{
  "abstract": "Pathogen expulsion from the gut via defecation is an important defence strategy against infection. The microbial factors that can subvert this defence reaction remain poorly understood. While many microbes have been found to increase host intestinal peristalsis, Pseudomonas entomophila infection in Drosophila melanogaster leads to infection-induced defecation blockage, particularly in females. Here, we show that this phenotype is driven by a secreted, thermosensitive protein regulated by the GacS/GacA two-component system. Proteomic comparison of the ΔgacA mutant, which only partially inhibits defecation, and the avirulent Δhfq mutant lacking RNA chaperon Hfq, which still triggers the phenotype, identified pore-forming toxin Monalysin as one of the candidate factors required for inhibiting defecation. Consistent with these findings, the Monalysin-deficient mutant failed to fully suppress defecation and exhibited attenuated virulence and reduced persistence in the gut. Hence, Monalysin besides causing intestinal damage, has a previously unknown role in suppressing defecation and pathogen expulsion. Overall, our study identified a bacterial factor that rapidly reduces defecation frequency, consistent with transient suppression of intestinal transit, thus advancing our understanding of pathogen strategies used to subvert host defences. Author summary: Many intestinal infections affect gut peristalsis, with increased peristalsis helping the host clear harmful microbes through defecation. However, some pathogens may benefit from slowing this process down and persisting in the intestine. We previously found that Pseudomonas entomophila greatly reduces defecation in female fruit flies, but the bacterial factors responsible for this effect remained unknown.",
  "abstract_shown": true,
  "affiliations": [
    "Research group Genetics of host-microbe interactions, Max Planck Institute for Infection Biology, Berlin, Germany.",
    "Max Planck Unit for the Science of Pathogens, Berlin, Germany.",
    "Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria."
  ],
  "article_type": "Research Article",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Marko Rubinić",
      "orcid": "0009-0005-0381-6499"
    },
    {
      "affs": [
        0
      ],
      "name": "Yi Yu",
      "orcid": "0000-0002-9061-0405"
    },
    {
      "affs": [
        1
      ],
      "name": "Kathirvel Alagesan"
    },
    {
      "affs": [
        0
      ],
      "name": "Dagmar Frahm"
    },
    {
      "affs": [
        0,
        2
      ],
      "name": "Igor Iatsenko",
      "orcid": "0000-0002-9249-8998"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1amd5prkb4qa4.bib",
  "cited_by": 0,
  "doi": "10.1371/journal.ppat.1014696",
  "fulltext_url": "https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014696",
  "id": "1amd5prkb4qa4",
  "issns": [
    "1553-7374",
    "1553-7366"
  ],
  "landing_url": "https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014696",
  "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",
      "2403|Invertebrate Immune Response Mechanisms"
    ],
    [
      "plos",
      "/Biology and life sciences/Anatomy/Digestive system/Gastrointestinal tract"
    ],
    [
      "plos",
      "/Biology and life sciences/Microbiology/Medical microbiology/Microbial pathogens/Bacterial pathogens"
    ],
    [
      "plos",
      "/Biology and life sciences/Organisms/Eukaryota/Animals/Invertebrates/Arthropoda/Insects/Drosophila/Drosophila melanogaster"
    ],
    [
      "plos",
      "/Biology and life sciences/Physiology/Physiological processes/Defecation"
    ],
    [
      "plos",
      "/Biology and life sciences/Toxicology/Toxic agents/Toxins"
    ],
    [
      "plos",
      "/Biology and life sciences/Zoology/Animals/Invertebrates/Arthropoda/Insects/Drosophila/Drosophila melanogaster"
    ],
    [
      "plos",
      "/Biology and life sciences/Zoology/Entomology/Insects/Drosophila/Drosophila melanogaster"
    ],
    [
      "plos",
      "/Medicine and health sciences/Anatomy/Digestive system/Gastrointestinal tract"
    ],
    [
      "plos",
      "/Medicine and health sciences/Pathology and laboratory medicine/Pathogens/Microbial pathogens/Bacterial pathogens"
    ],
    [
      "plos",
      "/Medicine and health sciences/Pathology and laboratory medicine/Pathogens/Virulence factors"
    ],
    [
      "plos",
      "/Medicine and health sciences/Pathology and laboratory medicine/Pathogens/Virulence factors/Pathogen motility"
    ],
    [
      "plos",
      "/Medicine and health sciences/Pathology and laboratory medicine/Toxicology/Toxic agents/Toxins"
    ],
    [
      "plos",
      "/Physical sciences/Chemistry/Chemical compounds/Organic compounds/Carbohydrates/Disaccharides/Sucrose"
    ],
    [
      "plos",
      "/Physical sciences/Chemistry/Organic chemistry/Organic compounds/Carbohydrates/Disaccharides/Sucrose"
    ],
    [
      "plos",
      "/Research and analysis methods/Animal studies/Experimental organism systems/Animal models/Drosophila melanogaster"
    ],
    [
      "plos",
      "/Research and analysis methods/Animal studies/Experimental organism systems/Model organisms/Drosophila melanogaster"
    ],
    [
      "plos",
      "/Research and analysis methods/Model organisms/Drosophila melanogaster"
    ]
  ],
  "openalex": "W7220972509",
  "pdf_url": "https://journals.plos.org/plospathogens/article/file?id=10.1371/journal.ppat.1014696&type=printable",
  "pmcid": "PMC13671641",
  "pmid": "42848827",
  "published": "2026-10-08",
  "publisher": "Public Library of Science",
  "ris": "https://research.draconitic.com/paper/1amd5prkb4qa4.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:30Z",
      "native_id": "10.1371/journal.ppat.1014696",
      "source": "plos",
      "url": "https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014696"
    },
    {
      "first_seen": "2026-10-30T12:18:02Z",
      "native_id": "MED:42848827",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42848827"
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  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "plos:zoology",
      "subfield": "zoology-behaviour"
    },
    {
      "field": "medicine",
      "origin": "plos:toxicology",
      "subfield": "pharmacology-toxicology"
    },
    {
      "field": "medicine",
      "origin": "plos:anatomy",
      "subfield": "physiology"
    }
  ],
  "title": "A pore-forming toxin monalysin contributes to infection-induced suppression of defecation in female Drosophila",
  "title_text": "A pore-forming toxin monalysin contributes to infection-induced suppression of defecation in female Drosophila",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:02Z",
  "url": "https://research.draconitic.com/paper/1amd5prkb4qa4",
  "venue": "PLOS Pathogens",
  "versions": []
}