Isolation of Staphylococcus epidermidis, Bacillus cereus and Pseudomonas stutzeri from diseased European sea bass (Dicentrarchus labrax) for the first time in Egypt

Abstract

During this study, 20 % mortality was recorded in Dicentrarchus labrax brood stock in marine hatchery of National Institute of Oceanography and Fishery at Alexandria province. Observed clinical signs were decrease appetite, off-food, skin ulcerations and tail erosions. The main post mortem lesion was enlarged liver with presence of hemorrhagic foci. Seven bacterial isolates were recovered by initial isolation on typtic soy agar media from topical lesions (skin, musculature and tail) and from internal organs (heart, liver, spleen and posterior kidney). No growth was detected on specific media including Rimler-Shotts, Pseudomonas selective agar, Thiosulfate Citrate Bile Salts Sucrose agar and Edwards media that indicate absence of major fish pathogens. Identification of the causative agents was performed using VITEK 2 automated biochemical identification system. Four Staphylococcus epidermidis, two Bacillus cereus and one Pseudomonas stutzeri isolates were identified as the causative agents responsible for mortalities in diseased Dicentrarchus labrax. Stress factors induced by hatchery conditions could be the predisposing caused of such infection.

Newly Emerging MDR B. cereus in Mugil seheli as the First Report Commonly Harbor nhe, hbl, cytK, and pc-plc Virulence Genes and bla1, bla2, tetA, and ermA Resistance Genes

“…Similar results have been reported in infected stinging catfish, 28 and seabass with B. cereus. 26 Consistent with the present findings, diffuse necrotizing dermatitis was observed in the naturally infected fish with B. cereus. 49 The recorded ante-and post-mortem lesions are a pre-determined consequence of the fish's immune response to the invading pathogen and may refer to successful colonization and reproduction of the isolated bacteria, in agreement with Aboyadak.…”

“…49 The recorded ante-and post-mortem lesions are a pre-determined consequence of the fish's immune response to the invading pathogen and may refer to successful colonization and reproduction of the isolated bacteria, in agreement with Aboyadak. 26 The variety of lesions also indicates the severity of the current infection and is primarily attributable to the virulence traits encoded by bacteria. B. cereus has been found to be related to the Epizootic Ulcerative Syndrome in Datnioides microlepsis.…”

Chemotherapeutic control of Gram-positive infection in white sea bream (Diplodus sargus, Linnaeus 1758) broodstock

“…Aboyadak et al . [7] recorded similar clinical signs and postmortem lesions in sea bass infected with B. cereus and S. epidermidis .…”

“…Bacterial diseases are the most dominant pathogens that are responsible for severe diseases and outbreaks in marine-cultured fish [5,6]. Most of the bacterial disease etiological agents are considered a part of the normal flora that is present in water, stress condition as bad water quality, inadequate diet, overcrowding, and frequent handling during artificial spawning are considered to be predisposing factors of lowering fish immunity and subsequently initiating disease conditions [7,8]. Streptococcus spp., Lactococcus garvieae, Staphylococcus epidermidis , and Micrococcus luteus are among the most common Gram-positive bacterial infection of cultured marine fish [9,10], while vibriosis is the most Gram-negative bacterial infection [11-13].…”

Multifaceted applications of probiotic Bacillus species in aquaculture with special reference to Bacillus subtilis

“…Among various Bacillus species, B. cereus is often associated with various types of infections in fish species (Pychynski et al 1981;Baya et al 1992;Oladosu et al 1994;Chandra et al 2015;Aboyadak et al 2016;Ali et al 2019). Nevertheless, enterotoxigenic B. cereus strains are found to colonize in the intestine of fish (Prasad 2014).…”