Amoebic gill disease resistance is not related to the systemic antibody response of Atlantic salmon, Salmo salar L

• Published in: Journal of Fish Diseases
• Main Authors: Taylor, RS, Crosbie, PBB, Cook, MT
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Publishing Ltd 2010
• Subjects: Agricultural; Veterinary and Food Sciences; Fisheries sciences; Fish pests and diseases; Atlantic salmon; Salmo salar
• Online Access: https://doi.org/10.1111/j.1365-2761.2009.01108.x; http://www.ncbi.nlm.nih.gov/pubmed/19943840; http://ecite.utas.edu.au/63068

AbstractAmoebic gill disease (AGD) is a proliferative gilltissue response caused by Neoparamoeba peruransand is the main disease affecting Australian marinefarmed Atlantic salmon. We have previously proposedthat macroscopic gill health (gill score) trajectoriesand challenge survival provide evidence ofa change in the nature of resistance to AGD. Inorder to examine whether the apparent developmentof resistance was because of an adaptiveresponse, serum was sequentially sampled from thesame individuals over the first three rounds ofnatural AGD infection and from survivors of asubsequent non-intervention AGD survival challenge.The systemic immune reaction to wildtypeNeoparamoeba sp. was characterized by Westernblot analysis and differentiated to putative carbohydrateor peptide epitopes by periodate oxidationreactions. The proportion of seropositive fishincreased from 46% to 77% with each AGD round.Antibody response to carbohydrate epitope(s) wasimmunodominant, occurring in 43-64% ofsamples. Antibodies that bound peptide epitopewere identified in 16% of the challenge survivors. A1:50 (single-dilution) enzyme-linked immunosorbentassay confirmed a measurable immune titrein 13% of the survivors. There was no evidence thatantibodies recognizing wildtype Neoparamoebaprovided significant protection against AGD.Keywords: AGD, ectoparasite, ELISA, Neoparamoeba,Western blot.