A. Domenech et al., WINTER DISEASE OUTBREAK IN SEA-BREAM (SPARUS-AURATA) ASSOCIATED WITH PSEUDOMONAS-ANGUILLISEPTICA INFECTION, Aquaculture, 156(3-4), 1997, pp. 317-326
The nature of an outbreak of 'winter disease' affecting both juvenile
and adult sea-bream (Sparus aurata) in several Iberian Peninsula farms
from January to April of 1996 is described. The average mortality rat
e was approximately 10-15%, although in some fish farms mortality reac
hed 30%. Pure cultures of aerobic Gram-negative filamentous rods were
isolated from the kidney of diseased fish, as well as from some of the
liver and ascitic fluid samples. 16S rRNA gene sequence analysis iden
tified the isolates from diseased fish as Pseudomonas anguilliseptica.
The results of biochemical and physiological tests of clinical isolat
es and the type strain of P. anguilliseptica were entirely consistent
with the genotypic identification. The isolation of P. anguilliseptica
exclusively from the diseased fish of all affected fish farms, togeth
er with the failure to isolate this bacterium from non-affected fish o
f the same farms. suggest that P. anguilliseptica is likely to be the
agent responsible for the 'winter disease' outbreak in the sea-bream e
xamined. The relationship of the 'winter disease' outbreaks to stressf
ul environmental conditions is discussed. (C) 1997 Elsevier Science B.
V.