Identification and genomic analysis of a pathogenic circovirus associated with maricultured Scophthalmus maximus L. in China

In China, a novel pathogen within the genus Circovirus has been identified as a causative agent of the ‘novel acute hemorrhage syndrome’ (NAHS) in aquacultured populations of turbot (Scophthalmus maximus L.). Histopathological examination using light microscopy revealed extensive necrosis within the...

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Bibliographic Details
Published in:Virus Research
Main Authors: Xiao Wu, Boyin Jiang, Yuanxing Zhang, Qiyao Wang, Yue Ma
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2024
Subjects:
Online Access:https://doi.org/10.1016/j.virusres.2024.199428
https://doaj.org/article/f8f18941eabf4817a265d54f99bb1d10
Description
Summary:In China, a novel pathogen within the genus Circovirus has been identified as a causative agent of the ‘novel acute hemorrhage syndrome’ (NAHS) in aquacultured populations of turbot (Scophthalmus maximus L.). Histopathological examination using light microscopy revealed extensive necrosis within the cardiac, splenic, and renal tissues of the afflicted fish. Utilizing transmission electron microscopy (TEM), we detected the presence of circovirus particles within the cytoplasm of these cells, with the virions consistently exhibiting a spherical morphology of 20–40 nm in diameter. TEM inspections confirmed the predominance of these virions in the heart, spleen, and kidney. Subsequent molecular characterization through polymerase chain reaction (PCR) analysis corroborated the TEM findings, with positive signals in the aforementioned tissues, in stark contrast to the lack of detection in gill, fin, liver, and intestinal tissues. The TEM observations, supported by PCR electrophoresis data, strongly suggest that the spleen and kidney are the primary targets of the viral infection. Further characterization using biophysical, biochemical assays, and genomic sequencing confirmed the viral classification within the genus Circovirus, resulting in the nomenclature of turbot circovirus (TurCV). The current research endeavors to shed light on the pathogenesis of this pathogen, offering insights into the infection mechanisms of TurCV in this novel piscine host, thereby contributing to the broader understanding of its impact on turbot health and aquaculture.