Now showing items 1-11 of 11

    • Book chapter

      Bacterial diseases 

      EV Alapide-Tendencia & LD de la Peña - In GD Lio-Po, CR Lavilla & ER Cruz-Lacierda (Eds.), Health Management in Aquaculture, 2001 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Fish and crustaceans that are not weakened by poor environmental conditions, or by other causes, such as parasitic infestation, nutritional deficiency, handling stress, or chemical intoxication, are more resistant to bacterial infections. This is due to the presence of a large amount of bactericidal substances in the blood, which helps overcome infections. So, the best precaution against the occurrence of bacterial infections is to provide the fish with optimum environmental conditions, adequate amounts of the right kinds of food and avoidance of stress, including overcrowding. Vaccination/ immunization and genetic manipulation (i.e., the development of specific pathogen resistant fry) are also some ways of preventing bacterial diseases. The use of antibiotics should always be an option of the last resort.
    • 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.
    • Conference paper

      Isolation, identification of causative agent of "red boil disease" in grouper (Epinephelus salmoides) and its possible control by vaccination 

      SY Wong, B Ong & TE Chua - In Proceedings of the International Workshop on Pen Cage Culture of Fish, 11-22 February 1979, Tigbauan, Iloilo, Philippines, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center; International Development Research Centre
      This report presents the initial results of studies on the isolation and identification of the causative agent as well as possible immunization of the estuary groupers. It is hoped that by a vaccination programme, fish could be made immune to such disease. Results indicate: (1) Vibrio parahaemolyticus is pathogenic to estuary grouper (2) that the vaccines did not seem to protect the fish against the vibrio when challenged one week after vaccination, but that this was due to slow antibody production of the fish as salmonids challenged about 30-35 days after vaccination reported good protection against Vibrio anguillarum and other bacterial diseases. Experiments are now in progress to challenge the vaccinated groupers at a later stage.
    • 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.
    • Conference paper

      Updates on the nervous necrosis virus and the koi herpesvirus in Southeast Asia 

      GD Lio-Po - In Proceedings of the 1st International Congress on Aquatic Animal Health Management and Diseases, 27-28 January 2009, 2009 - Veteran Council I.R.IRAN
      In Southeast Asia, the Viral Nervous Necrosis (VNN) or Viral Encephalopathy and Retinopathy (VER) and the Koi herpesvirus (KHV) infection are currently economically-important diseases of fishes. The VNN affects groupers (Epinephelus akaara, E. coioides, E. tauvina, E. fuscogutatus, E. septemfasciatus, E. malabaricus, E. moara and Cromileptes altivelis), Asian sea bass (Lates calcarifer), mangrove red snapper (Lutjanus argentimaculatus) and milkfish (Chanos chanos) in Thailand, Taiwan, Indonesia, Brunei, Malaysia, Singapore, Philippines and Vietnam. The Piscine nodavirus of the genus Betanodavirus, genotype red-spotted grouper nervous necrosis virus (RGNNV) is predominantly involved. Research on fish species pathogenicity, optimum temperature, cell susceptibility, organ predeliction, pathology, virus reservoirs, experimental infection, vaccination and diagnosis have been reported. The Koi herpesvirus (KHV) infection causes significant mortalities in common carp (Cyprinus carpio carpio), koi carp (Cyprinus carpio koi) and ghost carp (common x koi cross, Cyprinus carpio goi). Outbreaks have been reported among koi in Hongkong in 2001; common carp in Indonesia, in 2002; koi in Taiwan in 2002; and common carp in Japan, in 2003. A dramatic spread of the disease was subsequently observed among most prefectures in Japan, with outbreaks that eventually involved koi carp. In Thailand, KHV was first diagnosed in March 2005 while in Singapore, in Sept 2005. By Feb 2006, two batches of Thai koi exported to Singapore, tested KHV PCR positive from which the virus was successfully isolated on KF-1 cells. In Malaysia, no KHV outbreak was reported but the presence of the virus was detected among koi carp exported to UK in 2000 and in 2001. In 2004, koi carp in Malaysia tested positive for KHV by nested PCR. To date, annual active surveillance of the virus in Cambodia, Lao PDR, Myanmar, Philippines and Vietnam from 2004 to 2008 showed these countries are free of KHV. Recent developments on research of KHV focused on pathogenicity, cell line susceptibility, fish size susceptibility, predilection to fish organs, persistence in fish, vaccine development and application, surveillance and gene sequence analyses of KHV strains. The extensive international trading of live ornamental koi fish has largely contributed to the global spread of KHV. Hence, KHV was recently added to the list of notifiable diseases to the World Organisation of Animal Health or the Office International des Epizooties (OIE).
    • 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.
    • Book chapter

      Viral diseases of shrimp in the Philippines 

      KGS Andrino-Felarca, EG Estante & CC Lazado - In CMA Caipang, MBI Bacano-Maningas & FF Fagutao (Eds.), Biotechnological Advances in Shrimp Health Management in the Philippines, 2015 - Research Signpost
      Shrimp is a high-value commodity and one of the major aquaculture species in the world, including the Philippines. The shrimp farming industry is dominated by the black tiger shrimp Penaeus monodon and the Pacific white shrimp, Penaeus vannamei. Intensification in shrimp aquaculture to meet the global demand resulted to several socio-economic and biophysical production bottlenecks. Consequently, the issues besetting the industry had raised several questions on its sustainability. In particular, viral diseases remain a constant threat and a significant concern in many shrimp producing countries especially in the developing world. In this chapter, current knowledge on major viral pathogens affecting shrimp aquaculture in the Philippines is presented and discussed. The discussion is focused on white spot syndrome virus (WSSV), monodon baculovirus (MBV), infectious hypodermal and hematopoietic necrosis virus (IHHNV), hepatopancreatic parvovirus (HPV). yellow head virus (YHV), and taura syndrome virus (TSV). Updates on their clinical signs, transmission and distribution are presented. Records of incidence in the Philippines are provided as well. The second half of the chapter discusses some of the methods how to control viral diseases in shrimp farming with a particular focus on vaccination, biosecurity and diagnostics.