The pathogenic bacteria Photobacterium damselae subsp. piscicida affects the development of Solea senegalensis culture. Vaccines made with inactivated cells have produced a relative protection ...against the sickness, however the administration of subcellular and purified antigens as vaccine could increase the effectiveness of the immune response.
Thus, the aim of this work was the determination of antigens of P. damselae subsp. piscicida involved in the specific immune response of S. senegalensis.
Fish were immunized by intraperitoneal injection (i.p.) with inactivated extracellular polymeric substances (ECP) and whole cells of P. damselae subsp. piscicida, and Freund's incomplete adjuvant. Two months later fish were boosted with the same antigens. Serum from fish was collected to determine by ELISA the title of antibodies against subcellular fractions of bacteria (ECP, capsule, outer membrane proteins, O antigen and formalized whole cells). Significant differences were found between control and immunized fish, but differences between first immunization and booster were only found for O antigen and capsule.
Western blots derived from 2D-PAGE of ECP and Outer Membrane Proteins (OMP), using sole immunized serum, detected two high reactive antigens from ECP. Proteins were identified, by mass spectrometry, as ATP-dependent metalloprotease and Telurite resistance proteins. In the case of OMP, three antigenic proteins were detected and identified as Nrfa Y218f, Anti-oxidant AhpC/TSA, and a protein domain DNA binding heat shock related.
•Sole specimens were immunized with inactivated cells of P. damselae subsp. piscicida and ECP to obtain antiserum.•Specific immune response was detected by ELISA using P. damselae subsp. piscicida antigens.•2D Western blots of ECP and OMP, using sole immunized serum, identified five immunogenic proteins.•Two reactive antigens were identified from ECP: ATP-dependent metalloprotease and Telurite resistance proteins.•In OMP were detected three proteins: Nrfa Y218f, Anti-oxidant AhpC/TSA, and a protein domain DNA binding heat shock related.
The effects of dietary administration of two probiotics,
Shewanella
putrefaciens Pdp11 and
Shewanella
baltica Pdp13, on growth, respiratory burst activity of phagocytes of Senegalese sole (
Solea
...senegalensis), and survival of fish challenged with
Photobacterium
damselae subsp.
piscicida have been studied. Fish were fed for 60 days with three different diets: one control, and two diets supplemented with 10
9 cfu g
−
1
of probiotics Pdp11 (Pdp11 diet) and Pdp13 (Pdp13 diet). Respiratory burst activity of phagocytes from fish fed with diet Pdp11 significantly increased after 60 days of feeding, whilst this significant increase was not detected in phagocytes from fish fed control and Pdp13 diets. On the other hand, the cumulative percentage of mortality after the challenges with
P.
damselae subsp.
piscicida, was 100% in the groups fed with control diet, whereas mortality rates observed in the groups fed with diets supplemented with Pdp11 and Pdp13 ranged from 75–100% and 65–80%, respectively. These results suggest that an increased respiratory burst activity of the phagocytes is not essential to increase the protection against the
P.
damselae subsp.
piscicida. On the other hand, the use of both probiotics improved the growth, and the survival against the pathogen, in comparison with those fish receiving the control diet.
This study evaluated the control of streptococcosis outbreaks in Brazil, isolated from diseased sorubim and identified as Lactococcus garvieae by genetic sequencing. This report determined the ...potential for lactococcosis control in sorubim Pseudoplatystoma sp. with two vaccines: an aqueous‐based, whole‐cell inactivated vaccine (bacterin) and an oil‐adjuvanted bacterin. Their efficacy was evaluated at 30 days post‐vaccination (d.p.v.) by challenge with L. garvieae, and the antibody production response at 15, 30 and 60 d.p.v. and the non‐specific immune response were compared amongst treatments. High protection levels (P < 0.05) were achieved with the oil‐adjuvanted vaccine with a relative percentage survival value of 81.7% at 30 d.p.v. Additionally, the oil‐adjuvanted vaccine increased the immunogenicity of the bacterin as indicated by greater agglutination antibody titres from 15 until 60 d.p.v. This is the first report of a positive effect of vaccine administration on the specific immunity of sorubim, and the study showed that a specific antibody plays an important role in sorubim defence against lactococcosis because the innate immune responses were similar in all of the studied animals. These results demonstrated that oil‐adjuvanted vaccine can be an effective alternative for the protection of sorubim from L. garvieae disease.
Senegalese sole cultures are frequently affected by Vibrio harveyi disease outbreaks. Vaccines in aquaculture are one of the most successful methods of preventing fish pathologies; however, these ...vaccines are usually composed of inactivated whole cells containing a wide pool of antigens, and some do not induce any protection against pathogens. Thus, the aim of this study was to identify immunogenic proteins of V. harveyi involved in the specific antibody production by Senegalese sole.
S. senegalensis specimens were immunized, by intraperitoneal injection, with V. harveyi bacterin supplemented with inactivated extracellular polymeric substances (ECP) and Freund incomplete adjuvant to obtain polyclonal antiserum. One month later, specimens were re-inoculated with the same antigens. Sera from immunized fish were collected two months post first immunization.
Strong specific immune response to V. harveyi antigens was detected by ELISA using bacterin (limit dilutions of sera were 1:64000), ECP (1:4000) and outer membrane proteins (OMP) (1:4000) as antigens.
Presence of immunogenic proteins in V. harveyi ECP and OMP were determined by 2D-PAGE. For Western Blot analysis some gels were transferred onto nitrocellulose membranes and incubated with sera from S. senegalensis specimens immunized against V. harveyi. 2D-PAGE and Western Blot showed at least five reactive proteins in the ECP and two in the OMP fraction. The spots that clearly reacted with the sole antiserum were excised from stained gel, and analyzed by mass spectrometry (MALDI/TOFTOF). A database search was then performed, using MASCOT as the search method. According to the results, the five ECP spots were identified as Maltoporine, protein homologous to Metal dependent phosphohydrolase, two porins isoforms of V. harveyi and a protein homologous to the cell division protein FtsH. Reactive proteins in the OMP fraction were identified as the protein 3-hydroxyisobutyrate dehydrogenase and a protein homologous to acid phosphatase.
•Sole specimens were immunized with V. harveyi bacterin and ECP to obtain antiserum.•Specific immune response was detected by ELISA using V. harveyi antigens.•2D-PAGE and Western Blot showed five reactive proteins in ECP and two in OMP.•ECP proteins were identified as maltoporine, phosphohydrolase, two porins and FtsH.•OMP spots were identified as hydroxyisobutyrate dehydrogenase and acid phosphatase.
The effects of dietary administration of probiotic Pdp11, a bacterial probiotic strain from the Alteromonadaceae family, on growth and stress tolerance to high stocking density was analyzed in ...juvenile gilthead sea bream
Sparus auratus. In the first trial, juvenile specimens were fed during 116
days with control feed or diets supplemented with Pdp11, and growth, serum immunological parameters as well as plasmatic, hepatic and muscular metabolic parameters were assessed. Growth performance improved in group receiving probiotic compared to control group. No differences were observed for the assessed immunological or metabolic parameters. In the second trial, specimens from both groups from the first experiment were submitted to the following conditions for 15
days: i) group fed with control food and either under low density (3
kg/m
3), or high density (30
kg/m
3) and ii) group fed with probiotic supplemented feed and either under low density, or high density. Our results indicated that administration of probiotic Pdp11 in the diet promoted growth and improved stress tolerance under high stocking density, suggesting its use will be beneficial for the aquaculture industry of this species.
The application of probiotics on aquatic animals is increasing for a better fish welfare status as well as an environment-friendly activity which are actual demands of modern aquaculture industry. A ...bacterium from skin mucus of healthy gilthead seabream (
Sparus aurata
L.) has been isolated and identified as
Shewanella putrefaciens
Pdp11. Different studies have been done to know its application as probiotic in the Senegalese sole and gilthead seabream farming. This article reviews the studies carried out with this probiotic microorganism focusing on the current knowledge of its in vitro and in vivo mechanisms of action. The results suggested that the probiotic
S. putrefaciens
Pdp11, due to its beneficial effects, could be used in the aquaculture activity of both species.
The effects of the dietary administration of two bacterial probiotic strains (Ppd11 and Pdp13) from the Alteromonadaceae family for 60 days, were assessed by measuring growth and feed efficiency, ...activities of leucine aminopeptidase and alkaline phosphatase and structural changes in the intestine of juvenile Senegalese sole. In addition, the profile of intestinal microbiota was studied by Denaturing Gradient Gel Electrophoresis. Growth and nutrient utilization were significantly higher in fish receiving probiotics than in those fed the control diet. No differences were observed in proximal composition between treatments, though higher lipid muscle content was measured in fish receiving Pdp13. Those fish also exhibited higher activities of AP when compared to Ppd11 and control groups. The profile of intestinal microbiota clearly separated those fish receiving probiotics from those of the control group. Microscopical examination revealed accumulation of lipid droplets in the enterocytes of fish receiving the control diet, but not in those fed on probiotics. Interactions between those structural changes and growth performance are discussed.
Bacterial subcellular components and probiotics were successful for the stimulation of immunity and the prevention of Vibrio harveyi infections in rainbow trout, Oncorhynchus mykiss (Walbaum). ...Rainbow trout were immunized with whole inactivated cells of V. harveyi to obtain polyclonal antibodies against specific antigens. Western blotting showed a unique reactive band (~93 kDa) between serum and bacterial proteins from outer membrane proteins (OMP) and extracellular products (ECP). Probiotics were selected according to their capability to inhibit V. harveyi. Two of these bacteria, i.e. A3-47 and A3-51, showed cross-reactivity with V. harveyi antiserum. Their OMPs and ECPs were reactive with V. harveyi antiserum in bands of ~93 kDa for A3-51 and higher for A3-47. In vivo tests determined that fish fed with A3-51 produced cross-reactive antibodies against V. harveyi and also, the survival of these fish infected with V. harveyi was high, being similar to the level achieved with vaccinated fish. Thus, the probiotics, when administered as live preparations, were capable of producing cross-reactive antibody against specific bacterial pathogens.
Four bacterial isolates from farmed gilthead sea bream, Sparus aurata, included in a previous study as members of the Vibrionaceae and Pseudomonodaceae and the genus Micrococcus, have been evaluated ...for their adhesive ability to skin and intestinal mucus of farmed Senegalese sole, Solea senegalensis, and their antagonistic effect on Vibrio harveyi, a pathogen of sole. These isolates showed higher adhesion to sole mucus than the pathogenic strains of V. harveyi assayed. Only two of the isolates showed antagonistic activity to V. harveyi. Interactions of the four isolates with V. harveyi in respect of adhesion to skin and intestinal mucus under exclusion, competition and displacement conditions were studied. Three isolates were able to reduce the attachment to skin and intestinal sole mucus of a pathogenic strain of V. harveyi under displacement and exclusion conditions, but not under competition conditions. The in vivo probiotic potential of isolate Pdp11 was assessed by oral administration followed by challenge with the pathogenic V. harveyi strain Lg14/00. A group of 50 Senegalese sole received a commercial diet supplemented with 108 cfu g−1 of lyophilized Lg14/00 for 15 days. A second group of fish received a non‐supplemented commercial diet. After challenge the mortality of the fish receiving the diet supplemented with the potential probiotic isolate was significantly lower than that in the fish receiving the non‐supplemented commercial diet. This study has shown that the ability to interfere with attachment of pathogens, as well as the adhesion to host surfaces, are suitable criteria for selection of candidate probiotics for use in the culture of Senegalese sole.
A bacteriological study of 25 outbreaks affecting cultured gilthead sea bream (
Sparus aurata L.) in southwestern Spain from 1997 to 2000 has been carried out. Each year, the highest number of ...outbreaks occurred during winter and affected fish with sizes ranging between 2 and 25 g. The most frequently isolated microorganisms were identified as
Vibrio (69.90%). Other microorganisms belonging to
Pseudomonas spp.,
Photobacterium damselae ssp.
piscicida,
Cytophaga/
Flexibacter-like and
Aeromonas spp. were isolated with a frequency lower than 10%. The outbreaks with the highest mortalities of cultured gilthead sea bream were due to
P. damselae ssp.
piscicida. An increase in the number of resistances to different antimicrobials has been observed in this study with respect to previous studies carried out in the same area. This increase was very high in the case of some species of
Vibrio,
Pseudomonas spp. and
P. damselae ssp.
piscicida.
