_text": "Photoinactivation of multidrug-resistant Gram-positive bacteria isolated from dogs with otitis using tetra-cationic porphyrins bearing peripheral platinum(II) (3-PtTPyP) and palladium(II) (3-PdTPyP) complexes",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T12:21:49Z",
  "url": "https://research.draconitic.com/paper/cfthspt9b1djz",
  "venue": "Current Microbiology",
  "versions": []
}