Nocardiosis in sea bass, Lateolabrax japonicus, in Taiwan

Abstract

An epizootic in pond cultured sea bass, Lateolabrax japonicus, was caused by Nocardia sp. in Taiwan, in September and October 1997. The cumulative mortality within 1 month was 17.5% (3500 out of 20 000 fish) and diseased fish were 7 months old with total lengths from 25 to 30 cm. Multiple, yellowish white nodules, 0.1–0.2 cm in diameter, were scattered in the gill, heart, liver, spleen and kidney. Histopathologically, typical granulomatous lesions appeared in those organs. The morphology of isolated bacteria from brain heart infusion (BHI) medium or Lowenstein–Jensen medium (LJM) were bead‐like filaments, as shown by Ziehl‐Neelsen's (ZN) staining method. The gross lesion and histopathological changes found in experimentally infected fish were similar to those in naturally infected fish. Based on the growth characteristics, morphological and biochemical properties of the bacterium, and histopathological changes, the isolated bacteria were identified as Nocardiaseriolae. This is the first report of N. seriolae‐infected sea bass in aquaculture.

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

“…All properties are consistent with the classification of the isolates in the genus Nocardia (Chen et al, 2000;Wang et al, 2005). 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.…”

“…Most experimental fish exhibited various skin ulcers and granulomas in their internal organs. The multiple focal granulomas caused by nocardiosis have been described as predominant lesions in several fish (Campbell and Mackelvie, 1968;Ribelin and Migaki, 1975;Chen, 1992;Chen et al, 2000). In this investigation, affected fish that had anorexia, were emaciated and had distended abdomens with granulomas that were commonly diffused throughout the visceral organs.…”

“…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.…”

In vitro activity of some essential oils alone and in combination against the fish pathogen Nocardia seriolae

“…The genus Nocardia comprises several species that are known to be unusual causes of a wide spectrum of clinical diseases in both humans and animals (Brown and McNeil 2003).Three species of Nocardia have yellowtail, tiger fish, large yellow croaker, snakehead spotted butterfish and snubnose pompano in South East Asia (Chen et al 2000, Miyoshi and Suzuki 2003, Huang et al 2004, Wang et al 2005, Wang et al 2007, Labrie et al 2008, Wang et al 2009, Wang et al 2014, Vu-Khac et al 2016 ). In addition, N. seriolae has been reported to cause chronic mortalities in cultured weakfish in the USA (Cornwell et al 2011) and in cultured meagre in Greece (Elkesh et al 2013).…”

Comparison of Sensitivity between Yellowtail Seriola quinqueradiata and Red Sea Bream Pagrus major to Nocardia seriolae

“…Nocardiosis is characterized by formation of abscesses in the epidermis and tubercles in the gills, kidney and spleen (Kariya et al, 1968). This infection has been reported in seven different marine fish species, namely, yellowtail Seriola quinqueradiata, Japanese flounder Paralichthys olivaceus, goldstriped amberjack Seriola dumerlii, sea bass Lateolabrax japonicus, striped jack Pseudocaranx dentex, filefish Stephanolepis cirrhifer and Black Scraper Novodon modestus (Wakabayashi and Muroga, 2004;Chen et al, 2000). On the other hand, outbreak of nocardiosis has not been reported in other major cultured fish in Japan, i.e., red sea bream Pagrus major.…”