Now showing items 1-19 of 19

    • Article

      Agar-digesting bacteria associated with ‘rotten thallus syndrome’ of Gracilaria sp. 

      CR Lavilla-Pitogo - Aquaculture, 1992 - Elsevier
      A condition of the tetrasporophyte stage Gracilaria spp., characterized by white to pinkish discoloration and gradual disintegration of the thallus, has been observed in tank-held stocks. Microscopic observation revealed no fungal or protozoan parasites. Appropriate dilutions of homogenates plated on nutrient agar and bromthymol blue teepol agar showed the presence of bacteria, all of which were agar-digesting, at the rate of 1.42 × 107 cells per g of affected thalli. Colonies on bromthymol blue teepol agar were round and yellow, while those on nutrient agar appeared creamy and round with entire edges, and were rapid agar digesters. The bacteria were Gram negative, fermentative and motile rods. Based on biochemical characteristics, the isolates were classified as belonging to the genus Vibrio. Microscopic observations of thalli cross-sections showed erosion of the pericarp, thus revealing the cortical and the medullary cells. Scanning electron microscopy revealed rod-shaped bacteria, including dividing cells, in affected tissues. Antibiotic sensitivity tests indicated that the bacteria were sensitive to Polymyxin B, nalidixic acid, nitrofurazone and oxytetracycline.
    • Article

      Anti-luminous Vibrio factors associated with the ‘green water’ grow-out culture of the tiger shrimp Penaeus monodon 

      The ability of the “green water” grow-out culture of the tiger shrimp Penaeus monodon to prevent outbreaks of Luminous Vibriosis was investigated by screening associated isolates of bacteria, fungi, phytoplankton and fish skin mucus for anti-luminous Vibrio metabolites. Among the 85 bacterial isolates tested, 63 (74%) caused +∼+++ inhibition of the Vibrio harveyi pathogen after 24–48 h co-cultivation. The variation in growth inhibition rates of +, ++, and +++ were demonstrated by 15 (18%), 13 (15%), and 28 (33%) isolates, respectively, 24 h after treatment. Eight bacterial isolates showed consistently sustained maximum inhibition of luminous Vibrio after 24 to 48 h exposure. The majority of these luminous Vibrio inhibiting bacterial isolates were obtained from tilapia mucus and gut. In tests with fungi, 4 of 20 (20%) yeast isolates showed intracellular metabolites inhibitory to luminous Vibrio. Among filamentous fungi, 5 of 45 (11%) isolates yielded intracellular metabolites while 3 of 41 (7%) isolates had extracellular metabolites inhibitory to luminous Vibrio. These fungal isolates were identified as Rhodotorula sp., Saccharomyces sp., Candida sp., Penicillium sp., mycelia sterilia, and two unidentified species. The microalgae, Chaetoceros calcitrans and Nitzchia sp., consistently demonstrated complete inhibition of luminous Vibrio from 24 h and 48 h post exposure, respectively, and during the 7-day experiment. Leptolyngbia sp. caused a 94–100% reduction of the luminous Vibrio population from 104 to 101 cfu/ml 24 h post exposure which was sustained throughout the 10-day observation period. In contrast, the inhibitory effects of Skeletonema costatum on luminous Vibrio was bacteriostatic throughout the 7-day exposure while Nannochlorum sp. did not significantly inhibit luminous Vibrio. The skin mucus of jewel tilapia, Tilapia hornorum, had no resident luminous bacteria and inhibited this bacterial pathogen in 6–48 h, which was proportionate to the 103 and 105 cfu/ml test concentrations of luminous Vibrio. This study provides a scientific explanation that the effectiveness of the “green water” culture of tiger shrimp (P. monodon) in preventing outbreaks of luminous Vibriosis among P. monodon juveniles in grow-out ponds can be attributed to the presence of anti-luminous Vibrio factors in the bacterial, fungal, phytoplankton microbiota and the skin mucus of tilapia associated with this novel technique of shrimp culture.
    • Article | Short communication

      Bacteria associated with infection at hormone-implantation sites among milkfish, Chanos chanos (Forsskal), adults 

      G Lio-Po, C Pitogo & C Marte - Journal of Fish Diseases, 1986 - Blackwell Publishing
      SEAFDEC Contribution No. 164. Paper presented at the Second International Warmwater Fish Conference at Laie, Hawaii, 5–8 February 1985.
    • Book chapter

      Bacterial diseases 

      EA Tendencia & CR Lavilla-Pitogo - In K Nagasawa & ER Cruz-Lacierda (Eds.), Diseases of cultured groupers, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Bacteria are very common in the aquatic environment. Most bacterial disease agents are part of the normal flora of the water. They cause disease only when the fish are stressed due to poor environmental conditions, inadequate diet and poor husbandry techniques.

      This chapter focuses on the most common bacterial diseases of groupers.
    • 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%).
    • Book chapter

      Bacterial isolation, identification and storage 

      L Ruangpan & EA Tendencia - In Laboratory manual of standardized methods for antimicrobial sensitivity tests for bacteria isolated from aquatic animals and environment, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Bacterial isolation, purification and identification are the first steps to bacteriological studies. Isolation is done to obtain pure bacterial cultures. Bacteria are usually isolated from fish kidney and spleen; and from the hepatopancreas, lymphoid organ and muscles of shrimp. These tissues are monitor organs that usually harbor the disease-causing bacteria during infection.
    • Article

      Bacterial microbiota of eggs from cage-reared and tank-reared grouper, Epinephelus coioides 

      EA Tendencia - Bulletin of the European Association of Fish Pathologists, 2004 - European Association of Fish Pathologists
      At SEAFDEC AQD, opaque spawned grouper eggs are observed during collection in cage-reared brood stock; while opaque and multi-colored eggs are often observed in tank-reared fishes. This study aimed to investigate the occurrence of these opaque and multicolored eggs and at the same time to compare the bacterial microbiota of eggs from brood stock reared in cages, to those from fish reared in concrete tanks. Grouper eggs from brood stocks reared in cages and tanks were processed for bacterial count and identification. Results showed that total bacterial count (on MA) and presumptive Vibrio count (on TCBS) of eggs from brood stock reared in concrete tanks were lower than those from cage-reared fishes. Aeromonads (for tank-reared) and Pseudomonads (for cage-reared) were the dominant bacteria in the good eggs; while Vibrios were dominant in the bad eggs for both egg sources. Total bacterial count of the egg-incubating medium from the brood stock tanks (104 cfu/ml) was lower than the total bacterial count of water from the cages (107 cfu/ml). Presumptive Vibrio counts of water from the tanks (102 cfu/ml) were lower than those from the cages (106 cfu/ml). The Aeromonads dominated the water from the tanks; while Vibrios dominated those from the cages. Good eggs that did not hatch, turned yellow after 3 days, and pink after 5 days.
    • Article

      Biodegradition of monochloroacetic acid by a presumptive Pseudomonas sp. strain R1 bacterium isolated from Malaysian paddy (rice) field 

      SN Ismail, AM Taha, NH Jing, RA Wahab, AA Hamid, RV Pakingking Jr. & F Huyop - Biotechnology, 2008 - Asian Network for Scientific Information
      A bacterial strain tentatively identified as Pseudomonas sp. R1 was isolated from a paddy (rice) field that could degrade monochloroacetic acid (MCA) for concentrations ranging from 5 to 40 mM. Quantitative agreement between the amount of MCA introduced and chloride released was also found. MCA dehalogenase activity in this strain was found to be inducible. Cell-free extracts displayed dehalogenating activity with specific halogenated organic compound with no activity on dichloropropionic acid or monochloropropionic acid. The estimated Km values for MCA was 0.14 mM. The optimal pH range for MCA dehalogenase activity (between pH 6.5 and 8.0), whereas the thermal stability profile stable up to 50 °C. The results of our current study demonstrated the potential use of Pseudomonas sp. R1 as suitable biological agent for biodegradation of MCA in contaminated agricultural area.
    • Article

      Collection of the clam Anodontia edentula in mangrove habitats in Panay and Guimaras, central Philippines 

      JH Primavera, MJHL Lebata, LF Gustilo & JP Altamirano - Wetlands Ecology and Management, 2002 - Kluwer Academic Publishers
      The mangrove clam Anodontia edentula is highly prized in the Philippines for its flavor and large size. Because this infaunal species is found down to one meter deep in mangrove areas, harvesting the clam reportedly damages mangrove stands. To evaluate such reports, a survey of collection methods was undertaken in Panay and Guimaras, central Philippines in August 1997-December 1999. Host to chemosynthetic bacterial symbionts that utilize sulfide as energy source, A. edentula are strategically situated in sulfide-rich anoxic substrates but also gain access to oxygenated seawater through a ventilation burrow or tube. By locating the opening of this burrow, collectors can detect the presence of a buried clam and harvest it nondestructively with a blade or bare hands. In contrast, the indiscriminate tilling of wide mangrove areas can damage mangrove plants. Most collectors were 40-45 years old with 22-30 years collection experience, married with 5-7 children, and had low educational attainment. They sold clams directly in the local markets or through middlemen (to restaurants and beach resorts); sales provided from 10% to 100% of daily family income. Collectors complained of decreasing clam sizes and numbers and the physically strenuous work of collecting.
    • Article

      Effect of detention time on aerobic waste stabilization pond performance in Southeast Asia 

      OM Millamena - Bulletin of Environmental Contamination and Toxicology, 1994 - Springer Verlag
      The rising level of pollution in rivers, lakes and other bodies of water has created problems of significant magnitude in Southeast Asia. Apart from the aesthetic desirability of clean rivers are the pressing dangers to health and detrimental effects on aquatic life. Pollution of these sources must be controlled so as not to interfere with the waters' legitimate uses.

      Waste stabilization ponds are well-accepted as an effective and economical means of waste disposal. A "stabilization pond" is an artificially created body of water intended to retain sewage or organic wastes until biological processes have rendered the wastes stable. The stabilization process consists of bacteria and algae interaction. Bacteria oxidize the wastes and produce sludge, carbon dioxide and ammonia. The nutrients produced from bacterial oxidation, along with light energy, supply the requirements for algal photosynthesis. Algae produce oxygen needed to sustain the treatment process. Optimum detention time refers to the average length of time required for waste to become stabilized within a pond.

      Properly designed and operated, a stabilization pond can provide treatment comparable to a more costly waste treatment plant. However, the design criteria for a particular climate may not be applicable to other climates. This study was conducted to establish suitable detention times for aerobic stabilization ponds in Southeast Asia.
    • Article

      Effect of iodine disinfection on the bacterial flora and hatching rate of grouper, Epinephelus coioides eggs at the cleavage and eyed stages 

      EA Tendencia - Bulletin of the European Association of Fish Pathologists, 2001 - European Association of Fish Pathologists
      In this study, the effect of iodine disinfection on the bacterial flora and hatching rate of grouper egg at two different stages of development were investigated. The eggs (at cleavage and eyed stages) were soaked for 10 min in sterile seawater (control) and at different free iodine concentrations- 2.5, 5, 10, 15 and 20 ppm. Total bacterial and presumptive Vibrio count, as well as the hatching rate of the treated eggs were determined. Results showed that Vibrios are eliminated by iodine disinfection (2.5-20 ppm) but not by rinsing with sterile seawater. The total bacterial load and hatching rate of eggs decreased as the iodine concentration increased. Iodine concentrations of 15 and 20 ppm were effective in significantly reducing the total bacterial load of grouper egg at both the cleavage and eyed stages. However, at these concentrations the hatching rates were also significantly lower. Results also showed that grouper, Epinephelus coioides, eggs tolerate stress better at the eyed stage than at the cleavage stage.
    • Article

      Efficiency of Chlorella sp. and Tilapia hornorum in controlling the growth of luminous bacteria in a simulated shrimp culture environment 

      EA Tendencia, MR dela Peña & CH Choresca Jr. - Aquaculture, 2005 - Elsevier
      This study clarifies the effect of green water from Chlorella sp., Tilapia hornorum and the combination of the two organisms on the growth of luminous bacteria in a simulated shrimp culture environment. Results showed that the presence of Chlorella sp. (105 cells/ml) alone was not effective in the control of luminous bacteria in shrimp (biomass=80 g/m3) rearing water. The presence of T. hornorum alone (biomass=500 g/m3) was more efficient in controlling the growth of luminous bacteria than the co-existence of tilapia and Chlorella sp. Nevertheless, the presumptive Vibrio count was lowest in control tanks that had the highest shrimp survival rate, which was attributed to the presence of other micro-algae such as Chaetoceros, Thalassiosira, Navicula, Nitszchia, Melosira, and Fragilaria.
    • Article

      Elemental sulfur in the gills of the mangrove mud clam Anodontia edentula (Family Lucinidae) 

      JHL Lebata - Journal of Shellfish Research, 2000 - National Shellfisheries Association
      Different sizes of the mangrove mud clam Anodontia edentula were collected from the mangroves in Brgy. San Roque in Estancia, Iloilo, central Philippines, and the mantle, gill, and foot tissues were analyzed for elemental sulfur content. Mangrove mud (substrate) was also analyzed for total sulfur content to establish the possibility of clam-bacteria symbiosis in this lucinid clam. Sulfur analysis showed highly significant (p <0.0001) amounts of elemental sulfur in the gills (247.64 ± 63.28 μmoles/g FW) compared with the quantities observed in the mantle (0.84 ± 0.22 μmoles/g FW). Elemental sulfur was absent from the foot tissues. Results also showed a significantly (p <0.05) decreasing elemental sulfur from the newly collected clams (mean = 461.18 μmoles/g FW) compared to those reared in the laboratory (mean = 159.08 μmoles/g FW: with mangrove mud substrate; mean = 45.18 μmoles/g FW without substrate), which were analyzed weekly until week 3, indicating that stored elemental sulfur is being utilized by the bacteria in the absence of sulfide. Total sulfur content of mangrove mud in situ was higher than that used us substrate in the experiment; where there were no significant differences from initial to final readings. This shows that mangrove mud in situ is linked to a steady sulfur source.
    • Article

      Gill structure, anatomy and habitat of Anodontia edentula: Evidence of endosymbiosis 

      MJHL Lebata & JH Primavera - Journal of Shellfish Research, 2001 - National Shellfisheries Association
      Surveys and interviews were conducted to determine sources and habitat of Anodontia edentula. Results showed that they inhabit muddy substrate of mangrove areas or the adjacent mudflats, burying at 20-60 cm deep in the mud. They are strategically situated in the sulfide-rich, low-oxygen layer of the substrate but have access to oxygen through their inhalant tube; both sulfide and oxygen are essential for their survival. Study of the clam s gross anatomy revealed thick, fleshy, deep purple to blackish brown gills; reduced digestive structure; and a highly elastic foot capable of extending several times longer than its body length. These observations conform with the anatomy of fellow lucinid clams. Furthermore, scanning electron micrographs showed coccoid or spherical bacteria occupying bacteriocytes in the clam s gills. Intermediate cells separating bacteriocytes observed in other lucinids were also noted in the SEM.
    • Article

      Initial assessment of the bacterial population of Guimaras waters and soil after the Solar I oil spill 

      C Sombito, G Lio-Po, R Sadaba & R Torreta - Philippine Journal of Natural Sciences, 2009 - University of the Philippines Visayas
      A massive oil spill occurred near the shores of Guimaras Island, Philippines in 11 Aug 2006 caused by the Sunken MT Solar I vessel. The oil spill spread to neighboring towns of Guimaras damaging the marine coastal environment, consequently,causing health and economic problems, particularly, by affecting local fisheries, wildlife and tourism. Hence, this study was conducted to assess, quantify and isolate indigenous bacteria with potential petroleum hydrocarbon-degrading properties that could be used for bioremediation of oil spill contaminated areas in Guimaras and nearby provinces.
    • Article

      Level and percentage recovery of resistance to oxytetracycline and oxolinic acid of bacteria from shrimp ponds 

      EA Tendencia & LD dela Peña - Aquaculture, 2002 - Elsevier
      The bacterial level of the water, sediment and cultured shrimp (Penaeus monodon) from different ponds were determined using a general medium, a presumptive Vibrio medium and a presumptive Pseudomonas–Aeromonas medium. Samples were taken from ponds that had not used any antimicrobial, ponds that had previously used and also ponds that were currently using oxolinic acid (OXA). The bacterial level in the sediment was higher than in the water using all three media. More bacteria existed in the pond system than in the receiving environment. Shrimp hepatopancreas harbored more bacteria than the lymphoid organ. The Vibrio density of the pond and bacterial levels in the shrimp were correlated with the use of the antimicrobial. The Vibrio level of the pond samples and microbial density of shrimps were higher from ponds that had not used any antimicrobials.

      The percentage recoveries of resistance to oxytetracycline (OTC) and OXA in bacteria from shrimp ponds and cultured shrimps were also determined using Zobell's marine agar, Pseudomonas–Aeromonas selective agar and thiosulfate citrate bile sucrose agar (TCBS) with the addition of either 25 μg/ml OTC or 25 μg/ml OXA. Presumptive Vibrio bacteria and other bacterial taxa recovered from the pond/receiving water/sediment from all three sites showed some degree of resistance to OTC and OXA. However, a higher percentage recovery of strains resistant to OTC than to OXA was observed among the presumptive vibrios and other bacterial taxa. Pseudomonas and Aeromonas bacteria were more resistant to OXA compared with the vibrios. All bacterial taxa resistant to OTC were more readily recovered from the water samples than from the sediment samples. In general, between the samples from the pond and from the receiving environment, a higher percentage of resistant strains was observed in the latter. Higher percentage recovery of bacteria resistant to OXA was observed in shrimp from ponds currently using OXA than those from ponds that had not used any or those that had previously used them. The results of the present study showed that the percentage recovery of resistance reflected the pattern of antimicrobial use.
    • Article

      Major viral and bacterial disease problems in shrimp culture 

      CR Lavilla-Pitogo - Aquaculture Engineering (Philippines), 1998 - Society of Aquaculture Engineers of the Philippines
      Major disease problems particularly viral and bacterial in origin have resulted in significant decline in the production of farmed shrimps worldwide.

      The major diseases of viral and bacterial origins are listed and described. Innovations being applied to prevent and/or minimize their effects are enumerated.

      The paper suggests a broad outlook of shrimp disease by considering not only the etiological causes but also the epidemiological approach. Attempts to produce disease-free fry are still expensive and cannot be applied widely in commercial farms. The aim is to attain sustainable shrimp farming.
    • magazineArticle

      The trouble with antibiotics and pesticides is... 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The paper discusses the output of the meeting on the use of chemicals in aquaculture in Asia. The effects of chemical use on cultured stocks in the farm, the immediate environment through discharges and effluents, surrounding areas, farm staff, consumers and drug resistance organisms are also discussed. It also shows how an antibiotic-resistant microorganism develops as the result of indiscriminate use of antibiotics.
    • magazineArticle

      Using bacteria to fight bacteria 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The paper discusses about probiotics and its possible use in shrimp aquaculture. The paper also provides information on how the probiotics work and presents the preliminary results of the field tests conducted by Southeast Asian Fisheries Development Center, Aquaculture Department and BIOPOND Systems. The general characteristics of Bacillus are also discussed.