Nocardia seriolae infection in the three striped tigerfish, Terapon jarbua (Forsskål)

Abstract

An epizootic in pond cultured three striped tigerfish, Terapon jarbua, in Taiwan was caused by Nocardia seriolae. Diseased fish first showed clinical signs and mortalities in February and March 2003. The cumulative mortality within 2 months was 2.4% (1200 of 50 000) and affected fish were 7 months old with total lengths from 18 to 25 cm. Most affected fish were pale and lethargic with haemorrhages and ulcers on the skin. The most significant gross pathological changes were varying degrees of ascites and enlargement of the spleen, kidney and liver. Obvious white nodules, varying in size, were found in these organs. Bacteria were either coccal or filamentous in appearance, with bead-like forms. Isolates from diseased fish were characterized using the API ZYM (Analytical profile index; Bio Mérieux, France) systems and conventional tests and identified as Nocardia sp. The isolate was designated NS127 and was confirmed as N. seriolae by a polymerase chain reaction assay that gave the expected specific 432 bp amplicon. In addition, its 16S rDNA sequence gave 100% sequence identity with N. seriolae. A partial sequence of the 16S rRNA gene, heat shock protein gene and RNA polymerase gene (rpo B) of NS127 and the type strain of N. seriolae BCRC 13745 formed a monophyletic clade with a high sequence similarity and bootstrap value of 99.9%. White nodules induced in experimental fish were similar to naturally infected cases and N. seriolae was re-isolated on brain heart infusion agar. This is the first report of N. seriolae-infection in three striped tigerfish in aquaculture.

Nocardia seriolae, a causative agent of systematic granuloma in spotted butterfish, Scatophagus argus, Linn

“…N. seriolae which is an emerging pathogen in Taiwan, has been isolated from various fish species, including red snapper Lutjanus erythropterus, grey mullet Mugil cephalus, and three striped tigerfish Terapon jarbua in freshwater (Wang et al, 2009) and brackish water culture. Spotted butterfish when infected with N. seriolae exhibit gross lesions and histopathological changes that are similar to those observed in three striped tigerfish (Wang et al, 2009). Notably, N. seriolae dominates the nocardia infection of cultured fish in Taiwan.…”

“…Elkesh et al (2013) reported systemic nocardiosis in cultured meagre, Argyrosomus regius Asso with a low to variable morbidity and 1-4% total mortality. Recently, Japanese sea-perch, Lateolabrax japonicum, striped mullet, Mugil cephalus, large yellow croaker, Larimichthys crocea (Richardson), three striped tigerfish, Terapon jarbua, weakfish, Cynoscion regalis (Bloch and Schneider) and yellowtail have all been infected with N. seriolae (Chen et al, 2000;Wang et al, 2005;Shimahara et al, 2006;Shimahara et al, 2008;Wang et al, 2009;Cornwell et al, 2011). Although isolation and bacteriological analysis are complex and time-consuming, N. seriolae has been identified as one of the major nocardial pathogens in fish.…”

Application of α-glucosidase activity and drug susceptibility tests to epidemiological studies on the fish pathogen Nocardia seriolae

“…The disease has become a major cause of mortality in farmed yellowtail Seriola quinqueradiata and amberjack S. dumerili [4], which are the most intensively cultured fish species in Japan. N. seriolae has also been identified as a fish pathogen in other cultured fish, including Japanese flounder Paralichthys olivaceus [5], sea bass Lateolabrax japonicus [6], striped mullet Mugil cephalus [7], large yellow croaker Larimichthys crocea [8], snakehead Ophiocephalus argus [9], and three-striped tigerfish Terapon jarbua [10].…”

Immune response of largemouth bass, Micropterus salmoides, to whole cells of different Nocardia seriolae strains

“…N. seriolae has been reported in cultured fish, such as yellowtail (Seriola quinqueradiata Temminck and Schlegel), amberjack (Seriola dumerili Risso) [1] and Japanese flounder (Paralichthys olivaceus Temminck and Schlegel) [4] in Japan, sea bass (Lateolabrax japonicus Cuvier) [2], striped mullet (Mugil cephalus Linnaeus) [5] and three-striped tigerfish (Terapon jarbua Forsskål) [6] in Taiwan, and large yellow croaker (Larimichthys crocea Richardson) [3] and snakehead (Ophiocephalus argus Cantor) [7] in China.…”