title: Prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta.
abstract: The prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta from the province of Le6n (NW Spain) was studied by enzyme-linked immunosorbent assay (ELISA). Blood samples from healthy and Saprolegnia-infected brown trout were collected over 2 yr with a seasonal periodicity (January, April, July and October) from a hatchery and river with frequent presence of saprolegniosis (River Porma) and from a river in which the disease was rarely observed (River Omaña). The individual prevalence was 30.1%, but statistically significant differences were observed between the prevalence in trout from the hatchery (43.0%), from River Porma (31.8%) and from River Omaña (6.4%) and also between the prevalence observed in October (42.9%) and the values obtained in January (24.8%), April (22.7%) and July (27.5%). There was no difference between the seroprevalence in females (34.8%) and males (38.2%), but a positive correlation between raised serum antibody levels and larger (older) fish was found. The low prevalence of antibodies observed in Saprolegnia-infected trout (18.0%) suggests possible immune suppression and the lack of an effective specific immune response in fish with saprolegniosis.
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24071 León, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Fregeneda-Grandes
authors.forename: M T
authors.initials: MT
authors.lastname: Carbajal-González
authors.forename: J M
authors.initials: JM
authors.lastname: Aller-Gancedo
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D017756:Aquaculture; D005393:Fish Diseases / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology*; D007239:Infections / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology*; D045483:Rivers; D044762:Saprolegnia / Q000276:immunology*; D012621:Seasons; D013030:Spain / Q000453:epidemiology; D014337:Trout
chemical_list: D000907:Antibodies, Bacterial