Acquired immunity to amyloodiniosis is associated with an antibody response

Abstract

The dinoflagellate Amyloodlnium ocellatum, which causes amyloodiniosis or 'marine velvet disease', 1s one of the most senous ectoparasitic diseases plaguing warmwater manne fish culture worldwide We report that tomato clownfish Amphlpnon frenatus develop strong immunity to Amyloodlnlum ocellatum infection following repeated nonlethal challenges and that specific ant~bodies are associated with this response React~on of immune fish antisera against dinospore and trophont-denved antigens in Western blots indicated both shared and stage-speclfic antibody-antigen reactions A mannan-binding-protein affinity column was used to isolate IgM-like antibody from A frenatus serum The reduced Ig consisted of one 70 kD heavy chain and one 32 kD light chain with an estimated molecular weight of 816 kD for the native molecule Immunoglobulin (Ig) isolated from immune but not nonunmune fish serum significantly inhlblted parasite infectivity In vitro An enzyme-linked immunosorbent assay (ELISA) was developed using polyclonal rabbit antibody produced a g a~n s t aff~nity-punfied A frenatus Ig Anti-Amyloodlnium serum antibody was not always detectable in immune fish although serum antibody titers in immune fish increased after repeated exposure to the parasite These results suggest that there may be a localized antibody response in skin/gill epithelia1 tissue although antibody was rarely detected in skin mucus

Effectiveness of different vaccine formulations against vibriosis caused by Vibrio vulnificus serovar E (biotype 2) in European eels Anguilla anguilla

“…This influence was also observed in mucus, but in contrast to that found in serum, the route that elicited a specific, but low (titers of 1:4 to 1:16), humoral response was prolonged immersion. Similar results have been found in other fishes that showed negative results in cutaneous mucus after injection vaccination (Cobb et al 1998). The dilution of mucus, due to the sampling procedure, could partially explain the low antibody levels, but it is also possible that the secretory immunoglobulins were not well recognized by our ELISA.…”

Field testing of a vaccine against eel diseases caused by Vibrio vulnificus

“…This effect persisted in glass eels, reaching the highest level 6 mo after vaccination. Similar titres have been obtained by other authors, who rarely detected specific antibodies in skin mucus from immunised fish (Cobb et al 1998). The immune response in serum from glass eel could not be evaluated because their small size made sampling difficult.…”

Parâmetros hematológicos e alterações histopatológicas em bijupirá (Rachycentron canadum Linnaeus, 1766) com amyloodiniose

“…Observou-se grande intensidade parasitária média, embora com ampla variação individual (Quadro 4). Preparações a fresco de brânquias, examinados ao estereomicroscópio, permitiu observar hipersecreção de muco, congestão branquial e estruturas que caracterizam as formas parasitárias de Amyloodinium; presença de trofontes, nas lamelas (Fig.1A,B) e muco branquiais (Fig.1C) e no muco cutâneo com formato arredondado ou oval, desprovidas de ϐlagelo, formas descritas por Brown (1934) e que constituem o ciclo de vida trifásico do parasito (Cobb 1998), correspondendo as fases parasitária (trofontes) e de divisão ou multiplicação (quistos). A fase infectante (dinosporos) não foi evidenciada nesse estudo.…”