{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T03:06:22Z","timestamp":1774321582009,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2022,2,5]],"date-time":"2022-02-05T00:00:00Z","timestamp":1644019200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-029910 (PTDC\/BIA-MIC\/29910\/2017)"],"award-info":[{"award-number":["POCI-01-0145-FEDER-029910 (PTDC\/BIA-MIC\/29910\/2017)"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["Norma Transit\u00f3ria - DL57\/2016\/CP1355\/CT0010"],"award-info":[{"award-number":["Norma Transit\u00f3ria - DL57\/2016\/CP1355\/CT0010"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["2020.05402.BD"],"award-info":[{"award-number":["2020.05402.BD"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>Photobacterium damselae subsp. piscicida (Phdp) is a Gram-negative bacterium that infects a large number of marine fish species in Europe, Asia, and America, both in aquacultures and in the natural environment. Among the affected hosts are economically important cultured fish, such as sea bream (Sparus aurata), sea bass (Dicentrarchus labrax), yellowtail (Seriola quinqueradiata), and cobia (Rachycentron canadum). The best characterized virulence factor of Phdp is the Apoptosis-Inducing Protein of 56 kDa (AIP56), a secreted AB-type toxin that has been shown to induce apoptosis of sea bass phagocytes during infection. AIP56 has an A subunit that displays metalloprotease activity against NF-kB p65 and a B subunit that mediates binding and internalization of the A subunit in susceptible cells. Despite the fact that the aip56 gene is highly prevalent in Phdp isolates from different fish species, the toxicity of AIP56 has only been studied in sea bass. In the present study, the toxicity of AIP56 for sea bream was evaluated. Ex vivo assays showed that sea bream phagocytes are resistant to AIP56 cytotoxicity and that resistance was associated with an inefficient internalization of the toxin by those cells. Accordingly, in vivo intoxication assays revealed that sea bream is much more resistant to AIP56-induced lethality than sea bass. These findings, showing that the effect of AIP56 is different in sea bass and sea bream, set the basis for future studies to characterize the effects of AIP56 and to fully elucidate its virulence role in different Phdp susceptible hosts.<\/jats:p>","DOI":"10.3390\/toxins14020119","type":"journal-article","created":{"date-parts":[[2022,2,6]],"date-time":"2022-02-06T20:40:18Z","timestamp":1644180018000},"page":"119","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Susceptibility of Sea Bream (Sparus aurata) to AIP56, an AB-Type Toxin Secreted by Photobacterium damselae subsp. piscicida"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9756-3330","authenticated-orcid":false,"given":"In\u00eas Lua","family":"Freitas","sequence":"first","affiliation":[{"name":"Fish Immunology and Vaccinology Group, IBMC\u2014Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal"},{"name":"Fish Immunology and Vaccinology Group, i3S\u2014Instituto de Investiga\u00e7\u00e3o e Inova\u00e7\u00e3o em Sa\u00fade, Universidade do Porto, 4200-135 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7679-0529","authenticated-orcid":false,"given":"Alexandra","family":"Teixeira","sequence":"additional","affiliation":[{"name":"Fish Immunology and Vaccinology Group, IBMC\u2014Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal"},{"name":"Fish Immunology and Vaccinology Group, i3S\u2014Instituto de Investiga\u00e7\u00e3o e Inova\u00e7\u00e3o em Sa\u00fade, Universidade do Porto, 4200-135 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4310-4737","authenticated-orcid":false,"given":"In\u00eas","family":"Loureiro","sequence":"additional","affiliation":[{"name":"Fish Immunology and Vaccinology Group, IBMC\u2014Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal"},{"name":"Fish Immunology and Vaccinology Group, i3S\u2014Instituto de Investiga\u00e7\u00e3o e Inova\u00e7\u00e3o em Sa\u00fade, Universidade do Porto, 4200-135 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7329-8993","authenticated-orcid":false,"given":"Johnny","family":"Lisboa","sequence":"additional","affiliation":[{"name":"Fish Immunology and Vaccinology Group, IBMC\u2014Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal"},{"name":"Fish Immunology and Vaccinology Group, i3S\u2014Instituto de Investiga\u00e7\u00e3o e Inova\u00e7\u00e3o em Sa\u00fade, Universidade do Porto, 4200-135 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3673-9782","authenticated-orcid":false,"given":"Aur\u00e9lia","family":"Saraiva","sequence":"additional","affiliation":[{"name":"Biology Department, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal"},{"name":"CIIMAR\u2014Interdisciplinary Center of Marine and Environmental Research of the University of Porto, 4450-208 Matosinhos, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5960-0647","authenticated-orcid":false,"given":"Nuno Miguel Sim\u00f5es","family":"dos Santos","sequence":"additional","affiliation":[{"name":"Fish Immunology and Vaccinology Group, IBMC\u2014Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal"},{"name":"Fish Immunology and Vaccinology Group, i3S\u2014Instituto de Investiga\u00e7\u00e3o e Inova\u00e7\u00e3o em Sa\u00fade, Universidade do Porto, 4200-135 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4044-6328","authenticated-orcid":false,"given":"Ana","family":"do Vale","sequence":"additional","affiliation":[{"name":"Fish Immunology and Vaccinology Group, IBMC\u2014Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal"},{"name":"Fish Immunology and Vaccinology Group, i3S\u2014Instituto de Investiga\u00e7\u00e3o e Inova\u00e7\u00e3o em Sa\u00fade, Universidade do Porto, 4200-135 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1111\/j.1365-2958.2005.04893.x","article-title":"AIP56, a novel plasmid-encoded virulence factor of Photobacterium damselae subsp. piscicida with apoptogenic activity against sea bass macrophages and neutrophils","volume":"58","author":"Silva","year":"2005","journal-title":"Mol. 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