Now showing items 1-8 of 8

    • Article

      Characterization of a virus obtained from snakeheads Ophicephalus striatus with epizootic ulcerative syndrome (EUS) in the Philippines 

      GD Lio-Po, GS Traxler, LJ Albright & EM Leaño - Diseases of Aquatic Organisms, 2000 - Inter Research
      This is the first report of the isolation and characterization of a fish virus from the Philippines. The virus was isolated using snakehead spleen cells (SHS) from severely lesioned epizootic ulcerative syndrome (EUS)-affected snakehead Ophicephalus striatus from Laguna de Bay, in January 1991. The virus induced cytopathic effects (CPE) in SHS cells yielding a titer of 3.02 x 106 TCID50 ml-1 at 25°C within 2 to 3 d. Other susceptible cell lines included bluegill fry (BF-2), catfish spleen (CFS) and channel catfish ovary (CCO) cells. Replication in chinook salmon embryo cells (CHSE-214) was minimal while Epithelioma papulosum cyprini cells (EPC) and rainbow trout gonad cells (RTG 2) were refractory. Temperatures of 15 to 25°C were optimum for virus replication but the virus did not replicate at 37°C. The virus can be stored at -10 and 8°C for 30 and 10 d, respectively, without significant loss of infectivity. Viral replication was logarithmic with a 2 h lag phase; viral assembly in the host cells occurred in 4 h and release of virus occurred 8 h after viral infection. A 1-log difference in TCID50 titer between the cell-free virus and the total virus was noted. Freezing and thawing the virus caused a half-log drop in titer. Viral exposure to chloroform or heating to 56°C for 30 min inactivated the virus. Exposure to pH 3 medium for 30 min resulted in a more than 100 fold loss of viral infectivity. The 5-iododeoxyuridine (IUdR) did not affect virus replication, indicating a RNA genome. Neutralization tests using the Philippine virus, the ulcerative disease rhabdovirus (UDRV) and the infectious hematopoietic necrosis virus (IHNV) polyvalent antisera showed slight cross-reaction between the Philippine virus antiserum and UDRV but established no serological relationship with SHRV and IHN virus. Transmission electron microscopy (TEM) of SHS cells infected with the virus showed virus particles with typical bullet morphology and an estimated size of 65 x 175 nm. The Philippine virus was therefore a rhabdovirus, but the present study did not establish its role in the epizootiology of EUS.
    • Conference paper

      Country report: Philippines 

      GD Lio-Po, JP Pascual & JG Santos - In FB Davy & A Chouinard (Eds.), Fish quarantine and fish diseases in Southeast Asia : report of a workshop held in Jakarta, Indonesia, 7-10 December 1982, 1983 - International Development Research Centre
    • Article

      Establishment of cell lines from catfish (Clarias batrachus) and snakeheads (Ophicephalus striatus) 

      GD Lio-Po, GS Traxler & LJ Albright - Asian Fisheries Science, 1999 - Asian Fisheries Society
      Primary cell cultures from catfish (Clarias batrachus) and snakeheads (Ophicephalus striatus) were prepared from whole fry and fingerling organ tissues of the brain, fins, gonad, heart, kidney, liver, skin and spleen. Four methods were tried: method A, wherein explants were placed onto the surface of 25-cm2 Primaria flasks (Falcon), allowed to attach for an hour before addition of Leibovitz medium (L-15) supplemented with 15% fetal bovine serum (FBS)(L15-15); Method B, wherein explants were inoculated into 25-cm2 Primaria flasks (Falcon) already containing L15-15; Method C, which required forcing minced organ sections through a stainless steel sieve with the aid of a syringe plunger into a petri dish containing L15-15 medium; and Method D, wherein immersed sections of minced tissues to 0.5% trypsin-EDTA were slowly agitated using a magnetic stirrer for one hour at 25°C. Method B was most effective in the establishment of cell cultures from both fish species. Passage numbers of the cells are to date catfish gonad (CFG) P-56, catfish heart (CFH) P-51, catfish kidney (CFK) P-7, catfish liver (CFL) P-8, catfish spleen (CFS) P-54, snakehead gonad (SHG) P-26, snakehead heart (SHH) P-22, snakehead kidney (SHK) P-19, snakehead liver (SHL) P-49 and snakehead spleen (SHS) P-76. Attempts to derive primary cell cultures from organ tissues of the brain, fins, skin and whole fry were unsuccessful. Established cells were fibroblastic. The cells grew rapidly and became confluent 24 h after seeding at 20 and 25°C. Both SHS and CFS were susceptible to a virus isolated from EUS-affected fish in the Philippines. The cells were best maintained at 20°C and stored in liquid nitrogen or -70°C.
    • Article

      Experimental induction of lesions in snakeheads (Ophicephalus striatus) and catfish (Clarias batrachus) with Aeromonas hydrophila, Aquaspirillum sp., Pseudomonas sp. and Streptococcus sp. 

      GD Lio-Po, LJ Albright, C Michel & EM Leaño - Journal of Applied Ichthyology, 1998 - Wiley-Blackwell
      Isolates of Aquaspirilluni sp., Pseudomonas sp., and Streptococcus sp. recovered from epizootic ulcerative syndrome (EUS)-affected snakeheads (Ophicephalus striatus) in Thailand as well as an isolate of Aeromonas hydrophila recovered from EUS-affected snakeheads in the Philippines were characterized and identified. Each isolate was injected intramuscularly (IM) into healthy catfish (Clarias batrachus) and snakeheads (O. striatus). Results showed in tests with C. batraclius that 24 h after injection, Aquaspirillum sp., Pseudomonas sp., Streptococcus sp. and A. hydrophila induced slight, slight, moderate and severe dermomuscular necrotic lesions, respectively. Among O. striatus, only A. hydrophila induced severe lesions. Streptococcus sp. induced slight lesions 2 days post-injection which healed rapidly, while Aquaspirillum sp. and Pseudonionas sp. did not manifest any dermal lesions. Experiments indicated that among the four EUS-associated test bacteria, A. hydrophila was the most pathogenic, inducing severe dermomuscular necrotic lesions in intramuscularly injected catfish (C. batrachus) and snakeheads (O. striatus). Differences in the susceptibility of O. striatus and C. batrachus to Aquaspirillum sp., Pseudomonas sp. and Streptococcus sp. were evident. Furthermore, this is the first evidence of the association between Aquaspirillum sp. and diseased fish.
    • Article

      In vitro effects of fungicides on Haliphthoros philippinensis 

      GD Lio-Po, MCL Baticados, CR Lavilla & MEG Sanvictores - Journal of Fish Diseases, 1985 - Blackwell Publishing
      Pure cultures of the fungus Haliphthoros philippinensis isolated from infected Penaeus monodon larvae were exposed for 24 h to varying concentrations of the antifungal agents Benlate, calcium hypochlorite, clotrimazole, copper sulphate, Daconil, formalin, Fungitox, Furanace, griseofulvin, hydrogen peroxide, malachite green, Mysteclin C, phenol, potassium permanganate, Resiguard, Tide, tolnaftate and Treflan. The efficiency of each compound in inhibiting sporulation and mycelial growth of the fungus was measured. The results establish mycostatic and mycocidal levels for each fungicide.
    • Book chapter

      Infectious diseases of warmwater fish in fresh water 

      GD Lio-Po & LHS Lim - In PTK Woo, DW Bruno & LHS Lim (Eds.), Diseases and disorders of finfish in cage culture, 2014 - CABI Publishing
      This chapter presents the viral, bacterial, pseudofungal and parasitic diseases in cultured warm freshwater fish. Focus is given on the distribution, causative agent, pathology, diagnosis, prevention and control of these diseases.
    • Article

      Mycoflora of the 'green water' culture system of tiger shrimp Penaeus monodon Fabricius 

      EM Leaño, GD Lio-Po, LA Nadong, AC Tirado, RB Sadaba & NG Guanzon - Aquaculture Research, 2005 - Blackwell Publishing Ltd
      This study was conducted to quantify and characterize the mycoflora associated with the ‘green water’ culture system of Penaeus monodon. Samples of water, tilapia gut and mucus, and shrimp hepatopancreas from three shrimp farms were collected during 15, 30, 45 and 60 days of culture (DOC). Results showed that high fungal loads were observed in tilapia gut (total: 117–1352 colony forming unit (CFU) 5 cm hind gut−1; yeasts: 0–136 CFU 5 cm hind gut−1) and mucus (total: 12–311 CFU (5 cm2)−1; yeasts: 0–88 CFU (5 cm2)−1), while minimal fungal populations were observed in water samples (total: 0–110CFU mL−1; yeasts: 0–5 CFU ml−1). Shrimp hepatopancreas harboured a very low number of filamentous fungi (0–27 CFU 0.1 g−1) and yeasts (0–7CFU 0.1 g−1) especially at 60 DOC. The filamentous fungal isolates were dominated by Penicillium and Aspergillus species, while the yeast populations were dominated by Rhodotorula and Saccharomyces species. The dominance of these fungi on tilapia mucus and gut and their presence in the rearing water might play an important role in the overall mechanisms involved in the control of luminous Vibrio in the ‘green water’ grow-out culture of P. monodon.
    • Article

      Studies on the causative organism of Sarotherodon niloticus (Linnaeus) fry mortalities - 2. Identification and characterization of the physiological properties of Pseudomonas fluorescens 

      RC Duremdez & GD Lio-Po - Fish Pathology, 1985 - Japanese Society of Fish Pathology
      Identification and examination of the physiological characteristics of Pseudomonas sp. isolated from fry of Sarotherodon niloticus (L.) was conducted. Based on morphological and biochemical tests, the bacterium was identified to be a strain closest to Pseudomonas fluorescens. In vitro physiological growth patterns at varying temperatures, NaCl concentrations, and pH were observed for a maximum of eleven days incubation while growth of the test bacterium into various water media were observed for a maximum of 148 days. Bacterial growth occurred between 10° to 41°C with optimum growth at 25° to 30°C. The bacterium tolerated NaCl concentrations of 0 to 50 ppt. Optimum growth, however, was obtained from 0 to 15 ppt. It was found that growth was possible only at pH 5.0 to 9.7. Optimum growth occurred at pH ranging from 5.7 to 8.4. Inoculation of the test bacterium into different freshwater media obtained from various sources resulted in growth and rapid multiplication. Viability was maintained throughout the 148 day incubation period. Growth in the brackishwater medium was observed only until 50 days. No growth was observed in the seawater medium.