Hien Van Doan

Effects of Cordyceps militaris spent mushroom substrate and Lactobacillus plantarum on mucosal, serum immunology and growth performance of Nile tilapia (Oreochromis niloticus)

ABSTRACT An 8‐weeks feeding trial was performed to investigate the possible effects of supplementation of Nile tilapia diet with Cordyceps militaris spent mushroom substrate (SMS) single or combined with Lactobacillus plantarum on immune parameters and growth performance. For this aim, Nile tilapia fingerlings were fed with four experimental diets namely: Diet 1 (0 – control), Diet 2 (10 g kg−1 SMS), Diet 3 (108 CFU g−1 L. plantarum), and Diet 4 (10 g kg−1 SMS + 108 CFU g−1 L. plantarum). At the end of feeding trial, skin mucus parameters, serum immune parameters, and growth performance were measured. The results indicated that supplementations SMS + L. plantarum or/and resulted in a significant increase in skin mucus lysozyme and peroxidase activities compared with the control group after 8 weeks of feeding trial (P < 0.05). The highest values of these parameters were recorded for fish fed both SMS + L. plantarum supplementations. Nonetheless, no significant difference was recorded between other supplemented groups (P < 0.05). For serum immunology, the results showed that serum lysozyme activity, alternative complement, phagocytosis, serum peroxidase, and respiratory burst activities were significantly higher in supplemented groups compared to the control (P < 0.05). The highest values were recorded in fish fed both SMS and L. plantarum with respect to the individual application. No significant differences were observed between fish fed SMS and L. plantarum (P < 0.05). Results on growth performance indicated that fish fed supplemented diets showed a statistically significant increase in the specific growth rate (SGR), weight gain (WG), final weight (FW) compared to the control group (P < 0.05). The highest SGR and WG values were observed in fish fed both dietary SMS and L. plantarum. However, no significant differences in these parameters were observed in fish fed SMS or L. plantarum alone (P > 0.05). The FCR was significantly lower in fish fed 10 g kg−1 SMS + 108 CFU g−1 L. plantarum than in other groups, while control group presented the highest values (P < 0.05). The present results suggested that the combination of these natural substances could be considered as potential feed‐additives for aquaculture farmed fish. HighlightsO. niloticus fed with 10 g kg−1 SMS or 108 CFU g−1 L. plantarum enhanced growth performance.Fish fed diet 10 g kg−1 SMS or 108 CFU g−1 L. plantarum stimulated mucosal and serum immunology.Combined of 10 g kg−1 SMS and 108 CFU g−1 L. plantarum enhanced growth and innate immune of the fish.

Effects of low molecular weight agar and Lactobacillus plantarum on growth performance, immunity, and disease resistance of basa fish (Pangasius bocourti, Sauvage 1880).

This study evaluated effects of low molecular weight agar (LMWA) and Lactobacillus plantarum singly or combined on growth performance, immunity and disease resistance of basa fish (Pangasius bocourti). Two hundred forty fish were divided into four treatments, i.e. 0 g kg(-1) LMWA (Control), 2 g kg(-1) LMWA, 10(8) cfu g(-1)L. plantarum, and 2 g kg(-1) LMWA + 10(8) cfu g(-1)L. plantarum. Following 7, 14 and 28 days of the treatment, specific growth rate (SGR), feed conversion ratio (FCR), serum lysozyme, phagocytosis, respiratory burst and alternative complement activity (ACP) were measured. A Completely Randomized Design with four replications was applied. At the end of the feeding trial, five fish were randomly selected for a challenge test against Aeromonas hydrophila. The results showed that fish fed diet of 2 g kg(-1) LMWA and 10(8) cfu g(-1) of L. plantarum singly or combined significantly enhanced SGR, FCR, serum lysozyme, phagocytosis, respiratory burst, alternative complement activities and post-challenge survival rate of P. bocourti. The results inferred that dietary of LMWA and L. plantarum stimulated growth, immunity and disease resistance of the P. bocourti.

The effects of dietary kefir and low molecular weight sodium alginate on serum immune parameters, resistance against Streptococcus agalactiae and growth performance in Nile tilapia (Oreochromis niloticus)

ABSTRACT The present study evaluates the effects of dietary kefir and low molecular weight sodium alginate (LWMSA) (singular or combined) on non‐specific immune response, disease resistance and growth performance of Nile tilapia (Oreochromis niloticus). Fish with average weight of 18.60 ± 0.04 g were supplied and randomly stocked in sixteen glass tanks (150 L) at density of 20 fish per tank. Fish were fed experimental diets as follows: 0 g kg−1 LMWSA (Control, Diet 1), 10 g kg−1 LMWSA (Diet 2), 40 g kg−1 kefir (Diet 3), and 10 g kg−1 LMWSA + 40 g kg−1 kefir (Diet 4) for 50 days. At the end of the feeding trial, serum lysozyme (SL), phagocytosis (PI), respiratory burst (RB), and alternative complement (ACH50) activities as well as growth performance were measured. Singular and combined administration of kefir and low molecular weight sodium alginate (LMWSA) significantly increased serum SL, PI, RB, and ACH50 activities compared control group (P < 0.05); the highest innate immune responses were observed in fish fed combinational diet (kefir + LMWSA) (P < 0.05). The results of experimental challenge revealed significantly higher resistance against Streptococcus agalactiae in fish fed supplemented diets and the highest post challenge survival rate was observed in synbiotic diet (P < 0.05). Similar results obtained in case of growth parameters. Feeding on supplemented diet significantly improved SGR and FCR and the highest growth parameters was observed in fish fed synbiotic diet (P < 0.05). These finding revealed that combined administration of dietary kefir and LMWSA can be considered for improving immune response, disease resistance and growth performance of Nile tilapia. HighlightsDietary administration of 10 g kg−1 LMWSA and 40 g kg−1 kefir significantly improved growth performance.Nile tilapia fed 10 g kg−1 LMWSA and 40 g kg−1 kefir significantly stimulated immune response, and disease resistance.Combination of kefir and LMWSA stimulated immunity, disease resistance, and growth performance of fish.

Enrichment of common carp ( Cyprinus carpio ) diet with medlar ( Mespilus germanica ) leaf extract: Effects on skin mucosal immunity and growth performance

Abstract A feeding trial was performed to assess the effects of dietary Medlar (Mespilus germanica) leaf extract (MLE) on the growth performance, skin mucus non‐specific immune parameters as well as mRNA levels of immune and antioxidant related genes in the skin of common carp (Cyprinus carpio) fingerlings. Fish were fed diets supplemented with graded levels (0, 0.25, 0.50, and 1.00%) of MLE for 49 days. The results revealed an improvement to the growth performance and feed conversion ratio in MLE fed carps (P < 0.05), regardless of the inclusion level. The immunoglobulin levels and interleukin 8 levels in the skin mucous and skin, respectively, revealed significant increment in fish fed 1% MLE (P < 0.05) in comparison with the other MLE treatments and control group. Also, feeding on 0.25% and 0.50% MLE remarkably increased skin mucus lysozyme activity (P < 0.05). However, there were no significant difference between MLE treated groups and control (P > 0.05) in case protease activity in the skin mucous or tumor necrosis factor alpha and interleukin 1 beta gene expression in the skin of carps (P > 0.05). The expression of genes encoding glutathione reductase and glutathione S‐transferase alpha were remarkably increased in MLE fed carps compared to the control group (P < 0.05) while carp fed 0.50% or 1.00% MLE had significantly increased glutathione peroxidase expression in their skin (P < 0.05). The present results revealed the potentially beneficial effects of MLE on the mucosal immune system and growth performance in common carp fingerlings. HighlightsMedlar leaf extract (MLE) improved growth performance in fingerlings.MLE intake altered immune related genes expression in carp skin.MLE intake elevated the expression of antioxidant enzymes gene expression in skin.

The effects of dietary Myrtle (Myrtus communis) on skin mucus immune parameters and mRNA levels of growth, antioxidant and immune related genes in zebrafish (Danio rerio)

Abstract Myrtle (Myrtus communis L., Myrtaceae) is a significant plant which naturally distributed around the globe. Although numerous studies have demonstrated the benefits of myrtle in different species, studies using the oral route are rare in the literature. In the present study, we evaluated the effect of myrtle intake on the antioxidant, immune, appetite and growth related genes as well as mucosal immune responses in zebrafish (Danio rerio) model. Zebrafish were fed control or myrtle (5, 10 and 20 g kg−1 myrtle) supplemented diets for sixty days. The results showed that, oral administration of Myrtle significantly improved mucosal immune responses (the activity of lysozyme, total Ig and protease). Furthermore, fish fed 20 g kg−1 showed remarkably higher antioxidant (sod and cat) enzymes gene expression compared other treatment. There were significant difference between myrtle fed fish and control group regarding tnf‐alpha and lyz expression. Also, evaluation of growth (gh and igf1) related genes revealed remarkable upregulation in 20 g kg−1 myrtle treatment compared other myrtle treatments and control group. Similar results was observed regarding the mRNA levels of appetite related genes (ghrl) in zebrafish fed 20 g kg−1 myrtle. The present results indicated that dietary administration of myrtle improved mucosal immune parameters and altered mRNA levels of selected genes. These results on zebrafish model also highlights the potential use of Myrtle supplements as additive in human diets. HighlightsMyrtle intake altered antioxidant related genes expression in zebra fish model.Feeding with 20 g kg−1 Myrtle elevated the expression of GH, IGF1.Dietary Myrtle (20 g kg−1) significantly elevated appetite related gene expression.Myrtle beneficially affected mucosal immune parameters.

Effects of Cordyceps militaris spent mushroom substrate on mucosal and serum immune parameters, disease resistance and growth performance of Nile tilapia, (Oreochromis niloticus)

Abstract The aim of present study was determination effects of dietary administration of C. militaris spent mushroom substrate (SMS) on mucosal and serum immune parameters, disease resistance, and growth performance of Nile tilapia (Oreochromis niloticus). Two hundred twenty five fish of similar weight (37.28 ± 0.10 g) were assigned to the following diets [0 (T1‐ Control), 5 (T2), 10 (T3), 20 (T4) and 40 g kg−1 (T5) SMS]. After 60 days of feeding trial, growth performance, skin mucus lysozyme and peroxidase activities as well as serum innate immune were measured. In addition, survival rate and innate immune responses were calculated after challenge test (15 days) against Streptococcus agalactiae. The results revealed that regardless of inclusion levels, feeding Nile tilapia with SMS supplemented diets significantly increased skin mucus lysozyme and peroxidase activities as well as serum immune parameters (SL, ACH50, PI, RB, and RB) compared control group (P < 0.05). The highest increment of immune parameters was observed in fish fed 10 g kg−1 SMS which was significantly higher than other treatments (P < 0.05). Also, the relative percent survival (RSP) in T2, T3, T4, and T5 was 61.11%, 88.89%, 66.67, and 55.56%, respectively. Among the supplemented groups, fish fed 10 g kg−1 SMS showed significant higher RPS and resistance to S. agalactiae than other groups (P < 0.05). Regarding the growth performance, SGR, WG, FW, and FCR were remarkably improved (P < 0.05) in SMS groups; the highest improvement observed in 10 g kg−1 SMS treatment. According to these finding, administration of 10 g kg−1 SMS is suggested in tilapia to improve growth performance and health status. HighlightsTilapia fed 10 g kg−1 SMS significantly stimulated mucosal and serum immune response.Diet of 10 g kg−1 SMS significantly increased survival rate of O. niloticus against S. agalactiae.Fish fed 10 g kg−1 SMS significantly enhanced growth performance and feed conversion ratio.

Effects of orange peels derived pectin on innate immune response, disease resistance and growth performance of Nile tilapia (Oreochromis niloticus) cultured under indoor biofloc system

&NA; The present study investigates the effects of orange peels derived pectin (OPDP) on skin mucus and serum immune parameters, disease resistance and growth performance of O. niloticus cultured under indoor biofloc system. Six hundred Nile tilapia (average weight 9.09 ± 0.05 g) were distributed into 15 fiber tanks (300 L per tank) assigned to five treatments repeated in triplicate. Fish were fed experimental diets contain different levels OPDP as follows: 0 (control in clear water), 0 (control in biofloc system), 5, 10, and 20 g kg−1 OPDP for 8 weeks. At weeks 4 and 8 post feeding, skin mucus lysozyme (SMLA), peroxidase activities (SMPA), serum lysozyme (SL), serum peroxidase (SP), alternative complement (ACH50), phagocytosis (PI), and respiratory burst activities (RB) as well specific growth rate (SGR), weight gain (WG), final weight (FW), and feed conversion ratio (FCR) were measured. Also, resistance against Streptococcus agalactiae was assessed after 8 weeks post‐feeding. Nile tilapia fed OPDP supplemented diets had significantly higher SMLA and SMPA compared to the controls (P < 0.05). The maximum values were observed in tilapia fed 10 g kg−1 OPDP followed by 5 and 20 g kg−1 OPDP. Nevertheless, no significant differences were observed between these two supplemented diets and between the control groups (P > 0.05). Regarding the serum immunological parameters, dietary inclusion of 10 g kg−1 OPDP showed significant higher SL and PI than other supplemented groups and control groups (P < 0.05). However, no significant differences were observed in SL and PI of fish fed 5 and 20 g kg−1 OPDP (P > 0.05). Dietary administration of OPDP significantly increased SP and ACH50 compared to the controls (P < 0.05), regardless of inclusion level. Additionally, non‐significant change was found in RB of OPDP fed fish when compared with the controls (P > 0.05). The challenge test revealed that relative percent of survival (RPS) in OPDP treatments were 45.45%, 81.82%, 50%, respectively. The highest RPS was noticed in fish fed 10 g kg−1 OPDP. Furthermore, dietary administration of OPDP significantly improved SGR, WG, FW, and FCR (P < 0.05). Overall, the present findings suggested that OPDP can be taken into account as functional feed additives for O. niloticus. HighlightsDiet of 10 g kg−1 OPDP significantly stimulated innate immune response of tilapia culture under in door biofloc system.Inclusion of 10 g kg−1 OPDP significantly increased survival rate of O. niloticus against S. agalactiae.Fish fed 10 g kg−1 OPDP significantly improved growth performance and feed conversion ratio.

Dietary administration of Pontogammarus maeoticus extract affects immune responses, stress resistance, feed intake and growth performance of caspian roach (Rutilus caspicus) fingerlings

Abstract Dietary administration of immunostimulants showed promising results for elevation of immune responses and disease resistance. The aim of the present study was to investigate the effects of dietary Pontogammarus (Pontogammarus maeoticus) extract on innate immune response, stress resistance, feed intake and growth performance of the Caspian roach fingerling. Two levels of P. maeoticus extract dilution with distilled water 1:25 [T1] and 1:50 [T2] were prepared. Experimental diets were prepared by top‐spraying the basal diet with equal amount (2%) of diluted extracts. One hundred and eighty Caspian roach fingerlings (4.30 ± 0.10 g) were supplied, stocked in nine 100‐L tanks (three treatment repeated in triplicates) and fed on experimental diets for 8 weeks. At the end of the trial, serum innate immune parameters (Total Ig, ACH50, and lysozyme activity), resistance against salinity stress, feed intake and growth parameters were measured. The results revealed remarkable increase of innate immune parameters and resistance against salinity stress in roach fed P. maeoticus extracts (P < 0.05). Also, growth performance and food intake were notably improved in P. maeoticus extracts fed fish (P < 0.05). These results revealed beneficial effects of P. maeoticus extract on innate immune response, resistance, feed intake as well as growth performance of the Caspian roach. HighlightsPontogammarus extract increased innate immune responses in the Caspian roach fingerlings.Resistance against salinity stress remarkably increased in Pontogammarus extract fed fish.Pontogammarus extract improved feed intake and growth performance of the Caspian roach fingerlings.

Histopathological impairment of common carp (Cyprinus carpio) induced through povidone-iodine exposure

Histological biomarkers are one of the most advantageous tools in monitoring toxicological studies under experimental condition in laboratory. Since disinfectants are extensively inflowing into aquatic ecosystems, this study conducted on common carp to examine the effect of betadine solution on the liver and gill tissue. A 120‐carp were kept for 2 weeks in the 100‐l aquarium Different concentrations of povidone‐iodine (betadine) prepared in three replications and a control group was prepared with no betadine (0, 5, 7, 8, and 9 ppm). Most lesions observed at gill tissue include adhesion secondary lamella, bleeding, destruction of secondary lamellae, hyperplasia secondary blades, curvature second blade, destroying the primary lamellae. Whats more, most lesions observed in liver tissue include bleeding, ascites liver, destruction of liver cells, bile stagnation. Betadine solution, could cause damage to the liver and gills tissues, although gill lesions were more evident than liver. Also increase of concentration led to elevation at lesions of both organs. Overally, the results revealed that using povidon‐iodine as a disinfectant materials and entering into rivers and aquatic ecosystems could have undesirable effects and even death of this fish. Disinfectants, either in low or high concentration, could be very lethal for fish. However the defects seen in this study also could affect osmoregulation and metabolism as two main functions of gill and liver.

Lactic Acid Bacteria in Finfish—An Update

A complex and dynamic community of microorganisms, play important roles within the fish gastrointestinal (GI) tract. Of the bacteria colonizing the GI tract, are lactic acid bacteria (LAB) generally considered as favorable microorganism due to their abilities to stimulating host GI development, digestive function, mucosal tolerance, stimulating immune response, and improved disease resistance. In early finfish studies, were culture-dependent methods used to enumerate bacterial population levels within the GI tract. However, due to limitations by using culture methods, culture-independent techniques have been used during the last decade. These investigations have revealed the presence of Lactobacillus, Lactococcus, Leuconostoc, Enterococcus, Streptococcus, Carnobacterium, Weissella, and Pediococcus as indigenous species. Numerous strains of LAB isolated from finfish are able to produce antibacterial substances toward different potential fish pathogenic bacteria as well as human pathogens. LAB are revealed be the most promising bacterial genera as probiotic in aquaculture. During the decade numerous investigations are performed on evaluation of probiotic properties of different genus and species of LAB. Except limited contradictory reports, most of administered strains displayed beneficial effects on both, growth—and reproductive performance, immune responses and disease resistance of finfish. This eventually led to industrial scale up and introduction LAB-based commercial probiotics. Pathogenic LAB belonging to the genera Streptococcus, Enterococcus, Lactobacillus, Carnobacterium, and Lactococcus have been detected from ascites, kidney, liver, heart, and spleen of several finfish species. These pathogenic bacteria will be addressed in present review which includes their impacts on finfish aquaculture, possible routes for treatment. Finfish share many common structures and functions of the immune system with warm-blooded animals, although apparent differences exist. This similarity in the immune system may result in many shared LAB effects between finfish and land animals. LAB-fed fish show an increase in innate immune activities leading to disease resistances: neutrophil activity, lysozyme secretion, phagocytosis, and production of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α). However, some LAB strains preferentially induces IL-10 instead, a potent anti-inflammatory cytokine. These results indicate that LAB may vary in their immunological effects depending on the species and hosts. So far, the immunological studies using LAB have been focused on their effects on innate immunity. However, these studies need to be further extended by investigating their involvement in the modulation of adaptive immunity. The present review paper focuses on recent findings in the field of isolation and detection of LAB, their administration as probiotic in aquaculture and their interaction with fish immune responses. Furthermore, the mode of action of probiotics on finfish are discussed.