Presence of viruses in wild eels Anguilla anguilla L, from the Albufera Lake (Spain)

• Published in: Journal of fish diseases Vol. 37; no. 7; pp. 597 - 607
• Main Authors: Bandín, I, Souto, S, Cutrín, J M, López-Vázquez, C, Olveira, J G, Esteve, C, Alcaide, E, Dopazo, C P
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.07.2014
• Subjects: Anguilla; Anguilla anguilla; Anguillid herpesvirus; Animals; Aquabirnavirus; Aquabirnaviruses; Betanodavirus; betanodaviruses; DNA Virus Infections - epidemiology; DNA Virus Infections - veterinary; DNA Virus Infections - virology; DNA Viruses - classification; DNA Viruses - genetics; DNA Viruses - isolation & purification; Female; Fish Diseases - epidemiology; Fish Diseases - virology; Herpesvirus; Male; Molecular Sequence Data; Phylogeny; Polymerase Chain Reaction - veterinary; RNA Virus Infections - epidemiology; RNA Virus Infections - veterinary; RNA Virus Infections - virology; RNA Viruses - classification; RNA Viruses - genetics; RNA Viruses - isolation & purification; Seasons; Sequence Analysis, DNA - veterinary; Spain - epidemiology; Viral Proteins - genetics; wild eels; Spain; Anguillid herpesvirus; Anguilla anguilla; betanodaviruses; Aquabirnaviruses; wild eels
• ISSN: 0140-7775; 1365-2761
• DOI: 10.1111/jfd.1392

A virological analysis was conducted on wild eels from the Albufera Lake (Spain). A total of 179 individuals at different growth stages were collected in two different surveys (2004 and 2008). Presence of anguillid herpesvirus (AngHV‐1), aquabirnavirus and betanodavirus was confirmed by PCR procedures in both surveys, although the number of detections was clearly higher in 2008 (83% of the eels analysed resulted positive for virus presence). AngHV‐1 was the viral agent most frequently detected, followed by aquabirnaviruses. Betanodaviruses were detected by the first time in wild eels, and although the detections were only made by nested PCR, high percentage of positives were achieved. In addition, in 2008, seven aquabirnaviruses were isolated. Phylogenetic analysis performed using partial sequences of both genomic segments of aquabirnaviruses indicated that the seven isolates could be typed as WB (genogroup I) on the basis of segment A sequences, but when segment B was used six of them clustered with C1 strain (genogroup V) and one was typed as Ab (genogroup II). These results indicate natural reassortment between different strains of aquabirnaviruses in the eels. Although betanodaviruses were not isolated in cell culture, the analysis of the sequence of the nested PCR product indicated that they clustered with SJNNV genotype. The diversity of viral agents and the high level of viral detections suggest that viral infections may play a more prominent role in the decline of the European eel than initially thought.