Detection of cyprinid herpesvirus 2 by loop-mediated isothermal amplification in combination with a lateral flow dipstick.

We developed a convenient technique to detect Herpesviral haematopoietic necrosis attributed to cyprinid herpes virus 2 (CyHV-2), a serious disease of Crucian carp and goldfish related to high mortality. In the present study, we employed a lateral flow dipstick (LAMP-LFD) to present a loop-mediated isothermal amplification assay. The specificity was ascertained via other six viruses, and the sensitivity was compared using PCR method, which are the reaction conditions changes for the method improved. The results revealed that CyHV-2 performance was observable at 64 °C in a separated tube within 60 min, when the samples hybridized using an FITC-labeled probe. As the LAMP-LFD method's specificity was high, with its sensitivity identical to that of traditional PCR, the overall DNA collected revealed the lowest detection limit of 0.18 pg/µl from goldfish diseased by CyHV-2. In summary, the development of LAMP-LFD's method does not require expensive instruments, and it can be regarded as a fast, simple, and reliable method for CyHV-2 detection.

Studies on histopathological alteration of three major organs of the goldfish, Carassius auratus L., of India due to myxozoan infection with special reference to scanning electron microscopic observation.

Severe infections by the protozoan parasite belonging to the genera Myxozoa are causing serious problems in ornamental fish reared in breeding farms. Histopathological study is being used for diagnosis of the severity of diseases. Myxozoan infections result in large scale histopathological damages in different fish tissues. No information is available regarding the histopathological changes of goldfish due to infection with myxozoans. The present study deals with the histopathological changes of the gill, fin, and skin of goldfish, infected with myxozoan parasites along with an ultrastructural study using scanning electron microscope. Several histological alterations have been observed in goldfish, like tissue damage, epithelial hyperplasia, necrosis, anoxia, localized lymphocytic infiltration, excess mucus, cellular necrosis, and epithelial proliferation. The present study revealed the invasion intensified by the occurrence of morphological lesions in the gill, skin, and fin exposed to Myxosporidia, which may lead to respiratory insufficiency in fish and even cause mass mortality.

First record of the genus Paratrichodina (Ciliophora: Trichodinidae) in India from ornamental goldfish (Carassius auratus L.) supplemented with description of a new species Paratrichodina indiana n. sp.

The present investigation deals with the accounts of a novel species of ciliate parasite belonging to the genus Paratrichodina namely, Paratrichodina indiana n. sp. identified from the respiratory organ of goldfish Carassius auratus at Nadia district of West Bengal, India. 276 fish have been collected for parasitological examination from various fish farm of West Bengal, India. The parasitological investigation was conducted using the AgNO3 impregnation technique, which was supplemented by a taxonomic description, morphological variations and data comparison with previously documented closely related species. Paratrichodina indiana n. sp. is a small-sized trichodinid, measures uniquely 19.21 ± 1.6 µm in body diameter, with prominent adhesive disc measure 15.55 ± 1.22 µm. The current investigation supports the first record of the genus from C. auratus and adds one new species to the genus Paratrichodina, as well as report of a new host, region and prevalence rates.