Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jul 14;13(7):1660.
doi: 10.3390/microorganisms13071660.

Risk of Secondary Bacterial Infections Revealed by Changes in Trachinotus ovatus Skin and Gill Microbiota During a Cryptocaryon irritans Infection Cycle

Naiqi Liang  1   2 , Li Zhu  1   2 , Shifeng Wang  1   2 , Weihao Zhang  1   2 , Xinlei Lin  1   2 , Yongcan Zhou  1   2 , Haizhu Ke  1   2 , Shanheng Yuan  1   2 , Meijing Li  1   2 , Yan Cai  1   2
Affiliations

Risk of Secondary Bacterial Infections Revealed by Changes in Trachinotus ovatus Skin and Gill Microbiota During a Cryptocaryon irritans Infection Cycle

Naiqi Liang et al. Microorganisms. .

Abstract

This study aims to investigate the response of surface bacterial communities in Trachinotus ovatus to Cryptocaryon irritans infection at different stages of a single infection cycle (0~168 h). These samples were analyzed using high-throughput 16S rRNA sequencing. Alpha diversity analysis showed a reduction in the richness and diversity of skin microbiota during infection, with partial recovery post-detachment. Beta diversity analysis revealed distinct structural shifts in skin microbiota at early (24 h) and post-detachment (168 h) stages compared to other phases, while gill microbiota remained stable except during detachment. At the phylum level, Proteobacteria, Actinobacteriota, Bacteroidetes, and Firmicutes were dominant on the skin at different stages, whereas the gill microbiota was predominantly Proteobacteria (>90%). At the genus level, opportunistic pathogens, such as Vibrio and Nautella, increased in relative abundance on the skin with the infection progression, while gill microbiota composition barely changed. The hepatic bacterial load continued to increase with infection duration. These findings indicate that C. irritans alters microbiota composition on skin, facilitating pathogen invasion, thereby elevating the risk of secondary bacterial infections in T. ovatus.

Keywords: Cryptocaryon irritans; Trachinotus ovatus; microbiota; safety; secondary bacterial infections; skin and gill.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Changes in hepatic bacterial load of T. ovatus during C. irritans infection. *** represents p < 0.001, **** represents p < 0.0001.
Figure 2
Figure 2
Dynamic changes in the abundance of operational taxonomic units (OTUs) within the microbial community across different time points of C. irritans infection. (A) Skin (B) Gill.
Figure 3
Figure 3
Alpha diversity indices (Sobs, Shannon, Simpson, ACE, and Chao) of bacterial communities in (a) Skin and (b) Gill. * represents p < 0.05, ** represents p < 0.001 and *** represents p < 0.0001.
Figure 4
Figure 4
Principal coordinate analysis (PCoA) of microbiome composition at the phylum and genus taxonomic levels, with subplots illustrating the following: (a) skin microbiome at the phylum level; (b) skin microbiome at the genus level; (c) gill microbiome at the phylum level; and (d) gill microbiome at the genus level.
Figure 4
Figure 4
Principal coordinate analysis (PCoA) of microbiome composition at the phylum and genus taxonomic levels, with subplots illustrating the following: (a) skin microbiome at the phylum level; (b) skin microbiome at the genus level; (c) gill microbiome at the phylum level; and (d) gill microbiome at the genus level.
Figure 5
Figure 5
Relative abundance of bacteria at phylum level; (A) Skin, (B) Gills.
Figure 6
Figure 6
Relative abundance of bacteria at genus level, (A) Skin, (B) Gills.
Figure 7
Figure 7
Comparative taxonomic analysis of bacterial community composition across treatments via LEfSe. (a) Skin; (b) Gill.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Tan X., Sun Z., Huang Z., Zhou C., Lin H., Tan L., Xun P., Huang Q. Effects of dietary hawthorn extract on growth performance, immune responses, growth- and immune-related genes expression of juvenile golden pompano (Trachinotus ovatus) and its susceptibility to Vibrio harveyi infection. Fish Shellfish Immunol. 2017;70:656–664. doi: 10.1016/j.fsi.2017.09.041. - DOI - PubMed
    1. Zhao W., Fang H.H., Gao B.Y., Dai C.M., Liu Z.Z., Zhang C.W., Niu J. Dietary Tribonema sp. supplementation increased growth performance, antioxidant capacity, immunity and improved hepatic health in golden pompano (Trachinotus ovatus) Aquaculture. 2020;529:735667. doi: 10.1016/j.aquaculture.2020.735667. - DOI
    1. Chen F., Liang W., Chen M. Histopathological study on Cryptocaryon irritans infection in Trachinotus ovatus. Fish. Res. 2017;39:181–187.
    1. Su Y. Investigation and prevention and control strategies of Cryptocaryon irritans infection in marine cage-cultured fish in major mariculture areas of Fujian Province. J. Fish. Sci. Technol. Inf. 2009;36:4–7.
    1. Diggles B.K., Adlard R.D. Taxonomic affinities of Cryptocaryon irritans and Ichthyophthirius multifiliis inferred from ribosomal RNA sequence data. Dis. Aquat. Org. 1995;22:39–43. doi: 10.3354/dao022039. - DOI

LinkOut - more resources