Novel Gammaherpesvirus Infections in Narrow-Ridged Finless Porpoise (Neophocaena asiaeorientalis) and False Killer Whales (Pseudorca crassidens) in the Republic of Korea.

A female narrow-ridged finless porpoise (Neophocaena asiaeorientalis) stranded on a beach on Jeju Island showed epithelial proliferative skin lesions on its body. Two false killer whales (Pseudorca crassidens), caught using nets near Gangneung and Samcheok, respectively, had multiple plaques on their penile epidermis. Histological examination of the epidermis revealed that all the lesions had common features, including accentuated rete pegs, ballooning changes, and eosinophilic intranuclear inclusion (INI) bodies. Based on the histopathological results, herpesvirus infection was suspected, and thus further analysis was conducted using herpesvirus-specific primers. Based on nested polymerase chain reaction (PCR) tests using the herpesvirus-detectable primers, the PCR products demonstrated two fragments: a 222-base-pair (bp) sequence of the DNA polymerase gene, SNUABM_CeHV01, showing 96.4% identity with a bottlenose dolphin herpesvirus from the Jeju narrow-ridged finless porpoise; and a 222 bp sequence of the DNA polymerase gene, SNUABM_CeHV02, showing 95.95% identity with the same bottlenose dolphin herpesvirus from the Gangneung and Samcheok false killer whales. The significance of this study lies in its ability to demonstrate the existence of novel cetacean herpesviruses in South Korean seawater, representing an important step forward in studying potentially harmful pathogens that affect endangered whale and dolphin populations.

Blood Fluke Infection (Spirorchidiasis) and Systemic Granulomatous Inflammation: A Case Study of Green Sea Turtles (Chelonia mydas) on Jeju Island, South Korea.

Despite the precarious state of marine turtles as a highly endangered species, our understanding of their diseases remains limited. This case report presents a detailed pathological investigation of spirorchiidiasis, a blood fluke infection that poses a substantial threat to marine turtles. This retrospective study examined three cases of spirorchiid-infected sea turtles, specifically, green sea turtles stranded on Jeju Island, South Korea. Premortem examination of the three spirorchiid-infected green sea turtles demonstrated nonspecific clinical symptoms; blood analysis revealed dehydration, malnutrition, and anemia. Computed tomography scans provided insights into severe pulmonary and extrapulmonary manifestations, including the mass present in the joint region. Post-mortem examinations consistently indicated severe lung lesions and systemic manifestations, with histopathological examination confirming the presence of spirorchiid ova across various organs. Despite the global prevalence of spirorchiidiasis in sea turtles, disease severity varies regionally. This report provides a detailed demonstration of the pathology of spirorchiidiasis in sea turtles from Northeast Asia.

Effect of dietary heat-killed Lactiplantibacillus plantarum VSG3 on growth, immunity, antioxidant status, and immune-related gene expression in pathogen-aggravated Cyprinus carpio.

Heat-killed probiotics offer an alternative approach to enhance growth and disease resistance in farmed fish. In this study, we isolated Lactiplantibacillus plantarum VSG3 from the gut of Labeo rohita to investigate the effects of heat-killed L. plantarum (HK-LP) on the health and growth performance of Cyprinus carpio fingerlings. Different concentrations of HK-LP (0, 50, 100, 200, 300, and 400 mg/kg) were administered to the fish, followed by a challenge with Aeromonas hydrophila after 8 weeks of feeding. Notably, the LP200 group exhibited significantly improved percentage weight gain and specific growth rate, accompanied by the lowest feed conversion ratio. Post-challenge survival rates were considerably enhanced in the LP200 group, reaching 60.65%. Moreover, serum analysis indicated significantly higher levels of total protein and albumin in the LP200 group than in the control group. Although HK-LP had no substantial impact on certain serum parameters (glucose, total cholesterol, cortisol, and alanine aminotransferase), aspartate aminotransferase levels were considerably low in the LP200 group. Intestinal protease and trypsin activities significantly increased in the LP200 group, while no significant changes were observed in lipase and amylase activities post-pathogen challenge. Serum immunological indices, including lysozyme, alternative complement pathway, and phagocytic activity, improved considerably in the LP200 group. Additionally, serum antioxidant enzyme activities (superoxide dismutase [SOD], glutathione peroxidase [GPx], catalase [CAT], and myeloperoxidase) were significantly elevated in the LP200 group, while malondialdehyde level was reduced. Gene expression analysis in liver tissue indicated strong upregulation of antioxidant-related genes (SOD, CAT, nuclear factor erythroid 2 [NFE2]-related factor 2 [Nrf2], Kelch-like ECH-associated protein 1[Keap1]) in the LP100 and LP200 groups. Pro-inflammatory cytokines (IL-1ß and TNF-α) were considerably downregulated in the kidneys of the LP200 post-challenged fish, although the anti-inflammatory cytokine IL-10 showed an increased expression. Quadratic regression analysis identified the optimal dietary HK-LP level for maximizing growth and immune performance (200.381-270.003 mg/kg). In summary, our findings underscore the potential of HK-LP as a valuable dietary supplement for enhancing carp aquaculture, particularly at the appropriate concentration.

Impact of dietary piperine on growth performance, immune response, antioxidant status, and immune-related gene expression in pathogen-aggravated Cyprinus carpio.

This study investigated the effects of dietary piperine (PIP) on growth performance, digestive enzymes, serum biochemical parameters, antioxidant and immune responses, and gene expression in Cyprinus carpio challenged with Aeromonas hydrophila. Six diets were prepared with PIP doses of 0, 0.5, 1.0, 2.0, 3.0, and 4.0 g/kg, corresponding with the control, PR50, PR100, PR200, PR300, and PR400, respectively. Fish were challenged with Aeromonas hydrophila after 8 weeks of feeding with the respective diets. Weight gain (PWG) and specific growth rate (SGR) were significantly enhanced, whereas feed conversion ratio (FCR) was lowered in PR200. The cumulative post-challenge survival was improved to 68.43% in the PR200 group compared with 28.08% in the control. Serum total protein and albumin levels were significantly enhanced in the PR200 group compared to the control. However, dietary PIP up to 3 g/kg had no significant effect on serum glucose, cortisol, aspartate aminotransferase, or alkaline phosphatase activities; however, the alanine aminotransferase level was lower (P < 0.05) in the PR200 group than in the control. Intestinal amylase, lipase, and protease activities increased in PR300, and intestinal amylase and lipase increased in the PR100 group (P < 0.05). The serum immunological indices (lysozyme, alternative complement pathway, phagocytic activity, and respiratory burst activity) were higher (P < 0.05) in the PR200 group than in the control group. Serum superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities were significantly intensified in PR200-PR300 than in the control group, with the highest activity observed in the PR200 group. Malondialdehyde was significantly lower in the PR200 group than in the control group. Furthermore, SOD, CAT, and Nrf2 expression was strongly upregulated in the liver tissue of the PR200 and PR300 groups compared to that in the control. The transcript levels of pro-inflammatory cytokines viz. IL-1ß and TNF-α were significantly upregulated in the kidneys of the PR100 and PR200 post-challenged. In contrast, the anti-inflammatory cytokine IL-10 was significantly downregulated in the kidneys of PR200. The expression of HSP70 was upregulated only in the PR400. Quadratic regression analysis showed that the optimal dietary PIP level was estimated as 2.07-2.13 g/kg to maximize growth performance. Overall, these results indicate that dietary PIP at an appropriate level can improve immunity, cytokine gene expression, and disease resistance in C. carpio.

Female Reproductive Aging and Oxidative Stress: Mesenchymal Stem Cell Conditioned Medium as a Promising Antioxidant.

The recent tendency to delay pregnancy has increased the incidence of age-related infertility, as female reproductive competence decreases with aging. Along with aging, a lowered capacity of antioxidant defense causes a loss of normal function in the ovaries and uterus due to oxidative damage. Therefore, advancements have been made in assisted reproduction to resolve infertility caused by reproductive aging and oxidative stress, following an emphasis on their use. The application of mesenchymal stem cells (MSCs) with intensive antioxidative properties has been extensively validated as a regenerative therapy, and proceeding from original cell therapy, the therapeutic effects of stem cell conditioned medium (CM) containing paracrine factors secreted during cell culture have been reported to be as effective as that of direct treatment of source cells. In this review, we summarized the current understanding of female reproductive aging and oxidative stress and present MSC-CM, which could be developed as a promising antioxidant intervention for assisted reproductive technology.

Impact of dandelion polysaccharides on growth and immunity response in common carp Cyprinus carpio.

Natural products have gained considerable attention for improving fish growth performance and immunity to enhance disease resistance. This study evaluated the effect of dandelion polysaccharides (DP) on skin mucosal immune parameters, immune-related gene expression, and susceptibility to pathogen challenge in the Common carp Cyprinus carpio. Diets containing four different concentrations of DP (g Kg-1):0 g [basal diet], 0.5 g [D1], 1.5 g [D2], 2.5 g [D3], and 4.0 g [D4] were fed to the carp (average weight: 13.92 ± 0.83 g) for eight weeks. Growth parameters were analyzed four and eight weeks after feeding. Immunological, hematological, and antioxidant parameters were examined eight weeks post-feeding. Growth performance was significantly higher on D3, with a final weight gain of 71.48 ± 1.57 g and a specific growth rate of 3.06 ± 0.12. Among hematological parameters examined, erythrocyte, hematocrit, and mean corpuscular volume (MCV) levels were significantly higher in D3. Skin mucosal immune parameters, such as lysozyme (31.04 ± 1.02 Unit mL-1), alkaline phosphatase (122.6 ± 3.8 IU L-1), and protein level (10.6 ± 0.74 mg mL-1) were significantly higher in D3, while peroxidase activity was higher in D4. Furthermore, SOD activity was higher in D2-D3, whereas catalase activity was higher in D2-D4 (P < 0.05) than in the control. Malondialdehyde level decreased significantly in D3 (5.43 ± 0.36 nmol mL-1); whereas, serum ALT and AST levels were significantly lower on D2-D4. Intestinal tight-junction-related genes ZO-1 and Claudin 7 were significantly higher in the DP-fed groups; however, DP had no significant effect on claudin 3. Occludin expression was higher (p < 0.05) on D3 only. Pro-inflammatory cytokines (IL-1ß and TNF-α) and IFN-γ strongly upregulated in the head kidney at D3. Conversely, the expression of the anti-inflammatory cytokine interleukin-10, HSP70, and TOR were considerably downregulated in D3. Fish from D3 exhibited markedly higher relative post-challenge survival (66.67%) against Aeromonas hydrophila challenge. The results of the present study suggest that dietary supplements of DP at 2.5 g kg-1 can significantly improve the growth performance, skin mucosal, and serum antioxidant parameters, and strengthen the immunity of C. carpio. Therefore, DP is a promising food additive for carp aquaculture.

Bactericidal efficacy of non-thermal plasma activation against Aeromonas hydrophila and immunological responses of koi (Cyprinus carpio haematopterus).

In the aquaculture industry, an efficient and safe water purification system is important to prevent mass mortality by virulent pathogens. As extensive use of traditional methods (e.g.: povidone-iodine, ozone, ultraviolet irradiation, formalin, and chlorine dioxide) have adverse effects on cultured fish, an appropriate and alternative water purification method is vital for the sustainability of the industry. Non-thermal plasma technology has been successfully used for various biomedical purposes (e.g: food sterilization, medical device disinfection, wound healing, cancer therapy, etc.) and has great potential to be used as a sterilizing system. However, few studies have been conducted on its usefulness in the aquaculture industry. In this study, we investigated the bactericidal efficacy of plasma-activated water induced by non-thermal plasma and its histopathological as well as immunological adverse effects on koi. A highly virulent Aeromonas hydrophila SNU HS7, which caused massive mortality of koi, was used for this study. Non-thermal plasma was applied for 10 min to the fish tanks with 1.2 × 109 CFU/mL SNU HS7 using PLMB-20 system to confirm the sterilization efficacy and to observe the survival and immunological reaction of koi for 14 days. As a result, gross pathological, histopathological, and immunological investigations did not reveal any significant adverse effects in fish as compared to the control groups. To the best of our knowledge, this is the first study showing that non-thermal plasma can be used for sterilization of rearing water without giving significant physiological damage to the fish, even under the assumption of extreme situations. As plasma can effectively sterilize not only bacteria but also other unknown pathogens, the results of this study are showing a promising future in purifying water in aquaculture practice.

A Case of Submandibular Leiomyosarcoma, Mimicking an Abscess, in a Ball Python (Python regius).

A two-year-old ball python with a submandibular mass was evaluated. Fine needle aspiration resulted in debris containing purulent materials and bacterial cells on cytology. Radiography demonstrated multi-focal radiopaque lesions in the mass, which were suspected to be mineralization; there was an absence of mandibular invasion or lung involvement. Gross examination of the surgically excised mass revealed a multi-nodular, well-circumscribed lesion with purulent material. The postoperative recovery was uneventful. The histopathological examination followed by immunohistochemistry analysis gave a diagnosis of leiomyosarcoma. As tumors containing purulent materials can be confused with an abscess, diagnostic confirmation with various diagnostical tools should be considered.

Strategy for mass production of lytic Staphylococcus aureus bacteriophage pSa-3: contribution of multiplicity of infection and response surface methodology.

BACKGROUND: Antibiotic-resistant bacteria have emerged as a serious problem; bacteriophages have, therefore, been proposed as a therapeutic alternative to antibiotics. Several authorities, such as pharmacopeia, FDA, have confirmed their safety, and some bacteriophages are commercially available worldwide. The demand for bacteriophages is expected to increase exponentially in the future; hence, there is an urgent need to mass-produce bacteriophages economically. Unlike the replication of non-lytic bacteriophages, lytic bacteriophages are replicated by lysing host bacteria, which leads to the termination of phage production; hence, strategies that can prolong the lysis of host bacteria in bacteria-bacteriophage co-cultures, are required. RESULTS: In the current study, we manipulated the inoculum concentrations of Staphylococcus aureus and phage pSa-3 (multiplicity of infection, MOI), and their energy sources to delay the bactericidal effect while optimizing phage production. We examined an increasing range of bacterial inoculum concentration (2 × 108 to 2 × 109 CFU/mL) to decrease the lag phase, in combination with a decreasing range of phage inoculum (from MOI 0.01 to 0.00000001) to delay the lysis of the host. Bacterial concentration of 2 × 108 CFU/mL and phage MOI of 0.0001 showed the maximum final phage production rate (1.68 × 1010 plaque forming unit (PFU)/mL). With this combination of phage-bacteria inoculum, we selected glycerol, glycine, and calcium as carbon, nitrogen, and divalent ion sources, respectively, for phage production. After optimization using response surface methodology, the final concentration of the lytic Staphylococcus phage was 8.63 × 1010 ± 9.71 × 109 PFU/mL (5.13-fold increase). CONCLUSIONS: Therefore, Staphylococcus phage pSa-3 production can be maximized by increasing the bacterial inoculum and reducing the seeding phage MOI, and this combinatorial strategy could decrease the phage production time. Further, we suggest that response surface methodology has the potential for optimizing the mass production of lytic bacteriophages.

Immunomodulatory Role of Microbial Surfactants, with Special Emphasis on Fish.

Microbial surfactants (biosurfactants) are a broad category of surface-active biomolecules with multifunctional properties. They self-assemble in aqueous solutions and are adsorbed on various interfaces, causing a decrease in surface tension, as well as interfacial tension, solubilization of hydrophobic compounds, and low critical micellization concentrations. Microbial biosurfactants have been investigated and applied in several fields, including bioremediation, biodegradation, food industry, and cosmetics. Biosurfactants also exhibit anti-microbial, anti-biofilm, anti-cancer, anti-inflammatory, wound healing, and immunomodulatory activities. Recently, it has been reported that biosurfactants can increase the immune responses and disease resistance of fish. Among various microbial surfactants, lipopeptides, glycolipids, and phospholipids are predominantly investigated. This review presents the various immunological activities of biosurfactants, mainly glycolipids and lipopeptides. The applications of biosurfactants in aquaculture, as well as their immunomodulatory activities, that make them novel therapeutic candidates have been also discussed in this review.

Immunostimulation by starch hydrogel-based oral vaccine using formalin-killed cells against edwardsiellosis in Japanese eel, Anguilla japonica.

Edwardsiellosis outbreaks cause significant losses in Japanese eel aquaculture. The causative agent, Edwardsiella tarda, is an intracellular pathogen, and the use of antibiotics has a limited effectiveness. As Japanese eels are sensitive to stress, injection vaccines are not recommended for treatment; immersion methods are less stressful, but not cost-effective. Alternatively, oral vaccination methods are more promising. The aim of this study was to develop a starch hydrogel-based oral (SHO) vaccine against edwardsiellosis in Japanese eel, using formalin-killed cells. To assess the protective effect, we compared SHO vaccine with the conventional formalin-killed cell (FKC) vaccine. A bacterial agglutination test showed that agglutination titers in SHO-vaccinated group were higher than in the FKC-vaccinated group. Japanese eel survival rate (%) was monitored after challenge by E. tarda at four weeks post-vaccination. Survival rates in the FKC group (60%, first trial; 70%, second trial) were lower than in SHO groups. Percentage survival rates in three SHO groups (first and second trials, respectively) were as follows: 70% and 80% in the group vaccinated once per day for one day; and 80% and 90% in both groups vaccinated for four and eight days. Additionally, a boost SHO vaccination at 46 days prompted a similar or even higher protection against edwardsiellosis than after the initial vaccination. Both FKC and SHO vaccination upregulated levels of pro-inflammatory cytokines (interleukin (IL)-6, tumor necrosis factor (TNF)-α), and host defense cytokine (interferon (IFN)-α) in all immunized groups of fish when compared with the control. These results reveal the immunostimulation effect of SHO vaccine in Japanese eel, emphasizing its potential as an oral vaccine in aquaculture.

Synergistic phage-surfactant combination clears IgE-promoted Staphylococcus aureus aggregation in vitro and enhances the effect in vivo.

Currently, topical antibiotic treatment is a major strategy for decolonisation of Staphylococcus aureus, although it may result in antibiotic resistance or recolonisation of the organism. Recently, application of bacteriophages in the treatment of S. aureus infection has attracted attention. However, a single administration of bacteriophages did not effectively decolonise S. aureus in our first trial in vivo. Using a bacteriophage (pSa-3) and surfactant combination in vitro, we showed an increased (>8%) adsorption rate of the bacteriophage on the host. Moreover, the combination increased the eradication of immunoglobulin E (IgE)-stimulated aggregation, as the surfactant promoted the dissociation of S. aureus aggregates by decreasing the size by 75% and 50% in the absence and presence of IgE, respectively. Furthermore, the combined treatment significantly decolonised the pathogen with an efficacy double that of the phage-only treatment, and decreased the expression of pro-inflammatory cytokine genes (IL-1ß, IL-12 and IFNγ) for 5 days in the second in vivo trial. These results suggest that the bacteriophage-surfactant combination could act as an alternative to antibiotics for S. aureus decolonisation in patients with dermatitis.

Genome and Phylogenetic Analysis of Infectious Hematopoietic Necrosis Virus Strain SNU1 Isolated in Korea.

Infectious hematopoietic necrosis virus (IHNV), one of the most important pathogenic fish viruses, affects trout fisheries and causes considerable economic losses. Currently, in Korea, more studies on IHNV infection are being reported. However, relatively less data is available on Korean isolates than on those from other countries. Few studies have focused on gene sequence analyses of IHNV glycoprotein (G) gene and almost none have focused on other gene fragments. Therefore, considering the dearth of adequate phylogenetic and genomic studies on Korean IHNV strains because of the lack of data, our study aimed to provide sufficient relevant data by sequencing the complete genome of the IHNV strain SNU1, which was recently isolated from a Korean rainbow trout farm. Moreover, we focused on expanding the perspectives on the phylogenesis of IHNV isolates from Korea and other Asian countries. IHNV was isolated from pooled hematopoietic tissue samples using Epithelioma papulosum cyprinid (EPC) cells, and phylogenetic analysis and genome study were conducted using complete G, N, and nonvirion (NV) gene sequences. Our main achievements were the development of a phylogenetic analytical method based on the NV gene and complete genome sequence analysis of the IHNV strain SNU1, which was compared with other Asian isolate sequences.

Detoxification, Apoptosis, and Immune Transcriptomic Responses of the Gill Tissue of Bay Scallop Following Exposure to the Algicide Thiazolidinedione 49.

Thiazolidinedione 49 (TD49), a newly synthesized algicide, shows strong toxicity at low concentrations of 0.1-2.0 µM. However, its potential effects on non-target species at the transcript level were not investigated. Differentially expressed genes (DEGs) in the gills of the bay scallop, Argopecten irradians, were accessed after treatment with 0.68 µM TD49 for up to 48 h. Following exposure, it was observed that 5214 genes were upregulated and 3497 were downregulated. Functional enrichment analysis revealed that the apoptosis pathway was activated. The extrinsic apoptosis pathway was activated and the survival factors related pathway was suppressed. Furthermore, gene expressions related to ATP-binding cassette, nuclear factor erythroid 2-related factor, B cell lymphoma-2 family protein, glutathione reductase, glutathione peroxidase, catalase, NADPH2:quinone reductase, and superoxide dismutase were decreased. Conversely, gene expressions related to FAS-associated death domain protein, glutathione S-transferase, caspase 6, 8, cytochrome P450 1A1, and 2C8 were increased. These results comprehensively demonstrated the toxicity of the novel algicide TD49, and should draw the attention of researchers to the importance of analyzing the potential impact of chemical compounds as algicides to control the proliferation of harmful algae, due to the secondary pollution caused by their application.

Characterization of the antioxidant and anti-inflammatory properties of a polysaccharide-based bioflocculant from Bacillus subtilis F9.

Microbial flocculants are versatile class of novel biomacromolecules with numerous potential industrial applications. This study sought to investigate the antimicrobial, antioxidant, and anti-inflammatory potential of a polysaccharide-based bioflocculant (PBB) extracted from Bacillus subtilis F9. To achieve this, the antioxidant activity of different PBB concentrations(100 µg/mL ̶ 1000 µg/mL) was first examined in vitro using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radicals, and superoxide radical scavenging assays. Further, the anti-inflammatory activity of PBB against lipopolysaccharide (LPS; 1 µg/mL)-induced inflammatory mediators released from headkidney (HK)-derived macrophages of Labeo rohita was investigated. Our results revealed that the capacities of 800 µg/mL of PBB to scavenge DPPH, hydroxyl radicals, and superoxide radicals were 81.46 ±â€¯1.37%, 66.34 ±â€¯2.63%, and 78.03 ±â€¯2.46%, respectively, which were slightly higher that observed following treatment with 400 µg/mL of the positive control (ascorbic acid). Further, the radical scavenging capacity of PBB was found to steadily increase with increasing concentrations of PBB. Pre-treatment with PBB also inhibited nitric oxide production in a dose-dependent manner. We next examined the effect of PBB on proinflammatory cytokines (TNF-α, and IL-1ß) and anti-inflammatory cytokines (IL-10, TGF-ß) via qRT-PCR and ELISA. We found that PBB markedly inhibited the LPS-induced mRNA and protein expression levels of TNF-α and IL-1ß, while it significantly increased those of IL-10 and TGF-ß. Further, PBB exhibited an antibacterial activity against multiple food-borne pathogens with minimal inhibitory concentration values in the range of 3 ̶ 11 mg/mL. Importantly, PBB exhibited negligible cytotoxic effects against HK macrophages. Taken together these results suggest that PBB may serve as a natural antioxidant for application in functional therapies and may also be exploited for its anti-inflammatory potential.

Effects of bioactive substance from turmeric on growth, skin mucosal immunity and antioxidant factors in common carp, Cyprinus carpio.

Present study evaluated the effects of curcumin, the principal curcuminoid of turmeric, on Cyprinus carpio growth, skin mucosal immune parameters, immune-related gene expression, and susceptibility to pathogen challenge. Diets containing four various concentrations of curcumin (g Kg-1): 0 g [basal diet], 5 g [T5], 10 g [T10], and 15 g [T15] were fed to the carp (average weight: 16.37 g) for 8 weeks. Growth parameters were analysed at 4 and 8 weeks post-feeding. Skin mucosal immune responses and expression were examined in 8 weeks post-feeding. Growth performance was significantly higher in T10 and T15, with final weight gain of 102.26 ±â€¯2.31 g and specific growth rate of 3.24 ±â€¯0.37, respectively. The lowest feed conversion ratio (2.35 ±â€¯0.16) was recorded in T15 than in the control (P < 0.05). Among the skin mucosal immune parameters examined, lysozyme (36.8 ±â€¯4.03 U mL-1), total immunoglobulin (6.74 ±â€¯0.5 mg mL-1), protein level (18.7 ±â€¯1.62 mg mL-1), alkaline phosphatase (96.37 ±â€¯6.3 IU L-1), and protease activity (9.47 ±â€¯0.82%) were significantly higher in T15, while the peroxidase activity was higher in T10 (10.24 ±â€¯0.9 U mg-1 protein). Further, lysozyme, superoxide dismutase (SOD) and catalase (CAT) activities were measured in serum and found to be higher in T10 or T15 than in the control (P < 0.05). However, malondialdehyde level decreased significantly in T10 and T15. Furthermore, antioxidant genes (SOD, CAT, nuclear factor erythroid 2-related factor 2) and anti-inflammatory cytokine Interleukin-10 were upregulated in the head kidney, intestine, and hepatopancreas of fish in T10 and T15. Conversely, expression of pro-inflammatory cytokines (IL-1ß, tumour necrosis factor-alpha), signalling molecule NF-κBp65 were down-regulated in the tested tissues of T10 and T15. Expression of Toll-like receptor 22 (TLR22) was down regulated in head-kidney and intestine of T15. Fish from T15 exhibited significantly higher relative post-challenge survival (69.70%) against Aeromonas hydrophila challenge. Results of the present study suggest that dietary supplements of curcumin at 15 g Kg-1can significantly improve the growth performance, skin mucosal and serum antioxidant parameters, and strengthen the immunity of C. carpio. Therefore, curcumin represents a promising food additive for carps in aquaculture.

Immunostimulation of Cyprinus carpio using phage lysate of Aeromonas hydrophila.

Over the last 50 years, various approaches have been established for the development of antigens for immunostimulation. We used phage lysate (PL), composed of inactivated antigens by the lytic bacteriophage pAh 6-c for Aeromonas hydrophila JUNAH strain to develop a vaccine for the prevention of A. hydrophila infection in Cyprinus carpio (common carp). We also assessed the poly D,L lactide-co-glycolic acid (PLGA) microparticles encapsulation method to increase the efficiency of the vaccine. Six groups of vaccines involving encapsulated by PLGA, formalin killed cells, or phage lysate at low or high concentration were prepared for intraperitoneal injection in C. carpio. Blood specimens and head kidney samples were collected at various time points for bacterial agglutination assay and to assess relative expression of immune-related genes interleukin-1 beta (IL-1ß), tumor necrosis factor alpha (TNF-α), lysozyme C, and serum amyloid A (SAA). The vaccine groups using high dose phage lysate antigen showed significantly higher agglutination titers than all other groups at 4- and 6-weeks post vaccination (wpv), with the titer of the PLGA encapsulated vaccine group being highest from 10 wpv to the end of the experiment. The survival rate of fish immunized with the phage lysate vaccines were higher than that of fish immunized with the formailin killed cells vaccine in the challenge experiment conducted 6 wpv. Additionally, the PLGA-encapsulated high dose phage lysate antigen vaccinated groups showed the best protective efficacy in the challenge experiment 12 wpv. Vaccines using the phage lysate antigen also showed higher IL-1ß and lysozyme C gene expression at 7 days post vaccination (dpv) and 2 wpv, and higher TNF-α gene expression was seen at 7 dpv. Higher SAA gene expression was seen in these groups at 1 dpv. These results suggest that phage lysate antigen has the potential to induce robust immune responses than formalin killed cells-based vaccines, and could be more effective as a novel inactivated antigen in preventing A. hydrophila infection in C. carpio.

Detoxification- and Immune-Related Transcriptomic Analysis of Gills from Bay Scallops (Argopectenirradians) in Response to Algal Toxin Okadaic Acid.

To reveal the molecular mechanisms triggered by okadaic acid (OA)-exposure in the detoxification and immune system of bay scallops, we studied differentially-expressed genes (DEGs) and the transcriptomic profile in bay scallop gill tissue after 48 h exposure to 500 nM of OA using the Illumina HiSeq 4000 deep-sequencing platform. De novo assembly of paired-end reads yielded 55,876 unigenes, of which 3204 and 2620 genes were found to be significantly up- or down-regulated, respectively. Gene ontology classification and enrichment analysis of the DEGs detected in bay scallops exposed to OA revealed four ontologies with particularly high functional enrichment, which were 'cellular process' (cellular component), 'metabolic process' (biological process), 'immune system process' (biological process), and 'catalytic process' (molecular function). The DEGs revealed that cyclic AMP-responsive element-binding proteins, acid phosphatase, toll-like receptors, nuclear erythroid 2-related factor, and the NADPH2 quinone reductase-related gene were upregulated. In contrast, the expression of some genes related to glutathione S-transferase 1, C-type lectin, complement C1q tumor necrosis factor-related protein, Superoxide dismutase 2 and fibrinogen C domain-containing protein, decreased. The outcomes of this study will be a valuable resource for the study of gene expression induced by marine toxins, and will help understanding of the molecular mechanisms underlying the scallops' response to OA exposure.

Complete Genome Sequence of Staphylococcus aureus Bacteriophage pSa-3.

Staphylococcus aureus phage pSa-3, isolated in South Korea from a sewage sample, has a 137-kb genome with 29% G+C content. This phage was targeted to control the bacteria in clinical isolates (mainly from skin lesions) and can be used in the decolonization of S. aureus.

Marine Toxin Okadaic Acid Affects the Immune Function of Bay Scallop (Argopecten irradians).

Okadaic acid (OA) is produced by dinoflagellates during harmful algal blooms and is a diarrhetic shellfish poisoning toxin. This toxin is particularly problematic for bivalves that are cultured for human consumption. This study aimed to reveal the effects of exposure to OA on the immune responses of bay scallop, Argopecten irradians. Various immunological parameters were assessed (total hemocyte counts (THC), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), lactate dehydrogenase (LDH), and nitric oxide (NO) in the hemolymph of scallops at 3, 6, 12, 24, and 48 h post-exposure (hpe) to different concentrations of OA (50, 100, and 500 nM). Moreover, the expression of immune-system-related genes (CLT-6, FREP, HSP90, MT, and Cu/ZnSOD) was also measured. Results showed that ROS, MDA, and NO levels and LDH activity were enhanced after exposure to different concentrations of OA; however, both THC and GSH decreased between 24-48 hpe. The expression of immune-system-related genes was also assessed at different time points during the exposure period. Overall, our results suggest that exposure to OA had negative effects on immune system function, increased oxygenic stress, and disrupted metabolism of bay scallops.