Investigation of Potential Reservoirs of Non-Tuberculous Mycobacteria in a European Sea Bass (Dicentrarchus labrax) Farm

Fish mycobacteriosis is a widespread global problem caused by species of non-tuberculous mycobacteria (NTM). Mycobacterium marinum is one of the species most often involved in disease episodes of aquarium and farmed fish. Since there is currently no available effective therapy or vaccine, a prompt search for routes of entry is key to limiting the damage induced by the disease. Here we report a case of mycobacteriosis follow up in a European sea bass (Dicentrarchus labrax) farm located in Northern Italy, in which environmental samples and newly added fish batches were analyzed. Samples from fish present on the farm, sediment, and periphyton all resulted positive for M. marinum, whereas the new fish batches and the water samples resulted negative. The environmental resistance of NTM (alcohol-acid resistance, biofilm formation) and the lack of prophylactic and therapeutic strategies make these diseases difficult to manage. Prompt identification of biotic and abiotic reservoirs, combined with good zootechnical hygiene practices, are the most effective measures to control fish mycobacteriosis in intensive farms.

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Host-Parasite Interaction between Parasitic Cymothoid Ceratothoa oestroides and Its Host, Farmed European Sea Bass (Dicentrarchus labrax)

Pathogens ◽

10.3390/pathogens9030230 ◽

2020 ◽

Vol 9 (3) ◽

pp. 230

Author(s):

Ivona Mladineo ◽

Jerko Hrabar ◽

Olja Vidjak ◽

Ivana Bočina ◽

Slavica Čolak ◽

...

Keyword(s):

Dicentrarchus Labrax ◽

Aegean Sea ◽

Sea Bass ◽

Condition Index ◽

Bacterial Biofilm ◽

Body Parts ◽

Farmed Fish ◽

European Sea Bass ◽

Host Parasite ◽

Host Tissues

Parasitic isopod Ceratothoa oestroides (Cymothoidea, Isopoda) is a common and generalist buccal cavity-dweller in marine fish, recognised for its detrimental effect in fingerling and juvenile farmed European sea bass (Dicentrarchus labrax). Although distributed throughout the Mediterranean, the isopod provokes acute outbreaks mainly limited to particular endemic areas in Croatia (Adriatic Sea) and Greece (Aegean Sea). While numerous studies have previously evidenced its gross effect on farmed fish (i.e. decreased condition index, slower growth rate, lethargy and mortality), details on the host-parasite interaction are still lacking. Therefore, using a multimethodological approach, we closely examined the structure and appearance of isopod body parts acting in the attachment and feeding (stereomicroscopy, scanning and transmission electron microscopy), and the extent of host tissues damage (histology, immunohistochemistry, micro-computational tomography) induced by parasitation. Interestingly, while hematophagous nature of the parasite has been previously postulated we found no unambiguous data to support this; we observed host tissues fragmentation and extensive hyperplasia at the parasitation site, and no structures indicative of heme detoxifying mechanisms in the parasite gut, or other traces of a blood meal. The bacterial biofilm covering C. oestroides mouthparts and pereopods suggests that the isopod may play a role in conveying secondary pathogens to the infected host, or alternatively, it serves the parasite in normal interaction with its environment.

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Mechanisms of oocyte development in European sea bass (Dicentrarchus labrax L.): investigations via application of unilateral ovariectomy

Reproduction ◽

10.1530/rep-11-0040 ◽

2011 ◽

Vol 142 (2) ◽

pp. 243-253 ◽

Cited By ~ 9

Author(s):

Ángel García-López ◽

María I Sánchez-Amaya ◽

Charles R Tyler ◽

Francisco Prat

Keyword(s):

Transforming Growth Factor Beta ◽

Molecular Mechanisms ◽

Transforming Growth Factor ◽

Secondary Growth ◽

Dicentrarchus Labrax ◽

Sea Bass ◽

Oocyte Development ◽

Control Fish ◽

European Sea Bass ◽

Unilateral Ovariectomy

Unilateral ovariectomy (ULO) was performed in European sea bass (Dicentrarchus labrax L.) during late pre-vitellogenesis/early vitellogenesis. Plasma steroid levels and the expression of a suite of potential oogenesis-relevant genes in the ovary, brain, and pituitary were evaluated with the aim of understanding their involvement in the compensatory oocyte development occurring within the remaining ovarian lobe. After 69 days of surgery the remaining ovarian lobe in ULO fish was gravimetrically equivalent to an intact-paired ovary of sham operated, control fish. This compensatory ovarian growth was based on an increased number of early perinucleolar oocytes and mid-late stage vitellogenic follicles without an apparent recruitment of primary oocytes into the secondary growth phase. Plasma steroid levels were similar in ULO and control females at all time points analyzed, suggesting an increased steroid production of the remaining ovarian lobe in hemi-castrated females. Results of the gene expression survey conducted indicate that the signaling pathways mediated by Fsh and Gnrh1 constitute the central axes orchestrating the observed ovarian compensatory growth. In addition, steroid receptors, Star protein, Igfs, and members of the transforming growth factor beta superfamily including anti-Mullerian hormone and bone morphogenetic protein 4 were identified as potentially relevant players within this process, although their specific actions and interactions remain to be established. Our results demonstrate that ULO provides an excellent in vivo model for elucidating the interconnected endocrine and molecular mechanisms controlling oocyte development in European sea bass.

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Antimicrobial Peptides: Identification of Two Beta-Defensins in a Teleost Fish, the European Sea Bass (Dicentrarchus labrax)

Pharmaceuticals ◽

10.3390/ph14060566 ◽

2021 ◽

Vol 14 (6) ◽

pp. 566

Author(s):

Carolina Barroso ◽

Pedro Carvalho ◽

José F. M. Gonçalves ◽

Pedro N. S. Rodrigues ◽

João V. Neves

Keyword(s):

Antimicrobial Peptides ◽

Teleost Fish ◽

Tertiary Structure ◽

Dicentrarchus Labrax ◽

Alpha Helix ◽

Sea Bass ◽

Mediterranean Area ◽

Farmed Fish ◽

European Sea Bass ◽

Beta Defensins

Beta-defensins consist in a group of cysteine-rich antimicrobial peptides (AMPs), widely found throughout vertebrate species, including teleost fish, with antimicrobial and immunomodulatory activities. However, although the European sea bass (Dicentrarchus labrax) is one of the most commercially important farmed fish species in the Mediterranean area, the characterization of its beta-defensins and its potential applications are still missing. In this study, we characterized two members of the beta-defensin family in this species. Phylogenetic and synteny analysis places sea bass peptides in the beta-defensin subfamilies 1 and 2, sharing similar features with the other members, including the six cysteines and the tertiary structure, that consists in three antiparallel beta-sheets, with beta-defensin 1 presenting an extra alpha-helix at the N-terminal. Further studies are necessary to uncover the functions of sea bass beta-defensins, particularly their antimicrobial and immunomodulatory properties, in order to develop novel prophylactic or therapeutic compounds to be used in aquaculture production.

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By-products of farmed European sea bass (Dicentrarchus labrax L.) as a potential source of n-3 PUFA

Biologia ◽

10.2478/s11756-013-0148-8 ◽

2013 ◽

Vol 68 (2) ◽

Cited By ~ 7

Author(s):

Concetta Messina ◽

Giuseppe Renda ◽

Laura Barbera ◽

Andrea Santulli

Keyword(s):

Total Lipid ◽

Lipid Content ◽

Dicentrarchus Labrax ◽

Total Lipid Content ◽

Sea Bass ◽

Farmed Fish ◽

European Sea Bass ◽

Potential Source ◽

Percentage Yield ◽

By Products

AbstractTotal by-products (TBP) obtained by filleting farmed and wild European sea bass (Dicentrarchus labrax) were analyzed to evaluate if, on the basis of the percentage yield, total lipid content and fatty acid composition, they can be considered a resource of n-3 polyunsaturated fatty acids (PUFA). Results show that TBP from intensively farmed fish (IFF) contain higher total lipid content and have a higher level of n-3 PUFA rich in eicosapentaenoic (EPA) and docosaexaenoic acid (DHA), compared to extensively farmed fish (EFF) and to wild fish (WF) (P < 0.05). This difference may suggest a way of promotion of TBP from IFF sea bass through the n-3 PUFA recovery by extraction.

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Absence of Anisakid Larvae in Farmed European Sea Bass (Dicentrarchus labrax L.) and Gilthead Sea Bream (Sparus aurata L.) in Southeast Spain

Journal of Food Protection ◽

10.4315/0362-028x-73.7.1332 ◽

2010 ◽

Vol 73 (7) ◽

pp. 1332-1334 ◽

Cited By ~ 16

Author(s):

J. PEÑALVER ◽

E. MARÍA DOLORES ◽

P. MUÑOZ

Keyword(s):

Sparus Aurata ◽

Dicentrarchus Labrax ◽

Sea Bass ◽

Diagnostic Methods ◽

Gilthead Sea Bream ◽

Sea Bream ◽

Minimal Risk ◽

Farmed Fish ◽

European Sea Bass ◽

Anisakid Larvae

In the present study, a total of 871 farmed fish, 612 gilthead sea bream (Sparus aurata L.) and 259 European sea bass (Dicentrarchux labrax L.), were examined for the presence of anisakid larvae. Two diagnostic methods were applied, visual inspection and artificial digestion based on the degradation of fish soft tissue in an acidified pepsin enzyme solution. None of the samples examined in this study contained any anisakid parasite. The results suggest that consumption of these farmed fish species carries a minimal risk of exposure to these nematodes in this region.

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Shewanella putrefaciens – a new opportunistic pathogen of freshwater fish

Journal of Veterinary Research ◽

10.1515/jvetres-2016-0064 ◽

2016 ◽

Vol 60 (4) ◽

pp. 429-434 ◽

Cited By ~ 20

Author(s):

Ewa Paździor

Keyword(s):

Freshwater Fish ◽

Halophilic Bacteria ◽

Dicentrarchus Labrax ◽

Sea Bass ◽

Opportunistic Pathogen ◽

Shewanella Putrefaciens ◽

Farmed Fish ◽

Antimicrobial Drugs ◽

European Sea Bass ◽

Adhesion Ability

Abstract In recent years, Shewanella putrefaciens, commonly known as a halophilic bacteria, has been associated with serious health disorders in freshwater fish. Therefore, it has been described as a new aetiological agent of the disease, named shewanellosis. S. putrefaciens is a heterogeneous group of microorganisms, belonging to the Alteromonadaceae family. Based on different criteria, three biovars and biogroups as well as four genomic groups have been distinguished. The first infections of S. putrefaciens in fish were reported in rabbitfish (Siganus rivulatus) and European sea bass (Dicentrarchus labrax L.). Outbreaks in farmed fish were reported in Poland for the first time in 2004. The disease causes skin disorders and haemorrhages in internal organs. It should be noted that S. putrefaciens could also be associated with different infections in humans, such as skin and tissue infections, bacteraemia, otitis. Investigations on pathogenic mechanisms of S. putrefaciens infections are very limited. Enzymatic activity, cytotoxin secretion, adhesion ability, lipopolysaccharide (LPS), and the presence of siderophores are potential virulence factors of S. putrefaciens. Antimicrobial resistance of S. putrefaciens is different and depends on the isolates. In general, these bacteria are sensitive to antimicrobial drugs commonly used in aquaculture.

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