KOMBINASI SIRIH DAN KIPAHIT SEBAGAI IMUNOSTIMULAN TERHADAP PENYAKIT Streptococcosis PADA IKAN NILA (Oreochromis niloticus)

Serangan penyakit yang paling banyak ditemui menyerang kegiatan budidaya ikan nila adalah bakteri Streptococcus agalactiae sebagai salah satu agen penyakit Streptococcosis. Peningkatan sistem imun dari ikan yang dibudidayakan merupakan cara yang efektif untuk menanggulangi masalah tersebut. Salah satu fungsi tanaman obat adalah sebagai imunostimulan, di mana sistem imun akan meningkat terutama saat mengalami wabah penyakit ikan. Penelitian ini di tujukan untuk mengetahui efek penggunaan kombinasi ekstrak tanaman sirih dan kipahit dengan dosis yang berbeda terhadap respons imun bawaan dari ikan nila. Dosis yang digunakan adalah 1%, 2%, 4%, dan 8% per kg pakan pemberian pakan dilakukan selama empat minggu, diikuti dengan uji tantang menggunakan bakteri patogen S. agalactiae. Meskipun tidak terlihat perbedaan yang nyata, namun rerata respons imun hematokrit, eritrosit, leukosit, fagositik oksidase, dan lisosim pada kelompok perlakuan menunjukkan nilai yang yang lebih tinggi dibandingkan dengan kontrol. Perbedaan yang signifikan ditunjukkan oleh sintasan, di mana kelompok perlakuan mempunyai nilai sintasan yang lebih tinggi dibandingkan dengan kelompok kontrol. Hasil tersebut diduga disebabkan oleh kandungan bahan aktif yang terdapat dalam tanaman obat. Sehingga penggunaannya mampu bertindak sebagai sebagai upaya pencegahan dari infeksi bakteri patogen S. agalactiae. Perlu diketahui juga apakah kombinasi yang digunakan mampu bertindak untuk terapi (pengobatan).Streptococcosis disease in nile tilapia culture is caused by Streptococcus agalactiae, a bacterium commonly found in freshwater systems. Vaccines and probiotics have been used to prevent the disease outbreaks. However, increasing the innate immune system of cultured fish is more effective in preventing the disease. Medicinal plants have immunostimulant properties, which could be used as an alternative prevention measure against Streptococcosis. This research aimed to determine the effects of betel and kipahit combination as immunostimulant against S. agalactiae in nile tilapia. The combinations consisted of four different doses of 1%, 2%, 4%, and 8% of the plants’ extracts per kg of feed. Feeding experiment was carried out for four weeks, followed by a challenge test using the pathogenic bacteria S. agalactiae. Despite no observable significant differences, haematocrit, erythrocyte, leukocyte, phagocytic oxidase, and lysozyme in the treatment group showed higher values than the control. The treatment groups also had better survival rates than the control group. These results indicate the presence of active compounds within the medicinal plants. In conclusion, supplementation of the plants’ active compounds in feed has the potential as immunostimulant agents in tilapia to prevent Streptococcosis disease caused by pathogenic bacteria S. agalactiae. Determining the capability of this plant combination as a therapeutic agent against S. agalactiaeis an interesting future research direction to be pursued.

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Evaluation of resistance against Streptococcus agalactiae in four farmed strains of Nile tilapia (Oreochromis niloticus)

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n1p353 ◽

2020 ◽

Vol 41 (1) ◽

pp. 351

Author(s):

Gláucia Frasnelli Mian ◽

Charles Oswaldo Roncancio ◽

Maria Cristina de Souza Silva ◽

Amanda Carvalho Rosado Ferreira ◽

Dircéia Aparecida da Costa Custódio ◽

...

Keyword(s):

Fish Species ◽

Streptococcus Agalactiae ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Survival Rates ◽

Brain Heart Infusion ◽

Resistance Test ◽

Economic Losses ◽

Control Group ◽

Nile Tilapia Oreochromis Niloticus

Nile tilapia (Oreochromis niloticus) has always been considered more resistant to diseases compared to other fish species. However, in recent decades, this fish species has also been susceptible to many bacterial, fungal, parasitic, and nutritional diseases. In Brazil, streptococcosis is one of the main diseases that affect tilapia and has caused many economic losses. A resistance test was conducted with 93 tilapia of four varieties (UFLA strain and three commercial varieties: SC1, SC2, and SC3) to evaluate resistance to experimental inoculation with Streptococcus agalactiae. Each variety was distributed in five aquariums, with nine specimens of the same variety. Among the five aquariums, four housed fish were intraperitoneally inoculated with 107 CFU/fish of S. agalactiae and one aquarium harbored fish from the control group, which received 0.1 mL of sterile BHI (Brain Heart Infusion). Significant differences were observed in the survival rates accumulated at the end of the experiment (day 15), with values of 22, 36, 36, and 15% for SC1, SC2, SC3, and UFLA, respectively. The UFLA strain presented lower survival than other strains, which did not differ among the 15 days of challenge. These results demonstrate that there are animals with a better response to the resistance test than others.

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Isolation and selection of bacteria inhibiting Streptococcus agalactiae causing dark-body disease on snakeskin gourami fish (Trichogaster pectoralis)

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/14989 ◽

2021 ◽

Vol 19 (3) ◽

pp. 547-555

Author(s):

Le Thi Anh Hong ◽

Pham Thi Minh Ngoc ◽

Duong Khanh ◽

Vo Van Tuan ◽

Nguyen Hoang Dung

Keyword(s):

Streptococcus Agalactiae ◽

Pathogenic Bacteria ◽

Survival Rates ◽

Microbial Pathogens ◽

Control Treatment ◽

Fish Ponds ◽

16S Rrna Sequence ◽

Experimental Conditions ◽

Experimental Treatments ◽

Dark Body

Streptococcus agalactiae is one of the microbial pathogens causing the dark-body disease on snakeskin gourami fish (Trichogaster pectoralis) that affects the growth and quality of fish. This research aimed to isolate and select bacteria inhibiting S. agalactiae which are able to use for controling pathogenic bacteria instead of antibiotics. Fourteen bacteria strains were isolated and screened from healthy fishes, sediment and water samples at fish ponds in Dong Thap province. Among these strains, L7 strain showed the highest inhibition ability with the clear zone diameter was 9,3 mm. The results of the 16S rRNA sequence analysis indicated that the L7 strain belonged to Bacillus subtilis. The experiment to evaluate the inhibition capacity and fish disease control of selected B. subtilis in experimental conditions was conducted by challenging fish with S. agalactiae. Fishes in the control treatment was infected with S. agalactiae at 106 CFU/mL had survival rate 41,7%. The experimental treatments NT1, NT2, NT3 which were treated with B. subtilis at concentrations of 105 CFU/mL, 106 CFU/mL, and 107 CFU/mL gave higher survival rates compared with the non-treated control, with the rates of 60%, 76,7%, and 81,7%, respectively. These results revealed that the isolated B. subtilis is potential used in control dark-body disease on snakeskin gourami fish.

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Efek Kefir Terhadap Kadar Superokdidase Dismutase, Malondialdehyde Pada Mencit Balb/C Diinduksi Streptococcus Agalactiae

Journal Of Issues In Midwifery ◽

10.21776/ub.joim.2021.005.03.1 ◽

2021 ◽

Vol 5 (3) ◽

pp. 101-110

Author(s):

Mustika Dewi ◽

◽

Mega Ulfah ◽

Keyword(s):

Streptococcus Agalactiae ◽

Pathogenic Bacteria ◽

Neonatal Morbidity ◽

Enzyme Linked Immunosorbent Assay ◽

Control Group ◽

Vaginal Mucosa ◽

Control Group Design ◽

Inflammatory Parameters ◽

Significant Difference

Streptococcus agalactiae are pathogenic bacteria which cause vaginal infection. Vaginal and cervical infections in pregnant women can reduce elasticity of the membranes that cause premature rupture of membranes. This can also impact to neonatal morbidity and mortality in first week of birth. Kefir is known as a probiotic that can act as an immunomodulator. The role of kefir is believed to improve the immune system. The role of kefir in preventing infection is still rarely studied, especially as an immunomodulator and in reducing the number of pathogenic bacteria.This study aimed to evaluate superoxide dismutase (SOD) level, Malondialdehyde (MDA) level, and the population of the colonization Streptococcus agalactiae in BALB-C mice fed kefir. This study was true experimental with post test only control group design. Sample was BALB-C mice induced by Streptococcus agalactiae. SOD and MDA level was examined by enzyme-linked immunosorbent assay (ELISA) and Streptococcus agalactiae identification by colony count. The results of the one-way ANOVA analysis showed there was no significant differences between all groups for SOD levels (P 0.393). In the level of MDA there was also no difference between all groups (P 0.204). Whereas in the number of Streptococcus agalactiae colonies there was a significant difference (P 0.000) with the smallest number of colonies found at dose of 0.5 ml / day. Conclusion: kefir as a probiotic drink did not affect to the SOD and MDA level of BALB/ C mice induced by Streptococcus agalactiae, but kefir affected to number of Streptococcus agalactiae colonies. Further research needs to show the relation of kefir as probiotics with proinflammatory and other anti-inflammatory parameters such as interleukin and immunological vaginal mucosa.

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Bayesian genomic models boost prediction accuracy for survival to Streptococcus agalactiae infection in Nile tilapia (Oreochromus nilioticus)

Genetics Selection Evolution ◽

10.1186/s12711-021-00629-y ◽

2021 ◽

Vol 53 (1) ◽

Author(s):

Rajesh Joshi ◽

Anders Skaarud ◽

Alejandro Tola Alvarez ◽

Thomas Moen ◽

Jørgen Ødegård

Keyword(s):

Genomic Selection ◽

Streptococcus Agalactiae ◽

Nile Tilapia ◽

Prediction Accuracy ◽

Predictive Accuracy ◽

Challenge Test ◽

Bacterial Disease ◽

Nucleotide Polymorphisms ◽

Genomic Selection Model ◽

Selection For

Abstract Background Streptococcosis is a major bacterial disease in Nile tilapia that is caused by Streptococcus agalactiae infection, and development of resistant strains of Nile tilapia represents a sustainable approach towards combating this disease. In this study, we performed a controlled disease trial on 120 full-sib families to (i) quantify and characterize the potential of genomic selection for survival to S. agalactiae infection in Nile tilapia, and (ii) identify the best genomic model and the optimal density of single nucleotide polymorphisms (SNPs) for this trait. Methods In total, 40 fish per family (15 fish intraperitoneally injected and 25 fish as cohabitants) were used in the challenge test. Mortalities were recorded every 3 h for 35 days. After quality control, genotypes (50,690 SNPs) and phenotypes (0 for dead and 1 for alive) for 2472 cohabitant fish were available. Genetic parameters were obtained using various genomic selection models (genomic best linear unbiased prediction (GBLUP), BayesB, BayesC, BayesR and BayesS) and a traditional pedigree-based model (PBLUP). The pedigree-based analysis used a deep 17-generation pedigree. Prediction accuracy and bias were evaluated using five replicates of tenfold cross-validation. The genomic models were further analyzed using 10 subsets of SNPs at different densities to explore the effect of pruning and SNP density on predictive accuracy. Results Moderate estimates of heritabilities ranging from 0.15 ± 0.03 to 0.26 ± 0.05 were obtained with the different models. Compared to a pedigree-based model, GBLUP (using all the SNPs) increased prediction accuracy by 15.4%. Furthermore, use of the most appropriate Bayesian genomic selection model and SNP density increased the prediction accuracy up to 71%. The 40 to 50 SNPs with non-zero effects were consistent for all BayesB, BayesC and BayesS models with respect to marker id and/or marker locations. Conclusions These results demonstrate the potential of genomic selection for survival to S. agalactiae infection in Nile tilapia. Compared to the PBLUP and GBLUP models, Bayesian genomic models were found to boost the prediction accuracy significantly.

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Benefits of nanotechnology: Dietary supplementation with nerolidol-loaded nanospheres increases survival rates, reduces bacterial loads and prevents oxidative damage in brains of Nile tilapia experimentally infected by Streptococcus agalactiae

Microbial Pathogenesis ◽

10.1016/j.micpath.2020.103989 ◽

2020 ◽

Vol 141 ◽

pp. 103989 ◽

Cited By ~ 1

Author(s):

Matheus D. Baldissera ◽

Carine F. Souza ◽

Aleksandro S. da Silva ◽

Maiara C. Velho ◽

Aline F. Ourique ◽

...

Keyword(s):

Oxidative Damage ◽

Streptococcus Agalactiae ◽

Nile Tilapia ◽

Survival Rates ◽

Dietary Supplementation

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Meningoencephalitis in farmed monosex Nile tilapia (Oreochromis niloticus L.) caused by Streptococcus agalactiae

Archives of Polish Fisheries ◽

10.1515/aopf-2017-0018 ◽

2017 ◽

Vol 25 (3) ◽

pp. 187-200 ◽

Cited By ~ 4

Author(s):

Harresh Adikesavalu ◽

Sayani Banerjee ◽

Avijit Patra ◽

Thangapalam Jawahar Abraham

Keyword(s):

Streptococcus Agalactiae ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Bacterial Infections ◽

Pathogenic Bacteria ◽

Sequencing Analysis ◽

Isolation And Identification ◽

Aeromonas Sobria ◽

Rdna Sequencing ◽

New Research

Abstract Aquaculture of tilapia is a new research venture in India. With intensification in farming practices, tilapia are increasingly susceptible to bacterial infections. This article describes the isolation and identification of pathogenic bacteria from cultured monosex Nile tilapia, Oreochromis niloticus (L.), that experienced moderate to severe mortalities in West Bengal, India between September and August 2014 and histopathological alterations in various organs. Gram-positive diplococci, identified as Streptococcus agalactiae with Streptococcus identification kits and 16S rDNA sequencing analysis, were isolated from the brain, operculum, and kidney. Other bacteria from the kidney were identified as Aeromonas sobria, A. caviae, Klebsiella pneumoniae ssp. pneumoniae, Escherichia coli, and Enterobacter cloacae. Staphylococcus epidermis was isolated from opercular hemorrhages. Histological sections of the infected tilapia brain revealed meningoencephalitis and granulomatous lesions. Sections from other organs indicated congestion, hemorrhagic and hyperplastic cells, necrosis, vacuolation, hemosiderin deposition, hypertrophic nuclei, melanomacrophage aggregation, and ruptured veins. This report is the first description of S. agalactiae as a primary pathogen causing meningoencephalitis in cultured tilapia in India.

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Penggunaan bakteri probiotik untuk pencegahan infeksi bakteri Streptococcus agalactiae pada ikan Nila, Oreochromis niloticus

e-Journal BUDIDAYA PERAIRAN ◽

10.35800/bdp.6.2.2018.20556 ◽

2018 ◽

Vol 6 (2) ◽

Author(s):

Aisin Umasugi ◽

Reiny A. Tumbol ◽

Reni L. Kreckhoff ◽

Henky Manoppo ◽

Novie P.L. Pangemanan ◽

...

Keyword(s):

Statistical Analysis ◽

Survival Rate ◽

Streptococcus Agalactiae ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Challenge Test ◽

Probiotic Bacteria ◽

Growth And Survival ◽

Significant Difference ◽

Materials Used

This study aimed to evaluate the effect of probiotic on growth and survival of tilapia (Oreochromis niloticus) against Streptococcus agalactiae infection. The test materials used were commercial probiotic bacteria and Streptococcus agalactiae. The probiotic bacteria were administered by mixing into the feed with a dose of 0 mL (without probiotics), 10 mL / kg of feed, 15 mL / kg of feed and 20 mL / kg of feed. Feed was given 3 times a day at 08.00, 12.00 and 16.00 for 21 days. After that, the challenge test was done with Streptococcus agalactiae bacteria by cohabitation. Bacteria with a density of 107 cells / mL were mixed into the water and allowed for 2 hours. The result showed that B treatment (10 mL / kg of feed) gave the best result with 93,33 percent of survival rate. Statistical analysis showed that the survival of fish in treatments B, C and D was significantly different from treatment A (P <0.1). However, there was no significant difference between treatments B, C, and D. It was also found that the addition of probiotic in feed did not affect the growth of Nile tilapia (Orechromis niloticus). Keywords : Probiotic bacteria, nile tilapia, Streptococcus agalactiae, growth, infection

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Specific Immune Response Kinetics and Mortality Patterns of Tilapia Oreochromis niloticus on Post-Cocktail Vaccination Period against the Infection of Aeromonas hydrophila and Streptococcus agalactiae

Omni-Akuatika ◽

10.20884/1.oa.2017.13.2.279 ◽

2017 ◽

Vol 13 (2) ◽

Cited By ~ 2

Author(s):

Sukenda Sukenda ◽

Tuti Sumiati ◽

Sri Nuryati ◽

Angela Mariana Lusiastuti ◽

Dendi Hidayatullah

Keyword(s):

Immune Response ◽

Streptococcus Agalactiae ◽

Aeromonas Hydrophila ◽

Oreochromis Niloticus ◽

Challenge Test ◽

Specific Immune Response ◽

Single Infection ◽

Control Group ◽

Antibody Levels ◽

Kinetics Of

ABSTRACTFish vaccination aims to induce a specific immune response indicated by an increase of antibodies in vaccinated fish. However, in accordance with time the presence of antibodies will continue to decline. The purpose of this study was to determine the kinetics of specifik immune response and trend mortality against Aeromonas hydrophila and Streptococcus agalactiae on tilapia following vaccination with cocktail vaccine. Fish vaccinated through immersion for 30 minutes in a solution of diluted vaccine. Challenge test was performed for three periods, on day 22, 50, and 78 post-vaccination, fish were challenged with single infection of A. hydrophila 108 cfu. mL-1 and S. agalactiae 104 cfu. mL-1 and co-infection of both bacteria by intraperitoneal. During rearing, the blood fish were taken for determining of serum antibodies, and its measured by ELISA. The results showed that the concentration of specific antibodies vaccinated fish were significantly higher than the control. The basal antibody levels of A. hydrophila before vaccination were higher than S. agalactiae with OD of 0.104 and 0.069 respectively. The maximum antibody response was reached within 70 days of the A. hydrophila OD= 0.264 and 56 days against S. agalactiae OD= 0.188. The mortality rate in the control group was significantly higher than vaccinated on all types and each challenge test period. The trend of mortality due to a single infection of A. hydrophila and co-infections occur more quickly than by S. agalactiae. Lowest mortality occurred in the vaccinated group at 50 day tested challenge.Keywords: kinetics antibody, Aeromnas hydrophila, Streptococcus agalactiae, Oreochromis niloticus

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The used of chopped banana Musa paradisiaca stem for stimulating immune responses and streptococcosis resistance of Nile tilapia Oreochromis niloticus

Jurnal Akuakultur Indonesia ◽

10.19027/jai.17.2.147-157 ◽

2018 ◽

Vol 17 (2) ◽

pp. 147

Author(s):

Lilis Nurjanah ◽

Sri Nuryati ◽

Alimuddin Alimuddin ◽

Kukuh Nirmala

Keyword(s):

Immune System ◽

Streptococcus Agalactiae ◽

Respiratory Burst ◽

Nile Tilapia ◽

Lysozyme Activity ◽

Time Interval ◽

Active Compounds ◽

Percent Survival ◽

Banana Stem ◽

Replacement Time

ABSTRACT Streptococcosis caused by Streptococcus agalactiae bacteria, is a type of disease that often found in Nile tilapia farming. This study was performed to determine the effectiveness of the concentration and frequency of giving chopped banana stem as the immunostimulant to stimulate the non‒specific immune system of tilapia against S. agalactiae infection. This study used factorial completely randomized design, consisted of two factors: concentration and changing frequency (replacement time interval) of banana stem on Nile tilapia rearing media with 11 treatment and each treatment was given three replications. The concentration of 5 g/L, 10 g/L and 15 g/L and the three days, seven days and no replacement time interval were used in this study. The immersion treatment with the chopped banana stem was done for 14 days, then the challenge test with S. agalactiae was on the 15th day for 14 days observation. The result showed that chopped banana stem contained active compounds of alkaloids, namely: 17.63% flavonoids, 0.02% tannin and 0.24% saponins. This active compounds could increase the non-specific immune system including respiratory burst, lysozyme activity, phagocyte activity, erythrocyte, leucocyte and haemoglobin. Treatment with a concentration of 5 g/L and no replacement of the chopped banana stem was the best treatment with 75% relative percent survival, highest than other treatments. In addition, it also has highest phagocytes (36.3%), respiratory burst (0.58 at O.D. 630), and lysozyme activity (72.7 unit/mL) after four days challenged with S. agalactiae. Keywords: Banana stem, immunostimulant, Nile tilapia, non-specific immune system, Streptococcus agalatiae ABSTRAK Penyakit Streptococcosis yang disebabkan oleh bakteri Streptococcus agalactiae merupakan jenis penyakit yang sering ditemukan pada budidaya ikan nilaPenelitian ini bertujuan untuk menentukan konsentrasi dan frekuensi pergantian cacahan batang pisang sebagai imunostimulan yang optimum sehingga dapat meningkatkan daya tahan tubuh ikan nila terhadap serangan penyakit streptococcosis yang disebabkan oleh bakteri S. agalactiae. Penelitian ini menggunakan rancangan acak lengkap faktorial. Perlakuan terdiri dari dua faktor yaitu konsentrasi dan frekuensi pergantian cacahan batang pisang pada media pemeliharaan ikan dengan 11 perlakuan dan 3 ulangan. Konsentras batang pisang yang digunakan yaitu 5 g/L, 10 g/L dan 15 g/L, sedangkan frekuensi pergantian batang pisang dalam penelitian ini yaitu tiga hari, tujuh hari dan tanpa pergantian batang pisang. Perlakuan perendaman dengan cacahan batang pisang dilakukan selama 14 hari, kemudian dilakukan uji tantang dengan bakteri S. agalactiae pada hari ke-15 selama 14 hari pengamatan. Hasil penelitian menunjukkan bahwa cacahan batang pisang ambon mengandung senyawa aktif berupa alkaloid, flavonoid (17,63%), tanin (0,02%) dan saponin (0,24%). Senyawa aktif tersebut mampu meningkatkan respons imun non-spesifik pada ikan nila yaitu respiratory burst, aktivitas lisozim, aktivitas fagositik, total leukosit, total eritrosit dan hemoglobin. Perlakuan dengan konsentrasi 5 g/L dan tanpa pergantian cacahan batang pisang merupakan perlakuan terbaik dengan nilai relative percent survival (RPS) mencapai 70%, lebih besar dibandingkan dengan perlakuan lainnya. Selain itu, perlakuan ini memiliki nilai tertinggi pada aktivitas fagositik (36,6%), respiratory burst (0,58 pada O.D. 630 nm) dan aktivitas lisozim (72,7 Unit/mL) setelah hari ke‒4 uji tantang dengan bakteri S. agalactiae. Kata kunci: batang pisang, ikan nila, imunostimulan, respons imun, Streptococcus agalactiae

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Boesenbergia pandurata application in Goldfish (Cyprinus carpio) Feed to Enhancing Fish Growth, Immunity System, and Resistance to Bacterial Infection

F1000Research ◽

10.12688/f1000research.52889.2 ◽

2021 ◽

Vol 10 ◽

pp. 766

Author(s):

Esti Handayani Hardi ◽

Gina Saptiani ◽

Rudi Agung Nugroho ◽

fadlul Rahman ◽

Sulistyawati Sulistyawati ◽

...

Keyword(s):

Bacterial Infection ◽

Cyprinus Carpio ◽

Pathogenic Bacteria ◽

Challenge Test ◽

Fish Growth ◽

Control Treatment ◽

Control Group ◽

Feeding Period ◽

Feed Conversion ◽

Resistance To Infection

Background: This study investigated how the inclusion of Boesenbergia pandurata extract (BPE) in goldfish feed affects fish growth, immunity, and resistance to infection by Aeromonas hydrophila and Pseudomonas fluorescens. Methods: Four fish feeds, were prepared by adding BPE at the concentrations of 0 (control), 2, 4, and 6 g kg-1, respectively, and 120 goldfish (Cyprinus carpio; initial weight 5 g) were separated into 12 boxes and fed with specific pellets and examined thrice. The experiment lasted 12 weeks, beginning with the different feeds, fish growth was measured at Weeks 4 and 8 after the feeding period. Moreover, a challenge test with pathogen bacteria to assay disease resistance was administered at Week 8 after the feeding period, and the survival rate and relative percentage of survival were quantified at Week 12. Results: At Week 8, the goldfish that were fed BPE-containing feeds were significantly heavier than the fish that received the control feed (pellet without BPE), and the highest weight gain, reaching 72.44 g, was obtained with Pellet 3; accordingly, the specific growth rate after BPE treatment (5.7%) was higher than that after control treatment. Conversely, the feed conversion ratio in the control group, 2.03, was higher than the ratios in the BPE groups, which were decreased to 0.55–0.90. Lastly, BPE treatment consistently enhanced the immunity parameters of goldfish (relative to control treatment) at weeks 4 and 8, and following BPE treatment, the rate of resistance against bacterial infection, 68.3%–77.0%, was higher than that after control treatment. Conclusions: BPE addition in goldfish feed clearly produces a positive effect by enhancing fish growth, immunity, and resistance to infection by pathogenic bacteria, and 4 g kg-1 is the optimal BPE concentration in feed prepared for goldfish.

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