Identification of new amoebae strains in rainbow trout (Oncorhynchus mykiss, Walbaum) farms affected by nodular gill disease (NGD) in Northeastern Italy.

Autor: Brocca G; Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Padua, Italy.; Aquatic Diagnostic Services, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada., Truant A; Department of Animal Medicine, Production and Health, University of Padova, Legnaro, Padua, Italy., Peckova H; Institute of Parasitology, Biology Centre CAS, Ceske Budejovice, Czech Republic., Lisnerová M; Institute of Parasitology, Biology Centre CAS, Ceske Budejovice, Czech Republic., Perolo A; Servizio Tecnico Commerciale Aquafeed, Gruppo Veronesi, Verona, Veneto Region, Italy., Fioravanti M; Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, Ozzano dell'Emilia, Bologna, Italy., Fiala I; Institute of Parasitology, Biology Centre CAS, Ceske Budejovice, Czech Republic., Gabai G; Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Padua, Italy., Quaglio F; Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Padua, Italy., Gustinelli A; Department of Veterinary Medical Sciences, Alma Mater Studiorum University of Bologna, Ozzano dell'Emilia, Bologna, Italy.
Jazyk: angličtina
Zdroj: Journal of fish diseases [J Fish Dis] 2024 Jun; Vol. 47 (6), pp. e13933. Date of Electronic Publication: 2024 Feb 23.
DOI: 10.1111/jfd.13933
Abstrakt: 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.
(© 2024 The Authors. Journal of Fish Diseases published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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