Studies on "Kuchijiro-sho" of cultured tiger puffer Takifugu rubripes. 1. Histopathological findings of cultured tiger puffer Takifugu rubripes naturally infected with "Kuchijiro-sho".

Exogenous RNA Segments Detected Specifically in the Brain of Kuchijirosho (snout ulcer disease)-infected Fugu <i>Takifugu rubripes</i>: Molecular Diagnosis Tool for Kuchijirosho

“…Inouye (1988) indicated that the kuchijirosho virus is a DNA virus because, when a homogenate of kuchijirosho-affected fugu brain was treated with DNase, the infectivity of the pathogen of kuchijirosho was completely lost. Although the symptoms of kuchijirosho caused by infection with kuchijirosho virus used in this study are similar to those described in other reports (Hatai et al, 1983;Nakauchi et al, 1985;Wada et al, 1985Wada et al, , 1986Inoue et al, 1986Inoue et al, , 1992Miyadai et al, 2001;Takami et al, 2007aTakami et al, , 2007bTakami et al, , 2007c, more than one virus species might be involved in the development of kuchijirosho. We detected KARs in fugu showing symptomatic signs similar to kuchijirosho that had broken out at an aquaculture farm in 2020 in Japan (Fig.…”

“…The use of KAR-specific primers for cDNA synthesis allows us to diagnose kuchijirosho before the onset of the disease, and random primers are sufficient to detect KARs in fugu that have developed kuchijirosho. In earlier studies, histological damage in the brain of fugu infected with kuchijirosho was seen in the form of nucleolus condensation of giant neuronal cells in the region of the brain stem (Nakauchi et al, 1985;Wada et al, 1985;Miyadai et al, 2001). By a preliminary in situ hybridization experiment, we detected KARs in the cells distributed over almost all of the brain (data not shown).…”

Experimental infection of several fish species with the causative agent of Kuchijirosho (snout ulcer disease) derived from the tiger puffer Takifugu rubripes

“…2C). This histopathological feature has been observed as a typical lesion in the brain of tiger puffers infected by Kuchijirosho (Nakauchi et al 1985, Wada et al 1985. Even when the brains of other fish species examined appeared to be less or only slightly affected (Fig.…”

“…Cumulative mortalities of grass puffer Takifugu rubripes after inoculation with extract of kuchijirosho-affected brain. Forty-five diluted brain extracts from unaffected fish which had not been exposed to Kuchijirosho were used for the Control Condensation of chromatin-like granules in the nuclei of giant nerve cells was noted as a typical characteristic of Kuchijirosho, as observed in the brains of tiger puffers (Nakauchi et al 1985, Wada et al 1985. The condensation observed in the tiger puffers injected with brain extract from non-tiger puffers previously inoculated with the Kuchijirosho agent confirmed not only that the non-tiger puffers used in the present from Kuchijirosho-affected panther puffer (C) or from tiger puffer (A, E).…”

“…Resale or republication not permitted without written consent of the publisher (Nakauchi et al 1985, Wada et al 1985 and based on experimental infectivity of extracts from affected brains (Inouye et al 1992). Its filterability (Inouye et al 1992) suggests that the pathogen might be a virus, although it has not been characterized in detail.…”