Evidence map›Paper›PMID 42613647›Full record

ArticleAnimal microbiome2026

From onset to healing: temporal dynamics of microbial communities pinpoint Midichloria-like organism's key role in the development of the fish skin disease red mark syndrome.

Giulia Zarantonello, Fernando Puente-Sánchez, Jacob Günther Schmidt, Argelia Cuenca

Abstract read
In one paragraph

Article in Animal microbiome, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Giulia ZarantonelloSection for Fish and Shellfish Diseases, National Institute for Aquatic Resources (DTU Aqua), Technical University of Denmark (DTU), Kongens Lyngby, Denmark. giuz@aqua.dtu.dk.ORCID http://orcid.org/0000-0002-6742-9237
Fernando Puente-SánchezDivision of Microbial Ecology, Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.ORCID http://orcid.org/0000-0002-6341-3692
Jacob Günther SchmidtSection for Fish and Shellfish Diseases, National Institute for Aquatic Resources (DTU Aqua), Technical University of Denmark (DTU), Kongens Lyngby, Denmark.ORCID http://orcid.org/0000-0002-5956-7218
Argelia CuencaSection for Fish and Shellfish Diseases, National Institute for Aquatic Resources (DTU Aqua), Technical University of Denmark (DTU), Kongens Lyngby, Denmark. arcun@aqua.dtu.dk.ORCID http://orcid.org/0000-0001-8596-1086

Funding

Danmarks Tekniske Universitet PhD fundingEuropean Union's Horizon Europe Project EUPAHW 101136346Swedish Research Council for Sustainable Development (FORMAS) 2023-01573
6 · The paper itself

Abstract

backgroundRed mark syndrome (RMS) is an infectious disease affecting rainbow trout (Oncorhynchus mykiss), especially at market size, forcing farmers to downgrade the product with heavy economic repercussions. The causative agent of RMS has not been established according to Koch's postulates, since possible candidates have not been isolated and propagated in vitro. While the 16S rRNA gene of a Midichloria-like organism (MLO) is consistently detected in active skin lesions, the role of other bacteria in the disease has not been excluded. In this work, we provide a temporal perspective to elucidate the relationships between the bacteriome in rainbow trout skin and water, during the development and resolution of clinical disease in naive fish infected by cohabitation with RMS-affected fish in the same tank.

resultsWe quantified the MLO by qPCR in skin and, for the first time, in water using environmental DNA, showing that its quantity in both sample types corresponds with disease progression. Using 16S rRNA gene profiling, we provide further evidence that the MLO is likely the primary pathogen triggering RMS, as it was the only significantly enriched taxon in active lesions. Furthermore, the skin microbiome of affected fish reverted to a control-like state during healing. RMS also caused changes in the overall skin microbiome at peak pathology: the relative abundance of "Ca. Branchiomonas" and an unclassified gammaproteobacterium increased in apparently healthy skin areas of RMS-affected fish while remaining low in controls, suggesting they may be opportunistic bacteria implicated in skin dysbiosis.

conclusionsOur findings on the temporal dynamics of the skin microbiome during disease progression and recovery strengthen the evidence that Midichloria-like organism is the primary pathogen of RMS. The observed shifts in other bacterial taxa suggest possible secondary roles in disease-associated skin dysbiosis. Finally, detection of MLO in environmental DNA from water provides new insights into RMS transmission and potential monitoring strategies.

Indexed as

Aquaculture“Ca. Branchiomonas”eDNAMidichloria-like organism (MLO)Red mark syndrome (RMS)Skin microbiomeStrawberry disease (SD)Teleost

Identifiers

PMID42613647
PMCPMC13488072

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.