Lactate dehydrogenase in the guppy fish (Poecilia reticulata) as a biomarker of heavy-metal pollution in freshwater ecosystems

Heavy metal concentrations and allozyme variations were determined in females of guppy fish (Poecilia reticulata) populations collected from polluted and unpolluted sites. the concentrations of Cu and Fe were significantly (P0.05) in the Zn concentrations between the polluted and the unpolluted populations indicated that Zn, as a major essential metal, was regulated in this freshwater fish. seven enzyme systems EST, G6PDH, LDH, MDH, PGI, PGM, and SDH were tested. Only LDH (lactate dehydrogenase) was found to be agood biomarker for the contamination of Cu and Fe in P. reticulata. The zymogram of teh unpolluted wild population showed the same monomorphic allele as the unpolluted domesticated guppies from a pet shop,thus, further confirming LDH in P. reticulata as agood biomarker of contamination by Cu

Developments of lactic acid bacteria as probiotic for bacterial diseases control in aquaculture

In the recent decades, lactic acid bacteria (LAB) in aquatic organism have been one of the major interesting research subjects due to their various existence strains in fish microbiota. Moreover, LABs are sometimes abundant in the intestine of several fish species. Many recent papers indicated that several LAB strains are harmless and have been reported for beneficial effects on fish health. There was also converging evidence that led us for more research and findings regarding LAB as a promising probiotics in aquaculture. This article provides an overview of the variability of LAB in gastrointestinal (GI) tract of fish and the development of this species as probiotics. LAB was known able to colonise the gut, and has antagonistic activity against some fish pathogens. This harmless bactreriocin-producing strain may confer benefits in increasing disease resistance, improving nutrient digestibility and growth of the host animals. In addition, these strains may reduce the need of antibiotics usage in future aquaculture industry

Synthetic antibody: prospects in aquaculture biosecurity

The emerging technology of aptamers that is also known as synthetic antibodies is rivalling antibodies research in the recent years. The unique yet important features of aptamers are advancing antibodies in diverse applications, which include disease diagnosis, prophylactic and therapeutic. The versatility of aptamer has further extended its application to function as gene expression modulator, known as synthetic riboswitches. This report reviewed and discussed the applications of aptamers technology in the biosecurity of aquaculture, the promising developments in biosensor detection for disease diagnosis as well as prophylactic and therapeutic measurements. The application of aptamers technology in immunophenotyping study of aquatic animal is highlighted. Lastly, the future perspective of aptamers in the management of aquatic animal health is discussed, special emphasis on the potential application of aptamers as synthetic riboswitches to enhance host immunity, as well as the growth performance

Integration of Omics Tools for Understanding the Fish Immune Response Due to Microbial Challenge

Nowadays, fish production through aquaculture and wild capture is escalating due to the higher fish protein demand for human consumption. Thus, the needs for fish products to be improved in scale and quality are becoming increasingly important to meet the nutrition requirements. The negative impacts caused by pathogens infection both in hatchery and grow-out ponds, have resulted in low aquaculture productivity and economic losses for the farmers. Therefore, a systematic study exploring relevant omics datasets through a systems biology approach will enable scientist to describe the complexity and characteristics of interactions in the host-pathogen network, leading to identifying new targets or biomarkers for diseases infection caused by bacteria, viruses, and parasites. The use of different approaches and emerging technologies as a powerful tool in obtaining a new knowledge for sustainable aquaculture production has been increasingly applied by many researchers over the years. In this paper, several omics approaches used to assess the fish immune response were reviewed. A brief description is provided for the omics approaches applicable to aquacultures, such as genomics, transcriptomics, proteomics, and metabolomics. Each tool used are contributes to develop better treatment and prevention strategies to overcome aquaculture disease due to the microbial infections. In genomics and transcriptomics analysis, their parallel approach involving gene expression studies play important role in identifying immune-related genes of the host, response to infectious diseases. While for proteomics and metabolomics approaches, these omics will provide information on the biomarker discovery and understanding the immune-related biosynthetic pathway during pathogen infection. Additionally, examples of the integrative analysis of multi-omics tools required for researchers to better understand the biological systems of aquatic animals especially fish, will also be provided

Characterization of Enterococcus hirae isolated from the intestine of Seabass (Lates Calcarifer) as a new potential probiotic against pathogenic vibrios

In this study, we aimed to isolate, identify and characterize lactic acid bacteria (LAB) from the intestine of juvenile seabass (Lates calcarifer) as a new potential probiotic. Four strains of LABs were isolated from the intestines of ten healthy seabass juveniles. In the in vitro screening process using spot lawn assay, one isolate labeled as LAB3 showed inhibitory activity against Vibrio harveyi (ATCC 35,084). Strain LAB3 was determined to belong to the gram positive bacteria group with cocci shape and was identified as Enterococcus hirae using 16S rDNA analysis. This bacterium was able to grow at pH ranging from pH 2 to 10 with the best growth at pH 7. This strain was also able to grow at 0-4% NaCl after 24 h incubation and grew best at 1.5% NaCl. Enterococcus hirae strain LAB3 of the present study is worthy to be further characterized as a potential probiotic for use in seabass culture

Gut immune system and the implications of oral-administered immunoprophylaxis in finfish aquaculture

The gastrointestinal immune system plays an important role in immune homeostasis regulation. It regulates the symbiotic host-microbiome interactions by training and developing the host’s innate and adaptive immunity. This interaction plays a vital role in host defence mechanisms and at the same time, balancing the endogenous perturbations of the host immune homeostasis. The fish gastrointestinal immune system is armed with intricate diffused gut-associated lymphoid tissues (GALTs) that establish tolerance toward the enormous commensal gut microbiome while preserving immune responses against the intrusion of enteric pathogens. A comprehensive understanding of the intestinal immune system is a prerequisite for developing an oral vaccine and immunostimulants in aquaculture, particularly in cultured fish species. In this review, we outline the remarkable features of gut immunity and the essential components of gut-associated lymphoid tissue. The mechanistic principles underlying the antigen absorption and uptake through the intestinal epithelial, and the subsequent immune activation through a series of molecular events are reviewed. The emphasis is on the significance of gut immunity in oral administration of immunoprophylactics, and the different potential adjuvants that circumvent intestinal immune tolerance. Comprehension of the intestinal immune system is pivotal for developing effective fish vaccines that can be delivered orally, which is less labour-intensive and could improve fish health and facilitate disease management in the aquaculture industry

Intraoperative hyperthermic intraperitoneal chemotherapy as adjuvant chemotherapy for advanced gastric cancer patients with serosal invasion

AbstractBackgroundTo evaluate hyperthermic intraperitoneal chemotherapy (HIPEC) as an adjuvant chemotherapy in advanced gastric cancer (AGC) patients with serosal invasion.MethodsPatients who received radical surgery and palliative surgery between January 2002 and December 2010 were retrospectively examined. Patients were divided into two groups, namely, one group that underwent surgery and another group that underwent surgery with HIPEC. All patients who received HIPEC had suspected serosal invasion on an abdominal computed tomography or by the surgeon's assessment during the operation.ResultsThe prophylactic groups included 83 patients who underwent gastrectomy alone. A total of 29 patients underwent gastrectomy with HIPEC. The 5-year survival rates were 10.7% and 43.9%, respectively. The 5-year mean survival times were 22.66 (17.55–25.78) and 34.81 (24.97–44.66) months (p = 0.029), respectively. There were 52 patients who had a recurrence of carcinomatosis among 133 patients who had resections (52/133, 39.1%). The 3-year disease-free survival rate for carcinomatosis was 28.87% in the group that received surgery alone, whereas it was 66.03% in the group that received HIPEC. There was no significant difference in the rate of complication between the two groups in the prophylactic group (p = 0.542). Thus, curative surgery with HIPEC had a better prognosis for AGC with serosal invasion. The carcinomatosis recurrence time was longer in patients who underwent gastrectomy with HIPEC and received R0 resection.ConclusionThe survival benefit of HIPEC as an adjuvant therapy for gastric cancer patients with serosal invasion should be validated in a large cohort

Dietary sodium citrate improved oxidative stability in red hybrid tilapia (Oreochromis sp.) but reduced growth, health status, intestinal short chain fatty acids and induced liver damage

Among organic acids, citric acid and their salts are currently the most studied as a supplement in aquafeeds to potentially improve growth and nutrient utilization in fish. The results have been generally beneficial but no studies have been performed on tilapia. A 50 day experiment was conducted on the effects of dietary sodium citrate at 0, 1, 2 and 4% on the growth, feeding efficiency, body indices, muscle proximate composition, muscle lipid peroxidation, some plasma and blood parameters, intestinal short chain fatty acids (SCFA), and liver histopathology of red hybrid tilapia (Oreochromis sp.). Triplicate groups of 60 tilapia fingerlings (initial weight of 1.86 ± 0.01) were in each treatment. Results showed that, while not significant, increasing dietary sodium citrate reduced tilapia growth (p > 0.05). However, muscle crude protein (r2 = 0.931), lipid (r2 = 0.962), and ash (r2 = 0.834) significantly decreased at increasing dietary sodium citrate levels (p < 0.05). Plasma ALT significantly increased (p < 0.05; r2 = 0.357) with increasing dietary sodium citrate treatments along with histopathological liver damage that included hemorrhages, necrosis and inflammatory responses. Many of the cell differential counts were significantly (p < 0.05) altered by increasing dietary sodium citrate levels. Among the intestinal SCFA in tilapia, acetic acid was the highest, followed by propionic and butyric acid, and these all significantly decreased (p < 0.05) with increasing dietary sodium citrate. In all dietary sodium citrate treatments, muscle lipid peroxidation was significantly less (p < 0.05; r2 = 0.211) indicating increased oxidative stability. While dietary sodium citrate was toxic to tilapia at the levels used, and is not recommended as a supplement, the decreased lipid peroxidation warrants further investigation with other species. Such research may have important implications for filet quality over prolonged storage. Statement of relevance: Sodium citrate reduced growth but may increase shelf-life

Comparing the effects of different dietary organic acids on the growth, intestinal short-chain fatty acids, and liver histopathology of red hybrid tilapia (Oreochromis sp.) and potential use of these as preservatives

Dietary organic acids are increasingly being investigated as a potential means of improving growth and nutrient utilization in aquatic animals. A 9-week study was performed to compare equal amounts (2%) of different organic acids (sodium butyrate, acetate, propionate, or formate) on the growth, muscle proximate composition, fatty acid composition, cholesterol and lipid peroxidation, differential cell counts, plasma biochemistry, intestinal short-chain fatty acid (SCFA) level, and liver histopathology to red hybrid tilapia (Oreochromis sp.) (initial mean weight of 2.87 g). A second experiment was performed to determine their effects on lipid peroxidation and trimethylamine (TMA) when added at 1% to tilapia meat and left out for 24 h. The results of the first experiment showed no treatment effect to growth, feeding efficiencies, or muscle fatty acid composition, but all dietary organic acids significantly decreased intestinal SCFA. Dietary butyrate and propionate significantly decreased muscle lipid peroxidation compared to the control group, but the dietary formate treatment had the lowest lipid peroxidation compared to all treatments. Muscle crude protein and lipid in tilapia fed the formate diet were significantly lower and higher, respectively, and showed evidence of stress based on the differential cell counts, significantly higher plasma glucose and liver glycogen, as well as inflammatory responses in the liver. Although a potential benefit of dietary organic acids was a reduction to lipid peroxidation, this could be accomplished post-harvest by direct additions to the meat. In addition, inclusions of butyrate and propionate to tilapia meat significantly decreased TMA, which might be a more cost-effective option to improve the shelf life of tilapia products