title: Nocardiosis in large yellow croaker, Larimichthys crocea (Richardson).
abstract: An epizootic in seawater-cage reared large yellow croaker, Larimichthys crocea, in China was caused by a Nocardia sp. from August to October 2003. The cumulative mortality rate was 15% and the diseased fish were 16 months old with individual length varying from 25 to 30 cm. Multiple, white nodules, 0.1-0.2 cm in diameter, were scattered on the heart, spleen and kidney. The morphology of isolated bacteria from Lowenstein-Jensen medium and tryptic soy agar was bead-like or long, slender, filamentous rods. Experimental infection indicated that the isolated bacterium was the pathogen responsible for the mortalities. A partial sequence of the 16S rRNA gene of the organism and the type strain of Nocardia seriolae JCM 3360T (Z36925) formed a monophyletic clade with a high sequence similarity of 99.9%. Based on the morphological, physiological, biological properties and the phylogenetic analysis, the pathogenic organism was identified as N. seriolae. This is the first report on N. seriolae-infected large yellow croaker in aquaculture.
authors.affiliation: Faculty of Life-Science and Bio-Technology, Ningbo University, Ningbo, China. wanggl@nbip.net.cn
authors.forename: G-L
authors.initials: GL
authors.lastname: Wang
authors.forename: S-P
authors.initials: SP
authors.lastname: Yuan
authors.forename: S
authors.initials: S
authors.lastname: Jin
mesh_terms: D000818:Animals; D017756:Aquaculture; D001483:Base Sequence; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D017931:DNA Primers; D004196:Disease Outbreaks / Q000662:veterinary*; D005393:Fish Diseases / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D007668:Kidney / Q000648:ultrastructure; D008854:Microscopy, Electron / Q000662:veterinary; D008969:Molecular Sequence Data; D009206:Myocardium / Q000473:pathology; D009615:Nocardia / Q000235:genetics / Q000648:ultrastructure*; D009617:Nocardia Infections / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D010473:Perciformes; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013154:Spleen / Q000473:pathology
chemical_list: D017931:DNA Primers; D012336:RNA, Ribosomal, 16S