Identification of new amoebae strains in rainbow trout (Oncorhynchus mykiss, Walbaum) farms affected by nodular gill disease (NGD) in Northeastern Italy
© 2024 The Authors. Journal of Fish Diseases published by John Wiley & Sons Ltd.
| Publié dans: | Journal of fish diseases. - 1998. - 47(2024), 6 vom: 23. Juni, Seite e13933 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2024
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| Accès à la collection: | Journal of fish diseases |
| Sujets: | Journal Article Oncorhynchus mykiss Italy SSU rDNA amphizoic amoeba nodular gill disease (NGD) rainbow trout |
| Résumé: | © 2024 The Authors. Journal of Fish Diseases published by John Wiley & Sons Ltd. Nodular gill disease (NGD) is an emerging condition associated with amoeba trophozoites in freshwater salmonid farms. However, unambiguous identification of the pathogens still must be achieved. This study aimed to identify the amoeba species involved in periodic NGD outbreaks in two rainbow trout (Oncorhynchus mykiss) farms in Northeastern Italy. During four episodes (February-April 2023), 88 fish were euthanized, and their gills were evaluated by macroscopic, microscopic and histopathological examination. The macroscopic and microscopic severity of the lesions and the degree of amoebae infestation were scored and statistically evaluated. One gill arch from each animal was put on non-nutrient agar (NNA) Petri dishes for amoeba isolation, cultivation and subsequent identification with SSU rDNA sequencing. Histopathology confirmed moderate to severe lesions consistent with NGD and mild to moderate amoeba infestation. The presence of amoebae was significantly correlated with lesion severity. Light microscopy of cultured amoebae strains and SSU rDNA analysis revealed the presence of a previously characterized amoeba Naegleria sp. strain GERK and several new strains: two strains from Hartmannelidae, three vannelid amoebae from the genus Ripella and cercozoan amoeba Rosculus. Despite the uncertainty in NGD etiopathogenesis and amoebae pathogenic role, identifying known and new amoebae leans towards a possible multi-aetiological origin |
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| Description: | Date Completed 10.05.2024 Date Revised 10.05.2024 published: Print-Electronic RefSeq: HM363631, HM363629, AY145442 Citation Status MEDLINE |
| ISSN: | 1365-2761 |
| DOI: | 10.1111/jfd.13933 |