Now showing items 1-7 of 7

    • Article

      Bacterial flora in the hepatopancreas of pond-reared Penaeus monodon juveniles with luminous vibriosis 

      EM Leaño, CR Lavilla-Pitogo & MG Paner - Aquaculture, 1998 - Elsevier
      Quantification and characterization of bacterial flora in the hepatopancreas (hp) of pond-reared Penaeus monodon juveniles affected with luminous bacteria were conducted in 1994 and 1995. Shrimp samples were taken from 23 grow-out ponds, 14 of which had disease outbreaks. Luminous bacterial (LB) load of the shrimps' hp with (mean=2.4×101 colony forming units (CFU)/hp) and without (mean=0.3×101 CFU/hp) disease outbreaks were comparable during the first 15 days of culture (DOC). During disease outbreaks at 18 to 32 DOC, however, LB load of affected shrimps (mean=9.0×104 CFU/hp) were higher than healthy shrimps (mean=7.0×101 CFU/hp). At 50 to 60 DOC, levels of LB were comparable in older shrimps with or without disease. Total viable and presumptive Vibrio counts were also comparable in both shrimp samples from 1 to 60 DOC. Characterization of the 172 bacterial isolates collected showed that most (90.12%) were Vibrio species dominated by V. harveyi (27.91%), V. splendidus II (13.37%) and V. parahaemolyticus (10.46%).
    • Article

      Immune responses of Asian sea bass, Lates calcarifer Bloch, against an inactivated betanodavirus vaccine 

      RV Pakingking Jr., R Seron, LD de la Peña, K Mori, H Yamashita & T Nakai - Journal of Fish Diseases, 2009 - Blackwell Publishing
      Asian sea bass, Lates calcarifer (Bloch), exhibited strong immune responses against a single injection of the formalin-inactivated red-spotted grouper nervous necrosis virus (RGNNV), a betanodavirus originally isolated in Japan. Fish produced neutralizing antibodies at high titre levels from days 10 (mean titre 1:480) to 116 (1:1280), with the highest titre at day 60 post-vaccination (1:4480). When fish were challenged with the homologous RGNNV at day 54 post-vaccination, there were no mortalities in both the vaccinated and unvaccinated control fish. However, a rapid clearance of the virus was observed in the brains and kidneys of vaccinated fish, followed by a significant increase in neutralizing-antibody titres. Furthermore, the vaccine-induced antibodies potently neutralized Philippine betanodavirus isolates (RGNNV) in a cross-neutralization assay. The present results indicate the potential of the formalin-inactivated RGNNV vaccine against viral nervous necrosis (VNN) of Asian seabass.
    • Article

      Immuno-response in tilapia Sarotherodon niloticus vaccinated with Edwardsiella tarda by hyperosmotic infiltration method 

      G Lio-Po & H Wakabayashi - Veterinary Immunology and Immunopathology, 1986 - Elsevier
      Sarotherodon niloticus with average weight of 28.42 ± 1.87g were immunized with formalin-killed Edwardsiella tarda using the hyperosmotic infiltration method. Test fish maintained in 30 l aquaria were grouped into four treatments. Group 1 and 2 were exposed to a single hyperosmotic treatment on day 0. Group 1 was bled on day 14 and group 2 was bled on day 28. Group 3 was given hyperosmotic treatments twice: on day 0 and day 14 and bled on day 28. Group 4 was an untreated control bled on day 28. All sera were analyzed for agglutinating antibody titer against E. tarda flagellar and somatic antigens. Results showed that flagellar and somatic agglutinin titers in all treatments were not statistically significant. Likewise, infection experiments where test fish were challenged with intraperitoneal injection of the test bacterium showed that the vaccination experiment did not effectively protect the test fish from infection by Edwardsiella tarda.
    • Article

      Oral delivery in aquaculture: Controlled release of proteins from chitosan-alginate microcapsules 

      AE Polk, B Amsden, DJ Scarratt, A Gonzal, AO Okhamafe & MFA Goosen - Aquacultural Engineering, 1994 - Aquacultural Engineering Society (AES)
      Potentially, the most useful method of fish vaccination is oral administration. However, this technique is presently only partially effective because of the apparent destruction of the vaccine in the fish digestive system, as well as interaction of the vaccine with the feed components. The authors' approach to this problem was to protect the vaccine by entrapping it within semi-permeable biocompatible microcapsules. Two bioactive agents — a vaccine, Vibrio bacterin and a model protein, bovine serum albumin (BSA) — were entrapped in chitosan-alginate microcapsules by extrusion of a sodium alginate/bioactive agent suspension into a CaCl2/chitosan solution. The results of experiments on the effects of varying the encapsulation parameters and the presence of enzymes on the in-vitro release of entrapped bioactive material are presented. This technique has been developed as a simple, quick, and inexpensive method for oral delivery. Capsules may be dried and mixed with feed for ease of administration, particularly to young fish which are susceptible to high mortality from both the disease and harsher vaccination procedures.
    • Article

      Protective immunity against viral nervous necrosis (VNN) in brown-marbled grouper (Epinephelus fuscogutattus) following vaccination with inactivated betanodavirus 

      R Pakingking Jr., NB Bautista, EG de Jesus-Ayson & O Reyes - Fish and Shellfish Immunology, 2010 - Academic Press
      Viral nervous necrosis (VNN) caused by betanodaviruses has been recently implicated in serious mortalities of groupers in the grow-out culture system. A safe and effective vaccine against this disease is urgently needed. This study demonstrates that a single intramuscular vaccination with formalin-inactivated Philippine strain of piscine betanodavirus (genotype: redspotted grouper nervous necrosis virus; RGNNV) induces potent immune responses and substantial protective immunity against an intramuscular challenge with the homologous virus in brown-marbled grouper, Epinephelus fuscogutattus, a highly susceptible marine fish species to VNN. Seroneutralization assay conducted on sera of vaccinated fish revealed the occurrence of substantial neutralizing-antibody titers from Days 15 (mean titer 1:800) to 190 (1:400) with the highest titer observed at Day 60 post-vaccination (1:5120). When vaccinated fish were challenged with the homologous virus at Days 15, 30 and 75 post-vaccination, significantly higher survival rates were obtained in these fish compared with their corresponding controls (L-15 injected fish). Abrogation of virus multiplication in all vaccinated survivors was indicated by undetectable virus titers in the brains and kidneys paralleled by significantly high levels of neutralizing antibodies in the sera of these fish. Consecutively, replicates of vaccinated fish that survived betanodavirus challenge at Days 15 and 75 post-vaccination were maintained in flow-through aquaria and rechallenged with the homologous virus 3 and 5 months later, respectively. A significant drop in neutralizing-antibody titers of 3 and 8 folds, respectively, were observed in the sera of Days 15 and 75 post-vaccinated fish assayed before the virus rechallenge. Interestingly, reversion in the levels of neutralizing antibodies to significantly high levels (8–15 folds) were noted in these fish after the virus rechallenge. Taken together, our current data clearly demonstrate that a single administration of the inactivated Philippine strain of betanodavirus vaccine can effectively mount a specific anamnestic response and concomitant long-term protection against VNN in grouper at the grow-out culture system.
    • Article

      Susceptibility of hatchery-reared snubnose pompano Trachinotus blochii to natural betanodavirus infection and their immune responses to the inactivated causative virus 

      R Pakingking Jr., KI Mori, NB Bautista, EG de Jesus-Ayson & O Reyes - Aquaculture, 2011 - Elsevier
      Mass mortality of snubnose pompano Trachinotus blochii fry exhibiting dark coloration, anorexia, and abnormal swimming behavior was recently documented at the hatchery of the Aquaculture Department of the Southeast Asian Fisheries Development Center, Philippines. Samples of brain tissues were collected from affected fish and processed for RT-PCR amplification and virus isolation in cell culture. Infected E-11 cells exhibited cytopathic effect characteristic of betanodavirus. Histopathology of moribund fish showed pronounced vacuolations in the brain, spinal cord, and retina. An RT-PCR product of approximately 430 bp was amplified from the culture supernatant of betanodavirus-infected E-11 cells and sequenced. Sequencing of the T4 region of the coat protein gene (RNA 2) revealed clustering of the isolated virus within the red-spotted grouper nervous necrosis virus type. The pathogenicity of the isolated betanodavirus in healthy pompano juveniles and fry was determined via intramuscular injection and immersion challenges, respectively. Higher mortality rates were obtained in challenged fish compared with the controls. An inactivated vaccine was subsequently prepared by treating the clarified betanodavirus with formalin. Pompano juveniles intraperitoneally injected with the inactivated vaccine exhibited neutralizing antibodies from days 15 (mean titer 1:240) to 125 (1:560) with the highest titer noted at day 64 (1:2240) post-vaccination. Additionally, pompano fry bath-vaccinated and consequently bath-challenged with betanodavirus at day 35 post-vaccination showed higher survival rate compared with the control, indicating the potential of the inactivated betanodavirus vaccine against VNN in pompano fry and juveniles.
    • Article

      Vaccination of European sea bass fry through bioencapsulation of Artemia nauplii 

      M Chair, RSJ Gapasin, M Dehasque & P Sorgeloos - Aquaculture International, 1994 - European Aquaculture Society
      European sea bass (Dicentrarchus labrax) fry vaccinated orally via bioencapsulation in Artemia nauplii or by bath method exhibited better performance than control fish in terms of growth, food conversion and resistance to stress. The comparable survival between vaccinated and non-vaccinated animals suggests that vaccination methods are not stressful. The present study shows that oral vaccination can be used to enhance growth in fish fry.