Now showing items 1-9 of 9

    • Article

      Development of a polymerase chain reaction (PCR) assay targeted to the dnaJ gene of Vibrio harveyi, a bacterial pathogen in Asian seabass, Lates calcarifer 

      CMA Caipang, RV Pakingking Jr., MJS Apines-Amar, F Huyop & NB Bautista - Aquaculture, Aquarium, Conservation and Legislation, 2011 - Bioflux
      Partial sequence of the dnaJ gene of Vibrio harveyi, which was isolated from diseased juvenile Asian seabass, Lates calcarifer was identified. The partial sequence of dnaJ gene of V. harveyi was 447 bp and shared at least 77% identity at the nucleotide level with the dnaJ gene of other Vibrios. It was distinct from the dnaJ gene of other Vibrios but was closely related with the dnaJ gene of V. rotiferianus and V. campbellii having at least 90% nucleotide identity. PCR primers targeting this gene were designed to detect the pathogen in Asian seabass. The assay was specific to V. harveyi and the limit of detection was 100 pg of genomic DNA ml-1 or 100 fg of bacterial genomic DNA in a PCR reaction. This corresponded to a sensitivity of approximately 20 genome equivalents (GE) of V. harveyi. These results indicate that the dnaJ gene is a good candidate to develop primers for the PCR assay in detecting V.harveyi in fish.
    • Article

      Dietary onion and ginger enhance growth, hemato-immunological responses, and disease resistance in brown-marbled grouper, Epinephelus fuscoguttatus. 

      MJS Apines-Amar, EC Amar, JP Faisan Jr., RV Pakingking Jr. & S Satoh - Aquaculture, Aquarium, Conservation and Legislation, 2012 - Bioflux
      A 12-week (September to December 2009) feeding trial was conducted to evaluate theimmunostimulatory effects of different substances administered orally through the diet in the brown-marbled grouper, Epinephelus fuscoguttatus. Five experimental diets containing either onion, ginger, β–glucan, or vitamin C and a control diet (without immunostimulants) were fed to the fish weighing about 44 g for 12 weeks. Onion-fed fish showed significantly increased weight gain, hematocrit, and total Ig compared to the control group; however, leukocyte differential count and ROS production were unaffected. Ginger-fed fish likewise significantly increased total Ig, ROS production and lysozyme activity. However, it did not affect growth and hematocrit value. β-glucan significantly increased growth and total Ig but had no effect on the other parameters. Vitamin C significantly increased hematocrit, total Ig and ROS production but did not increase growth. Upon challenge with a bacterial pathogen Vibrio harveyi, mortality was significantly reduced in the onion, ginger and vitamin C-fed fish but not in the β–glucan-fed fish. This study demonstrated that onion and ginger could positively affect the innate immune responses and protect grouper against Vibrio harveyi infection.
    • Article

      Growth, plasma cortisol, liver and kidney histology, and resistance to vibriosis in brown-marbled grouper, Epinephelus fuscoguttatus fed onion and ginger 

      MJS Apines-Amar, EC Amar & JP Faisan Jr. - Aquaculture, Aquarium, Conservation and Legislation, 2013 - Bioflux
      The health-promoting effects of dietary onion and ginger were studied in brown marbled grouper, Epinephelus fuscoguttatus. An eight-week feeding trial was conducted to evaluate the effects of dietary onion and ginger on growth, cortisol levels, histology and disease resistance in the fish. Five experimental diets were formulated to contain either onion (2%), ginger (2%), β-glucan (1%) or vitamin C (3%) and a control diet (without immunostimulants). Each diet was fed to triplicate groups of fish with an average weight of 10.85±0.69 g. Fish supplemented with either of the immunostimulants exhibited a significantly higher growth compared to the control group. Specific growth rate (SGR) and feed conversion efficiency (FCE) were significantly higher in the onion and ginger-supplemented fish than the control. Cortisol level was higher in the control compared to the immunostimulant-fed groups with onion and ginger-fed fish showing significantly lower cortisol levels. When experimentally infected with Vibrio harveyi, fish fed onion or ginger exhibited significantly reduced mortality when compared with the control and β-glucan, but not when compared with the vitamin C-fed group. Liver sections sampled 4 days postinfection showed no remarkable pathology except for the slight reduction in glycogen granules in the supplement-fed fish. The liver of non-supplemented infected fish showed necrosis, fatty globule deposition, vacuolation, and presence of short rod-shaped bacteria. Kidney sections in the supplemented groups, likewise, did not show significant pathology similar to the uninfected control, whereas those of infected control fish showed necrosis of the tubules and glomeruli resulting in severely altered morphology of the tissues and presence of bacteria in the necrotic areas. As a result of circumventing tissue damage, wound healing was faster in fish supplemented with ginger, onion, and vitamin C compared to the β-glucan and the control groups. This study showed the benefits of onion and ginger in promoting growth and alleviating stress and severity of vibriosis in grouper.
    • Article

      Improved resistance against White Spot Virus (WSV) infection in tiger shrimp, Penaeus monodon by combined supplementation of peptidoglycan and mannan oligosaccharide (MOS) 

      MJS Apines-Amar, KGS Andrino, EC Amar, RE Cadiz & VL Corre Jr. - Extreme Life, Biospeology and Astrobiology, 2014 - Bioflux Society
      An eight-week feeding trial was conducted to evaluate the effects of combined supplementation of peptidoglycan and mannan oligosaccharide (MOS) in tiger shrimp, Penaeus monodon. Tiger shrimp (0.29 ± 0.02 g) were fed diets supplemented with different levels of peptidoglycan + (MOS) as immunostimulants for six (6) and eight (8) weeks. Four (4) experimental diets were formulated to contain 0, 0.1, 0.2, and 0.4% peptidoglycan + MOS. The feeding trial was conducted in 250 L capacity concrete circular tanks (replicated four (4) times) with 20 shrimp per tank. Growth, survival, respiratory burst activity, total hemocyte count (THC), and in vivo resistance to WSV infection were evaluated. Weight gain of the shrimp was significantly higher in the immunostimulant-fed groups compared to the control. However, different levels of the immunostimulants did not differ in their effect on the the growth of the shrimp. On the other hand, respiratory burst activity and total haemocyte count (THC) were significantly higher in the group supplemented with 0.2% peptidoglycan + MOS than the rest of the treatments. Likewise, survival after infection with White Spot Virus (WSV) was significantly increased in the 0.2% peptidoglycan + MOS compared to the other groups. The present results demonstrated that using peptidoglycan and MOS together at 0.2% of the diet improves growth, activates immune responses such as respiratory burst activity and THC in P. monodon and give better protection to the shrimp against WSV infection.
    • Article

      Screening of vibriosis in Asian seabass, Lates calcarifer using loop-mediated isothermal amplification (LAMP) assay 

      CMA Caipang, RV Pakingking Jr. & MJS Apines-Amar - Human & Veterinary Medicine, 2012 - Bioflux Society
      The aim of this study was to standardize a loop-mediated isothermal amplification (LAMP) assay for the detection of Vibrio harveyi , the causative agent of vibriosis in Asian seabass, Lates calcarifer . The dnaJ gene of the bacterial pathogen was used as the target gene for the LAMP assay. It was optimized at an incubation time of 1 h at 63°C. The assay was highly specific for V. harveyi and did not cross-react with other bacterial pathogens offish. However, the assay was able to detect V. harveyi that was isolated from infected shrimps. The limit of detection of the LAMP assay was 40 pg of DNA mL-1 or 40 fg of the genomic DNA per LAMP reaction and was 10 times more sensitive than conventional PCR in detecting the bacterial pathogen from infected samples. The LAMP products can be quantified spectrophotometrically using hydroxynaphthol blue (HNB) dye and showed positive correlation with the amount of the pathogen. These results demonstrated that LAMP is a simple and sensitive detection technique that has potential application for routine diagnosis of vibrosis caused by V. harveyi in Asian seabass and other aquatic species.
    • Article

      Temporal changes in innate immunity parameters, epinecidin gene expression, and mortality in orange-spotted grouper, Epinephelus coioides experimentally infected with a fish pathogen, Vibrio harveyi JML1 

      EC Amar, JP Faisan Jr., MJS Apines-Amar & RV Pakingking Jr. - Fish and Shellfish Immunology, 2017 - Elsevier
      Changes in innate immunity parameters and epinecidin mRNA transcript levels were examined to characterize the non-specific immune response of E. coioides to pathogenic V. harveyi JML1 isolated from affected cage-cultured fish. After fish had been injected with bacteria at a dose causing 30% mortality, blood and tissue samples were collected at 0, 6, 12, 24, 48, 72, 96, 120, and 240 h post-infection (hpi) for assessment of indices such as the oxidative burst (OB) and phagocytic index (PI) of head kidney cells, and lysozyme activity (LYS) and total immunoglobulin (Total Ig) levels of the plasma. The epinecidin mRNA transcript levels (EGE) from skin, gills, liver, kidney, and spleen tissues were also determined by gelbased RT-PCR. Lastly, daily mortality (DM), liver total bacterial load (TBC), and presumptive Vibrio count (TVC) were monitored up to 240 hpi. The results revealed that bacteria proliferated rapidly in fish tissue, reaching peak densities at 24 hpi for both TBC and TVC but was on a downward trend thereafter. The pattern in fish mortality closely correlated with TBC and TVC. Total Ig, OB, and PI in E. coioides were suppressed in the early part of infection when V. harveyi load was high but recovered and later increased as bacterial density declined. LYS and EGE were consistently high and their activities were not hampered by bacterial infection. The study demonstrated that V. harveyi JML1 interacts with E. coioides by transiently inhibiting some immune parameters resulting in mortalities. However, consistently high LYS, upregulated EGE, and resurgent PI, OB and Total Ig conferred resistance and subsequent recovery in the fish. The study provides new insights on the interaction between E. coioides and V. harveyi JML1 that can aid in formulating health management strategies for groupers. Further studies on prophylactic interventions to enhance the innate immune response in grouper during infection with V. harveyi JML1 are suggested.
    • Book chapter

      Use of immunostimulants in shrimp culture: An update 

      MJS Apines-Amar & EC Amar - In CMA Caipang, MBI Bacano-Maningas & FF Fagutao (Eds.), Biotechnological Advances in Shrimp Health Management in the Philippines, 2015 - Research Signpost
      Different approaches are used to prevent and control diseases in aquaculture. Immunostimulation is one method that is gaining popularity and is considered a promising development in aquaculture. Immunostimulants were found to be effective in enhancing parameters of non-specific immunity and resistance to diseases of fish and crustaceans. However, some issues raised on the use of immunostimulants pertains to the short-term nature of immune indices used during efficacy evaluation, possible detrimental effects during long-term administration, or self-damage due to unregulated production of immune effectors. Further testing in large-scale production units has been recommended. This chapter presents the various types and sources of immunostimulants commonly used in aquaculture and in shrimp culture in particular. The effects of each immunostimulant vary depending on its source, dose, route of administration, length of exposure, and the species to which it is administered.
    • Article

      Use of thraustochytrid Schizochytrium sp. as source of lipid and fatty acid in a formulated diet for abalone Haliotis asinina (Linnaeus) juveniles 

      MR de la Peña, MB Teruel, JM Oclarit, MJA Amar & EGT Ledesma - Aquaculture International, 2016 - Springer Verlag
      The effects of using thraustochytrid Schizochytrium sp. as source of lipid and fatty acids in a formulated diet on growth, survival, body composition, and salinity tolerance of juvenile donkey’s ear abalone, Haliotis asinina, were investigated. Treatments consisted of diets either containing a 1:1 ratio of cod liver oil (CLO) and soybean oil (SBO) (Diet 1) or thraustochytrid (Diet 2) as source of lipid and fatty acids at 2 % level. Natural diet Gracilariopsis heteroclada (Diet 3) served as the control. No significant difference in growth was observed in abalone fed Diet 3 (SGR: 5.3 % BW day−1; DISL: 265 μm day−1) and Diet 2 (SGR: 5.2 % BW day−1; DISL: 255 μm day−1). Survival ranged from 78 to 85 % for all treatments and was not significantly different from each other. A 96-h salinity stress test showed highest survival of 84 % in abalone fed Diet 2 compared with those fed diets 1 and 3 (42 %). The high growth rate of abalone fed Diet 2 and high tolerance to low salinity could be attributed to its high DHA content (8.9 %), which resulted to its high DHA/EPA ratio of 10.5 %. These fatty acids play a significant role in abalone nutrition. The fatty acid profile of abalone meat is a reflective of the fatty acid profile of the oil sources in the diet. The present study suggests that the use of Schizochytrium oil in lieu of CLO and SBO can support good growth of abalone which is comparable with abalone fed the natural seaweeds diet.
    • Article

      Utilization of mung bean, Vigna radiata (Linnaeus) as a novel protein source in practical-type diets for juvenile milkfish, Chanos chanos (Forsskal): Effects on growth, feed efficiency, body composition, and histology of gut and liver 

      MJS Apines-Amar, RM Coloso, MNG Amar, MSM Golez, MGB Bunda & CJ Jaspe - The Israeli Journal of Aquaculture-Bamidgeh, 2015 - Society of Israeli Aquaculture and Marine Biotechnology (SIAMB)
      A 15-week feeding trial was conducted to determine the optimum partial inclusion of mung bean protein in milkfish diet. Six isonitrogenous practical-type diets with mung bean included at 0%, 4%, 8%, 12%, 16%, and 20% of the diet equivalent to 0%, 3%, 7%, 10%, 13%, and 17% of the total dietary protein, respectively, were formulated. Milkfish with average body weight (ABW) of 8.5 ± 0.23g were distributed in eighteen tanks (6 treatments X 3 replications) with 10 fish each. The fish were fed the diets three times daily. Results showed that growth of milkfish was not adversely affected by the inclusion of mung bean protein at any dietary level. Feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly improved by the inclusion of mung bean at 20% of the diet. Nutrient compositions of the fish carcass were similar in all diets. Furthermore, no detrimental effects attributable to mung bean inclusion were seen in terms of protein retention, hepatosomatic index (HSI), and liver and midgut histology of the fish. Overall, mung bean is a promising protein source for milkfish and can be included up to 20% of the diet contributing as much as 17% of the total dietary protein without detrimental effects on growth, feed performance, PER, protein retention, HSI, and liver and intestinal histology.