Issue |
Parasite
Volume 32, 2025
|
|
---|---|---|
Article Number | 1 | |
Number of page(s) | 11 | |
DOI | https://doi.org/10.1051/parasite/2024078 | |
Published online | 22 January 2025 |
urn:lsid:zoobank.org:pub:66127F4D-3FA6-489B-9205-4B8FE445296A
Research Article
Identification of a new fish trypanosome from the large yellow croaker (Larimichthys crocea) and description of its impact on host pathology, blood biochemical parameters and immune responses
Identification d’un nouveau trypanosome de poisson parasite de Larimichthys crocea, y compris son impact sur la pathologie, les paramètres biochimiques sanguins et les réponses immunitaires de l’hôte
1
National Engineering Research Center of Marine Facilities Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, Zhejiang 316022, PR China
2
School of Fisheries, Zhejiang Ocean University, Zhoushan, Zhejiang 316022, PR China
3
Taizhou Key Laboratory of Biomedicine and Advanced Dosage Forms, School of Life Sciences, Taizhou University, Zhejiang, Taizhou 318000, PR China
* Corresponding author: peipeifu0720@163.com (Peipei Fu); guobaobao2000@126.com (Baoying Guo)
Received:
15
August
2024
Accepted:
26
December
2024
The aim of this study was to clarify the taxonomic identification of a hemoflagellate and assess the effect of trypanosome infection on Larimichthys crocea. Giemsa staining showed the presence of three morphotypes of trypomastigotes. The trypanosomes had the following morphological characteristics: a slender body with a long flagellum at the front; body size 12.30–30.90 × 1.13–2.33 μm; elongated oval nucleus situated in the median region; kinetoplast small, oval, located at the posterior end. The parasite had significant morphological differences from Trypanosoma epinepheli Su, Feng, Jiang, Guo, Liu & Xu, 2014 and Trypanosoma carassii (Mitrofanov) Doflein, 1901. The 18S rDNA sequences of the trypanosome from L. crocea had the highest homology (98.4%) with T. carassii. Phylogenetic analysis indicated that the parasite clustered with freshwater fish trypanosomes. Based on the differences in morphological characteristics and molecular data, it is considered a new species, Trypanosoma larimichthysi n. sp. Trypanosome infection had no effect on the growth of L. crocea, but significantly increased the concentration of blood urea nitrogen (BUN), and induced pathological changes in the gills, liver, spleen and kidney. The pro-inflammatory immune genes, including TNF-α, IFN-γ, IL-1β, CXCL8 and iNOS, were significantly upregulated in the L. crocea infected with trypanosomes. These results suggest that the trypanosome has negative impacts on host health.
Résumé
Le but de cette étude était de clarifier l’identification taxonomique d’un hémoflagellé et d’évaluer l’effet de l’infection trypanosomienne sur Larimichthys crocea. La coloration au Giemsa a montré la présence de trois morphotypes de trypomastigotes. Les trypanosomes avaient les caractéristiques morphologiques suivantes : un corps élancé avec long flagelle à l’avant; taille du corps 12,30–30,90 × 1,13–2,33 μm; noyau ovale allongé situé dans la région médiane; kinétoplaste petit, ovale, situé à l’extrémité postérieure. Le parasite présentait des différences morphologiques significatives par rapport à Trypanosoma epinepheli Su, Feng, Jiang, Guo, Liu & Xu, 2014 et Trypanosoma carassii (Mitrofanov) Doflein, 1901. Les séquences d’ADNr 18S du trypanosome de L. crocea présentaient la plus forte homologie (98,4 %) avec T. carassii. L’analyse phylogénétique a indiqué que le parasite se regroupait avec les trypanosomes de poissons d’eau douce. Sur la base des différences dans les caractéristiques morphologiques et les données moléculaires, il est considéré comme une nouvelle espèce, Trypanosoma larimichthysi n. sp. L’infection par les trypanosomes n’a eu aucun effet sur la croissance de L. crocea, mais a augmenté de manière significative la concentration d’azote uréique du sang (BUN) et a induit des modifications pathologiques des branchies, du foie, de la rate et des reins. Les gènes immunitaires pro-inflammatoires, dont TNF-α, IFN-γ, IL-1β, CXCL8 et iNOS, ont été significativement régulés à la hausse chez les L. crocea infectés par les trypanosomes. Ces résultats suggèrent que le trypanosome a des impacts négatifs sur la santé de l’hôte.
Key words: Trypanosoma / Larimichthys crocea / Identification / Pathology / Immunity
Edited by: Jean-Lou Justine
© X. Yang et al., published by EDP Sciences, 2025
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.