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Sample records for adult nile tilapia

  1. Successful xenogeneic germ cell transplantation from Jundia catfish (Rhamdia quelen) into adult Nile tilapia (Oreochromis niloticus) testes.

    PubMed

    Silva, M A; Costa, G M J; Lacerda, S M S N; Brandão-Dias, P F P; Kalapothakis, E; Silva Júnior, A F; Alvarenga, E R; França, L R

    2016-05-01

    Fish germ cell transplantation presents several important potential applications for aquaculture, including the preservation of germplasm from endangered fish species with high genetic and commercial values. Using this technique in studies developed in our laboratory with adult male Nile tilapias (Oreochromis niloticus), all the necessary procedures were successfully established, allowing the production of functional sperm and healthy progeny approximately 2months after allogeneic transplantation. In the present study, we evaluated the viability of the adult Nile tilapia testis to generate sperm after xenogeneic transplant of germ cells from sexually mature Jundia catfish (Rhamdia quelen) that belong to a different taxonomic order. Therefore, in order to investigate at different time-periods post-transplantation, the presence and development of donor PKH26 labeled catfish germ cells were followed in the tilapia seminiferous tubules. From 7 to 20days post-transplantation, only PKH26 labeled spermatogonia were observed, whereas spermatocytes at different stages of development were found at 70days. Germ cell transplantation success and progression of spermatogenesis were indicated by the presence of labeled PKH26 spermatids and sperm on days 90 and 120 post-transplantation, respectively. Confirming the presence of the catfish genetic material in the tilapia testis, all recipient tilapias evaluated (n=8) showed the genetic markers evaluated. Therefore, we demonstrated for the first time that the adult Nile tilapia testis offers the functional conditions for development of spermatogenesis with sperm production from a fish species belonging to a different order, which provides an important new venue for aquaculture advancement.

  2. Hydroyeast Aquaculture® as a reproductive enhancer agent for the adult Nile tilapia (Oreochromis niloticus Linnaeus, 1758).

    PubMed

    Mehrim, Ahmed I; Khalil, Fathy F; Hassan, Montaha E

    2015-04-01

    Tilapias are becoming increasingly popular culture fish because of their superior culture adaptability. In recent years, there has been a great interest in the use of probiotics in fish aquaculture. The objectives of the present study were to evaluate the effect of dietary graded levels (0, 5, 10, and 15 g/kg commercial diet, referred to treatments numbers T1, T2, T3, and T4, for males and T5, T6, T7, and T8 treatments for females) of a new probiotic Hydroyeast Aquaculture(®) on hematological and biochemical parameters, serum sex hormones, and the reproductive efficiency parameters of the adult Nile tilapia Oreochromis niloticus for 8 weeks. Results revealed that high levels of probiotics diet, 15 g (T4, ♂) and 10 g (T7, ♀) probiotic/kg diet, significantly (P ≤ 0.05) enhanced the physiological responses (hematological as well as serum biochemical parameters) together with, reproductive performances (sex hormones, testes and sperm quality parameters, absolute and relative fecundity, and ovarian measurements). Therefore, it could be conclude that Hydroyeast Aquaculture(®) is useful at levels of 15 g (T4) and 10 g (T7)/kg diet in improving the reproductive efficiency of adult O. niloticus males and females, respectively. Thus, the use of Hydroyeast Aquaculture(®) may be economically important for fish hatcheries.

  3. Substratum choice for nesting in male Nile tilapia Oreochromis niloticus.

    PubMed

    Mendonça, F Z; Volpato, G L; Costa-Ferreira, R S; Gonçalves-de-Freitas, E

    2010-10-01

    Four substrata were offered to groups of adult Nile tilapia Oreochromis niloticus (one male and two females) simultaneously: pure sand, a mixture of sand and shells, stones and no substratum. The results showed that males chose to dig nests in a lighter and more homogeneous substratum.

  4. Nile tilapia and blue tilapia fry production in a subtropical climate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship between production in earthen ponds located in a subtropical climate of fry suitable for hormonal sex inversion and degree-days was quantified for Nile tilapia (Oreochromis niloticus; Egypt strain) and blue tilapia (O. aureus). Degree-days were calculated for each trial as the sum o...

  5. First description of the adult stage of Clinostomum cutaneum Paperna, 1964 (Digenea: Clinostomidae) from grey herons Ardea cinerea L. and a redescription of the metacercaria from the Nile tilapia Oreochromis niloticus niloticus (L.) in Kenya.

    PubMed

    Gustinelli, Andrea; Caffara, Monica; Florio, Daniela; Otachi, Elick O; Wathuta, Euty M; Fioravanti, Maria L

    2010-05-01

    The combined use of morphological and molecular studies allowed for the first time the recognition and description of the adult stage of Clinostomum cutaneum Paperna, 1964 from the grey heron Ardea cinerea L. in Kenya. A redescription of the metacercaria that infect Nile tilapia Oreochromis niloticus niloticus (L.) from the same aquatic environment is also presented. C. cutaneum differs from all other species of Clinostomum Leidy, 1856 in the shape of its uterus. Sequencing the rRNA confirmed the morphological similarity between adults from the grey heron and the metacercarial stage from tilapia, and a level of genetic similarity with the other previously sequenced Clinostomum spp. was observed. The need for a reorganisation of Clinostomum using both morphological and molecular methods is highlighted.

  6. Human Streptococcus agalactiae isolate in Nile tilapia (Oreochromis niloticus).

    PubMed

    Evans, Joyce J; Klesius, Phillip H; Pasnik, David J; Bohnsack, John F

    2009-05-01

    Streptococcus agalactiae, the Lancefield group B streptococcus (GBS) long recognized as a mammalian pathogen, is an emerging concern with regard to fish. We show that a GBS serotype Ia multilocus sequence type ST-7 isolate from a clinical case of human neonatal meningitis caused disease and death in Nile tilapia (Oreochromis niloticus).

  7. Environmental color affects Nile tilapia reproduction.

    PubMed

    Volpato, G L; Duarte, C R A; Luchiari, A C

    2004-04-01

    We investigated the effects of environmental color on the reproductive behavior of Nile tilapia, Oreochromis niloticus. Two environmental colors were tested by covering the aquarium (60 x 60 x 40 cm) with white (12 groups) or blue (13 groups) cellophane and observing reproductive behavior in groups of 2 males (10.27 +/- 0.45 cm) and 3 females (10.78 +/- 0.45 cm) each. After assignment to the respective environmental color (similar luminosity = 100 to 120 Lux), the animals were observed until reproduction (identified by eggs in the female's mouth) or up to 10 days after the first nest building. Photoperiod was from 6:00 h to 18:00 h every day. Food was offered in excess once a day and water quality was similar among aquaria. Daily observations were made at 8:00, 11:00, 14:00 and 17:00 h regarding: a) latency to the first nest, b) number of nests, c) gravel weight removed (the male excavates the nest in the bottom of the aquarium), d) nest area, and e) mouthbrooding incubation (indication of reproduction). The proportion of reproducing fish was significantly higher (6 of 13) in the group exposed to the blue color compared the group exposed to the white color (1 of 12; Goodman's test of proportions). Moreover, males under blue light removed significantly larger masses of gravel (blue = 310.70 +/- 343.50 g > white = 130.38 +/- 102.70 g; P = 0.01) and constructed wider nests (blue = 207.93 +/- 207.80 cm(2) > white = 97.68 +/- 70.64 cm(2); P = 0.03) than the control (white). The other parameters did not differ significantly between light conditions. We concluded that reproduction in the presence of blue light was more frequent and intense than in the presence of white light.

  8. Masculinization of Nile tilapia (Oreochromis niloticus) by immersion in androgens

    USGS Publications Warehouse

    Gale, W.L.; Fitzpatrick, M.S.; Lucero, M.; Contreras-Sanchez, W.M.; Schreck, C. B.

    1999-01-01

    The use of all-male populations increases the efficiency and feasibility of tilapia aquaculture. The objective of this study was to determine the efficacy of a short-term immersion procedure for masculinizing Nile tilapia (Oreochromis niloticus). Two synthetic androgens were evaluated: 17α-methyldihydrotestosterone (MDHT) and 17α-methyltestosterone (MT). Exposure (3 h) on 10 and again on 13 days post-fertilization to MDHT at 500 μg/1 successfully masculinized fry in all experiments, resulting in 100, 94 and 83 ± 2% males in Experiments 1, 2 and 3, respectively. Immersions in MDHT or MT at 100 μg/1 resulted in significantly skewed sex ratios in Experiments 1 and 3 (MT resulted in 73 and 83 ± 3% males; and MDHT resulted in 72 and 91 ± 1% males) but not in Experiment 2. Immersion in MT at 500 μg/1 only caused masculinization in Experiment 3. Although further research and refinement is needed, immersion of Nile tilapia in MDHT may provide a practical alternative to the use of steroid-treated feed. Furthermore, when compared with current techniques for steroid-induced sex inversion of tilapia, short-term immersion reduces the period of time that workers are exposed to anabolic steroids.

  9. Identification and expression profiles of multiple genes in Nile tilapia in response to bacterial infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophi...

  10. A New and Fast Technique to Generate Offspring after Germ Cells Transplantation in Adult Fish: The Nile Tilapia (Oreochromis niloticus) Model

    PubMed Central

    Lacerda, Samyra M. S. N.; Batlouni, Sergio R.; Costa, Guilherme M. J.; Segatelli, Tânia M.; Quirino, Bruno R.; Queiroz, Bruno M.; Kalapothakis, Evanguedes; França, Luiz R.

    2010-01-01

    Background Germ cell transplantation results in fertile recipients and is the only available approach to functionally investigate the spermatogonial stem cell biology in mammals and probably in other vertebrates. In the current study, we describe a novel non-surgical methodology for efficient spermatogonial transplantation into the testes of adult tilapia (O. niloticus), in which endogenous spermatogenesis had been depleted with the cytostatic drug busulfan. Methodology/Principal Findings Using two different tilapia strains, the production of fertile spermatozoa with donor characteristics was demonstrated in adult recipient, which also sired progeny with the donor genotype. Also, after cryopreservation tilapia spermatogonial cells were able to differentiate to spermatozoa in the testes of recipient fishes. These findings indicate that injecting germ cells directly into adult testis facilitates and enable fast generation of donor spermatogenesis and offspring compared to previously described methods. Conclusion Therefore, a new suitable methodology for biotechnological investigations in aquaculture was established, with a high potential to improve the production of commercially valuable fish, generate transgenic animals and preserve endangered fish species. PMID:20505774

  11. Aggression and mortality among Nile tilapia (Oreochromis niloticus) maintained in the laboratory at different densities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because Nile tilapia (Oreochromis niloticus) density may affect stress levels, metabolism, and survival among tilapia in experimental studies and thus may affect experimental results, tilapia were held in a commonly-used commercial tank system to assess the relationship between fish density and beha...

  12. Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticus.

    PubMed

    Cerqueira, Marco; Rey, Sonia; Silva, Tome; Featherstone, Zoe; Crumlish, Margaret; MacKenzie, Simon

    2016-09-01

    Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 °C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice.

  13. Susceptibility of Nile tilapia (Oreochromis niloticus) fed dietary sodium chloride to nitrite toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile Nile tilapia (Oreochromis niloticus) were fed diets supplemented with 0 or 6% NaCl for 10 weeks. Tilapia were exposed to approximately 21 mg/l nitrite-N after five and ten weeks of feeding to determine the effect of dietary NaCl supplementation on resistance to nitrite toxicity. Fish were...

  14. Edwardsiella ictaluri as the causative agent of mortality in cultured Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri was consistently isolated from the spleens, livers, and head kidneys of diseased Nile tilapia Oreochromis niloticus from a farm experiencing mortality events in several culture ponds. We describe the first published outbreak of E. ictaluri–induced Edwardsiellosis in Nile tilapi...

  15. Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.).

    PubMed

    Castro, A L S; Gonçalves-de-Freitas, E; Volpato, G L; Oliveira, C

    2009-04-01

    Reproductive fish behavior is affected by male-female interactions that stimulate physiological responses such as hormonal release and gonad development. During male-female interactions, visual and chemical communication can modulate fish reproduction. The aim of the present study was to test the effect of visual and chemical male-female interaction on the gonad development and reproductive behavior of the cichlid fish Nile tilapia, Oreochromis niloticus (L.). Fifty-six pairs were studied after being maintained for 5 days under one of the four conditions (N = 14 for each condition): 1) visual contact (V); 2) chemical contact (Ch); 3) chemical and visual contact (Ch+V); 4) no sensory contact (Iso) - males and females isolated. We compared the reproductive behavior (nesting, courtship and spawning) and gonadosomatic index (GSI) of pairs of fish under all four conditions. Visual communication enhanced the frequency of courtship in males (mean +/- SEM; V: 24.79 +/- 3.30, Ch+V: 20.74 +/- 3.09, Ch: 0.1 +/- 0.07, Iso: 4.68 +/- 1.26 events/30 min; P < 0.05, two-way ANOVA with LSD post hoc test), induced spawning in females (3 spawning in V and also 3 in Ch+V condition), and increased GSI in males (mean +/- SEM; V: 1.39 +/- 0.08, Ch+V: 1.21 +/- 0.08, Ch: 1.04 +/- 0.07, Iso: 0.82 +/- 0.07%; P < 0.05, two-way ANOVA with LSD post hoc test). Chemical communication did not affect the reproductive behavior of pairs nor did it enhance the effects of visual contact. Therefore, male-female visual communication is an effective cue, which stimulates reproduction among pairs of Nile tilapia.

  16. Identification and transcriptional profile of multiple genes in the posterior kidney of Nile tilapia at 6h post bacterial infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophi...

  17. BIOLOG MICROLOG® IDENTIFICATION OF Lactococcus garvieae INFECTION IN NILE TILAPIA Oreochromis niloticus AND PINTADO Pseudoplathystoma corruscans FROM BRAZIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lactococcus garvieae infection in cultured Nile tilapia, Oreochromis niloticus, and pintado, Pseudoplathystoma corruscans from Brazil is reported. This is the first evidence of the presence of this pathogen from Brazilian fish and the first report of L. garvieae infection in either Nile tilapia or ...

  18. Outbreaks and genetic diversity of Francisella noatunensis subsp orientalis isolated from farm-raised Nile tilapia (Oreochromis niloticus) in Brazil.

    PubMed

    Leal, C A G; Tavares, G C; Figueiredo, H C P

    2014-07-25

    Francisella noatunensis subsp orientalis (FNO) is an emerging pathogen of warm water tilapia in a number of different countries. The disease caused by this bacterium in fish is characterized by a systemic granulomatous infection that causes high mortality rates during outbreaks. FNO has been previously described in Asia, Europe, and Central and North America. Its occurrence in South America has never been described. Since 2012, outbreaks of a granulomatous disease have been recorded in cage farms of Nile tilapia (Oreochromis niloticus L.) in Brazil. The current study aimed to identify the etiologic agent of recent francisellosis outbreaks at Brazilian tilapia farms, and to characterize the genetic diversity of the pathogen from farms with distinct geographic origins and without epidemiological connections. Bacteriological analysis of 44 diseased Nile tilapia collected from five cage farms in Brazil was performed during 2012 and 2013. The farms were in different locations and had no recent history of animal or biological material transport between each other. Sixty-two FNO isolates were identified on the basis of FNO-specific qPCR. The main predisposing factors for the occurrence of outbreaks on Brazilian farms were lower water temperature (<22°C) and life stage of fish, affecting mainly fry, fingerlings and young adults (live weight <100 g). The genetic diversity of the Brazilian FNO isolates was evaluated using repetitive extragenic palindromic-PCR. The isolates from different origins were shown to be clonally related. This is the first report of the occurrence and genetic diversity of FNO in South America.

  19. Investigation of antiaromatase activity using hepatic microsomes of Nile tilapia (Oreochromis niloticus).

    PubMed

    Sassa-Deepaeng, Tanongsak; Chaisri, Wasana; Pikulkaew, Surachai; Okonogi, Siriporn

    2017-03-19

    Microsomal aromatase enzymes of humans and rats have been used in antiaromatase assays, but enzyme activity is species-specific. The current study extracted hepatic microsomes of Nile tilapia (Oreochromis niloticus) to investigate and compare the antiaromatase activity of chrysin, quercetin, and quercitrin. This activity was evaluated using a dibenzylfluorescein (DBF) assay. Results revealed that the age and body weight of Nile tilapia affected the yield of extracted microsomes. Extraction of hepatic microsomes of Nile tilapia was most effective when using a reaction medium with a pH of 8.0. A DBF assay using Nile tilapia microsomes revealed significant differences in levels of antiaromatase activity for chrysin, quercetin, and quercitrin. Chrysin was the most potent aromatase inhibitor, with an IC50 of 0.25 mg/mL. In addition, chrysin is an aromatase inhibitor that also inhibits the proliferation of cancer cells. Hepatic microsomes of Nile tilapia can be used to investigate and compare the antiaromatase activity of different compounds.

  20. Identification and expression profiles of multiple genes in Nile tilapia in response to bacterial infections.

    PubMed

    Pridgeon, Julia W; Aksoy, Mediha; Klesius, Phillip H; Li, Yuehong; Mu, Xingjiang; Srivastava, Kunwar; Reddy, Gopal

    2011-11-15

    To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophila. A total of 31 unique expressed sequence tags (ESTs) were identified from 192 clones of the subtractive cDNA library. Quantitative PCR revealed that nine of the 31 ESTs were significantly (p<0.05) upregulated in Nile tilapia at 6h post infection with A. hydrophila at an injection dose of 10(5)CFU per fish (≈ 20% mortality). Of the nine upregulated genes, four were also significantly (p<0.05) induced in Nile tilapia at 6h post infection with A. hydrophila at an injection dose of 10(6)CFU per fish (≈ 60% mortality). Of the four genes induced by A. hydrophila at both injection doses, three were also significantly (p<0.05) upregulated in Nile tilapia at 6h post infection with Streptococcus iniae at doses of 10(6) and at 10(5)CFU per fish (≈ 70% and ≈ 30% mortality, respectively). The three genes induced by both bacteria included EST 2A05 (similar to adenylate kinase domain containing protein 1), EST 2G11 (unknown protein, shared similarity with Salmo salar IgH locus B genomic sequence with e value of 0.02), and EST 2H04 (unknown protein). Significant upregulation of these genes in Nile tilapia following bacterial infections suggested that they might play important roles in host response to infections of A. hydrophila and S. iniae.

  1. Molecular cloning and expression analysis of Foxp3 from Nile tilapia.

    PubMed

    Wei, Jing; Yu, Lintian; Sun, Lina; Zhang, Xiaoping; Li, Minghui; Qi, Wenchuang; Zhou, Linyan; Wang, Deshou

    2013-09-01

    Foxp3 is a crucial transcription factor for the development and function of CD4(+)CD25(+) regulatory T cells (Tr) which play a key role in preventing autoimmune diseases and maintaining maternal-fetal tolerance in mammals. However, the knowledge of Foxp3 and its regulation in teleosts is limited. In the present study, the Foxp3 cDNA was cloned from Nile tilapia and characterized. The full length cDNA of Nile tilapia (nt)Foxp3 contained a 5'UTR of 104 bp, a 3'UTR of 239 bp and an open reading frame of 1134 bp. The putative ntFoxp3 contained a C2H2 zinc finger domain, a winged-helix/fork head domain and a leucine zipper-like domain with a consensus of V-x(6)-L-x(6)-L-x(6)-L, which are typical motifs of a Foxp3. The highest mRNA expression of ntFoxp3 was observed in the spleen, with moderate expression in the head kidney, intestine, kidney, liver and brain. Stimulation of peripheral blood mononuclear cells with PHA and LPS led to a significant increase of ntFoxp3 mRNA expression at 6 and 24h, respectively. In contrast, stimulation with PMA had no effect during the sampling period. After injecting 1×10(7) cells of live Aeromonas hydrophila into adult female Nile tilapias, the mRNA expression of ntFoxp3 significantly increased in the gill and intestine at 6h, while unchanged in the spleen. In all the tissues examined, a clearly up-regulation of ntFoxp3 expression was detected at 24h after the second challenge. These results suggest that ntFoxp3 might be involved into lymphocyte activation and immune responses as reported in mammals. Meanwhile, the correlation between the expression profile of ntFoxp3 and serum estrogen (17-beta-estradiol, E2) concentration was investigated by real-time PCR and enzyme immunoassay. The results showed that E2 could regulate the expression of ntFoxp3 in the intestine and kidney but not in the spleen. This work will help future investigations into Tr cells and extend our understanding of interactions between sex hormones and immune related

  2. Diet supplemented with probiotic for Nile tilapia in polyculture system with marine shrimp.

    PubMed

    Jatobá, Adolfo; Vieira, Felipe do Nascimento; Buglione-Neto, Celso Carlos; Mouriño', José Luiz Pedreira; Silva, Bruno Corrêa; Seiftter, Walter Quadros; Andreatta, Edemar Roberto

    2011-12-01

    The aim of this study was to assess the effect of a probiotic (Lactobacillus plantarum) supplemented diet on Nile tilapia (Oreochromis niloticus) in a polyculture system with marine shrimp (Litopenaeus vannamei) as regards culture performance, hematology, and gut bacterial microbiota. Ten 20-m² pens were arranged in one earthen pond and stocked with 2 fish (41.9 g) m(-2) and 10 shrimp (2.3 g) m(-2), in total of 40 Nile tilapias and 200 shrimp per experimental unit. Tilapia groups in five of the experimental units were fed a commercial diet supplemented with L. plantarum and the other five with an unsupplemented commercial diet (control). After 12 weeks of culture, the tilapia groups fed the probiotic-supplemented diet presented values 13.6, 7.5, and 7.1% higher for feed efficiency, yield, and final weight, respectively. Viable culturable heterotrophic bacteria counts were reduced, and the number of lactic acid bacteria was increased in the gut of fish and shrimp fed the probiotic-supplemented diet. Hematological analyses showed higher number of thrombocytes and leukocytes in tilapia fed the supplemented diet. L. plantarum utilized in this study colonized the gut of tilapia and shrimp and resulted in reduced number of total bacteria and increased tilapia final weight and feed efficiency.

  3. Sinuolinea niloticus n. sp., a myxozoan parasite that causes disease in Nile tilapia (Oreochromis niloticus).

    PubMed

    Vaz Rodrigues, Marianna; Francisco, Claire Juliana; Biondi, Germano Francisco; Júnior, João Pessoa Araújo

    2016-11-01

    Sinuolinea species are myxozoans of the order Bivalvulida, suborder Variisporina, and family Sinuolineidae, which can be parasites for freshwater and marine fish. The aim of this study was to describe the occurrence of Sinuolinea niloticus n. sp. infecting Nile tilapia (Oreochromis niloticus) from aquaculture and from river sources with morphological and molecular analyses. Between March 2010 and November 2012, 116 Nile tilapia were randomly sampled from aquaculture net fishing (n = 56) in Mira Estrela, São Paulo, and from the Capivari River (n = 60) in Botucatu, São Paulo. The fishes that were sampled were examined by necropsy, microscopic observation and molecular techniques for detection and identification of the myxozoan causing disease in tilapia. All of the tissues that were sampled for analysis showed the presence of the parasite. It was observed by microscopy that the myxozoan belongs to the Sinuolinea genus. This identification was performed based on morphological characteristics and histopathology findings, such as structures consistent with myxozoan in the interstices in all analysed tissues, coagulative necrosis, haemorrhage, inflammatory processes, presence of melano-macrophages and eosinophils. The results of the molecular analyses revealed that the myxozoan detected and identified in this study is sister to a group of other Sinuolinea species. Because this is the first report of this parasite in Nile tilapia, the parasite was named S. niloticus n. sp. This is the first report of a Sinuolinea species in Brazil and in tilapia.

  4. Effect of parasitism on vaccine efficacy against Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited information is available on vaccine performance in parasitized fish. The objective of this study was to determine if parasitism of fish affected vaccine efficacy. Antibody level, hematology and survival of Nile tilapia vaccinated with a modified S. iniae bacterin were compared among non-para...

  5. Complete genome sequence of a virulent Streptococcus agalactiae strain 138P isolated from diseased Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae strain 138P was isolated from the kidney of diseased Nile tilapia in Idaho during a 2007 streptococcal disease outbreak. The full genome of S. agalactiae 138P is 1,838,716 bp. The availability of this genome will allow comparative genomics to identify genes for antigen disco...

  6. Bacterial distribution and tissue targets following experimental Edwardsiella ictaluri infection in nile tilapia Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri, a Gram-negative enteric bacterium, is the known etiological agent of enteric septicemia of catfish. In the last few years, different strains have been implicated as the causative agent of mortality events in cultured fish, including Nile tilapia Oreochromis niloticus L. Due to...

  7. Optimizing fish meal-free commercial diets for Nile Tilapia, Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A feeding trial was conducted in a closed recirculating aquaculture system with Nile tilapia Oreochromis niloticus juveniles (mean weight, 6.81 g) to examine the response to a practical diet containing protein primarily from menhaden fish meal (FM) and soybean meal (SBM) (control, Diet 1) or to diet...

  8. Parasitism affects vaccine efficacy against Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tilapia culture worldwide is estimated to be US$ 5 billion and is important to domestic and global food security. Parasites and bacteria co-occur in both extensive and intensive production of tilapia. The effect of parasitism on vaccine performance in fish is little studied. The objective of this ...

  9. Complete genome sequence of Edwardsiella ictaluri isolate RUSVM-1 recovered from nile tilapia (Oreochromis niloticus) in the Western Hemisphere

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri is a Gram-negative, bacillus that has recently been implicated in disease outbreaks in tilapia and zebrafish. We report here the complete and annotated genome of an isolate from a Nile Tilapia (Oreochromis niloticus), which contains a chromosome of 3,630,639 bp and two plasmids...

  10. Effects of Microcystis on Hypothalamic-Pituitary-Gonadal-Liver Axis in Nile Tilapia (Oreochromis niloticus).

    PubMed

    Chen, Jiazhang; Meng, Shunlong; Xu, Hai; Zhang, Zhen; Wu, Xiangyang

    2017-04-01

    In the present study, Nile tilapia (Oreochromis niloticus) were used to assess the endocrine disruption potential of Microcytis aeruginosa. Male Nile tilapia were exposed to lyophilized M. aeruginosa or purified microcystin-LR (8.3 μg/L) for 28 days. The levels of serum hormones (17β-estradiol and testosterone) and transcripts of selected genes in the hypothalamus-pituitary-gonadal-liver axis were analyzed. The results showed that serum hormones were significantly up-regulated, and transcripts of 13 genes (GHRH, PACAP, GH, GHR1, GHR2, IGF1, IGF2, CYP19a, CYP19b, 3β-HSD1, 20β-HSD, 17β-HSD1 and 17β-HSD8) were significantly altered after Microcytis exposure. These results indicate that fish reproduction can be altered in a Microcystis bloom-contaminated aquatic environment.

  11. Edwardsiella ictaluri as the causative agent of mortality in cultured Nile tilapia.

    PubMed

    Soto, Esteban; Griffin, Matt; Arauz, Maziel; Riofrio, Andres; Martinez, Alexis; Cabrejos, Maria Eugenia

    2012-06-01

    Edwardsiella ictaluri was consistently isolated from the spleens, livers, and head kidneys of diseased Nile tilapia Oreochromis niloticus from a farm experiencing mortality events in several culture ponds. We describe the first published outbreak of E. ictaluri-induced edwardsiellosis in Nile tilapia. Pure cultures of the isolated bacteria were characterized both biochemically and molecularly. Biochemical analysis was performed using the API-20E and RapID One systems, and antimicrobial susceptibility was determined by the broth microdilution method. Molecular analysis involved sequencing of the 16S rRNA gene, species-specific real-time polymerase chain reaction (PCR), and PCR-mediated genomic fingerprinting (rep-PCR). Pairwise sequence analysis of the 16S rRNA gene identified the case isolates to be a 100% match to E. ictaluri cultured from channel catfish in the southeastern United States. However, rep-PCR analysis identified the case isolates to be genetically different from representative strains isolated from disease outbreaks in cultured channel catfish in Mississippi. Infectivity challenges (intraperitoneal injection and immersion) demonstrated that a representative E. ictaluri strain isolated from tilapia was pathogenic to naive tilapia, reproducing clinical signs and mortality, thereby establishing Koch's postulates.

  12. Spatio-temporal expression patterns of anterior Hox genes during Nile tilapia (Oreochromis niloticus) embryonic development.

    PubMed

    Lyon, R Stewart; Davis, Adam; Scemama, Jean-Luc

    2013-01-01

    Hox genes encode transcription factors that function to pattern regional tissue identities along the anterior-posterior axis during animal embryonic development. Divergent nested Hox gene expression patterns within the posterior pharyngeal arches may play an important role in patterning morphological variation in the pharyngeal jaw apparatus (PJA) between evolutionarily divergent teleost fishes. Recent gene expression studies have shown the expression patterns from all Hox paralog group (PG) 2-6 genes in the posterior pharyngeal arches (PAs) for the Japanese medaka (Oryzias latipes) and from most genes of these PGs for the Nile tilapia (Oreochromis niloticus). While several orthologous Hox genes exhibit divergent spatial and temporal expression patterns between these two teleost species in the posterior PAs, several tilapia Hox gene expression patterns from PG3-6 must be documented for a full comparative study. Here we present the spatio-temporal expression patterns of hoxb3b, c3a, b4a, a5a, b5a, b5b, b6a and b6b in the neural tube and posterior PAs of the Nile tilapia. We show that several of these tilapia Hox genes exhibit divergent expression patterns in the posterior PAs from their medaka orthologs. We also compare these gene expression patterns to orthologs in other gnathostome vertebrates, including the dogfish shark.

  13. Development of a bacterial challenge test for gnotobiotic Nile tilapia Oreochromis niloticus larvae.

    PubMed

    Situmorang, Magdalena Lenny; Dierckens, Kristof; Mlingi, Frank Thomas; Van Delsen, Bart; Bossier, Peter

    2014-04-23

    Gastrointestinal microbiota have an important impact on fish health and disease, stimulating interest in a better understanding of how these gastrointestinal microbial communities are composed and consequently affect host fitness. In this respect, probiotic microorganisms have been extensively used in recent aquaculture production. To study the use of probiotics in the treatment of infectious diseases, the establishment of a method of experimental infection to obtain consistent results for mortality and infection in challenge tests is important. In pathogen-screening tests, 4 candidate pathogenic bacteria strains (Edwardsiella ictaluri gly09, E. ictaluri gly10, E. tarda LMG2793 and Streptococcus agalactiae LMG15977) were individually tested on xenic Nile tilapia larvae. Only Edwardsiella strains delivered via Artemia nauplii, with or without additional pathogen delivery via the culture water, led to increased mortality in fish larvae. A gnotobiotic Nile tilapia larvae model system was developed to provide a research tool to investigate the effects and modes-of-action of probiotics under controlled conditions. A double disinfection procedure using hydrogen peroxide and sodium hypochlorite solution was applied to the fish eggs, which were subsequently incubated in a cocktail of antibiotic and antifungal agents. In the gnotobiotic challenge test, E. ictaluri gly09R was added to the model system via Artemia nauplii and culture water, resulting in a significant mortality of the gnotobiotic fish larvae. The developed gnotobiotic Nile tilapia model can be used as a tool to extend understanding of the mechanisms involved in host-microbe interactions and to evaluate new methods of disease control.

  14. Effects of exposure to pile-driving sounds on the lake sturgeon, Nile tilapia and hogchoker

    PubMed Central

    Halvorsen, Michele B.; Casper, Brandon M.; Matthews, Frazer; Carlson, Thomas J.; Popper, Arthur N.

    2012-01-01

    Pile-driving and other impulsive sound sources have the potential to injure or kill fishes. One mechanism that produces injuries is the rapid motion of the walls of the swim bladder as it repeatedly contacts nearby tissues. To further understand the involvement of the swim bladder in tissue damage, a specially designed wave tube was used to expose three species to pile-driving sounds. Species included lake sturgeon (Acipenser fulvescens)—with an open (physostomous) swim bladder, Nile tilapia (Oreochromis niloticus)—with a closed (physoclistous) swim bladder and the hogchoker (Trinectes maculatus)—a flatfish without a swim bladder. There were no visible injuries in any of the exposed hogchokers, whereas a variety of injuries were observed in the lake sturgeon and Nile tilapia. At the loudest cumulative and single-strike sound exposure levels (SELcum and SELss respectively), the Nile tilapia had the highest total injuries and the most severe injuries per fish. As exposure levels decreased, the number and severity of injuries were more similar between the two species. These results suggest that the presence and type of swim bladder correlated with injury at higher sound levels, while the extent of injury at lower sound levels was similar for both kinds of swim bladders. PMID:23055066

  15. Vitamin C modulates cadmium-induced hepatic antioxidants' gene transcripts and toxicopathic changes in Nile tilapia, Oreochromis niloticus.

    PubMed

    El-Sayed, Yasser S; El-Gazzar, Ahmed M; El-Nahas, Abeer F; Ashry, Khaled M

    2016-01-01

    Cadmium (Cd) is one of the naturally occurring heavy metals having adverse effects, while vitamin C (L-ascorbic acid) is an essential micronutrient for fish, which can attenuate tissue damage owing to its chain-breaking antioxidant and free radical scavenger properties. The adult Nile tilapia fish were exposed to Cd at 5 mg/l with and without vitamin C (500 mg/kg diet) for 45 days in addition to negative and positive controls fed with the basal diet and basal diet supplemented with vitamin C, respectively. Hepatic relative mRNA expression of genes involved in antioxidant function, metallothionein (MT), glutathione S-transferase (GST-α1), and glutathione peroxidase (GPx1), was assessed using real-time reverse transcription polymerase chain reaction (RT-PCR). Hepatic architecture was also histopathologically examined. Tilapia exposed to Cd exhibited upregulated antioxidants' gene transcript levels, GST-⍺1, GPx1, and MT by 6.10-, 4.60-, and 4.29-fold, respectively. Histopathologically, Cd caused severe hepatic changes of multifocal hepatocellular and pancreatic acinar necrosis, and lytic hepatocytes infiltrated with eosinophilic granular cells. Co-treatment of Cd-exposed fish with vitamin C overexpressed antioxidant enzyme-related genes, GST-⍺1 (16.26-fold) and GPx1 (18.68-fold), and maintained the expression of MT gene close to control (1.07-fold), averting the toxicopathic lesions induced by Cd. These results suggested that vitamin C has the potential to protect Nile tilapia from Cd hepatotoxicity via sustaining hepatic antioxidants' genes transcripts and normal histoarchitecture.

  16. Chemical compositions and muddy flavour/odour of protein hydrolysate from Nile tilapia and broadhead catfish mince and protein isolate.

    PubMed

    Yarnpakdee, Suthasinee; Benjakul, Soottawat; Penjamras, Pimpimol; Kristinsson, Hordur G

    2014-01-01

    Chemical compositions and muddy compounds in dorsal and ventral muscles of Nile tilapia and broadhead catfish were comparatively studied. On a dry weight basis, Nile tilapia was rich in protein (93.1-93.8%), whilst broadhead catfish contained protein (55.2-59.5%) and lipid (36.6-42.4%) as the major constituents. Ventral portion had higher lipid or phospholipid contents with coincidentally higher geosmin and/or 2-methylisoborneol (2-MIB) contents. Geosmin was found in mince of Nile tilapia and broadhead catfish at levels of 1.5 and 3.2μg/kg, respectively. Broadhead catfish mince had 2-MIB at level of 0.8μg/kg, but no 2-MIB was detected in Nile tilapia counterpart. When pre-washing and alkaline solubilisation were applied for preparing protein isolate (PI), lipid and phospholipid contents were lowered with concomitant decrease in geosmin and 2-MIB contents. Protein hydrolysate produced from PI had a lighter colour and a lower amount of muddy compounds, compared with that prepared from mince. Therefore, PI from both Nile tilapia and broadhead catfish could serve as the promising proteinaceous material, yielding protein hydrolysate with the negligible muddy odour and flavour.

  17. Genome-Wide Identification and Transcriptome-Based Expression Profiling of the Sox Gene Family in the Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Wei, Ling; Yang, Chao; Tao, Wenjing; Wang, Deshou

    2016-01-01

    The Sox transcription factor family is characterized with the presence of a Sry-related high-mobility group (HMG) box and plays important roles in various biological processes in animals, including sex determination and differentiation, and the development of multiple organs. In this study, 27 Sox genes were identified in the genome of the Nile tilapia (Oreochromis niloticus), and were classified into seven groups. The members of each group of the tilapia Sox genes exhibited a relatively conserved exon-intron structure. Comparative analysis showed that the Sox gene family has undergone an expansion in tilapia and other teleost fishes following their whole genome duplication, and group K only exists in teleosts. Transcriptome-based analysis demonstrated that most of the tilapia Sox genes presented stage-specific and/or sex-dimorphic expressions during gonadal development, and six of the group B Sox genes were specifically expressed in the adult brain. Our results provide a better understanding of gene structure and spatio-temporal expression of the Sox gene family in tilapia, and will be useful for further deciphering the roles of the Sox genes during sex determination and gonadal development in teleosts. PMID:26907269

  18. Efficiency of eugenol as anesthetic for the early life stages of Nile tilapia (Oreochromis niloticus).

    PubMed

    Ribeiro, Paula A P; Miranda-Filho, Kleber C; Melo, Daniela C de; Luz, Ronald K

    2015-03-01

    In aquaculture, activities with anesthetic compounds are usually used in order to ensure the welfare of farmed fish, allowing handling out of water with decreased trauma by stress. Presently, there is no information about anesthetic action of eugenol in early life stages of Nile tilapia (Oreochromis niloticus). The objective of this study was to evaluate different concentrations of eugenol for larvae and juveniles of Nile tilapia. Sixty animals were used for each group of weight, group I = 0.02 g; group II = 0.08 g; group III = 0.22 g; group IV = 2.62 g; and group V = 11.64 g. The eugenol concentrations tested were 50, 75, 100, 125, 150 and 175 mg L-1. No mortality was reported during the tests with eugenol. Tilapia larvae with 0.02 g and juveniles around 11.64 g can be anesthetized with eugenol concentrations between 150 and 175 mg L-1, since they determine the shortest sedation time (23 and 72 seconds, for the group of lowest and highest weights, respectively).

  19. Bacterial distribution and tissue targets following experimental Edwardsiella ictaluri infection in Nile tilapia Oreochromis niloticus.

    PubMed

    Soto, Esteban; Illanes, Oscar; Revan, Floyd; Griffin, Matt; Riofrio, Andrés

    2013-05-27

    Edwardsiella ictaluri, a Gram-negative enteric bacterium, is the known etiological agent of enteric septicemia of catfish. In the last few years, different strains have been implicated as the causative agent of mortality events in cultured fish, including Nile tilapia Oreochromis niloticus L. Due to the emergent nature of edwardsiellosis in non-ictalurid fish, little is known about the dynamics of E. ictaluri infection in tilapia. The purpose of this study was to gain a better understanding of the pathogenesis of edwardsiellosis in tilapia by determining the median lethal and infective doses, tissue targets of infection, rate of bacterial dissemination, and the specific tissue response to E. ictaluri following an immersion challenge with bacterial strains recovered from outbreak events in tilapia. In addition to histopathology assessment, the bacterial burdens in several tissues of infected fish were determined over a 2 wk course of infection using quantitative real-time PCR (qPCR). The collected data suggest the cutaneous and oral routes as the main ports of entry for the organism, which later spreads hematogenously throughout the body. Even though histopathological assessment of infected fish revealed involvement of a wide range of tissues, the severity of the necrotizing and granulomatous lesions in the spleen and head kidney, with concomitant high levels of bacterial DNA in these organs determined by qPCR, identifies them as the main targets of infection.

  20. Global DNA Methylation Changes in Nile Tilapia Gonads during High Temperature-Induced Masculinization

    PubMed Central

    Wang, Hui; Li, Ning

    2016-01-01

    In some fish species, high or low temperature can switch the sex determination mechanisms and induce fish sex reversal when the gonads are undifferentiated. During this high or low temperature-induced sex reversal, the expressions of many genes are altered. However, genome-wide DNA methylation changes in fish gonads after high or low temperature treatment are unclear. Herein, we compared the global DNA methylation changes in the gonads from control females (CF), control males (CM), high temperature-treated females (TF), and high temperature-induced males (IM) from the F8 family of Nile tilapia (Oreochromis niloticus) using methylated DNA immunoprecipitation sequencing. The DNA methylation level in CF was higher than that in CM for various chromosomes. Both females and males showed an increase in methylation levels on various chromosomes after high-temperature induction. We identified 64,438 (CF/CM), 63,437 (TF/IM), 98,675 (TF/CF), 235,270 (IM/CM) and 119,958 (IM/CF) differentially methylated regions (DMRs) in Nile tilapia gonads, representing approximately 0.70% (CF/CM), 0.69% (TF/IM), 1.07% (TF/CF), 2.56% (IM/CM), and 1.30% (IM/CF)of the length of the genome. A total of 89 and 65 genes that exhibited DMRs in their gene bodies and promoters were mapped to the Nile tilapia genome. Furthermore, more than half of the genes with DMRs in the gene body in CF/CM were also included in the IM/CM, TF/CF, TF/IM, and IM/CF groups. Additionally, many important pathways, including neuroactive ligand-receptor interaction, extracellular matrix-receptor interaction, and biosynthesis of unsaturated fatty acids were identified. This study provided an important foundation to investigate the molecular mechanism of high temperature-induced sex reversal in fish species. PMID:27486872

  1. Global DNA Methylation Changes in Nile Tilapia Gonads during High Temperature-Induced Masculinization.

    PubMed

    Sun, Li-Xue; Wang, Yi-Ya; Zhao, Yan; Wang, Hui; Li, Ning; Ji, Xiang Shan

    2016-01-01

    In some fish species, high or low temperature can switch the sex determination mechanisms and induce fish sex reversal when the gonads are undifferentiated. During this high or low temperature-induced sex reversal, the expressions of many genes are altered. However, genome-wide DNA methylation changes in fish gonads after high or low temperature treatment are unclear. Herein, we compared the global DNA methylation changes in the gonads from control females (CF), control males (CM), high temperature-treated females (TF), and high temperature-induced males (IM) from the F8 family of Nile tilapia (Oreochromis niloticus) using methylated DNA immunoprecipitation sequencing. The DNA methylation level in CF was higher than that in CM for various chromosomes. Both females and males showed an increase in methylation levels on various chromosomes after high-temperature induction. We identified 64,438 (CF/CM), 63,437 (TF/IM), 98,675 (TF/CF), 235,270 (IM/CM) and 119,958 (IM/CF) differentially methylated regions (DMRs) in Nile tilapia gonads, representing approximately 0.70% (CF/CM), 0.69% (TF/IM), 1.07% (TF/CF), 2.56% (IM/CM), and 1.30% (IM/CF)of the length of the genome. A total of 89 and 65 genes that exhibited DMRs in their gene bodies and promoters were mapped to the Nile tilapia genome. Furthermore, more than half of the genes with DMRs in the gene body in CF/CM were also included in the IM/CM, TF/CF, TF/IM, and IM/CF groups. Additionally, many important pathways, including neuroactive ligand-receptor interaction, extracellular matrix-receptor interaction, and biosynthesis of unsaturated fatty acids were identified. This study provided an important foundation to investigate the molecular mechanism of high temperature-induced sex reversal in fish species.

  2. Effects of dietary genistein on GH/IGF-I axis of Nile tilapia Oreochromis niloticus

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Wang, Wei; Ru, Shaoguo

    2016-09-01

    There is considerable concern that isoflavones, such as genistein in fish feed composed of soybean protein, aff ects somatic growth in fish. Our previous works demonstrated that 30 and 300 μg/g dietary genistein had no significant eff ect on growth performance in Nile tilapia ( Oreochromis niloticus), but the higher level of genistein (3 000 μg/g) significantly depressed growth. This study was conducted to further examine the eff ects of dietary genistein on the endocrine disruption on growth hormone/insulin-like growth factor-I (GH/IGF-I) axis in Nile tilapia ( O. niloticus). Juvenile fish were fed by hand twice daily to satiation with one of four isonitrogenous and isoenergetic diets, each containing either 0, 30, 300 or 3 000 μg/g genistein. Following an 8-week feeding period, plasma GH and IGF-I levels were investigated by radioimmunoassay and gene expression levels of gh, ghrelin, gnrhs, ghr, npy, npyrs, pacap, ghrs, i gf-I, igf-Ir, and igfbp3 were examined by real-time PCR. The results show that no significant change in plasma GH and IGF-I levels in fish fed with diets containing 30 μg/g and 300 μg/g genistein. mRNA expression of genes along the GH/IGF-I axis remained unaff ected, except for igf-Ir, which was stimulated by the 300 μg/g genistein diet. While in fish fed the 3 000 μg/g genistein diet, the plasma GH and IGF-I levels decreased, and mRNA expression of gh, ghr2, npyr1, igf-I, and igf-Ir were also significantly depressed. In contrast, npy and igfbp3 mRNA expression were enhanced. This study provides convincing evidence for growth impediment by genistein by disturbing the GH/IGF-I axis in Nile tilapia O. niloticus.

  3. Biochemical alterations in caged Nile tilapia Oreochromis niloticus.

    PubMed

    Franco, Jeferson Luis; Trevisan, Rafael; Posser, Thais; Trivella, Daniela B B; Hoppe, Roberto; Martins Rosa, Juliana; Fernandes Dinslaken, Daniel; Decker, Helena; Inês Tasca, Carla; Bainy Leal, Rodrigo; Freire Marques, Maria Risoleta; Dias Bainy, Afonso Celso; Luiz Dafre, Alcir

    2010-07-01

    Joinville is an important industrial city in Santa Catarina, southern Brazil, and also a risk factor for the Babitonga drainage basin. Oxidative stress-related parameters were evaluated in caged tilapia (Oreochromis niloticus) exposed for 7 days (sites S1 and S2) in a Babitonga drainage basin tributary river. Site S1 showed enhanced levels of hepatic CYP1A, CYP2B-like and glutathione S-transferase activity, while site S2 showed decreased levels of glutathione and increased lipoperoxidation indexes, catalase, glutathione peroxidase and glutathione reductase activity. Correlation analyses revealed that oxidative stress-related parameters behaved like a group of interrelated variables, while CYPs and glutathione S-transferase seem to be independent. New putative biomarkers were evaluated in the tilapia brain. Caspase-3 activation (both sites), decreased in p38MAPK phosphorylation (site S2) and decreased expression in HSP70 (site S1) were observed. Data indicate that employed variables, when used as a group (oxidative stress-related parameters, CYP1A/2B-like, caspase-3, HSP70 and protein kinases) can be useful as predictors of pollution.

  4. Mianserin affects alarm reaction to conspecific chemical alarm cues in Nile tilapia.

    PubMed

    Barreto, Rodrigo Egydio

    2017-02-01

    In this study, I show that mianserin, a chemical with serotonin and adrenoceptor antagonist activities, increases fish vulnerability to a potential predator threat, when prey fish must deal with this threat based on conspecific chemical alarm cues. For that, I evaluated whether mianserin, diluted in the water, influences the behavioral responses of Nile tilapia (Oreochromis niloticus) to conspecific skin extract (chemical alarm cues). I found that, while mianserin did not abolished antipredator responses, this drug mitigates some components of this defensive reaction. Thus, a potential decrease in serotonin and adrenergic activities reduces the ability of dealing with predators when perceiving conspecific chemical alarm cues.

  5. Ameliorative effects of Rosmarinus officinalis leaf extract and Vitamin C on cadmium-induced oxidative stress in Nile tilapia Oreochromis niloticus.

    PubMed

    Al-Anazi, Marim Saleh; Virk, Promy; Elobeid, Mai; Siddiqui, Muzammil Iqbal

    2015-11-01

    The present studywas undertaken to assess the bioaccumulation potential of cadmium in liver, kidney, gills and muscles of freshwater fish, Nile tilapia Oreochromis niloticus and the changes in oxidative stress indices in liver and kidney with or without simultaneous treatment with waterborne vitamin C and rosemary leaf extract. Adult tilapia were divided into seven groups. Six groups were exposed to sublethal concentrations of Cd, three groups to 5 ppm, while other three to 10 ppm. Two groups from each of the Cd exposed groups were treated with Vitamin C (5ppm) and rosemary leaf extract (2.5 ppm) for a period of 21 days. Cadmium concentration in liver, kidneys and gills was significantly higher in the cadmium exposed groups being invariably high in the groups exposed to 10 ppm CdCl2.H2O.Treatment with Vitamin C and rosemary leaf extract significantly reduced cadmium concentration in comparison to non-treated Cd exposed groups. Treatment with Vitamin C and rosemary leaf extract significantly reduced oxidative stress in Cd exposed fish as evidenced from lower concentration of lipid peroxides and reduced activity of catalase and higher activity of superoxide dismutase in liver and kidney as compared to control fish. Reduction in Cd induced oxidative stress and bioaccumulation was comparable between the two antioxidant treatments, Vitamin C and rosemary leaf extract. The key findings suggest that both the antioxidants used showed ameliorative potential to reduce tissue accumulation of Cd and associated oxidative stress in fresh water fish, Nile tilapia.

  6. Development and efficacy of novobiocin and rifampicin-resistant Aeromonas hydrophila as novel vaccines in channel catfish and Nile tilapia.

    PubMed

    Pridgeon, Julia W; Klesius, Phillip H

    2011-10-19

    Three attenuated Aeromonas hydrophila vaccines were developed from the virulent 2009 West Alabama isolates through selection for resistance to both novobiocin and rifampicin. When channel catfish (Ictalurus punctatus) were IP injected with 4×105 colony-forming unit (CFU) of the mutants, no fish died. However, when the same age and size matched channel catfish were IP injected with similar amount of their virulent parents, 80-100% fish died. Similarly, when Nile tilapia (Oreochromis niloticus) were IP injected with 2×108 CFU of the mutants, no fish died. However, when Nile tilapia were IP injected with similar amount of the mutants, all fish died. Vaccination of channel catfish with the mutants at dose of 4×105 CFU/fish offered 86-100% protection against their virulent parents at 14 days post vaccination (dpv). Vaccination of Nile tilapia with the mutants at dose of 2×108 CFU/fish offered 100% protection against their virulent parents at 14, 28, and 56 dpv. Agglutination assay results suggested that protection elicited by the mutants was partially due to antibody-mediated immunity. Taken together, our results suggest that the three attenuated vaccines might be used to protect channel catfish and Nile tilapia against the highly virulent 2009 West Alabama isolates of A. hydrophila.

  7. Growth Responses and Resistance to Streptococccus iniae of Nile Tilapia, Oreochromis niloticus Fed Diets Containing Distiller's Dried Grains with Solubles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the effect of dietary levels of distiller’s dried grains with solubles (DDGS) on growth performance, body composition, hematology, immune response and resistance of Nile tilapia to Streptococcus iniae challenge. Five isocaloric diets containing DDGS at levels of ...

  8. Efficacy of QCDCR formulated CpG ODN 2007 in Nile tilapia against Streptococcus iniae and identification of upregulated genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential of using a QCDCR (quilA:cholesterol:dimethyl dioctadecyl ammonium bromide:carbopol:R1005 glycolipid) formulated CpG oligodeoxynucleotide (ODN), ODN 2007, to confer protection in Nile tilapia against Streptococcus iniae infection was evaluated in this study. At two days post treatment, ...

  9. Protection induced by a CpG oligonucelotide in Nile tilapia against Streptococcus iniae infection and identification of upregulated genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At two days post treatment, a CpG oligodeoxynucleotide (CpG 120818-9A) offered Nile tilapia (Oreochromis niloticus L.) significant (P<0.05) protection against Streptococcus iniae infection, with relative percent survival up to 63%. To understand the molecular mechanisms involved in the protective im...

  10. Effects of Yeast Oligosaccharide Diet Supplements on Growth and Disease Resistance in Juvenile Nile Tilapia, Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercially available yeast, and yeast subcomponents consisting mainly of beta-glucan or oligosaccharide feed additives, were added to diets of juvenile (12-18g) Nile tilapia (Oreochromis niloticus) at rates recommended by suppliers. Three experiments followed a basic protocol with varied rates of...

  11. Determination of florfenicol dose rate in feed for control of mortality in nile tilapia Oreochromis nilotica infected with streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A dose titration study was conducted to determine the dosage of florfenicol (FFC) in feed to control Streptococcus iniae-associated mortality in Nile tilapia Oreochromis niloticus. Six tanks were assigned to each of five treatments: (1) not challenged with S. iniae and fed unmedicated feed; (2) chal...

  12. Edwardsiella tarda and Aeromonas hydrophila isolated from diseased Southern flounder (Paralichthys lethostigma) are virulent to channel catfish and Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study is to identify bacterial pathogens isolated from diseased Southern flounder and determine their virulence to channel catfish and Nile tilapia. Twenty five Gram-negative bacteria isolates were recovered from five tissues (skin lesions, brain, liver, intestine, and posterior kidn...

  13. Prophylactic effect of Andrographis paniculata extracts against Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus).

    PubMed

    Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat

    2009-05-01

    Six herbs were assessed for their antimicrobial activity against Streptococcus agalactiae, a major fish pathogen causing streptococcosis. Each herb was extracted with 3 solvents: water, 95% ethanol, and methanol. Using swab paper disc assays, aqueous extracts of Andrographis paniculata and Allium sativum produced the largest (27.5 mm) and smallest (10.3 mm) inhibition zones, respectively. Determination of minimal inhibitory concentration (MIC) of herb extracts against S. agalactiae showed that the aqueous extract of A. paniculata had the lowest MIC value (31.25 microg/mL). Aqueous extract of A. sativum was the only herb extract with a MIC > 500 microg/mL. Based on mortalities in 2 weeks after intraperitoneal S. agalactiae injection, the median lethal dose (LD(50)) of S. agalactiae for Nile tilapia (Oreochromis niloticus) was 3.79 x 10(5) CFU/mL. In vivo experiments showed that fish feed supplemented with either A. paniculata leaf powder or dried matter of A. paniculata aqueous extract reduced mortality of S. agalactiae infected Nile tilapia. In addition, no mortality was found in fish receiving dried matter of A. paniculata aqueous extract supplemented feeds at ratios (w/w) of 4:36 and 5:35. During 2 weeks of feeding with A. paniculata supplemented feeds, no adverse effects on appearance, behavior, or feeding responses were observed.

  14. Arsenic-induced genotoxicity in Nile tilapia (Orechromis niloticus); the role of Spirulina platensis extract.

    PubMed

    Sayed, Alaa El-Din H; Elbaghdady, Heba Allah M; Zahran, Eman

    2015-12-01

    Arsenic (As) is one of the most relevant environmental global single substance toxicants that have long been regarded as a carcinogenic and genotoxic potential. In this respect, we evaluated the cytogenetic effect of arsenic exposure in Nile tilapia (Oreochromis niloticus), in terms of erythrocyte alteration, apoptosis, and induction of micronuclei. Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phytoantioxidant, anti-inflammatory, and anti-cancerous properties supplementation. The protective role of Spirulina as supplementary feeds was studied in Nile tilapia (O. niloticus) against arsenic-induced cytogenotoxicity. Four groups were assigned as control group (no SP or As), As group (exposed to water-born As in the form of NaAsO2 at 7 ppm), SP1 (SP at 7.5% + As at the same level of exposure), and SP2 (SP at 10% + As at the same level of exposure). As-treated group had a significant increase in all cytogenetic analyses including erythrocyte alteration, apoptosis, and induction of micronuclei after 2 weeks with continuous increase in response after 3 weeks. The combined treatment of Spirulina at two different concentrations of 7.5 and 10% had significantly declined the induction of erythrocyte alteration, apoptosis, and micronuclei formation induced by arsenic intoxication.

  15. Oxidative damage in gills and liver in Nile tilapia (Oreochromis niloticus) exposed to diazinon.

    PubMed

    Toledo-Ibarra, G A; Díaz Resendiz, K J G; Ventura-Ramón, G H; González-Jaime, F; Vega-López, A; Becerril-Villanueva, E; Pavón, L; Girón-Pérez, M I

    2016-10-01

    Agricultural activity demands the use of pesticides for plague control and extermination. In that matter, diazinon is one of the most widely used organophosphorus pesticides (OPs). Despite its benefits, the use of OPs in agricultural activities can also have negative effects since the excessive use of these substances can represent a major contamination problem for water bodies and organisms that inhabit them. The aim of this paper was to evaluate oxidative damage in lipids and proteins of Nile tilapia (Oreochromis niloticus) exposed acutely to diazinon (0.97, 1.95 and 3.95ppm) for 12 or 24h. The evaluation of oxidative damage was determined by quantifying lipid hydroperoxides (Fox method) and oxidized proteins (DNPH method). The data from this study suggest that diazinon induces a concentration-dependent oxidative damage in proteins, but not lipids, of the liver and gills of Nile tilapia. Furthermore, the treatment leads to a decrease in the concentration of total proteins, which can have serious consequences in cell physiology and fish development.

  16. New hosts and genetic diversity of Flavobacterium columnare isolated from Brazilian native species and Nile tilapia.

    PubMed

    Barony, G M; Tavares, G C; Assis, G B N; Luz, R K; Figueiredo, H C P; Leal, C A G

    2015-11-17

    Flavobacterium columnare is responsible for disease outbreaks in freshwater fish farms. Several Brazilian native fish have been commercially exploited or studied for aquaculture purposes, including Amazon catfish Leiarius marmoratus × Pseudoplatystoma fasciatum and pacamã Lophiosilurus alexandri. This study aimed to identify the aetiology of disease outbreaks in Amazon catfish and pacamã hatcheries and to address the genetic diversity of F. columnare isolates obtained from diseased fish. Two outbreaks in Amazon catfish and pacamã hatcheries took place in 2010 and 2011. Four F. columnare strains were isolated from these fish and identified by PCR. The disease was successfully reproduced under experimental conditions for both fish species, fulfilling Koch's postulates. The genomovar of these 4 isolates and of an additional 11 isolates from Nile tilapia Oreochromis niloticus was determined by 16S rRNA restriction fragment length polymorphism PCR. The genetic diversity was evaluated by phylogenetic analysis of the 16S rRNA gene and repetitive extragenic palindromic PCR (REP-PCR). Most isolates (n = 13) belonged to genomovar II; the remaining 2 isolates (both from Nile tilapia) were assigned to genomovar I. Phylogenetic analysis and REP-PCR were able to demonstrate intragenomovar diversity. This is the first report of columnaris in Brazilian native Amazon catfish and pacamã. The Brazilian F. columnare isolates showed moderate diversity, and REP-PCR was demonstrated to be a feasible method to evaluate genetic variability in this bacterium.

  17. Metacercarial Infection of Wild Nile Tilapia (Oreochromis niloticus) from Brazil

    PubMed Central

    Pinto, Hudson A.; Mati, Vitor L. T.; Melo, Alan L.

    2014-01-01

    Fingerlings of Oreochromis niloticus collected in an artificial urban lake from Belo Horizonte, Minas Gerais, Brazil, were evaluated for natural infection with trematodes. Morphological taxonomic identification of four fluke species was performed in O. niloticus examined, and the total prevalence of metacercariae was 60.7% (37/61). Centrocestus formosanus, a heterophyid found in the gills, was the species with the highest prevalence and mean intensity of infection (31.1% and 3.42 (1–42), resp.), followed by the diplostomid Austrodiplostomum compactum (29.5% and 1.27 (1-2)) recovered from the eyes. Metacercariae of Drepanocephalus sp. and Ribeiroia sp., both found in the oral cavity of the fish, were verified at low prevalences (8.2% and 1.6%, resp.) and intensities of infection (only one metacercaria of each of these species per fish). These species of trematodes are reported for the first time in O. niloticus from South America. The potential of occurrence of these parasites in tilapia farming and the control strategies are briefly discussed. PMID:25485302

  18. Pesticide residues in Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) from Southern Lake Victoria, Tanzania.

    PubMed

    Henry, L; Kishimba, M A

    2006-03-01

    Nile tilapia (Oreochromis niloticus) and Nile perch (Lates niloticus) samples were collected from fish landing stations in nine riparian districts on the Tanzanian side of Lake Victoria and screened for residues of 64 organochlorine, organophosphorus, carbamate, and pyrethroid pesticides. The residue levels in the fish fillet were up to 0.003, 0.03 and 0.2 mg/kg fresh weight (0.7, 3.8 and 42 mg/kg lipid weight) of fenitrothion, DDT and endosulfan, respectively. Mean levels within sites were up to 0.002, 0.02 and 0.1 mg/kg fresh weight (0.5, 0.5 and 16 mg/kg lipid weight), respectively. The detection of higher levels of p,p'-DDT than the degradation products (p,p'-DDD and p,p'-DDE), and higher levels of endosulfan isomers (alpha and beta) than the sulphate, in fish samples, implied recent exposure of fish to DDT and endosulfan, respectively. Generally, most of the fish samples had residue levels above the average method detection limits (MDLs), but were within the calculated ADI.

  19. First isolation and characterization of Lactococcus garvieae from Brazilian Nile tilapia, Oreochromis niloticus, (L.), and pintado, Pseudoplathystoma corruscans (Spix and Agassiz)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lactococcus garvieae infection in cultured Nile tilapia, Oreochromis niloticus, (Linnaeus) and pintado, Pseudoplathystoma corruscans, (Spix and Agassiz) from Brazil is reported. The commercial bacterial identification system, Biolog Microlog®, confirmed the identity of L. garvieae. Infectivity tri...

  20. Survival, Growth and Reproduction of Non-Native Nile Tilapia II: Fundamental Niche Projections and Invasion Potential in the Northern Gulf of Mexico

    DTIC Science & Technology

    2012-07-27

    Nile tilapia can alter the function of aquatic systems through eutrophication [76,77], altered trophic dynamics [12], and local extinction of native fish...Starling FLRM, Lazzaro X, Cavalcanti C, Moreira R (2002) Contribution of omnivorous tilapia to eutrophication of a shallow tropical reservoir: evidence

  1. Genetic differentiation among natural populations of the Nile tilapia Oreochromis niloticus (Teleostei, cichlidae).

    PubMed

    Agnèse, J F; Adépo-Gourène, B; Abban, E K; Fermon, Y

    1997-07-01

    We analysed the genetic differentiation among 17 natural populations of the Nile tilapia Oreochromis niloticus (Linnaeus, 1758) using allozymes and restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA). The populations studied, from the River Senegal to Lake Tana and from Lake Manzalla to Lake Baringo, represent all subspecies which have been previously described. Sixteen variable nuclear loci showed that these populations can be clustered in three groups: (1) West African populations (Senegal, Niger, Volta and Chad drainages), (2) Ethiopian Rift Valley populations (Lakes Awasa, Ziway, Koka and the Awash River) and (3) Nile drainage (Manzalla, Cairo, Lake Edward) and Kenyan Rift Valley populations (Lakes Turkana, Baringo and River Suguta). Nine different mtDNA haplotypes were found in the RFLP analysis of a 1 kb portion of the D-loop region. The network obtained showed that there are three geographically distinct groups; all West African populations and O. aureus are clustered, the two Ethiopian Rift Valley populations are distinct and between these two groups are the Kenyan and Ugandan Rift Valley populations. Nile populations show affinities both with West African populations and with specimens from Lakes Tana and Turkana. Taxonomic and biogeographical implications of these results are discussed.

  2. Live transport of Yellow Perch and Nile Tilapia in AQUI-S 20E (10% Eugenol) at high loading densities

    USGS Publications Warehouse

    Cupp, Aaron R.; Schreier, Theresa M.; Schleis, Sue M.

    2017-01-01

    Fish transport costs are a substantial portion of the operational expenses for aquaculture facilities in the USA. Safely transporting higher loading densities of fish would benefit haulers by increasing efficiency and reducing costs, but research evaluating transport for individual species is generally lacking. In this study, Yellow Perch Perca flavescens and Nile Tilapia Oreochromis niloticus were transported for 6 h immersed in water containing AQUI-S 20E (10% eugenol) at fish loading densities of 240 g/L (2 lb/gal) for perch and 480 g/L (4 lb/gal) for tilapia. Survival was quantified for fish transported in AQUI-S 20E concentrations of (1) control or 0 mg/L of water, (2) 100 mg/L, or (3) 200 mg/L. Yellow Perch had 98–100% survival, and Nile Tilapia had 100% survival up to through 14 d after transport across all AQUI-S 20E levels, including the control. Eugenol concentrations decreased rapidly in transport tank water, and fish showed no signs of sedation by the end of transport. We conclude that live transport of Yellow Perch and Nile Tilapia at higher loading densities resulted in high survival regardless of the AQUI-S 20E concentrations we tested.

  3. Two Myxobolus spp. infecting the kidney of Nile tilapia (Oreochromis niloticus) in the River Nile at Beni-Suef governorate, Egypt, and the associated renal changes.

    PubMed

    Abdel-Baki, Abdel-Azeem S; Abdel-Haleem, Heba M; Sakran, Thabet; Zayed, Eman; Ibrahim, Khalid E; Al-Quraishy, Saleh

    2015-03-01

    Two Myxobolus spp. are described from the kidney of the Nile tilapia (Oreochromis niloticus) collected from the River Nile, Egypt. The prevalence of infection was 61 % (47/77), with the infected fish in each case parasitized by the two Myxobolus species simultaneously. The infection was exhibited as free spores in Bowman capsules and renal glomeruli, which makes their original structures difficult to discern. In some cases, the infection appeared as a fibrous plasmodia-like structure containing degenerated developmental stages and spores in the interstitium. The paper identifies each species based on the morphological characteristics of its spores and identifies the histological impacts of Myxobolus infection in this species of fish.

  4. Stress responses of the fish Nile tilapia subjected to electroshock and social stressors.

    PubMed

    Barreto, R E; Volpato, G L

    2006-12-01

    Plasma cortisol and glucose levels were measured in 36 adult Nile tilapia males, Oreochromis niloticus (standard length, mean +/- SD, 14.38 +/- 1.31 cm), subjected to electroshock and social stressors. Pre-stressor levels were determined 5 days after the adjustment of the fish to the experimental aquaria (1 fish/aquarium). Five days later, the effects of stressors on both cortisol and glucose levels were assessed. The following stressors were imposed for 60 min: pairing with a larger resident animal (social stressor), or a gentle electroshock (AC, 20 V, 15 mA, 100 Hz for 1 min every 4 min). Each stressor was tested in two independent groups, one in which stress was quantified immediately after the end of the 60-min stressor imposition (T60) and the other in which stress was quantified 30 min later (T90). Pre-stressor values for cortisol and glucose were not statistically different between groups. Plasma cortisol levels increased significantly and were of similar magnitude for both electroshock and the social stressor (mean +/- SD for basal and final samples were: electroshock T60 = 65.47 +/- 15.3, 177.0 +/- 30.3; T90 = 54.8 +/- 16.0, 196.2 +/- 57.8; social stress T60 = 47.1 +/- 9.0, 187.6 +/- 61.7; T90 = 41.6 +/- 8.1, 112.3 +/- 26.8, respectively). Plasma glucose levels increased significantly for electroshock at both time points (T60 and T90), but only at T90 for the social stressor. Initial and final mean (+/- SD) values are: electroshock T60 = 52.5 +/- 9.2, 115.0 +/- 15.7; T90 = 35.5 +/- 1.1, 146.3 +/- 13.3; social stress T60 = 54.8 +/- 8.8, 84.4 +/- 15.0; T90 = 34.5 +/- 5.6, 116.3 +/- 13.6, respectively. Therefore, electroshock induced an increase in glucose more rapidly than did the social stressor. Furthermore, a significant positive correlation between cortisol and glucose was detected only at T90 for the social stressor. These results indicate that a fish species responds differently to different stressors, thus suggesting specificity of fish stress

  5. Immunologic parameters evaluations in Nile tilapia (Oreochromis niloticus) exposed to sublethal concentrations of diazinon.

    PubMed

    Girón-Pérez, M I; Velázquez-Fernández, J; Díaz-Resendiz, K; Díaz-Salas, F; Canto-Montero, C; Medina-Díaz, I; Robledo-Marenco, M; Rojas-García, A; Zaitseva, G

    2009-08-01

    Fish resistance to microorganisms depends basically on the immune response. Although there are several studies on the diazinon mammalian immunotoxicity, in the case of fish there are only few. The aim of present study was to evaluate the effect of diazinon on immunological parameters (relative spleen weight, splenocytes count, lysozyme activity, respiratory burst and IgM concentration) in Nile tilapia. Diazinon at sublethal concentrations (0.39 and 0.78 mg/L) did not alter RSW, splenocytes count or lysozyme activity. However, at the highest concentration tested (1.96 mg/L) diazinon significantly increased respiratory burst and IgM concentration. In summary, diazinon (and perhaps other pesticides) could alter immunological response and induce oxidative stress.

  6. Figla Favors Ovarian Differentiation by Antagonizing Spermatogenesis in a Teleosts, Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Sun, Lina; Wei, Jing; Nagahama, Yoshitaka; Wang, Deshou; Zhou, Linyan

    2015-01-01

    Figla (factor in the germ line, alpha), a female germ cell-specific transcription factor, had been shown to activate genetic hierarchies in oocytes. The ectopic expression of Figla was known to repress spermatogenesis-associated genes in male mice. However, the potential role of Figla in other vertebrates remains elusive. The present work was aimed to identify and characterize the functional relevance of Figla in the ovarian development of Nile tilapia (Oreochromis niloticus). Tissue distribution and ontogeny analysis revealed that tilapia Figla gene was dominantly expressed in the ovary from 30 days after hatching. Immunohistochemistry analysis also demonstrated that Figla was expressed in the cytoplasm of early primary oocytes. Intriguingly, over-expression of Figla in XY fish resulted in the disruption of spermatogenesis along with the depletion of meiotic spermatocytes and spermatids in testis. Dramatic decline of sycp3 (synaptonemal complex protein 3) and prm (protamine) expression indicates that meiotic spermatocytes and mature sperm production are impaired. Even though Sertoli cell (dmrt1) and Leydig cell (star and cyp17a1) marker genes remained unaffected, hsd3b1 expression and 11-KT production were enhanced in Figla-transgene testis. Taken together, our data suggest that fish Figla might play an essential role in the ovarian development by antagonizing spermatogenesis. PMID:25894586

  7. Body composition and compensatory growth in Nile tilapia Oreochromis niloticus under different feeding intervals

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Wang, Ziwei; Hur, Jun-wook; Lee, Jeong-Yeol

    2015-07-01

    We investigated the growth and body composition of Nile tilapia under five different feeding regimes. A control group was fed to satiation twice daily for 185 days; four treatment groups were fed at intervals of 2, 3, 4 or 7 days (dietary `restricted' period, days 0-80) and then fed to satiation (`refeeding' period, days 80-185). Compensatory growth in weight and length of the feed-restricted groups was observed during the refeeding period. However, the growth of none of the restricted groups caught up with that of the control group over the experimental period. Feed intake upon refeeding increased with the duration of deprivation. There were no significant differences in feed efficiency between the restricted and control groups during the refeeding stage, suggesting that hyperphagia was the mechanism responsible for the increased growth rates during this period. Tilapia preferentially used n-3 polyunsaturated fatty acids and nonessential amino acids during the restricted-feeding period. Higher production was achieved by higher feed consumption. We suggest that if attainment of market size in minimum time is required, fish should be consistently fed to satiation, while taking care to avoid the possible negative consequences of overfeeding.

  8. Can the parasitic fauna on Nile tilapias be affected by different production systems?

    PubMed

    Martins, Maurício L; Azevedo, Tatiana M P; Ghiraldelli, Luciana; Bernardi, Neuza

    2010-06-01

    This study compared the parasitic fauna on Nile tilapias kept with swine dejects and tilapia from fee fishing fed commercial ration. A total of 360 fish were analyzed from August 2003 to July 2004 in a facility situated in Nova Trento, Santa Catarina, Brazil. No significant difference was observed in both systems. The parasite fauna in both systems were slightly similar, with the presence of the following parasites: Trichodina magna and T compacta (Ciliophora); Cichlidogyrus sclerosus and Cichlidogyrus sp. (Monogenoidea); and Lamproglena sp. (Lernaeidae). Parasitological analyzes did not differ among fishes kept with swine dejects and in fee fishing with commercial diet (P >0.05). The total prevalence of trichodinids in the gills of fish kept with swine dejects was 1.7% as compared to the one kept in fee fishing with commercial diet (0.6%). The Monogenoidea prevalence and mean intensity in the gills and body of fish from fee fishing was 16.5% and 2.6, and compared to other system was 13.2% and 0.8, respectively. This study showed that low stocking density and low water temperature in that region were responsible for the maintenance of good health and lower parasitism rate.

  9. Establishment of a model of Streptococcus iniae meningoencephalitis in Nile tilapia (Oreochromis niloticus).

    PubMed

    Baums, C G; Hermeyer, K; Leimbach, S; Adamek, M; Czerny, C-P; Hörstgen-Schwark, G; Valentin-Weigand, P; Baumgärtner, W; Steinhagen, D

    2013-07-01

    Streptococcus iniae is an invasive pathogen causing meningitis and other lesions in various fish species. Furthermore, S. iniae is an emerging zoonotic agent that causes cellulitis in man. The aims of this study were to establish an intraperitoneal infection model for S. iniae in Nile tilapia (Oreochromis niloticus) and to develop a new histopathological scoring system to reflect the degree and extent of inflammation as well as the presence of necrosis in the brain and eye. Intraperitoneal administration of 10(6) colony-forming units (CFU) led to 80% mortality and numerous fish developing clinical signs of central nervous system dysfunction. Microscopical examination of four regions of the brain (olfactory bulb, cerebellum, cerebrum and optical lobe) and the eye revealed the presence of lymphohistiocytic leptomeningitis, meningoencephalitis and endophthalmitis. Lesions were dominated by macrophages that often contained intracellular bacteria. Necrosis was recorded in some cases. Bacteriological screening revealed that multiple organs, including brain and eye, were infected with S. iniae and S. iniae colonized the scales and gills in high number. S. iniae was detected in tank water during the first week post infection, suggesting that infected tilapia might shed up to 3 × 10(7) CFU of S. iniae within 24 h. A multiplex polymerase chain reaction allowed confirmation of the challenge strain by detection of the virulence factors simA, scpI, cpsD, pgi, pgm and sagA.

  10. Antimicrobial Susceptibility of Escherichia coli Isolated from Fresh-Marketed Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Rocha, Rafael dos Santos; Leite, Lana Oliveira; de Sousa, Oscarina Viana; Vieira, Regine Helena Silva dos Fernandes

    2014-01-01

    The contamination of seafood by bacteria of fecal origin, especially Escherichia coli, is a widely documented sanitary problem. The objective of the present study was to isolate E. coli strains from the gills, muscle, and body surface of farmed Nile tilapias (Oreochromis niloticus) fresh-marketed in supermarkets in Fortaleza (Ceará, Brazil), to determine their susceptibility to antibiotics of different families (amikacin, gentamicin, imipenem, cephalothin, cefotaxime, ciprofloxacin, aztreonam, ampicillin, nalidixic acid, tetracycline, and sulfametoxazol-trimetoprim), and to determine the nature of resistance by plasmid curing. Forty-four strains (body surface = 25, gills = 15, muscle = 4) were isolated, all of which were susceptible to amikacin, aztreonam, cefotaxime, ciprofloxacin, gentamicin, and imipenem. Gill and body surface samples yielded 11 isolates resistant to ampicillin, tetracycline, and sulfametoxazol-trimetoprim, 4 of which of plasmidial nature. The multiple antibiotic resistance index was higher for strains isolated from body surface than from gills. The overall high antibiotic susceptibility of E. coli strains isolated from fresh-marketed tilapia was satisfactory, although the occasional finding of plasmidial resistance points to the need for close microbiological surveillance of the farming, handling, and marketing conditions of aquaculture products. PMID:24808957

  11. Blocking of progestin action disrupts spermatogenesis in Nile tilapia (Oreochromis niloticus).

    PubMed

    Liu, Gang; Luo, Feng; Song, Qiang; Wu, Limin; Qiu, Yongxiu; Shi, Hongjuan; Wang, Deshou; Zhou, Linyan

    2014-08-01

    In vitro studies have indicated that the maturation-inducing hormone 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP, DHP), probably through nuclear progestin receptor (Pgr), might be involved in the proliferation of spermatogonial cells and the initiation of meiosis in several fish species. However, further in vivo evidence is required to elucidate the role of DHP in spermatogenesis during sexual differentiation in teleosts. In this study, we cloned pgr and analyzed its expression in Nile tilapia (Oreochromis niloticus) and treated XY fish with RU486 (a synthetic Pgr antagonist) from 5 days after hatching (dah) to determine the role of DHP in spermatogenesis. Sequence and phylogenetic analyses revealed that the Pgr identified in tilapia is a genuine Pgr. Pgr was found to be expressed in the Sertoli cells surrounding spermatogonia and spermatids in the testis of tilapia. Real-time PCR analysis revealed that the expression of pgr in the testis was significantly upregulated from 10 dah, further increased at 50 dah, and persisted until adulthood in fish. In the testis of RU486-treated fish, the transcript levels of germ cell markers and a meiotic marker were substantially reduced. However, the expression of markers in Sertoli cells remained unchanged. Moreover, the production of 11-ketotestosterone and the expression of genes encoding various steroidogenic enzymes were also not altered. In contrast, the expression of cyp17a2, encoding one of the critical steroidogenic enzymes involved in DHP biosynthesis, declined significantly, possibly indicating the inhibition of DHP production by RU486. RU486 treatment given for 2 months did not affect spermatogenesis; however, treatment given for more than 3 months resulted in a decrease in spermatogonial cell numbers and depletion of later-phase spermatogenic cells. Simultaneous excessive DHP supplementation restored spermatogenesis in RU486-treated XY fish. Taken together, our data further indicated that DHP, possibly through

  12. Fatty acid concentration, proximate composition, and mineral composition in fishbone flour of Nile Tilapia.

    PubMed

    Petenuci, Maria Eugênia; Stevanato, Flávia Braidoti; Visentainer, Jeane Eliete Laguila; Matsushita, Makoto; Garcia, Edivaldo Egea; de Souza, Nilson Evelázio; Visentainer, Jesui Vergilio

    2008-03-01

    Nile tilapia (Oreochormis niloticus) fishbone is a fish part with unknown composition. After elaboration of flour fishbone of tilapia it was analysede. The results in 100 g of flour were: moisture (14.2%), protein (40.8%), total lipids (25.3%), and ash (18.3%), and mineral (in 100 g) was 2715.9 mg (calcium), 1.3 mg (iron), and 1132.7 mg (phosphorus). A total of 22 fatty acids were detected in fishbone flour total lipids (TL), being the major ones in (g) of total lipids: 16:0 (208.5 mg); 18:1n-9 (344.3 mg); and 18:2n-6 (109.6 mg). The concentration of linolenic acid--LNA (18:3n-3); eicopentaenoic acid--EPA (20:5n-3), and docosahexaenoic acid--DHA (22:6n-3) were (29.9 mg), (3.3 mg), and (12.9 mg), respectively. The content to saturated (SFA) were (296.2 mg), monounsaturated (MUFA) 415.0 mg, and polyunsaturated (PUFA) 175.6 mg. The ratio PUFA:MUFA:SFA was 1:2.4:1.7, and the ratio omega-6/omega-3 fatty acids were 2.8. The last is within the recommended values. The results show low concentrations of omega-3 fatty acids in flour. The value caloric and calcium, iron, phosphorus, and protein content the fishbone flour of tilapia may results a valuable alternative food in the human diet.

  13. Effect of sub-lethal concentrations of endosulfan on phagocytic and hematological parameters in Nile tilapia (Oreochromis niloticus).

    PubMed

    Girón-Pérez, M I; Montes-López, M; García-Ramírez, L A; Romero-Bañuelos, C A; Robledo-Marenco, M L

    2008-03-01

    The effect of endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), an organochlorine pesticide, was evaluated on phagocytic (phagocytic index and percentage of active cells) and hematological parameters in Nile tilapia. Experimental data showed that an acute exposure to endosulfan (4.0 and 7.0 microg/L) induces a significant decrease in the phagocytic index and the percentage of active cells in peripherical blood of Nile tilapia. However, hemoglobin concentration (Hb), hematocrit (Hto), red blood cell count (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were not significantly altered in fish exposed to endosulfan compared with control group.

  14. Ecotoxicological effects of carbofuran and oxidised multiwalled carbon nanotubes on the freshwater fish Nile tilapia: nanotubes enhance pesticide ecotoxicity.

    PubMed

    Campos-Garcia, Janaína; Martinez, Diego Stéfani T; Alves, Oswaldo L; Leonardo, Antônio Fernando Gervásio; Barbieri, Edison

    2015-01-01

    The interactions of carbon nanotubes with pesticides, such as carbofuran, classical contaminants (e.g., pesticides, polyaromatic hydrocarbons, heavy metals, and dyes) and emerging contaminants, including endocrine disruptors, are critical components of the environmental risks of this important class of carbon-based nanomaterials. In this work, we studied the modulation of acute carbofuran toxicity to the freshwater fish Nile tilapia (Oreochromis niloticus) by nitric acid treated multiwalled carbon nanotubes, termed HNO3-MWCNT. Nitric acid oxidation is a common chemical method employed for the purification, functionalisation and aqueous dispersion of carbon nanotubes. HNO3-MWCNT were not toxic to Nile tilapia at concentrations ranging from 0.1 to 3.0 mg/L for exposure times of up to 96 h. After 24, 48, 72 and 96 h, the LC50 values of carbofuran were 4.0, 3.2, 3.0 and 2.4 mg/mL, respectively. To evaluate the influence of carbofuran-nanotube interactions on ecotoxicity, we exposed the Nile tilapia to different concentrations of carbofuran mixed together with a non-toxic concentration of HNO3-MWCNT (1.0 mg/L). After 24, 48, 72, and 96 h of exposure, the LC50 values of carbofuran plus nanotubes were 3.7, 1.6, 0.7 and 0.5 mg/L, respectively. These results demonstrate that HNO3-MWCNT potentiate the acute toxicity of carbofuran, leading to a more than five-fold increase in the LC50 values. Furthermore, the exposure of Nile tilapia to carbofuran plus nanotubes led to decreases in both oxygen consumption and swimming capacity compared to the control. These findings indicate that carbon nanotubes could act as pesticide carriers affecting fish survival, metabolism and behaviour.

  15. Gyrodactylus malalai sp. nov. (Monogenea, Gyrodactylidae) from Nile tilapia, Oreochromis niloticus (L.) and Redbelly tilapia, Tilapia zillii (Gervais) (Teleostei, Cichlidae) in the Lake Turkana, Kenya.

    PubMed

    Přikrylová, Iva; Radim, Blažek; Gelnar, Milan

    2012-06-01

    Gyrodactylus malalai sp. nov. is described from the fin surface of cichlid fishes Oreochromis niloticus (L.) and Tilapia zillii (Gervais) caught in Lake Turkana (Kenya). The new species morphologically resembles Gyrodactylus nyanzae Paperna, 1973, but can be readily distinguished by the shape of the marginal hook sickles and the size of its hamuli. The sequence data of rDNA spanning partial 18S, internal transcribe spacer 1 and 2 and the 5.8S gene is unique within GenBank. Genetically, as most similar Gyrodactylus ergensi Přikrylová, Matějusová, Musilová et Gelnar, 2009 was found (97.5%). Moreover, a specimen of G. cichlidarum from O. niloticus, and a specimen G. ergensi from Sarotherodon galilaeus (L.) were collected during sampling in Kenya. Likewise, additional sampling of O. niloticus from the Blue Nile in Sudan revealed the presence of the newly described species. These findings represent the first records of gyrodactylids in both African countries.

  16. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus.

    PubMed

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-03-08

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain's cDNA is composed of 3347 bp with a 31 bp of 5'-UTR, 3015 bp open reading frame (ORF) and 301 bp 3'-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia.

  17. Molecular characterization and expression of Lck in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.

    PubMed

    Gan, Zhen; Wang, Bei; Lu, Yishan; Zhu, Weiwei; Huang, Yu; Jian, JiChang; Wu, Zaohe

    2015-03-01

    Lymphocyte-specific protein tyrosine kinase (Lck) plays a critical role in effective signal transductions that are fundamental to T cell differentiation, proliferation, and effector functions. In this paper, the Lck gene of Nile tilapia, Oreochromis niloticus (designated as On-Lck), was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed important structural characteristics required for T cell receptor (TCR) signal transduction were detected in the deduced amino acid sequence of On-Lck, and the deduced genomic structure of On-Lck was similar to the known Lck. In healthy Nile tilapia, the On-Lck transcripts were mainly detected in the thymus, spleen, head kidney, and gill. When immunized with inactivated S. agalactiae, the On-Lck mRNA expression was significantly upregulated in the thymus, spleen, and head kidney. Moreover, there was a clear time-dependent expression pattern of On-Lck after immunization, and the expression reached the highest level at 48 h in the spleen and thymus and at 72 h in the head kidney, respectively. This is the first report on the expression of Lck induced by intracellular bacteria vaccination in teleosts. These findings indicated that On-Lck may play an important role in the immune response to intracellular bacteria in Nile tilapia.

  18. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus

    PubMed Central

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-01-01

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain’s cDNA is composed of 3347 bp with a 31 bp of 5′-UTR, 3015 bp open reading frame (ORF) and 301 bp 3′-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia. PMID:27005611

  19. Defining a breeding objective for Nile tilapia that takes into account the diversity of smallholder production systems.

    PubMed

    Omasaki, S K; van Arendonk, J A M; Kahi, A K; Komen, H

    2016-10-01

    In general, livestock and fish farming systems in developing countries tend to be highly diverse in terms of agro-ecological conditions and market orientation. There are no studies that have investigated if and how this diversity translates to varying preferences for breeding objective traits. This is particularly important for breeding programmes that are organized on a national level (e.g. government-supported nucleus breeding programmes). The aim of this study was to investigate whether Nile tilapia farmers with diverse production systems and economic constraints have different preferences for breeding objective traits. The second objective was to derive a consensus breeding goal, using weighted goal programming that could be used for a national breeding programme for Nile tilapia. A survey was conducted among 100 smallholder Nile tilapia farmers in Kenya to obtain preference values for traits of economic importance, by using multiple pairwise comparisons. Individual and group preference values were estimated using analytical hierarchy process. Low-income farmers preferred harvest weight, while medium- and high-income farmers preferred growth rate and survival. Grouping farmers according to market objective (fingerling production or fattening) showed that fingerling producers preferred growth rate and survival, while fattening farmers preferred harvest weight, height and thickness. Weighted goal programming was used to obtain consensus preference values, and these were used to derive desired gains for a breeding goal of a national breeding programme that takes into account the diversity of smallholder production systems.

  20. Increasing of temperature induces pathogenicity of Streptococcus agalactiae and the up-regulation of inflammatory related genes in infected Nile tilapia (Oreochromis niloticus).

    PubMed

    Kayansamruaj, Pattanapon; Pirarat, Nopadon; Hirono, Ikuo; Rodkhum, Channarong

    2014-08-06

    Temperature strongly affects the health of aquatic poikilotherms. In Nile tilapia (Oreochromis niloticus), elevated water temperatures increase the severity of streptococcosis. Here we investigated the effects of temperature on the vulnerability and inflammatory response of Nile tilapia to Streptococcus agalactiae (Group B streptococci; GBS). At 35 and 28 °C, GBS took 4 and 7h, respectively to reach the log-phase and, when incubated with tilapia whole blood, experienced survival rates of 97% and 2%, respectively. The hemolysis activity of GBS grown at 35 °C was five times higher than that of GBS grown at 28 °C. GBS expressed cylE (β-hemolysin/cytolysin), cfb (CAMP factor) and PI-2b (pili-backbone) much more strongly at 35 °C than at 28 °C. Challenging Nile tilapia reared at 35 and 28 °C with GBS resulted in accumulated mortalities of about 85% and 45%, respectively. At 35 °C, infected tilapia exhibited tremendous inflammatory responses due to a dramatic up-regulation (30-40-fold) of inflammatory-related genes (cyclooxygenase-2, IL-1β and TNF-α) between 6 and 96 h-post infection. These results suggest that the increase of GBS pathogenicity to Nile tilapia induced by elevated temperature is associated with massive inflammatory responses, which may lead to acute mortality.

  1. Immunoproteomic analysis of the antibody response obtained in Nile tilapia following vaccination with a Streptococcus iniae vaccine.

    PubMed

    LaFrentz, Benjamin R; Shoemaker, Craig A; Klesius, Phillip H

    2011-09-28

    Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. The USDA-ARS Aquatic Animal Health Research Unit developed a modified (contains concentrated culture supernatant) S. iniae bacterin that has been demonstrated to be efficacious, and protection is mediated by specific anti-S. iniae antibodies. Although effective, the specific vaccine components important for efficacy are not known. In the present study, an immunoproteomic approach was utilized to identify whole-cell lysate proteins of S. iniae that stimulated specific antibody production in Nile tilapia (Oreochromis niloticus) following vaccination. Groups of tilapia were vaccinated by intraperitoneal injection with the modified S. iniae bacterin or were mock-vaccinated, and at 30 d post-vaccination sera samples were obtained from individual fish. Vaccination of tilapia with the S. iniae vaccine stimulated significantly elevated specific antibody responses against proteins of the bacterium and passive immunization of tilapia with this serum demonstrated the antibodies were highly protective. Whole-cell lysate proteins of S. iniae were separated by 2D-PAGE and were probed with a pooled serum sample from vaccinated tilapia. A total of eleven unique immunogenic proteins were positively identified by mass spectrometry. Based on research conducted on homologous proteins in other Streptococcus spp., antibodies specific for three of the identified proteins, enolase, glyceraldehyde-3-phosphate dehydrogenase, and fructose-bisphosphate aldolase, are likely involved in protection from streptococcosis caused by S. iniae.

  2. Effect of dietary genistein on growth performance, digestive enzyme activity, and body composition of Nile tilapia Oreochromis niloticus

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Wang, Wei; Ru, Shaoguo

    2015-01-01

    An 8-week feeding experiment was performed to evaluate the effect of dietary genistein on growth performance, body composition, and digestive enzymes activity of juvenile Nile tilapia ( Oreochromis niloticus). Four isonitrogenous and isoenergetic diets were formulated containing four graded supplements of genistein: 0, 30, 300, and 3 000 μg/g. Each diet was randomly assigned in triplicate to tanks stocked with 15 juvenile tilapia (10.47±1.24 g). The results show that 30 and 300 μg/g dietary genistein had no significant effect on growth performance of Nile tilapia, but the higher level of genistein (3 000 μg/g) significantly depressed the final body weight and specific growth rate. There was no significant difference in survival rate, feed intake, feed efficiency ratio or whole body composition among all dietary treatments. An assay of digestive enzymes showed that the diet containing 3 000 μg/ggenistein decreased stomach and hepatopancreas protease activity, and amylase activity in the liver and intestine, while a dietary level of 300 μg/g genistein depressed stomach protease and intestine amylase activities. However, no significant difference in stomach amylase activity was found among dietary treatments. Overall, the results of the present study indicate that a high level of dietary genistein (3 000 μg/g, or above) would significantly reduce the growth of Nile tilapia, partly because of its inhibitory effect on the activity of major digestive enzymes. Accordingly, the detrimental effects of genistein, as found in soybean products, should not be ignored when applied as an alternative ingredient source in aquaculture.

  3. Retinal light input is required to sustain plasma melatonin rhythms in Nile tilapia Oreochromis niloticus niloticus.

    PubMed

    Martinez-Chavez, C C; Migaud, H

    2009-05-07

    The aim of this work was to confirm previous findings suggesting that the eyes are required for night-time melatonin production in Nile tilapia and further characterise this divergent circadian organisation. To do so, melatonin levels were firstly measured in eyecups and plasma to determine circadian patterns of melatonin production. Secondly, the effect of partial ophthalmectomy on the suppression of melatonin production was determined in vivo as well as ex vivo pineal light/dark sensitivity. Finally, to investigate whether such findings could be related to post-surgery stress, melatonin analyses were performed in the subsequent 24 h and 7 days post-ophthalmectomy with cortisol levels assessed as an indicator of stress. Our results showed an inverse pattern of melatonin production in the eye cups of tilapia compared to blood circulating levels, suggesting different roles played by melatonin in these two tissues. Results then demonstrated that total or partial ophthalmectomy resulted in the suppression of night-time melatonin production. Furthermore, although pineals in culture were shown to be photosensitive, night-time melatonin levels were much lower than seen in other species. Finally, when performing sampling immediately or one week post-surgery, no difference in the melatonin profiles were observed. It is therefore unlikely that post-surgery stress would explain such suppression in melatonin production although all fish displayed high cortisol levels most probably due to social and handling stress. Taken together, these results provide further evidence of a new type of circadian organisation in a teleost species where the eyes are required to sustain night-time melatonin levels.

  4. Differential expression analysis of genes involved in high-temperature induced sex differentiation in Nile tilapia.

    PubMed

    Li, Chun Ge; Wang, Hui; Chen, Hong Ju; Zhao, Yan; Fu, Pei Sheng; Ji, Xiang Shan

    2014-01-01

    Nowadays, high temperature effects on the molecular pathways during sex differentiation in teleosts need to be deciphered. In this study, a systematic differential expression analysis of genes involved in high temperature-induced sex differentiation was done in the Nile tilapia gonad and brain. Our results showed that high temperature caused significant down-regulation of CYP19A1A in the gonad of both sexes in induction group, and FOXL2 in the ovary of the induction group. The expressions of GTHα, LHβ and ERα were also significantly down-regulated in the brain of both sexes in the induction and recovery groups. On the contrary, the expression of CYP11B2 was significantly up-regulated in the ovary, but not in the testis in both groups. Spearman rank correlation analysis showed that there are significant correlations between the expressions of CYP19A1A, FOXL2, or DMRT1 in the gonads and the expression of some genes in the brain. Another result in this study showed that high temperature up-regulated the expression level of DNMT1 in the testis of the induction group, and DNMT1 and DNMT3A in the female brain of both groups. The expression and correlation analysis of HSPs showed that high temperature action on tilapia HSPs might indirectly induce the expression changes of sex differentiation genes in the gonads. These findings provide new insights on TSD and suggest that sex differentiation related genes, heat shock proteins, and DNA methylation genes are new candidates for studying TSD in fish species.

  5. Cinnamon (Cinnamomum sp.) inclusion in diets for Nile tilapia submitted to acute hypoxic stress.

    PubMed

    M Dos Santos, Welliene; S de Brito, Túlio; de A Prado, Samuel; G de Oliveira, Camila; C De Paula, Andréia; C de Melo, Daniela; A P Ribeiro, Paula

    2016-07-01

    The aim of this study was to evaluate the possible effects of diets supplemented with probiotics and different cinnamon levels (powder and essential oil) on immunological parameters of Nile tilapia after being subjected to acute stress by hypoxia. Three hundred and thirty juvenile male tilapia fish (66.08 ± 2.79 g) were distributed in 30 tanks of 100 L capacity (11/cage) with a water recirculation system. The animals were fed for 71 days with diets containing extruded cinnamon powder at different levels (0.5, 1, 1.5, 2%), cinnamon essential oil (0.05, 0.1, 0.15; 0.2%) and probiotics (0.4%), all in triplicate. At the end of the experiment, the fish (200.36 ± 19.88 g) of the different groups were subjected to stress by hypoxia. Hypoxia was achieved by capturing the animals with a net, keeping them out of the water for three minutes, and then sampling the blood 30 min after the procedure to determine the levels of cortisol, glucose, haematocrit, lysozyme, bactericidal index, total protein, and its fractions. The animals kept blood homeostasis after hypoxic stress. Diet supplementation with 0.5% cinnamon powder improved the fish immune response, since it resulted in an increase of 0.5% in γ-globulin level. Administration of 0.15% cinnamon essential oil resulted in an increase of α1 and α2-globulins, which may be reflected in increased lipid content of the carcass and the hepatosomatic index. More studies are necessary to better understand the effects of these additives for fish immunity.

  6. Characterization of gonadal transcriptomes from Nile tilapia (Oreochromis niloticus) reveals differentially expressed genes.

    PubMed

    Tao, Wenjing; Yuan, Jing; Zhou, Linyan; Sun, Lina; Sun, Yunlv; Yang, Shijie; Li, Minghui; Zeng, Sheng; Huang, Baofeng; Wang, Deshou

    2013-01-01

    Four pairs of XX and XY gonads from Nile tilapia were sequenced at four developmental stages, 5, 30, 90, and 180 days after hatching (dah) using Illumina Hiseq(TM) technology. This produced 28 Gb sequences, which were mapped to 21,334 genes. Of these, 259 genes were found to be specifically expressed in XY gonads, and 69 were found to be specific to XX gonads. Totally, 187 XX- and 1,358 XY-enhanced genes were identified, and 2,978 genes were found to be co-expressed in XX and XY gonads. Almost all steroidogenic enzymes, including cyp19a1a, were up-regulated in XX gonads at 5 dah; but in XY gonads these enzymes, including cyp11b2, were significantly up-regulated at 90 dah, indicating that, at a time critical to sex determination, the XX fish produced estrogen and the XY fish did not produce androgens. The most pronounced expression of steroidogenic enzyme genes was observed at 30 and 90 dah for XX and XY gonads, corresponding to the initiation of germ cell meiosis in the female and male gonads, respectively. Both estrogen and androgen receptors were found to be expressed in XX gonads, but only estrogen receptors were expressed in XY gonads at 5 dah. This could explain why exogenous steroid treatment induced XX and XY sex reversal. The XX-enhanced expression of cyp19a1a and cyp19a1b at all stages suggests an important role for estrogen in female sex determination and maintenance of phenotypic sex. This work is the largest collection of gonadal transcriptome data in tilapia and lays the foundation for future studies into the molecular mechanisms of sex determination and maintenance of phenotypic sex in non-model teleosts.

  7. Role of Hox PG2 genes in Nile tilapia pharyngeal arch specification: implications for gnathostome pharyngeal arch evolution.

    PubMed

    Le Pabic, Pierre; Scemama, Jean-Luc; Stellwag, Edmund J

    2010-01-01

    Phylogenetic reconstructions suggest that the ancestral osteichthyan Hox paralog group 2 gene complement was composed of two genes, Hoxa2 and b2, both of which have been retained in tetrapods, but only one of which functions as a selector gene of second pharyngeal arch identity (PA2). Genome duplication at the inception of the teleosts likely generated four Hox PG2 genes, only two of which, hoxa2b and b2a, have been preserved in zebrafish, where they serve as functionally redundant PA2 selector genes. Evidence from our laboratory has shown that other telelosts, specifically striped bass and Nile tilapia, harbor three transcribed Hox PG2 genes, hoxa2a, a2b, and b2a, with unspecified function(s). We have focused on characterizing the function of the three Nile tilapia Hox PG2 genes as a model to examine the effects of postgenome duplication gene loss on the evolution of developmental gene function. We studied Hox PG2 gene function in tilapia by examining the effects of independent morpholino oligonucleotide (MO)-induced knockdowns on pharyngeal arch morphology and Hox gene expression patterns. Morphological defects resulting from independent MO-induced knockdowns of tilapia hoxa2a, a2b, and b2a included the expected PA2 to PA1 homeotic transformations previously observed in tetrapods and zebrafish, as well as concordant and unexpected morphological changes in posterior arch-derived cartilages. Of particular interest, was the observation of a MO-induced supernumerary arch between PA6 and PA7, which occurred concomitantly with other MO-induced pharyngeal arch defects. Beyond these previously unreported morphant-induced transformations, a comparison of Hox PG2 gene expression patterns in tilapia Hox PG2 morphants were indicative of arch-specific auto- and cross-regulatory activities as well as a Hox paralog group 2 interdependent regulatory network for control of pharyngeal arch specification.

  8. Nile Tilapia Neu3 sialidases: molecular cloning, functional characterization and expression in Oreochromis niloticus.

    PubMed

    Chigwechokha, Petros Kingstone; Komatsu, Masaharu; Itakura, Takao; Shiozaki, Kazuhiro

    2014-11-15

    Mammalian Neu3 is a ganglioside specific sialidase. Gangliosides are involved in various physiological events such as cell growth, differentiation and diseases. Significance of Neu3 and gangliosides is still unclear in aquaculture fish species. To gain more insights of fish Neu3 sialidases, molecular cloning and characterization were carried out in tilapia (Oreochromis niloticus). A tilapia genome-wide search for orthologues of human NEU1, NEU2, NEU3 and NEU4 yielded eight putative tilapia sialidases, five of which were neu3-like and designated as neu3a, neu3b, neu3c, neu3d and neu3e. Among five neu3 genes, neu3a, neu3d and neu3e were amplified by PCR from adult fish brain cDNA with consensus sequences of 1227bp, 1194bp and 1155bp, respectively. Multiple alignments showed conserved three Asp-boxes (SXDXGXTW), YRIP and VGPG motifs. The molecular weights for Neu3a, Neu3d and Neu3e were confirmed using immunoblotting analysis as 45.9kDa, 44.4kDa and 43.6kDa, respectively. Lysate from neu3 genes transfected HEK293 cells showed sialidase activity in Neu3a towards ganglioside mix optimally at pH4.6. Using pure gangliosides as substrates, highest sialidase activity for Neu3a was observed towards GD3 followed by GD1a and GM3, but not GM1. On the other hand, sialidase activities were not observed in Neu3d and Neu3e towards various sialoglycoconjugates. Indirect immunofluorescence showed that tilapia Neu3a and Neu3d are localized at the plasma membrane, while most Neu3e showed a cytosolic localization. RT-PCR analyses for neu3a showed significant expression in the brain, liver, and spleen tissues, while neu3d and neu3e showed different expression patterns. Based on these results, tilapia Neu3 exploration is an important step towards full understanding of a more comprehensive picture of Neu3 sub-family of proteins in fish.

  9. Molecular characterization and expression of CD2 in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.

    PubMed

    Gan, Zhen; Wang, Bei; Tang, Jufen; Lu, Yishan; Jian, JiChang; Wu, Zaohe; Nie, Pin

    2016-03-01

    The cluster of differentiation 2 (CD2), functioning as a cell adhesion and costimulatory molecule, plays a crucial role in T-cell activation. In this paper, the CD2 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD2) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed On-CD2 protein consists of two extracellular Ig-like domains, a transmembrane region, and a long proline-rich cytoplasmic tail, which is a hallmark of CD2, and several important structural characteristics required for T-cell activation were detected in the deduced amino acid sequence of On-CD2. In healthy tilapia, the On-CD2 transcripts were mainly detected in the head kidney, spleen, blood and thymus. Moreover, there was a clear time-dependent expression pattern of On-CD2 after immunized by formalin-inactivated S. agalactiae and the expression reached the highest level at 12 h in the brain and head kidney, 48 h in the spleen, and 72 h in the thymus, respectively. This is the first report on the expression of CD2 induced by bacteria vaccination in teleosts. These findings indicated that On-CD2 may play an important role in the immune response to intracellular bacteria in Nile tilapia.

  10. Dietary supplementation with xylanase-expressing B. amyloliquefaciens R8 improves growth performance and enhances immunity against Aeromonas hydrophila in Nile tilapia (Oreochromis niloticus).

    PubMed

    Saputra, Febriyansyah; Shiu, Ya-Li; Chen, Yo-Chia; Puspitasari, Asthervina Widyastami; Danata, Ridha Handriany; Liu, Chun-Hung; Hu, Shao-Yang

    2016-11-01

    Bacillus amyloliquefaciens has attracted attention as a probiotic in aquaculture due to its immunostimulatory activity against pathogenic infection. Xylanases are extensively used in animal feed to degrade plant ingredients, enhancing nutrient utilization and increasing the growth rate of various animals. In the present study, the effects of dietary supplementation with B. amyloliquefaciens and xylanase-expressing B. amyloliquefaciens R8 on the growth of Nile tilapia (Oreochromis niloticus) and immunity against Aeromonas hydrophila were evaluated. The results showed that the xylanase activity in the intestine, weight gain (WG), feed efficiency (FE) and condition factor (CF) of Nile tilapia fed B. amyloliquefaciens R8 for 2 months were significantly increased compared with those of the fish fed the control diet and B. amyloliquefaciens. Moreover, the mRNA expression of growth- and metabolism-related genes, such as insulin-like growth factor-1 (igf-1), glucokinase (GK), glucose-6-phosphate 1-dehydrogenase (G6PD), and glucose-6-phosphatase (G6Pase), was significantly induced in Nile tilapia fed administered B. amyloliquefaciens R8, and this group also exhibited a higher survival rate than the control fish following a challenge with A. hydrophila. The phagocytic activity and respiratory burst activity of head kidney leukocytes as well as the serum lysozyme activity of B. amyloliquefaciens R8-fed Nile tilapia were significantly higher than those of fish fed the control diet for 2 months. Superoxide dismutase (SOD) levels in the head kidney leukocytes of Nile tilapia fed B. amyloliquefaciens R8 differed from those of fish fed the control diet, but this was not significant. These results indicate that dietary supplementation with xylanase-expressing B. amyloliquefaciens R8 improves growth performance and enhances immunity and disease resistance against A. hydrophila in Nile tilapia.

  11. Eutrophication, Ammonia Intoxication, and Infectious Diseases: Interdisciplinary Factors of Mass Mortalities in Cultured Nile Tilapia.

    PubMed

    Abu-Elala, Nermeen M; Abd-Elsalam, Reham M; Marouf, Sherif; Abdelaziz, Mohamed; Moustafa, Mohamed

    2016-09-01

    The present study was designed to assess the possible causes of the mass mortalities of Nile Tilapia Oreochromis niloticus at El-Behera Governorate, Egypt, in relationship to environmental and microbiotic factors. Water samples were collected from fish farms at different locations and from Lake Edku to analyze water temperature, water pH, salinity, biological oxygen demand, dissolved oxygen, total ammonia nitrogen, and un-ionized ammonia. A number of moribund and freshly dead fish were sampled and submitted to our laboratory for microbiological, molecular, and histopathological examination. Water analysis of the fish farms revealed noticeable increases in the previously mentioned physicochemical parameters. Clinical examinations of moribund fish showed severe gill rot and massive external and internal hemorrhages. Ordinary and molecular laboratory findings confirmed the presence of Branchiomyces sp. in gill tissue and mixed bacterial fish pathogens (Streptococcus agalactiae, Vibrio alginolyticus, V. parahaemolyticus, Pseudomonas anguilliseptica, and P. aeruginosa) in visceral organs. The histopathological and transmission electron microscopic examinations revealed severe necrosis of gill filaments and blockage of branchial blood vessels and lamellar capillaries with Branchiomyces sp. hyphae and spores mixed with different shapes of bacteria. Severe inflammations were detected in liver, kidney, heart, and brain tissues. Ultimately, we can conclude that the syndrome of mass fish kills in this area is a consequence of ecological damage to the aquatic environment, which is mainly related to natural and anthropogenic factors, as well as to the presence of infectious agents. Received September 30, 2015; accepted April 12, 2016.

  12. Utilization of diets containing graded levels of ethanol production co-products by Nile tilapia.

    PubMed

    Schaeffer, T W; Brown, M L; Rosentrater, K A; Muthukumarappan, K

    2010-12-01

    A feeding trial was performed to investigate inclusion levels of distillers dried grains with solubles (DDGS) as a fishmeal replacement for juvenile Nile tilapia (Oreochromis niloticus). On a dry matter basis, five isocaloric [19.3 ± 0.4 kJ/g (mean ± SE)], isonitrogenous (39.1 ± 0.5% crude protein) diets were formulated to contain 17.5%, 20%, 22.5%, 25%, and 27.5% DDGS and compared against a 0% DDGS, reference diet (gross energy = 14.5 kJ/g; crude protein = 39.8%). The reference diet resulted in significantly higher body weight gain (BWG), food conversion ratio (FCR), and protein efficiency ratio (PER) than experimental diets except that 17.5% DDGS provided similar FCR and PER. The diet containing 27.5% DDGS had significantly lower FCR and PER values than all other diets even though apparent digestibility did not significantly differ among experimental diets. Although DDGS can be incorporated at higher levels, 20% DDGS provided the highest apparent BWG among experimental diets, while 17.5% promoted the best FCR and PER. Fishmeal may be replaced with low levels of fuel-based DDGS to reduce feeding cost; however, additional supplements should be considered to enhance fish performance.

  13. High temperature-induced sterility in the female Nile tilapia, Oreochromis niloticus.

    PubMed

    Pandit, Narayan Prasad; Bhandari, Ramji Kumar; Kobayashi, Yasuhisa; Nakamura, Masaru

    2015-03-01

    High temperature treatments induce germ cell loss in gonads of vertebrate animals, including fish. It could be a reliable source for induction of sterility if the treatments led to a permanent loss of germ cells. Here we report that heat treatment at 37 °C for 45-60 days caused a complete loss of germ cells in female Nile tilapia, Oreochromis niloticus, and that sterility was achieved in fish at all stages of their life cycle. Unlike previous observations, germ cells did not repopulate even after returning them to the water at control conditions suggesting permanent depletion of germ cells. Gonadal somatic cells immunopositive for 3β-hydroxysteroid dehydrogenase (3β-HSD) were clustered at one end of the germ cell depleted gonads close to the blood vessel. Serum level of testosterone, 11-ketotestosterone, and 17β-estradiol was significantly decreased in sterile fish compared to control. Body weight of sterile fish was higher than control fish at the end of experiment. Our observations of increased growth and permanent sterilization in the high temperature-treated fish suggest that this method could be an appropriate and eco-friendly tool for inducing sterility in fish with a higher thermal tolerance.

  14. Integrated cytogenetics and genomics analysis of transposable elements in the Nile tilapia, Oreochromis niloticus.

    PubMed

    Valente, Guilherme; Kocher, Thomas; Eickbush, Thomas; Simões, Rafael P; Martins, Cesar

    2016-06-01

    Integration of cytogenetics and genomics has become essential to a better view of architecture and function of genomes. Although the advances on genomic sequencing have contributed to study genes and genomes, the repetitive DNA fraction of the genome is still enigmatic and poorly understood. Among repeated DNAs, transposable elements (TEs) are major components of eukaryotic chromatin and their investigation has been hindered even after the availability of whole sequenced genomes. The cytogenetic mapping of TEs in chromosomes has proved to be of high value to integrate information from the micro level of nucleotide sequence to a cytological view of chromosomes. Different TEs have been cytogenetically mapped in cichlids; however, neither details about their genomic arrangement nor appropriated copy number are well defined by these approaches. The current study integrates TEs distribution in Nile tilapia Oreochromis niloticus genome based on cytogenetic and genomics/bioinformatics approach. The results showed that some elements are not randomly distributed and that some are genomic dependent on each other. Moreover, we found extensive overlap between genomics and cytogenetics data and that tandem duplication may be the major mechanism responsible for the genomic dynamics of TEs here analyzed. This paper provides insights in the genomic organization of TEs under an integrated view based on cytogenetics and genomics.

  15. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    PubMed

    Toledo-Ibarra, G A; Díaz-Resendiz, K J G; Pavón-Romero, L; Rojas-García, A E; Medina-Díaz, I M; Girón-Pérez, M I

    2016-08-01

    Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement.

  16. Identification of (L)-fucose-binding proteins from the Nile tilapia (Oreochromis niloticus L.) serum.

    PubMed

    Argayosa, Anacleto M; Lee, Yuan C

    2009-09-01

    Lectins are carbohydrate-binding proteins with many biological functions including cellular recognition and innate immunity. In this study, a major l-fucose-binding lectin from the serum of Nile tilapia (Oreochromis niloticus L.), designated as TFBP, was isolated by l-fucose-BSA Sepharose CL6B affinity chromatography. The SDS-PAGE (10%) analysis of TFBP revealed a major band of approximately 23 kDa with an N-terminal amino acid sequence of DQTETAGQQSXPQDIHAVLREL which did not give significant similarities to the protein databases using BLASTp searches. Ruthenium red staining indicate positive calcium-binding property of TFBP. The purified TFBP agglutinated human type O erythrocytes but not the type A and B fresh erythrocytes. Live Aeromonas hydrophila and Enterococcus faecalis cells were also agglutinated by the lectin. The fucose-binding proteins were detected in the soluble protein extracts from the gills, gut, head kidneys, liver, serum and spleen using a fucose-binding protein probe (l-fucose-BSA-horseradish peroxidase). The binding of TFBP with the l-fucose-BSA probe was inhibited by l-fucose but not by alpha-methyl-d-mannose.

  17. Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus (L.)

    USGS Publications Warehouse

    El Gamal, A.-R.A.; Davis, K.B.; Jenkins, J.A.; Les, Torrans E.

    1999-01-01

    Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus, was investigated by heat shock, cold shock, hydrostatic pressure, and/ or chemicals (cytochalasin A, B, and D). Additionally, efficacy of combined protocols was determined. Heat shock 10 min after fertilization induced triploidy when incubation temperature was 24 C but not when incubation temperature was 31 C. Heat shock of 40-41 C at 4-6 min after fertilization was effective in inducing up to 100% triploidy with hatchability similar to controls. Cold shock at 13 C for 45 min five min after fertilization induced 85-100% triploids. Heat shock and multiple heat shocking were the most effective treatments for the induction of tetraploidy. Two heat treatments of 41 C applied at 65 and 80 min after fertilization for 5 min each produced approximately 80% tetraploidy in hatched fry. Immersion of fertilized eggs in cytochalasin A, B, or D at concentrations up to 10 ??g/L applied at various times and durations was ineffective in inducing triploidy or tetraploidy.

  18. Heterogeneous growth fingerlings of the Nile tilapia Oreochromis niloticus: effects of density and initial size variability.

    PubMed

    Barbosa, J M; Brugiolo, S S S; Carolsfeld, J; Leitão, S S

    2006-05-01

    In this study, the effect of initial heterogeneity of weight and density on heterogeneous growth (HetG) evaluated by the coefficient of the variation of weight in the young Nile tilapia Oreochromis niloticus of the territorial species was tested. Fish were maintained in a glass aquarium (8 and 2 L of water) with two levels of initial heterogeneity of weight: low and high, under two density conditions: low and high, thus constituting four conditions (six replications for each). Initially, the weights of the animals were taken after 8, 16, 22 and 30 days (end of experiment). The results, evaluated by the non-parametric test of Kruskal- Wallis, demonstrated that in the groups where the animals were stored under high initial HetG, there was a reduction of the same and that in the groups where the animals were stored under high density, there was exacerbation or maintained high values of HetG. High density in association with high initial heterogeneity caused more exacerbation of HetG in such a way that the density appeared to be a determining factor for exacerbation or the maintenance of high values of HetG, whereas the initial heterogeneity of the weight could be a secondary factor.

  19. Nutritional background changes the hypolipidemic effects of fenofibrate in Nile tilapia (Oreochromis niloticus)

    PubMed Central

    Ning, Li-Jun; He, An-Yuan; Lu, Dong-Liang; Li, Jia-Min; Qiao, Fang; Li, Dong-Liang; Zhang, Mei-Ling; Chen, Li-Qiao; Du, Zhen-Yu

    2017-01-01

    Peroxisome proliferation activated receptor α (PPARα) is an important transcriptional regulator of lipid metabolism and is activated by high-fat diet (HFD) and fibrates in mammals. However, whether nutritional background affects PPARα activation and the hypolipidemic effects of PPARα ligands have not been investigated in fish. In the present two-phase study of Nile tilapia (Oreochromis niloticus), fish were first fed a HFD (13% fat) or low-fat diet (LFD; 1% fat) diet for 10 weeks, and then fish from the first phase were fed the HFD or LFD supplemented with 200 mg/kg body weight fenofibrate for 4 weeks. The results indicated that the HFD did not activate PPARα or other lipid catabolism-related genes. Hepatic fatty acid β-oxidation increased significantly in the HFD and LFD groups after the fenofibrate treatment, when exogenous substrates were sufficiently provided. Only in the HFD group, fenofibrate significantly increased hepatic PPARα mRNA and protein expression, and decreased liver and plasma triglyceride concentrations. This is the first study to show that body fat deposition and dietary lipid content affects PPARα activation and the hypolipidemic effects of fenofibrate in fish, and this could be due to differences in substrate availability for lipid catabolism in fish fed with different diets. PMID:28139735

  20. Ectoparasites of Nile tilapia (Oreochromis niloticus) in cage farming in a hydroelectric reservoir in Brazil.

    PubMed

    Zago, Aline Cristina; Franceschini, Lidiane; Garcia, Fabiana; Schalch, Sérgio Henrique Canello; Gozi, Kátia Suemi; Silva, Reinaldo José da

    2014-01-01

    For this study, we performed a parasitological analysis of cage-cultured Nile tilapia (Oreochromis niloticus) from the Água Vermelha Reservoir, Southeastern Brazil, and verified relationships with limnological data, seasonality, and fish growth phase. From March 2010 to March 2011, sixty-three specimens of O. niloticus in three growth phases (i.e., initial, intermediate, and final) were collected. All fish specimens were infested with at least one ectoparasite species (prevalence = 100%). Five species of protozoans (Trichodina compacta, Trichodina magna, Ichthyophthirius multifiliis, Piscinoodinium pillulare, and Epistylis sp.) and five species of monogenoids (Cichlidogyrus halli, Cichlidogyrus thurstonae, Cichlidogyrus sp. 1, Scutogyrus longicornis, and Gyrodactylus sp.) were observed. The abundance of Trichodina spp. and the prevalence of Epistylis sp. were higher in the dry season, and the prevalence of C. halli was higher in the rainy season. For the majority of ectoparasites found in this study, fish in the intermediate and final phases had higher parasitism rates than those in the initial phase. The data presented may help fish farmers to understand the parasite dynamics of the fish species studied in cage-farming systems.

  1. Pathogenicity and oxidative stress in Nile tilapia caused by Aphanomyces laevis and Phoma herbarum isolated from farmed fish.

    PubMed

    Ali, Esam H; Hashem, Mohamed; Al-Salahy, M Bassam

    2011-03-16

    Identified (n = 17) and unidentified (n = 1) fish-pathogenic fungal species from 10 genera of Oomycetes and soil fungi were isolated from 40 infected freshwater fish samples of the species Oreochromis niloticus niloticus (Nile tilapia) and Clarias gariepinus (African catfish). Samples were collected from various fish farms in the Nile Delta, Egypt. Nile tilapia were tested in aquaria for their susceptibility to the commonest Oomycetes species, Aphanomyces laevis and Achlya klebsiana, and also against the 2 most prevalent pathogenic soil fungi, Paecilomyces lilacinus and Phoma herbarum. Two techniques were used: water bath exposure and intramuscular (subcutaneous) injection. Water bath exposure to the 2 species of Oomycetes caused greater mortalities of O. niloticus niloticus than intramuscular injection, but the reverse was true of the soil fungal species. Regardless of the infection method, the 2 Oomycetes species were more potent pathogens than the soil fungal species. In both gills and mytomal muscles of fish infected by A. laevis and P. herbarum, we measured and compared with controls the oxidative stress parameters total peroxide (TP), lipid peroxidation (LPO) and nitric oxide (NO), as well as levels of the antioxidants vitamin E and glutathione (GSH), and superoxide dismutase (SOD) and catalase (CAT) activities. Infection by these 2 fungal species through either spore suspension or spore injection significantly increased oxidative damage in gills and induced marked decrease in most studied antioxidants. In addition, both routes showed similar effects and A. laevis depressed the antioxidants CAT, vitamin E and GSH more than P. herbarum.

  2. A piscirickettsiosis-like syndrome in cultured Nile tilapia in Latin America with Francisella spp. as the pathogenic agent.

    PubMed

    Mauel, M J; Soto, E; Moralis, J A; Hawke, J

    2007-03-01

    In 2004, cultured Nile tilapia Oreochromis niloticus in several Latin America farms began to succumb to a disease similar to the piscirickettsiosis-like syndrome previously reported in tilapia in Taiwan and the United States. Mortality increased during 2005; reductions in tilapia biomass ranged from 5% to 80% in individual ponds and averaged 50% overall. All ages of fish have been involved. Clinical signs include lethargy, loss of appetite, petechia, exophthalmia, and abnormal swimming behavior. Gross lesions have included splenomegaly, renomegaly, and numerous white nodules observed in the spleen, kidney, testes, heart, ovaries, and occasionally the liver. A previously unreported black granulomatous lesion was reported in up to 30% of the fillets. Histologically, granulomatous infiltrates were observed in the kidney, spleen, liver, testes, ovary, and choroid gland, and rarely in the brain and heart. A small pleomorphic bacterium was observed in Giemsa-stained blood smears and spleen imprints. The bacterium did not grow on standard microbiological media and has not been isolated in cell culture. We obtained a near-complete 16S ribosomal DNA sequence with high similarity to Francisella spp. sequences previously identified in tilapias Oreochromis spp. (Taiwan), Atlantic cod Gadus morhua (Norway), and three-line grunts Parapristipoma trilineatum (Japan).

  3. Competitive interactions between invasive Nile tilapia and native fish: the potential for altered trophic exchange and modification of food webs.

    PubMed

    Martin, Charles W; Valentine, Marla M; Valentine, John F

    2010-12-21

    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important.

  4. Effect of poly-β-hydroxybutyrate on growth and disease resistance of Nile tilapia Oreochromis niloticus juveniles.

    PubMed

    Situmorang, Magdalena Lenny; De Schryver, Peter; Dierckens, Kristof; Bossier, Peter

    2016-01-01

    The growth promoting effect of the bacterial storage compound poly-β-hydroxybutyrate (PHB) has been studied for young fish of high trophic level (European sea bass) and intermediate trophic level (Siberian sturgeon). Here, the effect of PHB on growth, digestive enzyme activities, body composition and diseases resistance of juvenile Nile tilapia (Oreochromis niloticus) of low trophic level was investigated. Although dietary PHB supplementation (5, 25 and 50 g PHB kg(-1) formulated semi-purified diet) during 28 days resulted in a trend of increased weight gain, there was no significant difference in the mean final body weight (258-284 mg) when compared to the fish from the control group (on average 218 mg). Lipase activity increased significantly with about 20-40% by the supplementation of PHB in the diet, which may have led to the significant increase in total lipid content with about 10% in the PHB treatment groups. However, the profile of total (n-6) fatty acids (FAs), total monounsaturated FAs and total saturated FAs relative to the total lipid was similar among various PHB treatments. An additional challenge test on gnotobiotic Nile tilapia larvae using the pathogen Edwardsiella ictaluri gly09R showed that feeding challenged larvae with PHB-enriched Artemia nauplii resulted in a 20% higher survival as compared to the challenged control larvae. Overall, it is suggested that the trend of increased body weight gain resulted from intestinal lipid digestion, absorption and deposition and that PHB is effective as an antimicrobial agent for application in Nile tilapia larviculture.

  5. Establishment and growth responses of Nile tilapia embryonic stem-like cell lines under feeder-free condition.

    PubMed

    Fan, Zhenhua; Liu, Linyan; Huang, Xiaohuan; Zhao, Yang; Zhou, Linyan; Wang, Deshou; Wei, Jing

    2017-02-01

    Embryonic stem (ES) cells provide an invaluable tool for molecular analysis of vertebrate development and a bridge linking genomic manipulations in vitro and functional analysis of target genes in vivo. Work towards fish ES cells so far has focused on zebrafish (Danio renio) and medaka (Oryzias latipes). Here we describe the derivation, pluripotency, differentiation and growth responses of ES cell lines from Nile tilapia (Oreochromis niloticus), a world-wide commercial farmed fish. These cell lines, designated as TES1-3, were initiated from blastomeres of Nile tilapia middle blastula embryos (MBE). One representative line, TES1, showed stable growth and phenotypic characteristics of ES cells over 200 days of culture with more than 59 passages under feeder-free conditions. They exhibited high alkaline phosphatase activity and expression of pluripotency genes including pou5f3 (the pou5f1/oct4 homologue), sox2, myc and klf4. In suspension culture together with retinoic acid treatment, TES1 cells formed embryoid bodies, which exhibited expression profile of differentiation genes characteristics of all three germ cell layers. Notably, PKH26-labeled TES1 cells introduced into Nile tilapia MBE could contribute to body compartment development and led to hatched chimera formation with an efficacy of 13%. These results suggest that TES1 cells have pluripotency and differentiation potential in vitro and in vivo. In the conditioned DMEM, all of the supplements including the fetal bovine serum, fish embryonic extract, fish serum, basic fibroblast growth factor and non-protein supplement combination 5N were mitogenic for TES1 cell growth. This study will promote ES-based biotechnology in commercial fish.

  6. Digestive enzyme activity in the intestine of Nile tilapia (Oreochromis niloticus L.) under pond and cage farming systems.

    PubMed

    Santos, Juliana Ferreira; Soares, Karollina Lopes Siqueira; Assis, Caio Rodrigo Dias; Guerra, Carlos Augusto Martins; Lemos, Daniel; Carvalho, Luiz Bezerra; Bezerra, Ranilson Souza

    2016-10-01

    The effect of different farming systems (cage, pond) upon digestive enzyme activities of Nile tilapia was evaluated. Juvenile Nile tilapia (87.61 ± 1.52 g) were simultaneously cultured in pond and cage systems during 90 days. Cages used nutritional biphasic plan (35 and 32 % crude protein-CP feeds) and ponds used nutritional triphasic plan (35, 32 and 28 % CP feeds). Biometric measurements were monthly performed for adjustments in feeding regimes and removal of intestine tissues to evaluate the performance of enzyme activities. Total proteolytic, amylase and lipase activities were not statistically different between the treatments throughout the periods analyzed (31, 63 and 94 days of culture). However, trypsin and chymotrypsin activities were higher with 31 and 63 days of culture in fish from pond system, suggesting that natural food may have influenced these activities. A positive correlation was observed between the recommended concentration of essential amino acids for Nile tilapia and specific aminopeptidases activity in fish cage system. Substrate-SDS-PAGE revealed 12 active proteolytic bands in both systems. However, integrated density (ID) values were higher in the bands of ponds. Specimens of either cage or pond exhibited five bands of amylolytic activity. Fish from cage and pond systems showed the highest values of ID within 31 days of cultivation. In this study, the complexity of digestive functions could be verified for animals maintained under commercial conditions. Some of the assessed enzymes may show adaptations of their activities and/or expression that allow the fish to achieve a more efficient nutrient assimilation.

  7. Molecular characterization and expression of CD2BP2 in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.

    PubMed

    Gan, Zhen; Wang, Bei; Lu, Yishan; Cai, Shuanghu; Cai, Jia; Jian, JiChang; Wu, Zaohe

    2014-09-10

    CD2BP2 (CD2 cytoplasmic tail binding protein 2), one of several proteins interacting with the cytoplasmic tail of CD2, plays a crucial role in CD2-triggered T cell activation and nuclear splicing. The studies on CD2BP2 have tended to be confined to a few mammals, and little information is available to date regarding fish CD2BP2. In this paper, a CD2BP2 gene (On-CD2BP2) was cloned from Nile tilapia, Oreochromis niloticus. Sequence analysis showed that the full length of On-CD2BP2 cDNA was 1429 bp, containing a 5'untranslated region (UTR) of 111 bp, a 3'-UTR of 193 bp and an open reading frame of 1125 bp which is encoding 374 amino acids. Two important structural features, a GYF domain and a consensus motif GPFXXXXMXXWXXXGYF were detected in the deduced amino acid sequence of On-CD2BP2, and the deduced genomic structure of On-CD2BP2 was similar to the known CD2BP2. The mRNA expression of On-CD2BP2 in various tissues of Nile tilapia was analyzed by fluorescent quantitative real-time PCR. In healthy Nile tilapia, the On-CD2BP2 transcripts were mainly detected in the head kidney and spleen. While vaccinated with inactivated Streptococcus agalactiae, the On-CD2BP2 mRNA expression was significantly up-regulated in the head kidney, spleen and brain 48 h post immunization. Moreover, there was a clear time-dependent expression pattern of On-CD2BP2 after immunization and the expression reached the highest level at 24h in the brain and 48 h in the head kidney and spleen. This is the first report of proving the presence of a CD2BP2 ortholog in fish, and investigating its tissue distribution and expression profile in response to bacterial stimulus. These findings indicated that On-CD2BP2 may play an important role in the immune response to bacteria in Nile tilapia.

  8. Effects of dietary levels of vitamin A on growth, hematology, immune response and resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the effect of supplemental levels of vitamin A (0, 2,500, 5,000, 10,000, and 20,000 IU/kg diet) on the growth performance, hematology, immune response and resistance of Nile tilapia, Oreochromis niloticus to Streptococcus iniae challenge. Each diet was fed to Nil...

  9. Use of biofuel by-product from the green algae Desmochloris sp. and diatom Nanofrustulum sp. meal in diets for nile tilapia Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Algal by-product meals from the Hawaiian biofuels industry were evaluated as protein ingredients in diets for juveniles of Nile tilapia (Oreochromis niloticus). Four experimental diets were formulated to contain 40% protein and were made with fish meal, soybean meal, whole diatom (Nanofrustulum sp.)...

  10. The effect of NovaSil dietary supplementation on the growth and health performance of Nile tilapia (Oreochromis niloticus) fed aflatoxin-B1 contaminated feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the ability of NovaSil (NS) clay to sorb and mitigate the toxic effects of aflatoxin B1 (AFB1) in Nile tilapia (Oreochromis niloticus). Growth performance, specific innate immunological function, intestinal microbial community, and histology were evaluate...

  11. Molecular characterization, functional analysis, and defense mechanisms of two CC chemokines in Nile tilapia (Oreochromis niloticus) in response to severely pathogenic bacteria.

    PubMed

    Nakharuthai, Chatsirin; Areechon, Nontawith; Srisapoome, Prapansak

    2016-06-01

    Two full-length cDNAs encoding CC chemokine genes in Nile tilapia (Oreochromis niloticus) (On-CC1 and On-CC2) were cloned and characterized. On-CC1 and On-CC2 showed signature cysteine motifs consisting of four cysteines. The expression levels of On-CC1 and On-CC2 were analyzed by RT-PCR, which showed that low expression of these two genes was only observed in the peripheral blood leukocytes (PBLs) and spleen of normal fish. Expression levels of these two molecules were quantified in 13 tissues of fish infected with virulent strains of Streptococcus agalactiae and Flavobacterium columnare. Most tissues, especially PBLs, the spleen and the liver, expressed significantly higher mRNA levels than the controls, particularly at 12 and 24 h after infection (P < 0.05). The current study strongly indicates that CC chemokine genes in Nile tilapia are crucially involved in the early immune responses to pathogens. Functional analyses clearly demonstrated that 10 and 100 μg/ml of recombinant rOn-CC1 and rOn-CC2 proteins efficiently enhanced the phagocytic activity (in vitro) of Nile tilapia phagocytes. Finally, Southern blot analysis and searching in Ensembl databases demonstrated that two different functional CC chemokine genes and other pseudogene fragments were discovered in the Nile tilapia genome.

  12. Complete Genome Sequence of Streptococcus iniae UEL-Si1, Isolated in Diseased Nile Tilapia (Oreochromis niloticus) from Northern Paraná, Southern Brazil

    PubMed Central

    Gonçalves, Kátia B.; Scarpassa, Josiane A.; Pretto-Giordano, Lucienne G.

    2017-01-01

    ABSTRACT The Streptococcus iniae UEL-Si1 strain was isolated from diseased Nile tilapia within the Paranapanema River Basin, Northern Paraná, Brazil. This is an emerging infectious disease agent of fish from Brazil, and sequencing of the complete genome is fundamental to understanding aspects relative to pathogenesis, infection, epidemiology, and immunity. PMID:28082497

  13. Draft Genome Sequence of Francisella noatunensis subsp. orientalis STIR-GUS-F2f7, a Highly Virulent Strain Recovered from Diseased Red Nile Tilapia Farmed in Europe

    PubMed Central

    Larsson, Pär; Wehner, Stefanie; Bekaert, Michaël; Öhrman, Caroline; Metselaar, Matthijs; Thompson, Kimberly Dawn; Richards, Randolph Harvey; Penman, David James; Adams, Alexandra

    2017-01-01

    ABSTRACT A highly virulent strain of Francisella noatunensis subsp. orientalis, STIR-GUS-F2f7, was isolated from moribund red Nile tilapia (Oreochromis niloticus) farmed in Europe. In this communication, the complete genome sequencing of this bacterium is reported. PMID:28302784

  14. Evaluation of plant and animal protein sources as partial or total replacement of fish meal in diets for juvenile Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A feeding trial was conducted in a closed system with Nile tilapia (Oreochromis niloticus) juveniles (mean weight, 2.84 g) to examine the effects of total replacement of fish meal (FM), with and without supplementation of DL-methionine (Met) and L-lysine (Lys), by plant protein sources. Fish were f...

  15. Histopathological alterations in the gills of Nile tilapia exposed to carbofuran and multiwalled carbon nanotubes.

    PubMed

    Campos-Garcia, Janaína; Martinez, Diego Stéfani Teodoro; Rezende, Karina Fernandes Oliveira; da Silva, José Roberto Machado Cunha; Alves, Oswaldo Luiz; Barbieri, Edison

    2016-11-01

    Carbofuran is a nematicide insecticide with a broad spectrum of action. Carbofuran has noxious effects in several species and has been banned in the USA and Europe; however, it is still used in Brazil. Aquatic organisms are not only exposed to pesticides but also to manufactured nanoparticles, and the potential interaction of these compounds therefore requires investigation. The aim of this study was to examine the histopathological alterations in the gills of Nile tilapia (Oreochromis niloticus) to determine possible effects of exposure to carbofuran, nitric acid-treated multiwalled carbon nanotubes (HNO3-MWCNTs) and the combination of carbofuran with nanotubes. Juvenile fish were exposed to different concentrations of carbofuran (0.1, 0.5, 2.0, 4.0 and 8.0mg/L), different concentrations of HNO3-MWCNTs (0.5, 1.0 and 2.0mg/L) or different concentrations of carbofuran (0.1, 0.5, 2.0, 4.0 and 8.0mg/L) with 1.0mg/L of HNO3-MWCNTs. After 24h of exposure, the animals were removed from the aquarium, the spinal cord was transversely sectioned, and the second gill arch was removed for histological evaluation. Common histological changes included dislocation of the epithelial cells, hyperplasia of the epithelial cells along the secondary lamellae, aneurism, and dilation and disarrangement of the capillaries. All the groups exposed to carbofuran demonstrated a dose-dependent correlation in the Histological Alteration Index; the values found for carbofuran and carbon nanotubes were up to 25% greater than for carbofuran alone. This result indicates an interaction between these toxicants, with enhanced ecotoxic effects. This work contributes to the understanding of the environmental impacts of nanomaterials on aquatic organisms, which is necessary for the sustainable development of nanotechnologies.

  16. Haploinsufficiency of SF-1 Causes Female to Male Sex Reversal in Nile Tilapia, Oreochromis niloticus.

    PubMed

    Xie, Qing-Ping; He, Xue; Sui, Yi-Ning; Chen, Li-Li; Sun, Li-Na; Wang, De-Shou

    2016-06-01

    Steroidogenic factor-1 (Sf-1) (officially designated nuclear receptor subfamily 5 group A member 1 [NR5A1]) is a master regulator of steroidogenesis and reproduction in mammals. However, its function remains unclear in nonmammalian vertebrates. In the present study, we used immunohistochemistry to detect expression of Sf-1 in the steroidogenic cells, the interstitial, granulosa, and theca cells of the ovary, and the Leydig cells of the testis, in Nile tilapia. Clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (Cas9) cleavage of sf-1 resulted in a high mutation rate in the F0 generation and a phenotype of gonadal dysgenesis and reduced steroidogenic cells in XX and XY fish. Sf-1 deficiency also resulted in decreased cytochrome P450, family 19, subfamily A, polypeptide 1a, forkhead box L2 expression, and serum estradiol-17β in XX fish. In XY fish, Sf-1 deficiency increased cytochrome P450, family 19, subfamily A, polypeptide 1a and forkhead box L2 expression but decreased cytochrome P450, family 11, subfamily B, polypeptide 2 expression and serum 11-ketotestosterone levels. 17α-methyltestosterone treatment successfully rescued the gonadal phenotype of Sf-1-deficient XY fish, as demonstrated by normal spermatogenesis and production of F1 mutants. In contrast, estradiol-17β treatment only partially rescued the gonadal phenotype of Sf-1-deficient XX fish, as demonstrated by the appearance of phase II oocytes. Furthermore, both sf-1(+/-) F1 XX and XY mutants developed as fertile males, although spermatogenesis was delayed and efferent duct formation was disordered. Our data suggest that Sf-1 is a major regulator of steroidogenesis and reproduction in fish, as it is in mammals. Sf-1 deficiency resulted in gonadal dysgenesis and feminization of XY gonads. However, unlike in mammals, Sf-1 deficiency also resulted in female to male sex reversal in 8.1% of F0 and 92.1% of sf-1(+/-) F1 in XX fish.

  17. Ecological Risk Assessment of Metal Pollution along Greater Cairo Sector of the River Nile, Egypt, Using Nile Tilapia, Oreochromis niloticus, as Bioindicator

    PubMed Central

    Omar, Wael A.; Mikhail, Wafai Z. A.; Abdo, Hanaa M.; Abou El Defan, Tarek A.; Poraas, Mamdouh M.

    2015-01-01

    The present work aims to evaluate seasonal metal pollution along Greater Cairo sector of the River Nile, Egypt, using wild Nile tilapia, Oreochromis niloticus, as bioindicator and to conduct a risk assessment for human consumers. Greater Cairo is the largest populated area along the whole course of River Nile with a wide range of anthropogenic activities. Effects of metal pollution on fish body indices were studied using condition factor (CF) and scaled mass index (SMI). Metal pollution index (MPI) showed that the total metal load in fish organs followed the follwoing order: kidney > liver > gill > muscle which gives a better idea about the target organs for metal accumulation. Metal concentrations in fish muscle (edible tissue) showed the following arrangement: Fe > Zn > Cu > Mn > Pb > Cd. Metal's bioaccumulation factor (BAF) in fish muscle showed the following arrangement: Zn > Cu > Fe > Mn > Cd and Pb. The hazard index (HI) as an indicator of human health risks associated with fish consumption showed that adverse health effects are not expected to occur in most cases. However, the metals' cumulative risk effects gave an alarming sign specifically at high fish consumption rates. PMID:26617637

  18. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Sarker, Pallab K.; Kapuscinski, Anne R.; Lanois, Alison J.; Livesey, Erin D.; Bernhard, Katie P.; Coley, Mariah L.

    2016-01-01

    We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds. PMID:27258552

  19. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus).

    PubMed

    Sarker, Pallab K; Kapuscinski, Anne R; Lanois, Alison J; Livesey, Erin D; Bernhard, Katie P; Coley, Mariah L

    2016-01-01

    We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds.

  20. Use of asiatic pennywort Centella asiatica aqueous extract as a bath treatment to control columnaris in Nile tilapia.

    PubMed

    Rattanachaikunsopon, P; Phumkhachorn, P

    2010-03-01

    To develop antibiotic-free and chemical-free aquaculture, it is necessary to have natural substances to control diseases of aquatic animals. The aim of this study was to find an herb having therapeutic effect against columnaris, a fish disease caused by the bacterium Flavobacterium columnare. Of all tested herbs (including kalmegh Andrographis paniculata, candle bush Cassia alata, Asiatic pennywort Centella asiatica, mangosteen Garcinia mangostana, pomegranate Punica granatum, and guava Psidium guajava), the aqueous extract of Asiatic pennywort exhibited the strongest antimicrobial activity against F. columnare; the minimal inhibitory concentration was 31.25 lg/mL. It was also found to have a bactericidal effect on F. columnare. When experimental bath exposures of Nile tilapia Oreochromis niloticus to F. columnare were performed, the median lethal dose was determined to be 2.37 x 10(5) colony forming units/mL. For in vivo trials, six different concentrations (0, 20, 40, 60, 80, and 100 mg/L) of Asiatic pennywort aqueous extract were used as bath treatments to control experimentally induced columnaris in Nile tilapia. The decrease in fish mortality was dose dependent, and at a concentration of 100 mg/L no mortality or adverse effects were noted in the infected fish. This study suggests that Asiatic pennywort aqueous extract has the potential to control disease caused by F. columnare.

  1. ABC transporters, CYP1A and GSTα gene transcription patterns in developing stages of the Nile tilapia (Oreochromis niloticus).

    PubMed

    Costa, Joana; Reis-Henriques, Maria Armanda; Castro, L Filipe C; Ferreira, Marta

    2012-09-15

    In fish, some ABC transporters are implicated in a multixenobiotic resistance (MXR) mechanism to deal with the presence of xenobiotics, by effluxing them, or their metabolites, from inside the cells. These efflux transporters have been considered an integral part of cellular detoxification pathways, acting in coordination with phase I and II detoxification enzymes. However, the full characterization of this detoxification system is still incomplete, especially during the developmental stages of aquatic organisms, which are particularly sensitive periods to the presence of anthropogenic contamination. The goal of this study was to evaluate the mRNA expression dynamics of putatively important MXR proteins (ABCB1b, ABCB11, ABCC1, ABCC2 and ABCG2a) and phase I (CYP1A) and II (GSTα) biotransformation enzymes, during the embryonic and larval developments of the specie Oreochromis niloticus (Nile tilapia). Our results showed that ABCB1b, ABCC1, CYP1A and GSTα transcripts are maternally transmitted. Transcripts for ABCB11, ABCC2 and ABCG2a were only detected after the pharyngula period, which precedes a highly sensitive stage in the embryonic development, the hatching. This study has shown, for the first time, very distinct expression patterns of genes encoding for proteins involved in protection mechanisms against pollutants during the development of Nile tilapia. Moreover, the temporal pattern of gene expression suggests that increased intrinsic protection levels are required at specific developmental stages.

  2. Preliminary study of acceleration based sensor to record nile tilapia (Oreochromis niloticus) feeding behavior at water surface

    NASA Astrophysics Data System (ADS)

    Subakti, Aji; Khotimah, Zarah F.; Darozat, Fajar M.

    2017-01-01

    In this preliminary study, the acceleration based sensor was developed to monitor the activity of Nile tilapia (Oreochromis niloticus) feeding behavior at the water surface. This study was conducted for three weeks in a fish pond with 40 m2 in size, stocked with 850 fingerlings of Nile tilapia strain Nirwana-2 (average biomass of 13 g, fed four times a day at 8 am, 12 pm, 4 pm, and 8 pm). The acceleration sensor system was installed floating in the pond and was designed in a way so that the xz plane of the sensor will be parallel with water surface, while the y-axis will be pointing downward. By sensing the acceleration caused by the surface wave, the activities of fish near surface water could be monitored. The result showed that there were three distinctive patterns could be observed which was related to the feeding activity of fish. Generally, it can be concluded that this acceleration based sensor system can be integrated with automatic feeder machine, in particular by analyzing the recorded patter, it is possible to monitor when the fish stop eating, and so the right amount of feed could be given to the fish.

  3. Identification and expression profile of multiple genes in Nile tilapia in response to formalin killed Streptococcus iniae vaccination.

    PubMed

    Pridgeon, Julia W; Klesius, Phillip H

    2011-08-15

    Twenty-eight expressed sequence tags (ESTs) were isolated from a Nile tilapia (Oreochromis niloticus) vaccinated vs non-vaccinated subtractive library at 12-h post injection of a formalin killed Streptococcus iniae ARS-98-60 vaccine. The 28 ESTs were classified in terms of their putative functions. Half of the ESTs identified were unknown proteins. Of the remaining half ESTs, 17% have putative functions in protein biosynthesis and 11% have putative functions in immunity, energy production, and signal transduction, respectively. Immunity-related ESTs identified included high density lipoprotein-binding protein vigilin, immunoglobulin heavy chain, and QM-like protein. Quantitative PCR revealed that one EST (cytochrome c oxidase subunit II) was highly upregulated (1825 ± 336 fold) in vaccinated fish compared to that in non-vaccinated fish. Of the remaining 27 ESTs, nine were significantly (P<0.05) upregulated (<20 fold) in vaccinated fish. The nine significantly upregulated genes included five unknown or hypothetical proteins and four known proteins (high density lipoprotein-binding protein vigilin, QM-like protein, ribosomal protein S13, and ribosomal protein L5). The upregulation of these genes induced by killed S. iniae vaccines suggest that they might play important role in Nile tilapia defense against S. iniae infection.

  4. DNA methylation of pituitary growth hormone is involved in male growth superiority of Nile tilapia (Oreochromis niloticus).

    PubMed

    Zhong, Huan; Xiao, Jun; Chen, Wenzhi; Zhou, Yi; Tang, Zhanyang; Guo, Zhongbao; Luo, Yongju; Lin, Zhengbao; Gan, Xi; Zhang, Ming

    2014-05-01

    Growth hormone (GH) and its receptors are critical regulators of somatic growth and metabolism. It has been shown in mammals that the methylation of cytosines within the GH promoter plays a key role in regulating transcripts expression. In the present study, the GH, GHR1 and GHR2 proximal promoters were identified and the methylation levels of these genes in corresponding tissues were assayed. The results suggested that significant arising of GH putative promoter methylation levels in pituitary was observed in females compared with males. However, no such sex-specific changes were found in GHR1 and GHR2 promoters. The GH mRNA expression also was influenced by GH promoter methylation levels in pituitary, which resulted in the higher growth rate of Nile tilapia males. Meanwhile, the methylation levels of GH putative promoter were negatively correlated with growth rate as well as mRNA expression of GH. Furthermore, the methylation of specific E-Box CpG site is also negatively related to the mRNA expression of GH in pituitary. Taken together, our data provide an epigenetic mechanism of explicating the sex duality in phenotypic plasticity of growth rate in male and female of Nile tilapia.

  5. The effect of mistletoe, Viscum album coloratum, extract on innate immune response of Nile tilapia (Oreochromis niloticus).

    PubMed

    Park, Kwan-Ha; Choi, Sang-Hoon

    2012-06-01

    The purpose of the present study was to evaluate the effect of dietary mistletoe extracts on non-specific immune response and disease resistance of Nile tilapia (Oreochromis niloticus) against Aeromonas hydrophila infection. Tilapia fingerlings were fed with a diet containing 0 mg as a control, 10 mg, 50 mg, and 200 mg mistletoe powder kg(-1) dry diet for 80 days. The immunological parameters, respiratory burst activity, lysozyme activity, alternative complement haemolysis activity (ACH(50)), and phagocytic activity of fish were investigated following 20, 40 and 80 days of feeding. Fish were challenged with A. hydrophila on 80 days after feeding and mortalities were checked over 10 days post-infection. The results show that fish fed with mistletoe extract exhibited an increase in activity in all immunological parameters (P < 0.05) compared to the control group depending on feeding periods and doses of mistletoe. Following challenge with A. hydrophila, 42% less survivability was observed in the control group than in other experimental diet groups. The highest survival rate (83%) was shown in the group fed with a 50 mg mistletoe kg(-1) diet. The results suggest that mistletoe enables tilapia to promote immunity and be more resistant to A. hydrophila infection.

  6. Effects of temperature and salt concentration on Francisella noatunensis subsp. orientalis infections in Nile tilapia Oreochromis niloticus.

    PubMed

    Soto, Esteban; Abrams, Stephanie B; Revan, Floyd

    2012-11-19

    Little is known about the environmental conditions that allow Francisella noatunensis subsp. orientalis, a worldwide emergent bacterial fish pathogen, to colonize and infect wild and cultured fish. We evaluated the effect of temperature and salinity on the infectivity of F. noatunensis subsp. orientalis in Nile tilapia Oreochromis niloticus (L). Immersion challenges of tilapia with F. noatunensis subsp. orientalis at water temperatures of 25 and 30°C in both sea and fresh water were conducted for 14 d. Morbidity and mortality were recorded daily, and at the completion of the study, a quantitative assessment of the splenic bacterial burden was performed in surviving fish. Fish maintained at 25°C developed francisellosis and had considerably higher mortality and splenic bacterial concentrations compared to control fish and fish maintained at 30°C. Moreover, increasing the water temperature from 25 to 30°C prevented the development of clinical signs and mortality in Francisella-challenged fish. In conclusion, temperature significantly influenced the development of francisellosis in tilapia, whereas salinity had no effect. Our findings may be useful in the establishment of improved prophylactic practices and in the management of outbreaks of francisellosis in the aquaculture industry.

  7. Development and efficacy of a novobiocin-resistant Streptococcus iniae as a novel vaccine in Nile tilapia (Oreochromis niloticus).

    PubMed

    Pridgeon, Julia W; Klesius, Phillip H

    2011-08-11

    A novel attenuated Streptococcus iniae vaccine was developed from a virulent strain of Streptococcus iniae (ISET0901) through selection for novobiocin resistance (named ISNO). The safety of ISNO was then evaluated in Nile tilapia (Oreochromis niloticus) through intraperitoneal (IP) injection. When male tilapia (average weight 10 g) were IP injected with 2×10(7) colony-forming units (CFU) of the attenuated S. iniae vaccine strain, no fish died. However, when the same age and size matched tilapia were IP injected with 2×10(7) and 1×10(5)CFU of the virulent parent strain of S. iniae, 100 and 90% fish died, respectively. Backpassage safety studies revealed that ISNO was unable to revert back to a virulent state. When IP vaccinated fish were challenged by the virulent ISET0901 strain of S. iniae, relative percent survival (RPS) values of vaccinated fish at 14, 28, 60, 90, and 180 days post ISNO vaccination (dpv) were 100, 100, 100, 89, and 75%, respectively, The RPS values of ISNO vaccinated fish (IP vaccination) against infections by five heterologous virulent strains of S. iniae (F3CB, 102 F1K, 405 F1K, IF6, and ARS60) at 60 dpv were 78, 90, 100, 100, and 100%, respectively. When tilapia were IP vaccinated by ISNO at dose of 1×10(2), 1×10(3), 1×10(4), 1×10(5), 1×10(6), and 1×10(7)CFU/fish, RPS values at 28 dpv were 81, 94, 100, 100, 100, and 100%, respectively. At 28 dpv, RPS of vaccinated fish by ISNO through bath immersion (1×10(7)CFU/ml) was 88%. ELISA results revealed that protection elicited by ISNO was due to antibody- as well as cell- mediated immunity. Our results suggest that ISNO could be used as a novel safe and efficacious vaccine to protect Nile tilapia from S. iniae infections.

  8. Survival, growth and reproduction of non-native Nile tilapia II: fundamental niche projections and invasion potential in the northern Gulf of Mexico

    USGS Publications Warehouse

    Lowe, Michael R.; Wu, Wei; Peterson, Mark S.; Brown-Peterson, Nancy J.; Slack, William T.; Schofield, Pamela J.

    2012-01-01

    Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi.

  9. Survival, growth and reproduction of non-native Nile tilapia II: fundamental niche projections and invasion potential in the northern Gulf of Mexico.

    PubMed

    Lowe, Michael R; Wu, Wei; Peterson, Mark S; Brown-Peterson, Nancy J; Slack, William T; Schofield, Pamela J

    2012-01-01

    Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0-60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2-368%) and decreased during extremely dry years (86-92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi.

  10. Controlled laboratory challenge demonstrates substantial additive genetic variation in resistance to Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. An alternative and ...

  11. Spring forward with improved Nile tilapia Oreochromis niloticus resistant to Streptococcus iniae and Streptococcus agalactiae IB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tilapia aquaculture worldwide is valued around US $ 7 billion. Tilapia are an important source of protein for domestic (top 5 most consumed seafoods) and global food security. Two gram postitive bacteria, Streptococcus iniae and S. agalactiae, are responsible for billion dollar losses annually. Gen...

  12. Genome-wide identification, phylogeny, and gonadal expression of fox genes in Nile tilapia, Oreochromis niloticus.

    PubMed

    Yuan, Jing; Tao, Wenjing; Cheng, Yunying; Huang, Baofeng; Wang, Deshou

    2014-08-01

    The fox genes play important roles in various biological processes, including sexual development. In the present study, we isolated 65 fox genes, belonging to 18 subfamilies named A-R, from Nile tilapia through genome-wide screening. Twenty-four of them have two or three (foxm1) copies. Furthermore, 16, 25, 68, and 45 fox members were isolated from nematodes, protochordates, teleosts, and tetrapods, respectively. Phylogenetic analyses indicated fox gene family had undergone three expansions parallel to the three rounds of genome duplication during evolution. We also analyzed the clustered fox genes and found that apparent linkage duplication existed in teleosts, which further supported fish-specific genome duplication hypothesis. In addition, species- and lineage-specific duplication is another reason for fox gene family expansion. Based on the four pairs of XX and XY gonadal transcriptome data from four critical developmental stages, we analyzed the expression profile of all fox genes and identified sexually dimorphic fox genes at each stage. All fox genes were detected in gonads, with 15 of them at the background expression level (total read per kb per million reads, RPKM < 10), 29 at moderate expression level (10 < total RPKM < 100), and 21 at high expression level (total RPKM > 100). There are 27, 24, 28, and 9 sexually dimorphic fox genes at 5, 30, 90, and 180 days after hatching (dah), respectively. foxq1a, foxf1, foxr1, and foxr1 were identified as the most differentially expressed genes at each stage. foxl2 was characterized as XX-dominant gene, while foxd5, foxi3, foxn3, foxj1a, foxj3b, and foxo6b were characterized as XY-dominant genes. qPCR and in situ hybridization of foxh1 and foxj1a were performed to confirm the expression profiles and to validate the transcriptome data. Our results suggest that fox genes might play important roles in sex determination and gonadal development in teleosts.

  13. Spatial and temporal variation in population genetic structure of wild Nile tilapia (Oreochromis niloticus) across Africa

    PubMed Central

    2011-01-01

    Background Reconstructing the evolutionary history of a species is challenging. It often depends not only on the past biogeographic and climatic events but also the contemporary and ecological factors, such as current connectivity and habitat heterogeneity. In fact, these factors might interact with each other and shape the current species distribution. However, to what extent the current population genetic structure reflects the past and the contemporary factors is largely unknown. Here we investigated spatio-temporal genetic structures of Nile tilapia (Oreochromis niloticus) populations, across their natural distribution in Africa. While its large biogeographic distribution can cause genetic differentiation at the paleo-biogeographic scales, its restricted dispersal capacity might induce a strong genetic structure at micro-geographic scales. Results Using nine microsatellite loci and 350 samples from ten natural populations, we found the highest genetic differentiation among the three ichthyofaunal provinces and regions (Ethiopian, Nilotic and Sudano-Sahelian) (RST = 0.38 - 0.69). This result suggests the predominant effect of paleo-geographic events at macro-geographic scale. In addition, intermediate divergences were found between rivers and lakes within the regions, presumably reflecting relatively recent interruptions of gene flow between hydrographic basins (RST = 0.24 - 0.32). The lowest differentiations were observed among connected populations within a basin (RST = 0.015 in the Volta basin). Comparison of temporal sample series revealed subtle changes in the gene pools in a few generations (F = 0 - 0.053). The estimated effective population sizes were 23 - 143 and the estimated migration rate was moderate (m ~ 0.094 - 0.097) in the Volta populations. Conclusions This study revealed clear hierarchical patterns of the population genetic structuring of O. niloticus in Africa. The effects of paleo-geographic and climatic events were predominant at macro

  14. Prevalence and seasonal variation of ectoparasites in cultured Nile tilapia Oreochromis niloticus in Saudi Arabia.

    PubMed

    Suliman, El Amin M; Al-Harbi, Ahmed H

    2016-12-01

    The prevalence, mean intensity and abundance of ectoparasites (monogeneans and trichodinids) from Nile tilapia Oreochromis niloticus were investigated during different seasons of two consecutive years, from January 2011 to December 2012. A total of 360 O. niloticus was collected from three fish farms located in the central region of Saudi Arabia. Prevalence, mean intensity and mean abundance of monogeneans on fish gills were found to be significantly (p < 0.01) higher in farm(C) (81.67, 495.23, 405.84 %) than farm (A) (7.5, 81.25, 8.34 %) and farm (B) (4.17, 62.5, 5 %) respectively. Similarly, the same parameters for trichodinids on gills were found to be significantly (p < 0.01) higher in farm (C) (97.5, 97.5, 97.5 %), followed by farm (A) (39.17, 234.37, 35.00 %) and farm (B) (6.67, 347.92, 30.00 %) respectively. The results of monogenean parameter on fish skin were found to be significantly (p < 0.01) higher in farm (C) (66.67, 443.68, 294.16) followed by farm (A) (16.67, 124.58, 21.67 %) then farm (B) (0.83, 25, 0.83 %) respectively. Similar results for trichodinid parameters on the skin were found to be higher (p < 0.01) in farm (C) (97.5, 875, 857.5 %), then farm (A) (26.67, 399.70, 215.01 %) and farm (B) (4.17, 154.17, 12.5 %) respectively. These results indicated that water quality and nutritional qualities were the major factors that affecting parasite occurrence, while the effect of temperature, seasonality and stocking density might have a secondary role on ectoparasite occurrence. Further studies should investigate that how the nutritional and water qualities affect the immunity of the fish to resist parasite infection.

  15. Characterization of two paralogous StAR genes in a teleost, Nile tilapia (Oreochromis niloticus).

    PubMed

    Yu, Xiangguo; Wu, Limin; Xie, Lang; Yang, Shijie; Charkraborty, Tapas; Shi, Hongjuan; Wang, Deshou; Zhou, Linyan

    2014-07-05

    Steroidogenic acute regulatory protein (StAR) transports cholesterol, the substrate for steroid synthesis, to the inner membranes of mitochondria. It is well known that estrogen is essential for female sex determination/differentiation in fish. However, no reports showed that the conventional StAR, which was supposed to be essential for estrogen production, was expressed in female gonads during the critical timing of sex determination/differentiation. In this study, two different StAR isoforms, named as StAR1 and StAR2, were characterized from the gonads of Nile tilapia (Oreochromis niloticus). Phylogenetic and synteny analysis revealed that two StAR genes existed in teleosts, Xenopus and chicken indicating that the duplication event occurred before the divergence of teleosts and tetrapods. Real-time PCR revealed that StAR1 was dominantly expressed in the testis, head kidney and kidney; while StAR2 was expressed exclusively in the gonads. In situ hybridization and immunohistochemistry demonstrated that StAR1 was expressed in the interrenal cells of the head kidney and Leydig cells of the testis; while StAR2 was expressed in the Leydig cells of the testis and the interstitial cells of the ovary. Ontogenic analysis demonstrated that StAR2 was expressed abundantly from 5 days after hatching (dah) in the somatic cells in XX gonads, whereas in XY gonads, both StARs could be detected from 30 dah until adulthood. Intraperitoneal injection of human chorionic gonadotropin experiments showed that expression of StAR1 and 2 was significantly elevated at 8h and persisted until 24h after injection in the testis. Taken together, our data suggested that StAR1 is likely to be required for cortisol production in the head kidney, and StAR2 is probably involved in estrogen production during early sex differentiation in XX gonads. In contrast, both StARs might be required for androgen production in testes. For the first time, our data demonstrated that two fish StARs might be involved

  16. Sexual dimorphic expression of genes in gonads during early differentiation of a teleost fish, the Nile tilapia Oreochromis niloticus.

    PubMed

    Ijiri, Shigeho; Kaneko, Hiroyo; Kobayashi, Tohru; Wang, De-Shou; Sakai, Fumie; Paul-Prasanth, Bindhu; Nakamura, Masaru; Nagahama, Yoshitaka

    2008-02-01

    The Nile tilapia, a gonochoristic teleost fish with an XX/XY sex-determining system, provides an excellent model for studying gonadal sex differentiation because genetic all-females and all-males are available. In this study, we used quantitative real-time RT-PCR to determine the precise timing of the gonadal expression of 17 genes thought to be associated with gonadal sex differentiation in vertebrates. Gonads were isolated from all-female and all-male tilapia before (5-15 days after hatching [dah]) and after (25-70 dah) morphological sex differentiation. The transcript of aromatase (cyp19a1a), an enzyme responsible for producing estradiol-17beta, was expressed only in XX gonads at 5 dah, with a marked elevation in expression thereafter. In contrast, mRNA expression of steroid 11beta-hydroxylase (cyp11b2), an enzyme responsible for the synthesis of 11-ketotestosterone (11-KT, a potent androgen in fish), was found in XY gonads from 35 dah only. These results, combined with the presence of transcripts for other steroidogenic enzymes and estrogen receptors in XX gonads at 5-7 dah, are consistent with our earlier suggestion that estradiol-17beta plays a critical role in ovarian differentiation in tilapia, whereas a role for 11-KT in testicular differentiation is questionable. A close relationship between the expression of foxl2, but not nr5a1 (Ad4BP/SF-1), and that of cyp19a1a in XX gonads suggests an important role for Foxl2 in the transcriptional regulation of cyp19a1a. Dmrt1 exhibited a male-specific expression in XY gonads from 6 dah onward, suggesting an important role for Dmrt1 in testicular differentiation. Sox9 and amh (anti-Mullerian hormone) showed a testis-specific expression, being evident only in the later stages of testicular differentiation. It is concluded that the sex-specific expression of foxl2 and cyp19a1a in XX gonads and dmrt1 in XY gonads during early gonadal differentiation (5-6 dah) is critical for undifferentiated gonads to differentiate into

  17. Transcriptome profiling and digital gene expression analysis of Nile tilapia (Oreochromis niloticus) infected by Streptococcus agalactiae.

    PubMed

    Zhang, Rui; Zhang, Li-li; Ye, Xing; Tian, Yuan-yuan; Sun, Cheng-fei; Lu, Mai-xin; Bai, Jun-jie

    2013-10-01

    Tilapia is an important freshwater aquaculture species worldwide. In recent years, streptococcal diseases have severely threatened development of tilapia aquaculture, while effective prevention and control methods have not yet been established. In order to understand the immunological response of tilapia to infection by Streptococcus agalactiae (S. agalactiae), this study employed Solexa/Illumina RNA-seq and digital gene expression (DGE) technology to investigate changes in the tilapia transcriptome before and after S. agalactiae infection. We obtained 82,799 unigenes (mean size: 618 bp) using de novo assembly. Unigenes were annotated by comparing against databases including Nr, Swissprot, cluster of orthologous groups of proteins, Kyoto encyclopedia of genes and genomes, and gene ontology. Combined with DGE technology, transcriptomic changes in tilapia before and after bacteria challenging were examined. A total of 774 significantly up-regulated and 625 significantly down-regulated unigenes were identified, among which 293 were mapped to 181 signaling pathways including 17 immune-related pathways involving 65 differentially expressed genes. We observed a change in the expression of six genes in the Toll-like receptor signaling pathway, and this was subsequently confirmed via quantitative real-time PCR. This comparative study of the tilapia transcriptome before and after S. agalactiae infection identified important differentially-expressed immune-related genes and signaling pathways that will provide useful insights for further analysis of the mechanisms of tilapia defense against S. agalactiae infection.

  18. Characterization and expression analysis of the transferrin gene in Nile tilapia (Oreochromis niloticus) and its upregulation in response to Streptococcus agalactiae infection.

    PubMed

    Poochai, Watsida; Choowongkomon, Kiattawee; Srisapoome, Prapansak; Unajak, Sasimanas; Areechon, Nontawith

    2014-10-01

    In this study, full-length tilapia transferrin (OnTF) isolated from liver cDNA of Nile tilapia (Oreochromis niloticus) was found to have an open reading frame of 2,091-bp encoding 696 amino acid residues. Two additional amino acids: Gly(369) and Gly(370) were observed compared with the reported Nile tilapia transferrin protein sequence. Pre-mature protein has a predicted molecular weight of 78.2 kDa, while mature protein is 73.28 kDa in size. Comparative sequence analysis with transferrin from other species revealed two major putative iron-binding domains designated as the N-lobe and the C-lobe in accordance with the transferrin protein characteristics. The predicted tertiary structure of tilapia transferrin confirmed the presence of iron and anion-binding sites on both lobes that are conserved among transferrins from other species. Quantitative real-time PCR analysis showed significantly higher expression of tilapia transferrin gene in liver than in other tissues (p < 0.05). Transferrin expression in tilapia experimentally infected with 10(6) and 10(8) colony-forming units mL(-1) of Streptococcus agalactiae was significantly upregulated at 24 and 12 h post-infection (hpi), respectively, and decreased afterward. Iron-deficiency in serum of bacterially infected fish was detected at 48 and 24 hpi, respectively. The expression pattern of the transferrin gene and the iron levels of infected tilapia in this study were consistent with the function of transferrin in innate immunity.

  19. Molecular characterization of Galectin-8 from Nile tilapia (Oreochromis niloticus Linn.) and its response to bacterial infection.

    PubMed

    Unajak, Sasimanas; Pholmanee, Nutthida; Songtawee, Napat; Srikulnath, Kornsorn; Srisapoome, Prapansak; Kiataramkul, Asama; Kondo, Hidehiro; Hirono, Ikuo; Areechon, Nontawith

    2015-12-01

    Galectins belong to the family of galactoside-binding proteins and play a major role in the immune and inflammatory responses of vertebrates and invertebrates. The galectin family is divided into three subtypes based on molecular structure; prototypes, chimera types, and tandem-repeated types. We isolated and characterized the cDNA of galectin-8 (OnGal-8) in Nile tilapia (Oreochromis niloticus). OnGal-8 consisted of a 966 bp open reading frame (ORF) that encoded a 321 amino acid protein (43.47 kDa). Homology and phylogenetic tree analysis suggested the protein was clustered with galectin-8s from other animal species and shared at least 56.8% identity with salmon galectin-8. Structurally, the amino acid sequence included two distinct N- and C- terminus carbohydrate recognition domains (CRDs) of 135 and 133 amino acids, respectively, that were connected by a 39 amino acid polypeptide linker. The N- and C-CRDs contained two conserved WG-E-I and WG-E-T motifs, suggesting they have an important role in mediating the specific interactions between OnGal-8 and saccharide moieties such as β-galactoside. The structure of OnGal-8 was characterized by a two-fold symmetric pattern of 10-and 12-stranded antiparallel ß-sheets of both N- and C-CRDs, and the peptide linker presumably formed a random coil similar to the characteristic tandem-repeat type galectin. The expression of OnGal-8 in healthy fish was highest in the skin, intestine, and brain. Experimental challenge of Nile tilapia with S. agalactiae resulted in significant up-regulation of OnGal-8in the spleen after 5 d. Our results suggest that OnGal-8 is involved in the immune response to bacterial infection.

  20. Jatropha platyphylla kernel meal as feed ingredient for Nile tilapia (Oreochromis niloticus L.): growth, nutrient utilization and blood parameters.

    PubMed

    Akinleye, A O; Kumar, V; Makkar, H P S; Angulo-Escalante, M A; Becker, K

    2012-02-01

    Jatropha platyphylla is a multipurpose and drought-resistant shrub, available in Mexico, locally known as 'sangregrado' and belonging to the family Euphorbiaceae. Its seeds are rich in oil and protein and do not contain the main toxin, phorbol esters present in other Jatropha species. Jatropha platyphylla kernel meal (JPKM) obtained after oil extraction contained 70-75% crude protein (CP); however, it contained phytate, lectin and trypsin-inhibitor. The levels of essential amino acids (except lysine) were higher in JPKM than in soybean meal (SBM). Using Nile tilapia (Oreochromis niloticus) fingerlings a 12-week experiment was conducted to evaluate the nutritional quality of the heated JPKM and compare with that of SBM and fishmeal. Fingerlings (15 fish; average weight 13.7 ± 0.21g) were randomly distributed in three treatment groups with five replicates. Fish were fed three isonitrogenous diets (CP 36%): control diet containing fishmeal-based protein and two other diets replacing 62.5% fishmeal protein with JPKM (Jatropha group) and SBM (Soybean group). The growth performance, feed conversion ratio, protein efficiency ratio, protein productive and energy retention did not differ significantly among the three groups. A lower apparent lipid conversion was observed in the plant protein-fed group than in the control group. RBC count, haematocrit and blood glucose contents were higher in plant-protein fed groups than control group. Other haematological parameters (WBC count, haemoglobin, mean cell volume: calcium and sodium ions, total bilirubin and urea-nitrogen in the blood) and metabolic enzymes (alkaline phosphatase and alanine transaminase) activities in blood did not differ significantly among the three groups. The results from the present study established that JPKM is a promising and good quality protein source for Nile tilapia feed.

  1. Biodegradation of 17alpha-methyltestosterone and isolation of MT-degrading bacterium from sediment of Nile tilapia masculinization pond.

    PubMed

    Homklin, Supreeda; Wattanodorn, Theerachit; Ong, Say Kee; Limpiyakorn, Tawan

    2009-01-01

    The fast growing and highly tolerant fish Nile tilapia is one of the most commonly raised fish in the aquaculture industry. To produce an all-male population, a common practice is to feed the Nile tilapia fry with 17alpha-methyltestosterone (MT)-impregnated food. Uneaten fish food with MT may accumulate in the masculinization ponds and be released into the receiving waters. Not much is known about the fate of MT in the fish farms and in the receiving streams. The objective of this study is to investigate the biodegradation of MT under aerobic condition and to isolate responsible microorganisms. Aerobic biodegradation tests were conducted with MT concentrations of 0.3, 1.0, 5.0, 7.0, and 10.0 mg/L using sediment from the masculinization pond as microbial seed. The results suggested that MT is biodegradable. Lag phase was not observed in all cases. With initial concentrations of 0.3, 1.0, 5.0, 7.0, and 10.0 mg/l, the first-order degradation rates were 0.52, 0.23, 0.17, 0.13 and 0.10 day(-1), respectively. Degradation rates were found to decrease with an increase in the initial MT concentration. Analysis of 16S rRNA gene sequences of a strain isolated from the sediment indicated that the strain was highly similar to Pimelobacter simplex strain S151 (100%) which is in the genus Nocardioidaceae. Using this strain, MT is degraded with a first-order degradation rate of 0.044 h(-1) excluding the lag phase. This is the first work reporting biodegradation of MT and isolation of MT-degrading bacterium from environment.

  2. The effects of composting on the nutritional composition of fibrous bio-regenerative life support systems (BLSS) plant waste residues and its impact on the growth of Nile tilapia ( Oreochromis niloticus)

    NASA Astrophysics Data System (ADS)

    Gonzales, John M.; Lowry, Brett A.; Brown, Paul B.; Beyl, Caula A.; Nyochemberg, Leopold

    2009-04-01

    Utilization of bio-regenerative life support systems (BLSS) plant waste residues as a nutritional source by Nile tilapia ( Oreochromis niloticus) has proven problematic as a result of high concentrations of fibrous compounds in the plant waste residues. Nutritional improvement of plant waste residues by composting with the oyster mushroom ( Pleurotus ostreatus), and the effects on growth and nutrient utilization of Nile tilapia fed such residues were evaluated. Five Nile tilapia (mean weight = 70.9 ± 3.1 g) were stocked in triplicate aquaria and fed one of two experimental diets, cowpea (CP) and composted cowpea (CCP), twice daily for a period of 8 weeks. Composting of cowpea residue resulted in reduced concentrations of nitrogen-free extract, hemi-cellulose and trypsin inhibitor activity, though trypsin inhibitor activity remained high. Composting did not reduce crude fiber, lignin, or cellulose concentrations in the diet. No significant differences ( P < 0.05) were observed in weight gain, specific growth rate, survival rate, daily consumption, and food conversion ratio between tilapia fed CP and CCP. These results suggest that P. ostreatus is not a suitable candidate for culture in conjunction with the culture of Nile tilapia. Additional work is needed to determine what, if any, benefit can be obtained from incorporating composted residue as feed for Nile tilapia.

  3. Hepatic antioxidant enzymes SOD and CAT of Nile tilapia (Oreochromis niloticus) in response to pesticide methomyl and recovery pattern.

    PubMed

    Meng, Shun Long; Chen, Jia Zhang; Xu, Pao; Qu, Jian Hong; Fan, Li Min; Song, Chao; Qiu, Li Ping

    2014-04-01

    Hepatic antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) of Nile tilapia in response to pesticide methomyl and recovery pattern were researched by exposing tilapia to sub-lethal methomyl concentrations of 0, 0.2, 2, 20 and 200 μg/L for 30 days, and then transferred to methomyl-free water for 18 days. Hepatic SOD and CAT were measured at 10 min (day 0), 6, 12, 18, 24 and 30 days after starting the experiment and at 18 days after transferring to methomyl-free water. The results showed hepatic SOD and CAT activities in 2, 20 and 200 μg/L groups were affected significantly, however, that in 0.2 μg/L group didn't change significantly compared to control during 30-day exposure period. Thus it would appear the 0.2 μg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that, for SOD, the effects produced by lower concentration of methomyl 2 μg/L were reversible but not at concentrations higher than 20 μg/L, however, for CAT, the effects produced by all the concentrations were reversible.

  4. Does selection in a challenging environment produce Nile tilapia genotypes that can thrive in a range of production systems?

    PubMed

    Thoa, Ngo Phu; Ninh, Nguyen Huu; Knibb, Wayne; Nguyen, Nguyen Hong

    2016-02-19

    This study assessed whether selection for high growth in a challenging environment of medium salinity produces tilapia genotypes that perform well across different production environments. We estimated the genetic correlations between trait expressions in saline and freshwater using a strain of Nile tilapia selected for fast growth under salinity water of 15-20 ppt. We also estimated the heritability and genetic correlations for new traits of commercial importance (sexual maturity, feed conversion ratio, deformity and gill condition) in a full pedigree comprising 36,145 fish. The genetic correlations for the novel characters between the two environments were 0.78-0.99, suggesting that the effect of genotype by environment interaction was not biologically important. Across the environments, the heritability for body weight was moderate to high (0.32-0.62), indicating that this population will continue responding to future selection. The estimates of heritability for sexual maturity and survival were low but significant. The additive genetic components also exist for FCR, gill condition and deformity. Genetic correlations of harvest body weight with sexual maturity were positive and those between harvest body weight with FCR were negative. Our results indicate that the genetic line selected under a moderate saline water environment can be cultured successfully in freshwater systems.

  5. Effects of exercise training on carbohydrate and lipid catabolism in the swimming muscles of Nile tilapia (Oreochromis niloticus).

    PubMed

    Li, D; Wei, X L; Lin, X T; Xu, Z N; Mu, X P

    2015-10-01

    This study aims to determine the effects of exercise training on carbohydrate and lipid catabolism in the swimming muscles of Nile tilapia (Oreochromis niloticus) by measuring the levels of related enzymes, lipids and free fatty acids. We designed one control group and two training groups of fish that were exercised at different training intensities [0, 1 and 1.5 body lengths per second (bl/s)]. The fish in the experimental groups were trained for 12 h/day for 4 weeks. Compared with the control group, the 1 and 1.5 bl/s groups showed significantly increased hexokinase and pyruvate kinase activities in red muscle (p < 0.05). In white muscle, pyruvate kinase activity was significantly higher in the 1.5 bl/s group than in the control group (p < 0.05), and hexokinase activity did not significantly differ between the groups. The activities of hormone-sensitive lipase and carnitine palmitoyltransferase I in both muscle types were significantly lower in the training groups than in the control group (p < 0.05). The plasma-free fatty acid level decreased (p < 0.05), while the lipid percentages increased in red muscle (p < 0.05) after exercise training. These findings clearly indicated that with exercise training, glycolysis increased and lipid oxidation decreased in the swimming muscle of tilapia.

  6. Flow cytometric evaluation of antibiotic effects on viability and mitochondrial function of refrigerated spermatozoa of Nile tilapia

    USGS Publications Warehouse

    Segovia, M.; Jenkins, J.A.; Paniagua-Chavez, C.; Tiersch, T.R.

    2000-01-01

    Improved techniques for storage and evaluation of fish sperm would enhance breeding programs around the world. The goal of this study was to test the effect of antibiotics on refrigerated sperm from Nile tilapia (Oreochromis niloticus) by use of flow cytometry with 2 dual-staining protocols for objective assessment of sperm quality. Concentrations of 1 x 109 sperm/mL were suspended in Ringer's buffer at 318 mOsmol/kg (pH 8.0). The fluorescent stains Sybr 14 (10 ??M), propidium iodide (2.4 mM), and rhodamine 123 (0.13 ??M) were used to assess cell viability and mitochondrial function. Three concentrations of ampicillin, gentamicin, and an antibiotic/antimycotic solution were added to fresh spermatozoa. Motility estimates and flow cytometry measurements were made daily during 7 d of refrigerated storage (4 ??C). The highest concentrations of gentamicin and antibiotic/antimycotic and all 3 concentrations of ampicillin significantly reduced sperm viability. The highest of each of the 3 antibiotic concentrations significantly reduced mitochondrial function. This study demonstrates that objective sperm quality assessments can be made using flow cytometry and that addition of antibiotics at appropriate concentrations can lengthen refrigerated storage time for tilapia spermatozoa. With minor modifications, these protocols can be adapted for use with sperm from other species and with other tissue types.

  7. Does selection in a challenging environment produce Nile tilapia genotypes that can thrive in a range of production systems?

    PubMed Central

    Thoa, Ngo Phu; Ninh, Nguyen Huu; Knibb, Wayne; Nguyen, Nguyen Hong

    2016-01-01

    This study assessed whether selection for high growth in a challenging environment of medium salinity produces tilapia genotypes that perform well across different production environments. We estimated the genetic correlations between trait expressions in saline and freshwater using a strain of Nile tilapia selected for fast growth under salinity water of 15–20 ppt. We also estimated the heritability and genetic correlations for new traits of commercial importance (sexual maturity, feed conversion ratio, deformity and gill condition) in a full pedigree comprising 36,145 fish. The genetic correlations for the novel characters between the two environments were 0.78–0.99, suggesting that the effect of genotype by environment interaction was not biologically important. Across the environments, the heritability for body weight was moderate to high (0.32–0.62), indicating that this population will continue responding to future selection. The estimates of heritability for sexual maturity and survival were low but significant. The additive genetic components also exist for FCR, gill condition and deformity. Genetic correlations of harvest body weight with sexual maturity were positive and those between harvest body weight with FCR were negative. Our results indicate that the genetic line selected under a moderate saline water environment can be cultured successfully in freshwater systems. PMID:26892814

  8. An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus).

    PubMed

    Munang'andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

    2016-12-13

    Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia (Niloticus oreochromis) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy.

  9. An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Munang’andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

    2016-01-01

    Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia (Niloticus oreochromis) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy. PMID:27983591

  10. Nutrient retention capabilities of Nile tilapia ( Oreochromis niloticus) fed bio-regenerative life support system (BLSS) waste residues

    NASA Astrophysics Data System (ADS)

    Gonzales, John M.; Brown, Paul B.

    Nile tilapia were evaluated as a bio-regenerative sub-process for reducing solid waste potentially encountered in bio-regenerative life support systems. Ten juvenile Nile tilapia (mean weight = 2.05 g) were stocked into triplicate aquaria and fed one of seven experimental diets consisting of vegetable, bacterial, or food waste for a period of seven weeks. Weight gain (g), specific growth rate (mg/d), and daily consumption (g) was significantly higher ( p < 0.05) in the control group (13.80, 281.60, and 47.49, respectively) followed by the wheat bran/wheat germ group (4.25, 86.87, and 24.24). Carbon and crude lipid retention was significantly higher ( p < 0.001) in fish fed the control diet (37.99 and 68.54, respectively) followed by fish fed the wheat bran/wheat germ diet (23.19 and 63.67, respectively). Nitrogen, sulfur, and crude protein retention was significantly higher ( p < 0.001) in fish fed the wheat bran/wheat germ group (40.73, 98.65, and 40.75, respectively) followed by fish fed the control diet (23.68, 21.89, and 23.68, respectively). A general loss of minerals was observed among all groups. Strong associations were observed between crude lipid retention and sulfur retention ( r2 = 0.94), crude lipid retention and carbon retention ( r2 = 0.92), WG and fiber content of dietary treatments ( r2 = 0.92), WG and carbon retention and ( r2 = 0.88), WG and lysine content of waste residues ( r2 = 0.86), crude protein retention and carbon retention ( r2 = 0.84), sulfur retention and crude protein retention ( r2 = 0.84), and total sulfur amino acid (TSAA) content of residues and WG ( r2 = 0.81). Weaker associations existed between WG and crude lipid retention ( r2 = 0.77), crude fiber content and carbon retention ( r2 = 0.76), and WG and methionine content of waste residues ( r2 = 0.75). Additional research is needed to improve the nutritional quality of fibrous residues as a means to improve tilapia's ability to utilize these residues as a food source in bio

  11. Improvement of immunity and disease resistance in the Nile tilapia, Oreochromis niloticus, by dietary supplementation with Bacillus amyloliquefaciens.

    PubMed

    Selim, Khaled M; Reda, Rasha M

    2015-06-01

    Probiotics can be used as immunostimulants in aquaculture. The aim of this study was to evaluate the immune responses of Nile tilapia Oreochromis niloticus following feeding with Bacillus amyloliquefaciens spores at concentrations of 1 × 10(6) (G3) and 1 × 10(4) (G2) colony-forming units per gram (CFU/g) of feed compared with a basal diet with no probiotics (G1). A total of 180 fingerlings (27.7 ± 0.22 g) were divided into three groups (G1-G3 of 20 fish per group) in triplicate. Innate immunities were measured every two weeks based on serum bactericidal activity, lysozyme activity, a nitric oxide assay (mmo/l) and phagocytic activity, and the expressions of interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF α) were examined after one month. Moreover, the survival of tilapia upon challenge with Yersinia ruckeri or Clostridium perfringens type D was determined at the end of feeding trial. After 15 d, the serum killing percentages and phagocytic activities were significantly higher in G3 than in G1 and G2, whereas the same parameters had significantly higher values in G3 and G2 than in G1 after 30 d. After both 15 d and 30 d, the lysozyme activities and nitric oxide assay results (mmo/l) were significantly higher in G3 than G2, and the lowest values were observed in G1. The percentage of serum killing, serum nitric oxide and serum lysozyme activity were significantly increased by the time of B. amyloliquefaciens administration independently of the probiotic dose, and the phagocytic activity percentage was significantly decreased at the end of the experiment. Dietary B. amyloliquefaciens caused significant increases in IL-1 and TNF α mRNA levels in the kidneys in the following pattern: G3 > G2 > G1. Fish that were fed B. amyloliquefaciens exhibited better relative survival percentages than the controls when challenged by Y. ruckeri or C. perfringens type D. Dietary supplementation with B. amyloliquefaciens improves immune status and disease

  12. Isolation and molecular identification of the etiological agents of streptococcosis in Nile tilapia (Oreochromis niloticus) cultured in net cages in Lake Sentani, Papua, Indonesia.

    PubMed

    Anshary, Hilal; Kurniawan, Rio A; Sriwulan, Sriwulan; Ramli, Ramli; Baxa, Dolores V

    2014-01-01

    Infections with Streptococcus spp. were observed in Nile tilapia cultured in net cages in Lake Sentani, Papua, Indonesia. Clinical signs included exophthalmia, erratic swimming, ascites in abdominal cavity, and external hemorrhages. Four types of bacterial colonies (SK, K10, P20, and M12) were isolated from the brain, kidney, and eyes. Based on phenotypic and genetic (16S rDNA sequencing) characteristics, the isolates were identified as Streptococcus iniae (SK), Streptococcus agalactiae (K10 and P20) and Lactococcus garvieae (M12). The latter species has not been previously isolated or reported from fish streptococcosis in Indonesia. Intraperitoneal injection of healthy tilapia with the bacterial species caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post injection. Experimental infections and reisolation of the bacteria from morbid and dead fish suggest they are the causative agents of streptococcosis, which rendered high mortality among cage cultured Nile tilapia in Lake Sentani. Our results suggest the need for developing diagnostic tools for accurate identification of the agents of streptococcosis. As tilapia aquaculture continues to expand as a means of food production and livelihood in Indonesia, it becomes crucial to ensure that fish resources are monitored and protected from the adverse effects of infectious diseases.

  13. Genome-wide identification, evolution of chromobox family genes and their expression in Nile tilapia.

    PubMed

    Liu, Xing-Yong; Zhang, Xian-Bo; Li, Ming-Hui; Zheng, Shu-Qing; Liu, Zhi-Long; Cheng, Yun-Ying; Wang, De-Shou

    2017-01-01

    Chromobox (Cbx) family proteins are transcriptional repressors that involved in epigenetic and developmental processes. In this study, comprehensive analyses of Cbxs were performed using available genome databases from representative animal species. The Cbx family were originated from one Polycomb (Pc) gene like the yeast Pc, which duplicated into two and gave rise to the Pc and the Heterochromatin protein 1 (Hp1) identified in invertebrates from protozoon to lancelet. Rapid expansion of Cbx family members was observed in vertebrates as ~8 (5 Pc and 3 Hp1) were identified in spotted gar, coelacanth and tetrapods. Further expansion of the members to ~14 (9 Pc and 5 Hp1) was observed in teleosts due to the third round genome duplication (3R). Based on transcriptome data from eight adult tilapia tissues, most of the Cbxs were found to be dominantly expressed in the brain, testis, ovary and heart. Analyses of the gonadal transcriptome data from four developmental stages revealed that all Cbxs were expressed in both ovary and testis except Cbx7b, with significant increase of the total and average RPKM from 5 to 90dah (days after hatching). By in situ hybridization, the three most highly and sexual dimorphically expressed Cbx genes in gonads, Cbx1b, Cbx3a and Cbx5, were found to be expressed in phase I and II oocytes of the ovary, and in secondary spermatocytes (Cbx1b and Cbx3a) and spermatids (Cbx5) of the testis. Our results revealed the evolution of Cbx genes and indicated a potential role of Cbxs in epigenetic regulation of gametogenesis.

  14. Enzymatic characterizations and activity regulations of N-acetyl-β-D-glucosaminidase from the spermary of Nile tilapia (Oreochromis niloticus).

    PubMed

    Zhang, Wei-Ni; Bai, Ding-Ping; Huang, Yi-Fan; Hu, Chong-Wei; Chen, Qing-Xi; Huang, Xiao-Hong

    2014-02-01

    N-Acetyl-β-D-glucosaminidase (NAGase) is proved to be correlated with reproduction of male animals. In this study, enzymatic characterizations of NAGase from spermary of Nile tilapia (Oreochromis niloticus) were investigated in order to further study its reproductive function in fish. Tilapia NAGase was purified to be PAGE homogeneous by the following techniques: (NH4)2SO4 fractionation (40-55%), DEAE-cellulose (DE-32) ion exchange chromatography, Sephadex G-200 gel filtration and DEAE-Sephadex (A-50). The specific activity of the purified enzyme was 4100 U/mg. The enzyme molecular weight was estimated as 118.0 kD. Kinetic studies showed that the hydrolysis of p-nitrophenyl-N-acetyl-β-D-glucosaminide (pNP-NAG) by the enzyme followed Michaelis-Menten kinetics. The Michaelis-Menten constant (Km) and maximum velocity (Vm) were determined to be 0.67 mM and 23.26 μM/min, respectively. The optimum pH and optimum temperature of the enzyme for hydrolysis of pNP-NAG was to be at pH 5.7 and 55°C, respectively. The enzyme was stable in a pH range from 3.3 to 8.1 at 37°C, and inactive at temperature above 45°C. The enzyme activity was regulated by the following ions in decreasing order: Hg(2+) > Zn(2+) > Cu(2+) > Pb(2+) > Mn(2+). The IC50 of Cu(2+), Zn(2+) and Hg(2+) was 1.23, 0.28, and 0.0027 mM, respectively. However, the ions Li(+), Na(+), K(+), Mg(2+) and Ca(2+) had almost no influence on enzyme activity. In conclusion, the enzymatic characterizations of NAGase from tilapia were special to the other animals, which were correlated with its living habit; besides, CuSO4 and ZnSO4 should used very carefully as insecticides in tilapia cultivation since they both had strong regulations on the enzyme.

  15. Gene transfer and mutagenesis mediated by Sleeping Beauty transposon in Nile tilapia (Oreochromis niloticus).

    PubMed

    He, Xiaozhen; Li, Jie; Long, Yong; Song, Guili; Zhou, Peiyong; Liu, Qiuxiang; Zhu, Zuoyan; Cui, Zongbin

    2013-10-01

    The success of gene transfer has been demonstrated in many of vertebrate species, whereas the efficiency of producing transgenic animals remains pretty low due to the random integration of foreign genes into a recipient genome. The Sleeping Beauty (SB) transposon is able to improve the efficiency of gene transfer in zebrafish and mouse, but its activity in tilapia (Oreochromis niloticus) has yet to be characterized. Herein, we demonstrate the potential of using the SB transposon system as an effective tool for gene transfer and insertional mutagenesis in tilapia. A transgenic construct pT2/tiHsp70-SB11 was generated by subcloning the promoter of tilapia heat shock protein 70 (tiHsp70) gene, the SB11 transposase gene and the carp β-actin gene polyadenylation signal into the second generation of SB transposon. Transgenic tilapia was produced by microinjection of this construct with in vitro synthesized capped SB11 mRNA. SB11 transposon was detected in 28.89 % of founders, 12.9 % of F1 and 43.75 % of F2. Analysis of genomic sequences flanking integrated transposons indicates that this transgenic tilapia line carries two copies of SB transposon, which landed into two different endogenous genes. Induced expression of SB11 gene after heat shock was detected using reverse transcription PCR in F2 transgenic individuals. In addition, the Cre/loxP system was introduced to delete the SB11 cassette for stabilization of gene interruption and bio-safety. These findings suggest that the SB transposon system is active and can be used for efficient gene transfer and insertional mutagenesis in tilapia.

  16. The Fish Immune System, with Particular Emphasis on Nile Tilapia (Oreochromis niloticus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of the immune system is important for a better understanding of disease resistance mechanisms and the development of vaccine strategies. This understanding is also relevant in the control of infectious diseases under intensive tilapia farming. The immune system first recognizes the patho...

  17. The use of nile tilapia (Oreochromis niloticus) cultivation wastewater for the production of romaine lettuce (Lactuca sativa L. var. longifolia) in water recirculation system

    NASA Astrophysics Data System (ADS)

    Effendi, Hefni; Wahyuningsih, Sri; Wardiatno, Yusli

    2016-05-01

    In the recirculation aquaponic system (RAS), fish farming waste was utilized as a nutrient for plant, minimizing the water need, reducing the waste disposal into the environment, and producing the fish and plant as well. The study aimed to examine the growth of romaine lettuce (Lactuca sativa L. var. Longifolia) in aquaponic system without the addition of artificial nutrient. The nutrient relies solely on wastewater of nile tilapia (Oreochromis niloticus) cultivation circulated continuously on the aquaponic system. The results showed that tilapia weight reached 48.49 ± 3.92 g of T3 (tilapia, romaine lettuce, and inoculated bacteria), followed by T2 (tilapia and romaine lettuce) and T1 (tilapia) of 47.80 ± 1.97 and 45.89 ± 1.10 g after 35 days of experiment. Tilapia best performance in terms of growth and production occurred at T3 of 3.96 ± 0.44 g/day, 12.10 ± 0.63 %/day, 96.11 ± 1.44 % and 1.60 ± 0.07 for GR, SGR, SR, and FCR, respectively. It is also indicated by better water quality characteristic in this treatment. Romaine lettuce harvests of T2 and T3 showed no significant difference, with the final weight of 61.87 ± 5.59 and 57.74 ± 4.35 g. Overall, the integration of tilapia fish farming and romaine lettuce is potentially a promising aquaponic system for sustainable fish and horticulture plant production.

  18. Allelic variant in the anti-Müllerian hormone gene leads to autosomal and temperature-dependent sex reversal in a selected Nile tilapia line.

    PubMed

    Wessels, Stephan; Sharifi, Reza Ahmad; Luehmann, Liane Magdalena; Rueangsri, Sawichaya; Krause, Ina; Pach, Sabrina; Hoerstgen-Schwark, Gabriele; Knorr, Christoph

    2014-01-01

    Owing to the demand for sustainable sex-control protocols in aquaculture, research in tilapia sex determination is gaining momentum. The mutual influence of environmental and genetic factors hampers disentangling the complex sex determination mechanism in Nile tilapia (Oreochromis niloticus). Previous linkage analyses have demonstrated quantitative trait loci for the phenotypic sex on linkage groups 1, 3, and 23. Quantitative trait loci for temperature-dependent sex reversal similarly reside on linkage group 23. The anti-Müllerian hormone gene (amh), located in this genomic region, is important for sexual fate in higher vertebrates, and shows sexually dimorphic expression in Nile tilapia. Therefore this study aimed at detecting allelic variants and marker-sex associations in the amh gene. Sequencing identified six allelic variants. A significant effect on the phenotypic sex for SNP ss831884014 (p<0.0017) was found by stepwise logistic regression. The remaining variants were not significantly associated. Functional annotation of SNP ss831884014 revealed a non-synonymous amino acid substitution in the amh protein. Consequently, a fluorescence resonance energy transfer (FRET) based genotyping assay was developed and validated with a representative sample of fish. A logistic linear model confirmed a highly significant effect of the treatment and genotype on the phenotypic sex, but not for the interaction term (treatment: p<0.0001; genotype: p<0.0025). An additive genetic model proved a linear allele substitution effect of 12% in individuals from controls and groups treated at high temperature, respectively. Moreover, the effect of the genotype on the male proportion was significantly higher in groups treated at high temperature, giving 31% more males on average of the three genotypes. In addition, the groups treated at high temperature showed a positive dominance deviation (+11.4% males). In summary, marker-assisted selection for amh variant ss831884014 seems to be

  19. Β-defensin in Nile tilapia (Oreochromis niloticus): Sequence, tissue expression, and anti-bacterial activity of synthetic peptides.

    PubMed

    Dong, Jun-Jian; Wu, Fang; Ye, Xing; Sun, Cheng-Fei; Tian, Yuan-Yuan; Lu, Mai-Xin; Zhang, Rui; Chen, Zhi-Hang

    2015-07-15

    Beta-defensins (β-defensins) are small cationic amphiphilic peptides that are widely distributed in plants, insects, and vertebrates, and are important for their antimicrobial properties. In this study, the β-defensin (Onβ-defensin) gene of the Nile tilapia (Oreochromis niloticus) was cloned from spleen tissue. Onβ-defensin has a genomic DNA sequence of 674 bp and produces a cDNA of 454 bp. Sequence alignments showed that Onβ-defensin contains three exons and two introns. Sequence analysis of the cDNA identified an open reading frame of 201 bp, encoding 66 amino acids. Bioinformatic analysis showed that Onβ-defensin encodes a cytoplasmic protein molecule containing a signal peptide. The deduced amino acid sequence of this peptide contains six conserved cysteine residues and two conserved glycine residues, and shows 81.82% and 78.33% sequence similarities with β-defensin-1 of fugu (Takifugu rubripes) and rainbow trout (Oncorhynchus mykiss), respectively. Real-time quantitative PCR showed that the level of Onβ-defensin expression was highest in the skin (307.1-fold), followed by the spleen (77.3-fold), kidney (17.8-fold), and muscle (16.5-fold) compared to controls. By contrast, low levels of expression were found in the liver, heart, intestine, stomach, and gill (<3.0-fold). Artificial infection of tilapia with Streptococcus agalactiae (group B streptococcus [GBS] strain) resulted in a significantly upregulated expression of Onβ-defensin in the skin, muscle, kidney, and gill. In vitro antimicrobial experiments showed that a synthetic Onβ-defensin polypeptide had a certain degree of inhibitory effect on the growth of Escherichia coli DH5α and S. agalactiae. The results indicate that Onβ-defensin plays a role in immune responses that suppress or kill pathogens.

  20. Are Tilapia Infected with Gyrodactylus More Susceptible to Streptococcus?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae and Gyrodactylus niloticus are two common pathogens of cultured Nile tilapia, Oreochromis niloticus. We studied concurrent infection of tilapia by G. niloticus and S. iniae and evaluated whether parasitism in tilapia with Gyrodactylus increased susceptibility and mortality follo...

  1. Francisella noatunensis subsp. orientalis pathogenesis analyzed by experimental immersion challenge in Nile tilapia, Oreochromis niloticus (L.).

    PubMed

    Soto, Esteban; Kidd, Scott; Mendez, Susan; Marancik, David; Revan, Floyd; Hiltchie, David; Camus, Alvin

    2013-05-31

    Francisella noatunensis subsp. orientalis (Fno) (syn. F. asiatica) is an emergent warmwater fish pathogen and the causative agent of francisellosis in tilapia (Oreochromis sp). To study the pathogenesis of this bacterium, tilapia fingerlings were experimentally infected by immersion challenge with wild type (WT) Fno and the distribution of bacteria to multiple organs, as well as associated lesion development, investigated after 3, 24, 48, 96, and 192h by real-time PCR and histopathological examination. Surface mucus collected 3h post-infection contained the highest number of Fno genome equivalents (GE). After 96h, marked increases of WT Fno GE were detected in spleen, anterior kidney, posterior kidney, gill, heart, liver, brain, gonad, and the gastrointestinal tract. Increases in bacterial GE also corresponded to the appearance, size and number of granulomas typical of francisellosis, predominantly in the spleen and anterior and posterior kidney segments. A simultaneous comparison was also made in tilapia challenged with an attenuated Fno strain containing a mutation in the intracellular growth locus C (iglC) gene, essential to intracellular survival. Compared to the WT, the mutant iglC strain was present in most tissues in similar numbers prior to 48h post-challenge. While the mutant did not replicate significantly or produce lesions in any tissue, it persisted for up to 192h. These findings provide insight into the pathophysiology of francisellosis in tilapia, which may also prove useful as a model for the study of mammalian tularemia, and advance our understanding of the utility of the ΔiglC mutant as a potential vaccine candidate.

  2. Survival, growth and reproduction of non-indigenous Nile tilapia, Oreochromis niloticus (Linnaeus 1758). I. Physiological capabilities in various temperatures and salinities

    USGS Publications Warehouse

    Schofield, Pamela J.; Peterson, Mark S.; Lowe, Michael R.; Brown-Peterson, Nancy J.; Slack, William T.

    2011-01-01

    The physiological tolerances of non-native fishes is an integral component of assessing potential invasive risk. Salinity and temperature are environmental variables that limit the spread of many non-native fishes. We hypothesised that combinations of temperature and salinity will interact to affect survival, growth, and reproduction of Nile tilapia, Oreochromis niloticus, introduced into Mississippi, USA. Tilapia withstood acute transfer from fresh water up to a salinity of 20 and survived gradual transfer up to 60 at typical summertime (30°C) temperatures. However, cold temperature (14°C) reduced survival of fish in saline waters ≥10 and increased the incidence of disease in freshwater controls. Although fish were able to equilibrate to saline waters in warm temperatures, reproductive parameters were reduced at salinities ≥30. These integrated responses suggest that Nile tilapia can invade coastal areas beyond their point of introduction. However, successful invasion is subject to two caveats: (1) wintertime survival depends on finding thermal refugia, and (2) reproduction is hampered in regions where salinities are ≥30. These data are vital to predicting the invasion of non-native fishes into coastal watersheds. This is particularly important given the predicted changes in coastal landscapes due to global climate change and sea-level rise.

  3. Ameliorating effect of β-carotene on antioxidant response and hematological parameters of mercuric chloride toxicity in Nile tilapia (Oreochromis niloticus).

    PubMed

    Elseady, Y; Zahran, E

    2013-08-01

    The impact of different levels of dietary β-carotene to alleviate the effect of mercuric chloride toxicity in Nile tilapia was assessed. Semi-purified diets containing 0, 40, and 100 mg β-carotene kg(-1) dry diet were fed for 21 days, which were subjected to sublethal concentration of mercuric chloride (0.05 ppm). Hematological and biochemical parameters, lipid profile, and antioxidant response were examined. All hematological parameters of tilapia fish starting from second week of toxicity were significantly decreased. A significant increasing trend in liver enzymes (ALT and AST) were observed parallel to the time of toxicity and peroxide radicals (MDA) appearing significantly increased in toxicated group without carotene supplement, although carotene supplementation return all parameters within the control levels. Mercury accumulated significantly in fish liver and white muscles in toxicated group while it showed a significant reduction in dietary β-carotene-treated group. Overall, it can be used as immunostimulant and alleviate the suppression effect resulted from immune depressive stressful condition in farmed Nile tilapia.

  4. Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

    PubMed

    Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

    2016-07-01

    PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia.

  5. Tilapia show immunization response against Ich

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compares the immune response of Nile tilapia and red tilapia against parasite Ichthyophthirius multifiliis (Ich) using a cohabitation challenge model. Both Nile and red tilapia showed strong immune response post immunization with live Ich theronts by IP injection or immersion. Blood serum...

  6. Inhibition of cadmium- induced genotoxicity and histopathological changes in Nile tilapia fish by Egyptian and Tunisian montmorillonite clay.

    PubMed

    Mahrous, Karima F; Hassan, Aziza M; Radwan, Hasnaa A; Mahmoud, M A

    2015-09-01

    Cadmium (Cd) is an important inorganic toxicant widely distributed in the environment because of its various industrial uses. The aims of the current study were to investigate the efficacy of purified Egyptian and Tunisian montmorillonite clays (EMC and TMC) to inhibit genotoxicity and histological alterations induced by cadmium chloride (CdCl2) utilizing the Nile tilapia fish as an in vivo model. Chromosomal aberrations (CAs), micronucleus (MN) frequencies and DNA fingerprinting profile were genotoxic end points and histopathological changes that were used in this investigation. Six groups of fish were treated for 2 weeks and included control group, CdCl2-treated group and groups treated with EMC or TMC alone or in combination with CdCl2. The present results revealed that, treatment of fish with CdCl2 exhibited significant increased in the number of micronucleated erythrocytes (MnRBCs), frequency of CAs and instability of genomic DNA. Treatment of EMC and TMC in combination with CdCl2 significantly reduced the frequency of MnRBCs by the percentage of 53.28% and 60.77% and the frequency of CAs by 43.91% and 52.17% respectively. As well as, normalized DNA fingerprinting profile and significantly improved histopathological picture induced by Cadmium treatment. It is worth mention that both clays have the ability to tightly bind CdCl2 and decreased its cytotoxicity and genotoxicity; however, Tunisian clay was more efficient in binding with the CdCl2 than Egyptian clay.

  7. Acanthocephalan Parasites (Acanthogyrus sp.) of Nile Tilapia (Oreochromis niloticus) as Biosink of Lead (Pb) Contamination in a Philippine Freshwater Lake.

    PubMed

    Paller, Vachel Gay V; Resurreccion, Dan Jacob B; de la Cruz, Christian Paul P; Bandal, Modesto Z

    2016-06-01

    The potential use of acanthocephalans as bioindicators of Lead (Pb) pollution in Sampaloc Lake, Laguna, Philippines was investigated. Nile tilapias (Oreochromis niloticus) were collected and Pb concentrations were determined in fish tissues and in their acanthocephalan parasites, Acanthogyrus sp. Significantly higher levels of Pb were detected in the parasites relative to the fish host tissues (p = 0.001). Bioaccumulation capacity of the parasites against fish tissues were 102, 119, and 147 times higher than the fish intestine, liver, and muscles, respectively. Pb sensitivity of the parasites was quantified by exact logistic analysis showing higher odds of Pb detection ranging from 18 to 45 folds (p = 0.001-0.009). Interestingly, infected fish showed significantly lower Pb concentration in their tissues compared to uninfected fish (p = 0.001), suggesting parasites were able to sequester Pb and served as active biosinks. The Pb levels in the parasites were also hundred folds higher (988 times) relative to the ambient waters, indicating a potential role of fish parasites as metal biosinks in aquatic ecosystems.

  8. Transcriptome Profiling and Molecular Pathway Analysis of Genes in Association with Salinity Adaptation in Nile Tilapia Oreochromis niloticus

    PubMed Central

    Xu, Zhixin; Gan, Lei; Li, Tongyu; Xu, Chang; Chen, Ke; Wang, Xiaodan; Qin, Jian G.; Chen, Liqiao; Li, Erchao

    2015-01-01

    Nile tilapia Oreochromis niloticus is a freshwater fish but can tolerate a wide range of salinities. The mechanism of salinity adaptation at the molecular level was studied using RNA-Seq to explore the molecular pathways in fish exposed to 0, 8, or 16 (practical salinity unit, psu). Based on the change of gene expressions, the differential genes unions from freshwater to saline water were classified into three categories. In the constant change category (1), steroid biosynthesis, steroid hormone biosynthesis, fat digestion and absorption, complement and coagulation cascades were significantly affected by salinity indicating the pivotal roles of sterol-related pathways in response to salinity stress. In the change-then-stable category (2), ribosomes, oxidative phosphorylation, signaling pathways for peroxisome proliferator activated receptors, and fat digestion and absorption changed significantly with increasing salinity, showing sensitivity to salinity variation in the environment and a responding threshold to salinity change. In the stable-then-change category (3), protein export, protein processing in endoplasmic reticulum, tight junction, thyroid hormone synthesis, antigen processing and presentation, glycolysis/gluconeogenesis and glycosaminoglycan biosynthesis—keratan sulfate were the significantly changed pathways, suggesting that these pathways were less sensitive to salinity variation. This study reveals fundamental mechanism of the molecular response to salinity adaptation in O. niloticus, and provides a general guidance to understand saline acclimation in O. niloticus. PMID:26305564

  9. Acute inflammation and hematological response in Nile tilapia fed supplemented diet with natural extracts of propolis and Aloe barbadensis.

    PubMed

    Dotta, G; Ledic-Neto, J; Gonçalves, E L T; Brum, A; Maraschin, M; Martins, M L

    2015-05-01

    This study evaluated the acute inflammatory response induced by carrageenin in the swim bladder of Nile tilapia supplemented with the mixture of natural extracts of propolis and Aloe barbadensis (1:1) at a concentration of 0.5%, 1% and 2% in diet during 15 days. Thirty-six fish were distributed into four treatments with three replicates: fish supplemented with 0.5% of admix of extracts of propolis and Aloe (1:1) injected with 500 µg carrageenin; fish supplemented with 1% of admix of extracts of propolis and Aloe (1:1) injected with 500 µg carrageenin; fish supplemented with 2% of admix of extracts of propolis and Aloe (1:1), injected with 500 µg carrageenin and unsupplemented fish injected with 500 µg carrageenin. Six hours after injection, samples of blood and exudate from the swim bladder of fish were collected. It was observed an increase in the leukocyte count in the swim bladder exudate of fish supplemented with extracts of propolis and Aloe injected with carrageenin. The most frequent cells were macrophages followed by granular leukocytes, thrombocytes and lymphocytes. Supplementation with propolis and Aloe to 0.5% caused a significant increase in the number of cells on the inflammatory focus mainly macrophages, cells responsible for the phagocytic activity in tissues, agent of innate fish immune response.

  10. Duration of protective antibodies and correlation with survival in Nile tilapia Oreochromis niloticus following Streptococcus agalactiae vaccination.

    PubMed

    Pasnik, David J; Evans, Joyce J; Klesius, Phillip H

    2005-09-05

    Streptococcus agalactiae is a major piscine pathogen that causes significant morbidity and mortality among numerous species of freshwater, estuarine and marine fishes. Considering the economic importance of fishes susceptible to S. agalactiae throughout the world, an efficacious S. agalactiae vaccine was developed using an extracellular product (ECP) fraction and formalin-killed whole cells of S. agalactiae. A vaccine study was conducted by intraperitoneal (i.p.) injection in Nile tilapia Oreochromis niloticus in order to determine the duration of protection and its correlation to antibodies specific for this pathogen. After 47, 90 or 180 d post-vaccination (DPV), the fish were i.p. challenged with approximately 2.0 x 10(4) S. agalactiae colony-forming units (CFU) fish(-1) to determine the duration of protective immunity. The percent survival in control fish i.p.-injected with sterile TSB was 16,16, and 4% on 47, 90 and 180 DPV, respectively, while the percent survival for the vaccinated fish was 67, 62 and 49%, respectively. The specific mean antibody concentration of the vaccinated fish was significantly higher than that of the control fish, with significant correlation between the ELISA optical density (OD) and protection. These results indicate that the specific antibody has a correlation with protection following immunization with the S. agalactiae vaccine and that the vaccine can confer protection against S. agalactiae up to 180 DPV.

  11. Transcriptome Profiling and Molecular Pathway Analysis of Genes in Association with Salinity Adaptation in Nile Tilapia Oreochromis niloticus.

    PubMed

    Xu, Zhixin; Gan, Lei; Li, Tongyu; Xu, Chang; Chen, Ke; Wang, Xiaodan; Qin, Jian G; Chen, Liqiao; Li, Erchao

    2015-01-01

    Nile tilapia Oreochromis niloticus is a freshwater fish but can tolerate a wide range of salinities. The mechanism of salinity adaptation at the molecular level was studied using RNA-Seq to explore the molecular pathways in fish exposed to 0, 8, or 16 (practical salinity unit, psu). Based on the change of gene expressions, the differential genes unions from freshwater to saline water were classified into three categories. In the constant change category (1), steroid biosynthesis, steroid hormone biosynthesis, fat digestion and absorption, complement and coagulation cascades were significantly affected by salinity indicating the pivotal roles of sterol-related pathways in response to salinity stress. In the change-then-stable category (2), ribosomes, oxidative phosphorylation, signaling pathways for peroxisome proliferator activated receptors, and fat digestion and absorption changed significantly with increasing salinity, showing sensitivity to salinity variation in the environment and a responding threshold to salinity change. In the stable-then-change category (3), protein export, protein processing in endoplasmic reticulum, tight junction, thyroid hormone synthesis, antigen processing and presentation, glycolysis/gluconeogenesis and glycosaminoglycan biosynthesis-keratan sulfate were the significantly changed pathways, suggesting that these pathways were less sensitive to salinity variation. This study reveals fundamental mechanism of the molecular response to salinity adaptation in O. niloticus, and provides a general guidance to understand saline acclimation in O. niloticus.

  12. Pre-Slaughter Stress Affects Ryanodine Receptor Protein Gene Expression and the Water-Holding Capacity in Fillets of the Nile Tilapia

    PubMed Central

    Lara, Jorge A. F.; Gasparino, Eliane; Del Vesco, Ana P.; Goes, Marcio D.; Alexandre Filho, Luiz

    2015-01-01

    Current study evaluated the effect of pre-slaughter stress on serum cortisol levels, pH, colorimetry, water-holding capacity (WHC) and gene expression of ryanodine receptors (RyR1 and RyR3) in the Nile tilapia. A 3x4 factorial scheme experiment was conducted comprising three densities (100, 200, 400 kg/m³) with four transportation times (60, 120, 180, and 240 minutes).Transportation times alone reduced cortisol levels up to 180 minutes, followed by increased WHC and mRNA expression, RyR1 and RyR3 (200 kg/m³ density). No effect of density x transportation time interacted on the evaluated parameters. Results provided the first evidence that pre-slaughter stress affected ryanodine gene expression receptors and, consequently, the water-holding capacity in tilapia fillets. PMID:26053858

  13. Effects of malachite green on the mRNA expression of detoxification-related genes in Nile tilapia (Oreochromis niloticus) and other major Chinese freshwater fishes.

    PubMed

    Li, Guangyu; Shen, Dan; Liang, Xu-Fang; He, Yan; He, Shan

    2013-03-01

    The use of malachite green (MG) in fish farming is prohibited in China due to its potentially toxicological and carcinogenic nature, but it is still illegally used in some places. The aim of this study was to investigate the time and concentration-dependent responses of xenobiotic metabolizing and detoxification-related genes in diverse fishes exposed to MG both in vivo and in vitro. Experimental fish were administered to two exposure groups of malachite green (MG) (0.10 and 0.50 mg L⁻¹) for 8 h. The hepatocytes isolated from Nile tilapia were incubated with MG (0.5, 1.0, and 2.0 mg L⁻¹) for 8 and 24 h, respectively. In vivo, exposure to 0.10 and 0.50 mg L⁻¹ MG for 8 h caused significant changes of the detoxification-related genes on the mRNA expression levels. Low-concentration (0.10 mg L⁻¹) level of MG induced significant increase on the mRNA expression level of GSTR gene in Nile tilapia and other fishes. The mRNA expression of grass carp UCP2 was significantly induced when exposed to 0.5 mg L⁻¹ MG. However, the mRNA expression levels of GSTA, CYP1A, and GPX were inhibited significantly by 0.5 mg L⁻¹ MG in Nile tilapia, grass carp, and Taiwan snakehead. In vitro, the significant increase of mRNA expression of these genes was detected after exposure to 0.5 mg L⁻¹ MG (UCP2), and 1.0 mg L⁻¹ MG (CYP1A1, GSTA, GSTR, and UCP2). The induction of hepatic CYP1A1, GSTA, GSTR, and UCP2 in response to MG suggested a potential role of fish CYP1A1, GSTA, GSTR, and UCP2 in MG metabolism.

  14. Enhancing growth and non-specific immunity of grass carp and Nile tilapia by incorporating Chinese herbs (Astragalus membranaceus and Lycium barbarum) into food waste based pellets.

    PubMed

    Mo, Wing Yin; Lun, Clare Hau In; Choi, Wai Ming; Man, Yu Bon; Wong, Ming Hung

    2016-12-01

    The effects of Astragalus membranaceus and Lycium barbarum on the growth performance and non-specific immunity of grass carp and Nile tilapia were studied. Herb extracts of Chinese medicinal herbs (2 g kg(-1) or 20 g kg(-1)) were incorporated into food waste based fish feed pellets. Fish growth and selected non-specific immune parameters of grass carp and Nile tilapia were studied in two separate feeding trials. Both grass carp and Nile tilapia fed diets of feed pellets containing 2 g kg(-1)Lycium barbarum extract achieved the best relative weight gain, feed conversion ratio, specific growth rate and protein efficiency ratio among all experimental diets. Fish fed with diets containing 2 g kg(-1)Lycium barbarum also resulted in significantly higher total immunoglobin, bactericidal activity and anti-protease activity; and also a lower mortality when challenged with pathogenic bacteria. On the other hand, both fish species fed with diets containing 20 g kg(-1) of Astragalus membranaceus and 20 g kg(-1)Lycium barbarum, resulted in significantly impaired weight gain. In addition, incorporation of 2 g kg(-1)Lycium barbarum extract would be a more suitable dose for both fish species, in terms of achieving better feed conversion ratio, specific growth rate, protein digestibility, and improved non-specific immune parameters. Based on this study, it can be concluded that waste based feed pellets incorporated with Chinese medicinal herb extracts have the ability to enhance growth and immunity of fish. Therefore, the use of Chinese medicinal herbs in aquaculture should be encouraged, in order to replace certain antibiotics known to impose environmental and health effects through the discharge of aquaculture effluents.

  15. Non-specific immune parameters and physiological response of Nile tilapia fed β-glucan and vitamin C for different periods and submitted to stress and bacterial challenge.

    PubMed

    Barros, Margarida Maria; Falcon, Dario Rocha; Orsi, Ricardo de Oliveira; Pezzato, Luiz Edivaldo; Fernandes, Ademir Calvo; Guimarães, Igo Gomes; Fernandes, Ary; Padovani, Carlos Roberto; Sartori, Maria Márcia Pereira

    2014-08-01

    This study attempts to describe the effects of different administration periods of dietary β-glucan and Vit C on the non-specific immune response, physiological parameters and disease resistance of Nile tilapia against Aeromonas hydrophila infection. Therefore, a feeding trial (288 fish) was conducted to determine the best administration period (7, 15, 30 and 45 days) for a Nile tilapia diet supplemented with 0.1% β-glucan and 600 mg Vit C/kg diet. After the administration period, three different groups of 96 fish were exposed to one of the following three stresses: cold-induced stress, transport-induced stress, and A. hydrophila challenge. Hematological, biochemical and immunological responses were analyzed before and/or after stress. Cold-induced stress increased cortisol levels and reduced the leukocyte count in fish fed the test diet for seven days compared with the other periods. After transport-induced stress, fish fed the test diet for seven days required more hours to return to the baseline levels of cortisol and neutrophils. Moreover, independently of the administration period, fish needed 24 h for leukocyte and glucose levels to return to the initial values. The lowest survival after bacterial infection was observed in fish test diet for seven days. Based on fish hematological and biochemical responses, diet supplemented with 0.1% of β-glucan and 600 mg of Vit C/kg fed for at least 15 days is recommended for Nile tilapia especially when fish are likely to encounter transport-induced stress, and this stress was more severe than cold-induced stress or bacterial challenge.

  16. Neuropeptide B in Nile tilapia Oreochromis niloticus: molecular cloning and its effects on the regulation of food intake and mRNA expression of growth hormone and prolactin.

    PubMed

    Yang, Lu; Sun, Caiyun; Li, Wensheng

    2014-05-01

    Neuropeptide B (NPB) regulates food intake, energy homeostasis and hormone secretion in mammals via two G-protein coupled receptors, termed as GPR 7 and GPR 8. However, there is no study that reports the function of NPB in teleosts. In this study, the full-length cDNA of prepro-NPB with the size of 663bp was cloned from the hypothalamus of Nile tilapia. The CDS of the prepro-NPB is 387bp which encodes a precursor protein with the size of 128a.a. This precursor contains a mature peptide with the size of 29a.a, and it was named as NPB29. Tissue distribution study showed that this gene was mainly expressed in different parts of brain, especially in the diencephalon as well as hypothalamus, and the spinal cord in Nile tilapia. Fasting significantly stimulated the mRNA expression of NPB in the brain area without hypothalamus, and refeeding after fasting for 3 and 14days also showed similar effects on NPB expression. While, only short-term fasting (3days) and refeeding after fasting for 7 and 14days induced mRNA expression of NPB in the hypothalamus. Intraperitoneal (i.p.) injection of NPB remarkably elevated the mRNA expression of hypothalamic neuropeptide Y (NPY), cholecystokinin 1 (CCK1) and pituitary prolactin (PRL), whereas significantly inhibited growth hormone (GH) expression in pituitary. These observations in the present study suggested that NPB may participate in the regulation of feeding and gene expression of pituitary GH and PRL in Nile tilapia.

  17. Molecular cDNA cloning and analysis of the organization and expression of the IL-1beta gene in the Nile tilapia, Oreochromis niloticus.

    PubMed

    Lee, Dae-Sim; Hong, Su Hee; Lee, Hyun-Jeong; Jun, Lyu Jin; Chung, Joon-Ki; Kim, Ki Hong; Jeong, Hyun Do

    2006-03-01

    The full-length cDNA sequence of interleukin-1beta (IL-1beta) from the Nile tilapia, Oreochromis niloticus, was determined by using PCR with primers designed from known fish IL-1beta sequences followed by elongation of the 5' and 3' ends using Rapid Amplification of cDNA Ends (RACE). The cDNA contains a 92-bp 5' untranslated region (UTR), a single open reading frame (ORF) of 732 bp that translates into a 243-amino acid molecule, a 341-bp 3' UTR with four cytokine RNA instability motifs (ATTTA), and a polyadenylation signal (AATAAA) at 15 nucleotides upstream of the poly(A) tail. The organization of the genomic IL-1beta based on the cDNA sequence appeared to be 4 introns and 5 exons. In comparison with known IL-1beta amino acid sequences, including human, catshark, trout, turbot, carp, sea bream, sea bass and goldfish, the amino acid sequence deduced from the cDNA sequence of Nile tilapia showed different levels of identity ranging from 25.32% to 66.80% and homology ranging from 41.88% to 82.19%. Although the entire cDNA sequence of Nile tilapia IL-1beta showed from 49.45% to 67.05% identity to those of other reported IL-1beta cDNAs, each exon also showed different levels of identity to the corresponding exons of other reported IL-1beta cDNAs. The highest nucleotide sequence identity for exon 1 and exons 2-5 of Nile tilapia IL-1beta was found in the corresponding exons of sea bream and sea bass, respectively. After in vitro stimulation with lipopolysaccharide (LPS), we found an increased level of IL-1beta expression in head kidney cells compared to that of unstimulated cells. However, this difference was no longer apparent after 4 h of stimulation, at which time the levels were similar in stimulated and unstimulated cells. Head kidney cells stimulated in vivo by an intraperitoneal injection of LPS showed a peak level of IL-1beta expression after 1 day and a decreased level after 3 days. At 7 days after stimulation, we were hardly able to detect IL-1beta expression.

  18. Innate immune defenses exhibit circadian rhythmicity and differential temporal sensitivity to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus).

    PubMed

    Lazado, Carlo C; Skov, Peter Vilhelm; Pedersen, Per Bovbjerg

    2016-08-01

    The present study investigated the daily dynamics of humoral immune defenses and the temporal influence in the sensitivity of these responses to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus). The first experiment subjected the fish to two photoperiod conditions, 12L:12D (LD) and 0L:24D (DD), for 20 days to characterize the rhythms of humoral immunity. Serum alkaline phosphatase (ALP), lysozyme (LYZ), peroxidase (PER) and protease (PRO) exhibited significant rhythmicity under LD but not in DD. No significant rhythms were observed in esterase (ESA) and anti-protease (ANTI) in both photoperiod conditions. Fish reared under LD were subsequently subjected to DD while the group previously under DD was exposed to LD, and this carried on for 3 days before another set of samples was collected. Results revealed that the rhythms of LYZ, PER and PRO but not ALP persisted when photoperiod was changed from LD to DD. Nonetheless, immune parameters remained arrhythmic in the group subjected from DD to LD. Cluster analysis of the humoral immune responses under various light conditions revealed that each photic environment had distinct daily immunological profile. In the second experiment, fish were injected with bacterial endotoxin lipopolysaccharide (LPS) either at ZT3 (day) or at ZT15 (night) to evaluate the temporal sensitivity of humoral immunity to a pathogen-associated molecular pattern. The results demonstrated that responses to LPS were gated by the time of day. LPS significantly modulated serum ALP and ANTI activities but only when the endotoxin was administered at ZT3. Serum LYZ and PER were stimulated at both injection times but with differing response profiles. Modulated LYZ activity was persistent when injected at ZT3 but transient when LPS was applied at ZT15. The magnitude of LPS-induced PER activity was higher when the endotoxin was delivered at ZT3 versus ZT15. It was further shown that plasma cortisol was significantly elevated but only when LPS

  19. Effects of some dietary crude plant extracts on the growth and gonadal maturity of Nile tilapia (Oreochromis niloticus) and their resistance to Streptococcus agalactiae infection.

    PubMed

    Kareem, Zana H; Abdelhadi, Yasser M; Christianus, Annie; Karim, Murni; Romano, Nicholas

    2016-04-01

    A 90-day feeding trial was conducted on the growth performance, feeding efficacy, body indices, various hematological and plasma biochemical parameters, and histopathological examination of the gonads from male and female Nile tilapia fingerlings when fed different crude plant extracts from Cinnamomum camphora, Euphorbia hirta, Azadirachta indica, or Carica papaya at 2 g kg(-1) compared to a control diet. This was followed by a 14-day challenge to Streptococcus agalactiae. All treatments were triplicated, and each treatment consisted of 30 fish. Results showed that C. papaya extracts were the most effective at delaying gonadal maturation to both male and female tilapia, as well as significantly increasing (P < 0.05) growth performance compared to the control treatment. Similarly, dietary C. camphora and E. hirta extracts also significantly improved growth, while no significant growth effect was detected between the A. indica and control treatments (P > 0.05). Further, crude body lipid was lower in the C. camphora, E. hirta and C. papaya treatments, but was only significantly lower for the E. hirta treatment compared to the control. Meanwhile, none of the hematological or biochemical parameters were significantly affected, although plasma ALT was significantly lower for tilapia fed A. indica compared to the control. After the 14-day bacterial challenge, tilapia fed C. camphora supplementation had significantly higher survival, compared to the control, but was not significantly higher than the other supplemented diets. Results indicate that dietary C. papaya extract can significantly promote growth and delay gonadal maturation to both male and female tilapia, while C. camphora was the most effective prophylactic to S. agalactiae and may be a cost-effective and eco-friendly alternative to antibiotics.

  20. Growth response and resistance to Streptococcus iniae of Nile tilapia, Oreochromis niloticus, fed diets containing different levels of wheat distiller dried grains with solubles with or without lysine supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to evaluate the effect of dietary levels of wheat distiller’s dried grains with solubles (DDGS) with or without lysine supplementation on growth, body composition, hematology, immune response, and resistance of Nile tilapia, Oreochromis niloticus, to Streptococcus iniae challen...

  1. Salmon testes meal as a functional feed additive in fish meal and plant-protein based diets for rainbow trout(Oncorhynchus mykiss walbaum)and nile tilapia(Oreochromis niloticus L.) fry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report that salmon testes meal (TM) produced from Alaskan seafood processing byproducts is a potential protein source for aquafeed formulations. A series of feeding trials was conducted using three different fish species; including Nile tilapia, rainbow trout, and white sturgeon at their early gr...

  2. Effect of dietary probiotic supplementation on intestinal microbiota and physiological conditions of Nile tilapia (Oreochromis niloticus) under waterborne cadmium exposure.

    PubMed

    Zhai, Qixiao; Yu, Leilei; Li, Tianqi; Zhu, Jiamin; Zhang, Chengcheng; Zhao, Jianxin; Zhang, Hao; Chen, Wei

    2017-04-01

    The heavy metal cadmium (Cd) is a hazardous pollutant that exerts various toxic effects on aquatic animals. The biomagnifying effects of this non-essential element in the food chain also pose threats to human health. In this study, the protective effect of a dietary probiotic supplementation, Lactobacillus plantarum CCFM8610, on the intestinal microbiota and physiological conditions of Nile tilapia (Oreochromis niloticus) exposed to waterborne Cd was evaluated. Two hundred fish were divided into four groups, i.e., control, probiotic-only, Cd-only and Cd-plus-probiotic. The fish were exposed to waterborne Cd at a level of 1 mg L(-1) for 4 weeks and the probiotic was administered twice daily at 10(8) CFU g(-1) in the fish diet. Waterborne Cd exposure caused a profound decline in the gut microbial diversity and marked alterations in the composition of the microbiota. Dietary supplementation with L. plantarum CCFM8610 reversed the changes in the intestinal microbiota composition in the Cd-exposed fish and reduced the abundance of Flavobacterium and Pseudomonas. Compared with the Cd-only group, the probiotic treatment significantly promoted growth performance and prevented the death of the Cd-exposed fish. L. plantarum CCFM8610 supplementation also decreased Cd accumulation and alleviated oxidative stress in the tissues, and reversed the alterations in hemato-biochemical parameters in the blood of fish. The results suggest that L. plantarum CCFM8610 can be considered a safe dietary supplement for the prevention of Cd-exposure-induced problems in aquaculture and food safety.

  3. Mapping and Validation of the Major Sex-Determining Region in Nile Tilapia (Oreochromis niloticus L.) Using RAD Sequencing

    PubMed Central

    Khan, Mohd G. Q.; Taggart, John B.; Gharbi, Karim; McAndrew, Brendan J.; Penman, David J.

    2013-01-01

    Sex in Oreochromis niloticus (Nile tilapia) is principally determined by an XX/XY locus but other genetic and environmental factors also influence sex ratio. Restriction Associated DNA (RAD) sequencing was used in two families derived from crossing XY males with females from an isogenic clonal line, in order to identify Single Nucleotide Polymorphisms (SNPs) and map the sex-determining region(s). We constructed a linkage map with 3,802 SNPs, which corresponded to 3,280 informative markers, and identified a major sex-determining region on linkage group 1, explaining nearly 96% of the phenotypic variance. This sex-determining region was mapped in a 2 cM interval, corresponding to approximately 1.2 Mb in the O. niloticus draft genome. In order to validate this, a diverse family (4 families; 96 individuals in total) and population (40 broodstock individuals) test panel were genotyped for five of the SNPs showing the highest association with phenotypic sex. From the expanded data set, SNPs Oni23063 and Oni28137 showed the highest association, which persisted both in the case of family and population data. Across the entire dataset all females were found to be homozygous for these two SNPs. Males were heterozygous, with the exception of five individuals in the population and two in the family dataset. These fish possessed the homozygous genotype expected of females. Progeny sex ratios (over 95% females) from two of the males with the “female” genotype indicated that they were neomales (XX males). Sex reversal induced by elevated temperature during sexual differentiation also resulted in phenotypic males with the “female” genotype. This study narrows down the region containing the main sex-determining locus, and provides genetic markers tightly linked to this locus, with an association that persisted across the population. These markers will be of use in refining the production of genetically male O. niloticus for aquaculture. PMID:23874606

  4. Degradation of 17α-methyltestosterone by Rhodococcus sp. and Nocardioides sp. isolated from a masculinizing pond of Nile tilapia fry.

    PubMed

    Homklin, Supreeda; Ong, Say Kee; Limpiyakorn, Tawan

    2012-06-30

    17α-Methyltestosterone (MT), a synthetic anabolic androgenic steroid, is widely used in aquafarming for the production of an all male fish population such as Nile tilapia. This study isolated, identified and characterized MT-degrading bacteria in the sediment and water from a masculinizing pond of Nile tilapia fry. Based on the phylogeny, physiological properties and cell morphology, the three isolated MT-degrading bacteria were related closely to Rhodococcus equi, Nocardioides aromaticivorans, and Nocardioides nitrophenolicus. Growth of the three isolated strains was found to be inhibited for MT concentrations in the range of 1.0-10mg/L. The inhibition of cell growth was found to be modeled using the Haldane's substrate inhibition model. The kinetic constants ranged from 0.13 to 0.19h(-1) for μ(max), 0.7-24.8mg/L for K(s) and 19.6-76.2mg/L for K(i). Androgenic activity using β-galactosidase assay showed that all strains degraded MT to the products with no androgenic potency.

  5. Gene delivery to Nile tilapia cells for transgenesis and the role of PI3K-c2α in angiogenesis

    PubMed Central

    Tonelli, Fernanda Maria Policarpo; Lacerda, Samyra Maria dos Santos Nassif; Procópio, Marcela Santos; Lemos, Breno Luiz Sales; de França, Luiz Renato; Resende, Rodrigo Ribeiro

    2017-01-01

    Microinjection is commonly performed to achieve fish transgenesis; however, due to difficulties associated with this technique, new strategies are being developed. Here we evaluate the potential of lentiviral particles to genetically modify Nile tilapia cells to achieve transgenesis using three different approaches: spermatogonial stem cell (SSC) genetic modification and transplantation (SC), in vivo transduction of gametes (GT), and fertilised egg transduction (ET). The SC protocol using larvae generates animals with sustained production of modified sperm (80% of animals with 77% maximum sperm fluorescence [MSF]), but is a time-consuming protocol (sexual maturity in Nile tilapia is achieved at 6 months of age). GT is a faster technique, but the modified gamete production is temporary (70% of animals with 52% MSF). ET is an easier way to obtain mosaic transgenic animals compared to microinjection of eggs, but non-site-directed integration in the fish genome can be a problem. In this study, PI3Kc2α gene disruption impaired development during the embryo stage and caused premature death. The manipulator should choose a technique based on the time available for transgenic obtainment and if this generation is required to be continuous or not. PMID:28317860

  6. Sensitivity and specificity of real-time PCR and bacteriological culture for francisellosis in farm-raised Nile tilapia (Oreochromis niloticus L.).

    PubMed

    Assis, G B N; de Oliveira, T F; Gardner, I A; Figueiredo, H C P; Leal, C A G

    2016-09-27

    Despite the worldwide occurrence of Francisella noatunensis subsp. orientalis (Fno) infection in farmed tilapia, sensitivity and specificity estimates of commonly used diagnostic tests have not been reported. This study aimed to estimate the sensitivity and specificity of bacteriological culture and qPCR to detect Fno infection. We tested 559 fish, sampled from four farms with different epidemiological scenarios: (i) healthy fish in a hatchery free of Fno; (ii) targeted sampling of diseased fish with suggestive external clinical signs of francisellosis during an outbreak; (iii) convenience sampling of diseased and clinically healthy fish during an outbreak; and (iv) sampling of healthy fish in a cage farm without a history of outbreaks, but with francisellosis reported in other farms in the same reservoir. The qPCR had higher median sensitivity (range, 48.8-99.5%) than culture (range, 1.6-74.4%). Culture had a substantially lower median sensitivity (1.6%) than qPCR (48.8%) to detect Fno in carrier tilapia (farm 4). Median specificity estimates for both tests were >99.2%. The qPCR is the superior test for use in surveillance and monitoring programmes for francisellosis in farmed Nile tilapia, but both tests have high sensitivity and specificity which make them fit for use in the diagnosis of Fno outbreaks.

  7. Characterization of four heat-shock protein genes from Nile tilapia (Oreochromis niloticus) and demonstration of the inducible transcriptional activity of Hsp70 promoter.

    PubMed

    Zhang, Lili; Sun, Chengfei; Ye, Xing; Zou, Shuming; Lu, Maixin; Liu, Zhigang; Tian, Yuanyuan

    2014-02-01

    Heat-shock proteins (Hsps), known as stress proteins and extrinsic chaperones, play important roles in the folding, translocation, and refolding/degradation of proteins. In this study, we identified four Hsps in Nile tilapia (Oreochromis niloticus), which display conserved Hsp characteristics in their predicted amino acid sequences. Further analyses on the structures, homology, and phylogenetics revealed that the four Hsps belong to Hsp70 family. One of them does not contain introns and is named Hsp70, while all the other three contain introns and are named Hsc70-1, Hsc70-2, and Hsc70-3. Expressions of the four Hsp proteins were observed in all examined tissues. Six hours after infection of Streptococcus agalactiae in Nile tilapia, the expression of Hsp70 was significantly increased in the liver, head kidney, spleen and gill, while Hsc70s' expression was unchanged in all examined tissues except the head kidney that showed significantly reduced expression of both Hsc70-2 and Hsc70-3. These results suggest that Hsp70 may participate in the defense against S. agalactiae infection. We then isolated the promoter of Hsp70 gene and inserted it into the donor plasmid of Tgf2 transposon system containing green fluorescent protein (GFP) gene. The plasmid was microinjected into zebrafish embryos, where the expression of GFP was induced by heat shock, S. agalactiae immersion challenge, indicating that the isolated Hsp70 promoter has transcriptional activity and is inducible by both heat shock and bacterial challenge. This promoter may facilitate the future construction of disease-resistant transgenic fish. The work also contributes to the further study of immune response of tilapia after bacterial infection.

  8. Effect of N-acetyl cysteine and glycine supplementation on growth performance, glutathione synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus.

    PubMed

    Xie, Shiwei; Zhou, Weiwen; Tian, Lixia; Niu, Jin; Liu, Yongjian

    2016-08-01

    An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione (GSH) synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus. Four practical diets were formulated, control, control +0.2% NAC, control +0.5% glycine, control +0.2% NAC +0.5% glycine. Each diet was randomly assigned to quadruplicate groups of 30 fish (approximately 9.5 g). The weight gain and specific growth rate were significantly increased with the supplementation of NAC and glycine. While they had no effect on feed efficiency feed intake and survival. Glutathion peroxidase (GPx) was increased by NAC and γ-glutamine cysteine synthase (γ-GCS) in plasma were increased by glycine. After the feeding trail, fish were challenged by Streptococcus iniae, fish fed the diet supplemented with NAC obtained significantly higher survival rate after 72 h challenge test. NAC also decreased malonaldehyde (MDA) in liver, increased glutathione S-transferase (GST) activity in plasma, up-regulated mRNA expression of Superoxide dismutase (SOD) and GPx in liver and headkidney. Dietary supplementation of glycine increased the anti-oxidative ability of tilapia through increase anti-oxidative enzyme activity (SOD, glutathione reductase, myeloperoxidase) and up-regulate anti-oxidative gene expression (SOD). Immune ability only enhanced by the supplementation of NAC through increased interleukin-1β (IL-1β) mRNA expression. These results clearly indicated that the supplementation of NAC and glycine can significantly improve the growth performance of tilapia, and NAC also enhance the anti-oxidative and immune capacity of tilapia, glycine could only enhance the anti-oxidative ability.

  9. Controlled challenge experiment demonstrates substantial additive genetic variation in resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. A complimentary pre...

  10. Effects of dietary acidifiers on growth, hematology, immune response and disease resistance of Nile tilapia, Oreochromis niloticus.

    PubMed

    Reda, Rasha M; Mahmoud, Rania; Selim, Khaled M; El-Araby, Iman E

    2016-03-01

    between G1 and G2 after 30 d. The lowest immune parameters were recorded in G4. After 30 d, the highest expression of interleukin-1β and tumor necrosis factor-alpha in the liver and kidney were found in G3. The best protection against challenged Aeromonas sobria was in G3, followed by G2 and G4. Dietary supplementation with a combination of formic acid, propionic acid and calcium propionate improves the performance of Nile tilapia.

  11. Short periods of fasting followed by refeeding change the expression of muscle growth-related genes in juvenile Nile tilapia (Oreochromis niloticus).

    PubMed

    Nebo, Caroline; Portella, Maria Célia; Carani, Fernanda Regina; de Almeida, Fernanda Losi Alves; Padovani, Carlos Roberto; Carvalho, Robson Francisco; Dal-Pai-Silva, Maeli

    2013-04-01

    Muscle growth mechanisms are controlled by molecular pathways that can be affected by fasting and refeeding. In this study, we hypothesized that short period of fasting followed by refeeding would change the expression of muscle growth-related genes in juvenile Nile tilapia (Oreochromis niloticus). The aim of this study was to analyze the expression of MyoD, myogenin and myostatin and the muscle growth characteristics in the white muscle of juvenile Nile tilapia during short period of fasting followed by refeeding. Juvenile fish were divided into three groups: (FC) control, feeding continuously for 42 days, (F5) 5 days of fasting and 37 days of refeeding, and (F10) 10 days of fasting and 32 days of refeeding. At days 5 (D5), 10 (D10), 20 (D20) and 42 (D42), fish (n=14 per group) were anesthetized and euthanized for morphological, morphometric and gene expression analyses. During the refeeding, fasted fish gained weight continuously and, at the end of the experiment (D42), F5 showed total compensatory mass gain. After 5 and 10 days of fasting, a significant increase in the muscle fiber frequency (class 20) occurred in F5 and F10 compared to FC that showed a high muscle fiber frequency in class 40. At D42, the muscle fiber frequency in class 20 was higher in F5. After 5 days of fasting, MyoD and myogenin gene expressions were lower and myostatin expression levels were higher in F5 and F10 compared to FC; at D42, MyoD, myogenin and myostatin gene expression was similar among all groups. In conclusion, this study showed that short periods of fasting promoted muscle fiber atrophy in the juvenile Nile tilapia and the refeeding caused compensatory mass gain and changed the expression of muscle growth-related genes that promote muscle growth. These fasting and refeeding protocols have proven useful for understanding the effects of alternative warm fish feeding strategies on muscle growth-related genes.

  12. Influence of water temperature and waterborne cadmium toxicity on growth performance and metallothionein-cadmium distribution in different organs of Nile tilapia, Oreochromis niloticus (L.).

    PubMed

    Abdel-Tawwab, Mohsen; Wafeek, Mohammed

    2014-10-01

    Cadmium (Cd) is believed to be one of the most abundant and ubiquitously distributed toxins in the aquatic system. This metal is released to the aquatic environment from both anthropogenic sources, such as industrial, agricultural and urban effluents as well as natural sources, such as rocks and soils. Otherwise, the temperature increase of water bodies, which has been observed due to global climatic changes, has been shown to increase Cd toxicity for several aquatic animal species including fish. In the present study, Nile tilapia, Oreochromis niloticus (L.), (26.0 ± 0.38 g) were reared at 20, 24, 28, or 32 °C and exposed to 0.0 or 0.5mg Cd/L for 8 weeks to investigate effects of water temperature, Cd toxicity and their interaction on fish performance as well as metallothionein (MT) and Cd distribution in different fish organs. It was found that fish reared in Cd-free group at 28 °C showed the optimum growth and feed intake, while Cd-exposed fish showed low growth and feed intake irrespective to water temperature. A synergetic relationship between water temperature and Cd toxicity was observed where Cd toxicity increased as water temperature increased and the worse growth was obtained in Cd-exposed fish reared at 32 °C. Additionally, the highest Cd residues in different fish organs were detected in Cd-exposed fish reared at 32 °C. Similarly, MT concentrations in different fish organs increased as water temperature increased especially in Cd-exposed fish groups. A high positive correlation between MT and Cd concentrations in fish organs was detected. The distribution of MT and Cd levels was in the order of liver>kidney>gills>muscles. The present study revealed that the optimum water temperature suitable for Nile tilapia growth is 28 °C. Additionally, Cd exposure had a deteriorate effect on the growth and health of Nile tilapia. This hazardous effect increased as water temperature increased. Further, liver and kidney were the prime sites of Cd accumulation

  13. Production and characterization of crude and refined oils obtained from the co-products of Nile tilapia and hybrid sorubim processing.

    PubMed

    Menegazzo, Mariana Lara; Petenuci, Maria Eugenia; Fonseca, Gustavo Graciano

    2014-08-15

    In this study, crude oil was extracted by heating and filtering of the residual fat obtained from the processing of mechanically separated meats of Nile tilapia (Oreochromis niloticus) and hybrid sorubim (Pseudoplatystoma corruscans×P. fasciatum) for protein concentrate obtaining. The crude oil was refined by the following steps: degumming with 85% phosphoric acid, neutralization with 20% NaOH, washing with hot water at 85 °C, drying at 90 °C, clarification with activated charcoal and filtration with diatomaceous earth and anhydrous sodium sulfate. The quality of crude and refined oils was verified by acidity, peroxide, iodine, refractive, and saponification indexes, beyond moisture, lipid and free fatty acids contents, and density. The results show that the refining reduced the acidity index of the crude oil, however, favored the oil oxidation, as demonstrated by the increase in peroxide index. In most of the cases there was no change in the identity of the fish oils.

  14. The potential effects of Spirulina platensis (Arthrospira platensis) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level

    PubMed Central

    Ibrahem, Mai D.; Ibrahim, Marwa A.

    2013-01-01

    The current study was designed to investigate the potential effect of Spirulina platensis, Arthrospira platensis, (SP) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level. Five isonitrogenous and isocaloric rations containing graded levels of dried SP 5, 7.5,10, 15, and 20 g/kg diet were fed separately to five equal groups of O. niloticus fingerlings, additional control group was assigned for 3 months. Liver samples were separately collected from each group by the end of each month. The expression level of P53 showed a substantial decrease among the treated groups in a time-dependent manner. It is therefore advisable to incorporate SP in diets for tissue protection and antioxidant effects in cultured O. niloticus. PMID:25685480

  15. Effects of dietary levels of carbohydrate, lipid, phosphorus and zinc on the growth, feed conversion and protein efficiency ratio of Nile tilapia ( Oreochromis niloticus)

    NASA Astrophysics Data System (ADS)

    Li, Zhongjie; Lei, Wu; Yang, Yunxia; Ye, Jun

    1993-09-01

    A 54-day feeding experiment was conducted on juvenile Nile tilapia using isonitrogenous, isocaloric semipurified diets. The carbohydrate content in the diet was 9%, 32% and 50%; the corresponding lipid content was 22.2%, 12%, and 4%. The diets were supplemented with 0.85% or 1.5% phosphorus and 40 mg/kg or 100 mg/kg zinc. The experiment was carried out in flow-through aquaria using dechlorinated tap water at 23 26°C. The experiment showed that the increase of the carbohydrate content in the diets resulted in a 43 249% increase in weight gain, a 27 59% decrease in feed conversion ratio, and a 65 121% increase in protein efficiency ratio. In fish fed diets containing 36 50% carbohydrate, an increase in supplemented phosphorus to 1.5% greatly increased the weight gain. On the contrary, a high content of supplemented zinc (100 mg/kg) inhibited growth and increased feed conversion ratio.

  16. Assessment and control of an invasive aquaculture species: An update on Nile tilapia (Oreochromis niloticus) in coastal Mississippi after Hurricane Katrina

    USGS Publications Warehouse

    Schofield, Pamela J.; Slack, W. Todd; Peterson, Mark S.; Gregoire, Denise R.

    2007-01-01

    We provide information about the effects of Hurricane Katrina on populations of an invasive fish, the Nile tilapia (Oreochromis niloticus) in southern Mississippi. By resampling areas surveyed before the storm, we attempted to determine whether the species expanded its range by moving with storm-related floods. Additionally, we used rotenone to eradicate individuals of this species at a hurricane-damaged aquaculture facility on the Mississippi coast. Although our survey was limited geographically, we did not find the species to occur beyond the aquaculture facility, other than in an adjacent bayou. Our rotenone treatment of the facility appeared effective with only a single O. niloticus being collected six weeks after the treatment. To reduce the spread of O. niloticus in the southeastern U.S., it is important to continue to control feral populations, work to eliminate vectors for dispersal, and continue monitoring their distribution.

  17. Combined administration of low molecular weight sodium alginate boosted immunomodulatory, disease resistance and growth enhancing effects of Lactobacillus plantarum in Nile tilapia (Oreochromis niloticus).

    PubMed

    Van Doan, Hien; Hoseinifar, Seyed Hossein; Tapingkae, Wanaporn; Tongsiri, Sudaporn; Khamtavee, Pimporn

    2016-11-01

    The present study investigates the effects of combined or singular administration of low molecular weight sodium alginate (LWMSA) and Lactobacillus plantarum on innate immune response, disease resistance and growth performance of Nile tilapia (Oreochromis niloticus). Three hundred and twenty fish were supplied and randomly stocked in sixteen glass tanks (150 L) assigned to four treatments as follows: 0 g kg(-1) LMWSA (Control, Diet 1), 10 g kg(-1) LMWSA (Diet 2), 10(8) CFU g(-1)L. plantarum (Diet 3), and 10 g kg(-1) LMWSA + 10(8) CFU g(-1)L. plantarum (Diet 4). Following 30 and 60 days of the feeding trial, serum lysozyme, phagocytosis, respiratory burst and alternative complement activities as well as growth performance parameters (specific growth rate, feed conversion ratio) were measured. Serum lysozyme, phagocytosis, respiratory burst, and alternative complement activities of fish were significantly stimulated by both LMWSA and L. plantarum diets, however, the highest innate immune response were observed in fish fed synbiotic diet. At the end of the experiment, eight fish per replication were randomly selected for a challenge test against Streptococcus agalactiae. The survival rate of the fish fed supplemented diets was significantly greater than the control treatment and the highest post challenge survival rate was observed in synbiotic diet. Furthermore, SGR and FCR were significantly improved in fish fed supplemented diets after 60 days and the highest growth performance was observed in fish fed synbiotic diet. These results suggest combined LMWSA and L. plantarum can be considered as a promising immunostimulant and growth enhancer in Nile tilapia diet.

  18. The effect of water quality on the immunoreactivity of stress-response cells and gonadotropin-secreting cells in the pituitary gland of Nile tilapia, Oreochromis niloticus.

    PubMed

    Mousa, Mostafa A; Ibrahim, Amal A E; Hashem, Amal M; Khalil, Noha A

    2015-03-01

    The present experiments investigated the effect of water quality characteristics on the condition factor, the ovarian activity, cortisol level, and the immunoreactivity of stress-response cells (adrenocorticotropic hormone; ACTH- and melanin stimulating hormone; MSH- and somatolactin; SL- secreting cells) and gonadotropin (GTH)-secreting cells in the pituitary gland of Nile tilapia, Oreochromis niloticus. After 3 months of exposure to mixtures of water from different sources (Tap and Lake Manzalah waters), with high levels of minerals and heavy metals, water quality affected the number, size, and immunostaining of stress-response-immunoreactive (ir) cells and GTH-ir cells, which showed a dramatic decrease in their size. The integrated optical density (IOD) of immunoreactivity of MSH- and GTH- cells was significantly increased; however, it was significantly decreased for ACTH- and SL- cells. Also, high levels of cortisol were observed in females exposed to waters with high concentrations of minerals and heavy metals. In parallel, low values of gonadosomatic index (GSI%) and the ovarian histology revealed a decrease of maturing follicles concomitant with an increase of atretic follicles in females exposed to Lake Manzalah polluted water. Taken together, the increased activity of stress-response-ir pituitary cells, serum cortisol level and ovarian atretic follicles in response to elevated concentrations of minerals and heavy metals, supports the possible role of ACTH, MSH, and SL in the adaptive stress response of fish. Therefore, minerals and heavy metals must be considered when discussing tilapia aquaculture status.

  19. Synchronization to light and mealtime of daily rhythms of locomotor activity, plasma glucose and digestive enzymes in the Nile tilapia (Oreochromis niloticus).

    PubMed

    Guerra-Santos, Bartira; López-Olmeda, José Fernando; de Mattos, Bruno Olivetti; Baião, Alice Borba; Pereira, Denise Soledade Peixoto; Sánchez-Vázquez, Francisco Javier; Cerqueira, Robson Bahia; Albinati, Ricardo Castelo Branco; Fortes-Silva, Rodrigo

    2017-02-01

    The light-dark cycle and feeding can be the most important factors acting as synchronizers of biological rhythms. In this research we aimed to evaluate synchronization to feeding schedule of daily rhythms of locomotor activity and digestive enzymes of tilapia. For that purpose, 120 tilapias (65.0±0.6g) were distributed in 12 tanks (10 fish per tank) and divided into two groups. One group was fed once a day at 11:00h (zeitgeber time, ZT6) (ML group) and the other group was fed at 23:00h (ZT18) (MD group). The fish were anesthetized to collect samples of blood, stomach and midgut at 4-hour intervals over a period of 24h. Fish fed at ML showed a diurnal locomotor activity (74% of the total daily activity occurring during the light phase) and synchronization to the feeding schedule, as this group showed anticipation to the feeding time. Fish fed at MD showed a disruption in the pattern of locomotor activity and became less diurnal (59%). Alkaline protease activity in the midgut showed daily rhythm with the achrophase at the beginning of the dark phase in both ML and MD groups. Acid protease and amylase did not show significant daily rhythms. Plasma glucose showed a daily rhythm with the achrophase shifted by 12h in the ML and MD groups. These results revealed that the feeding time and light cycle synchronize differently the daily rhythms of behavior, digestive physiology and plasma metabolites in the Nile tilapia, which indicate the plasticity of the circadian system and its synchronizers.

  20. Effects of dietary live and heat-inactive baker's yeast on growth, gut health, and disease resistance of Nile tilapia under high rearing density.

    PubMed

    Ran, Chao; Huang, Lu; Hu, Jun; Tacon, Philippe; He, Suxu; Li, Zhimin; Wang, Yibing; Liu, Zhi; Xu, Li; Yang, Yalin; Zhou, Zhigang

    2016-09-01

    In this study, the effects of baker's yeast as probiotics was evaluated in Nile tilapia reared at high density. Juvenile tilapia were distributed to tanks at high density (436 fish/m(3)) and fed with basal diet (CK) or diets supplemented with live (LY) or heat-inactivated yeast (HIY). Another group of fish reared at low density (218 fish/m(3)) and fed with basal diet was also included (LowCK). After 8 weeks of feeding, growth, feed utilization, gut microvilli morphology, digestive enzymes, and expressions of hsp70 and inflammation-related cytokines in the intestine were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Fish were challenged with Aeromonas hydrophila to evaluate disease resistance. High rearing density significantly decreased the growth, feed utilization, microvilli length, and disease resistance of fish (CK versus LowCK). Moreover, the intestinal hsp70 expression was increased in fish reared at high density, supporting a stress condition. Compared to CK group, supplementation of live yeast significantly increased gut microvilli length and trypsin activity, decreased intestinal hsp70 expression, and enhanced resistance of fish against A. hydrophila (reflected by reduced intestinal alkaline phosphatase activity 24 h post infection). The gut microbiota was not markedly influenced by either rearing density or yeast supplementation. Heat-inactivated yeast (HIY) didn't display the beneficial effects observed in LY except an increase in gut trypsin activity, suggesting the importance of yeast viability and thus secretory metabolites of yeast. In conclusion, live baker's yeast may alleviate the negative effects induced by crowding stress, and has the potential to be used as probiotics for tilapia reared at high density.

  1. Construction of a Streptococcus iniae sortase A mutant and evaluation of its potential as an attenuated modified live vaccine in Nile tilapia (Oreochromis niloticus).

    PubMed

    Wang, J; Zou, L L; Li, A X

    2014-10-01

    Streptococcus iniae is a major Gram-positive aquatic pathogen, which causes invasive diseases in cultured fish worldwide. The identification of potential virulence determinants of streptococcal infections will help to understand and control this disease, but only a few have been confirmed in S. iniae. Sortase A (srtA) is the key enzyme that anchors pre-mature cell wall-attached proteins to peptidoglycan and it can affect the correct positioning of surface proteins, as well as the course of Gram-positive bacterial infection, thereby making it a potential target in the study of virulence factors and disease control. In this study, the 759 bp srtA gene was cloned from pathogenic S. iniae TBY-1 strain and the mutant strain TBY-1ΔsrtA was constructed via allelic exchange mutagenesis. We found that srtA shares high similarities with sortase A from other Streptococcus spp. Direct survival rate assay and challenge experiments were performed, which showed that the mutant strain TBY-1ΔsrtA had a lower survival capacity in healthy tilapia blood and it was less virulent than the wild type strain in tilapia, thereby indicating that the deletion of sortase A affects the virulence and infectious capacity of S. iniae. The mutant strain TBY-1ΔsrtA was used as a live vaccine, which was administered via intraperitoneal injection, and it provided the relative percent survival value of 95.5% in Nile tilapia, thereby demonstrating its high potential as an effective attenuated live vaccine candidate.

  2. Analysis of differential gene expression under low-temperature stress in Nile tilapia (Oreochromis niloticus) using digital gene expression.

    PubMed

    Yang, Changgeng; Jiang, Ming; Wen, Hua; Tian, Juan; Liu, Wei; Wu, Fan; Gou, Gengwu

    2015-06-15

    Tilapia (Oreochromis niloticus) do not survive well at low temperatures. Therefore, improvement of the low-temperature resistance has become an important issue for aquaculture development of tilapia. The objective of this study was to construct a digital gene expression tag profile to identify genes potentially related to low temperature in tilapia. In this study, tilapia was treated at 30°C to lethal temperature 10°C in decrement of 1°CD(-1). Digital gene expression analysis was performed using the Illumina technique to investigate differentially expressed genes in tilapia cultured at different temperatures (30°C, 26°C, 20°C, 16°C, and 10°C). A total of 206,861, 188,082, 185,827, 188,067, and 214,171 distinct tags were obtained by sequencing these five libraries, respectively. Compared with the 30°C library, there were 304, 407, 709, and 772 upregulated genes and 342, 793, 771, and 1466 downregulated genes in 26°C, 20°C, 16°C, and 10°C libraries, respectively. Trend analysis of these differentially expressed genes identified six statistically significant trends. Functional annotation analysis of the differentially expressed genes identified various functions associated with the response to low-temperature stress. When tilapia are subjected to low-temperature stress, expression changes were observed in genes associated with nucleic acid synthesis and metabolism, amino acid metabolism and protein synthesis, lipid and carbohydrate content and types, material transport, apoptosis, and immunity. The differentially expressed genes obtained in this study may provide useful insights to help further understand the effects of low temperature on tilapia.

  3. The study on the candidate probiotic properties of encapsulated yeast, Saccharomyces cerevisiae JCM 7255, in Nile Tilapia (Oreochromis niloticus).

    PubMed

    Pinpimai, Komkiew; Rodkhum, Channarong; Chansue, Nantarika; Katagiri, Takayuki; Maita, Masashi; Pirarat, Nopadon

    2015-10-01

    Saccharomyces cerevisiae JCM 7255 was tested as a probiotic candidate in tilapia after encapsulating and freeze drying. Viability and morphology during storage and during transit through simulated gut and bile conditions were determined. Growth performance, anti-streptococcal activity and gut mucosal immune parameters were also tested. The viability of encapsulated yeasts was significantly high in simulated gastric and bile conditions and remained high after storage at room temperature for 14 days. The morphology of free S. cerevisiae revealed rough, bumpy, ruptured surface during incubation in gut and bile conditions. Agar spot anti-streptococcal activity showed inhibition of 20 out of 30 strains of Streptococcus agalactiae. Supplementation improved the intestinal structure and growth performance in tilapias. Intraepithelial lymphocytes in the proximal intestine were significantly observed. Lower cumulative mortality after the oral streptococcal challenge was also seen. The results suggest that encapsulated S. cerevisiae JCM 2755 could be a potential probiotic strain in tilapia culture.

  4. Effects of chronic exposure of methomyl on the antioxidant system in kidney of Nile tilapia (Oreochromis niloticus) and recovery pattern.

    PubMed

    Meng, Shun Long; Hu, Geng Dong; Qiu, Li Ping; Song, Chao; Fan, Li Min; Chen, Jia Zhang; Xu, Pao

    2013-01-01

    Tilapia were exposed to sublethal methomyl concentrations of 0, 0.2, 2, 20, or 200 μg/L for 30 d, and then were transferred to methomyl-free water for 18 d. Renal antioxidant parameters, including catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPx) , glutathione reductase (GR), total glutathione (GSH), and reduced glutathione (GSSG), were examined in tilapia at d 0, 6, 12, 18, 24, and 30 after starting the experiment and at 18 d after transferring to methomyl-free water. There were no significant changes in enzymatic activity and content of antioxidants in kidney of tilapia exposed to 0.2 μg/L methomyl compared to controls. The results showed significant increases in SOD, CAT, GST, GR, GPx, and level of GSSG accompanied by a decrease in GSH levels following methomyl exposure in tilapia to 2, 20, or 200 μg/L over the 30-d exposure period, suggesting the presence of oxidative stress. Thus, it would appear the 0.2 μg/L methomyl might be considered the no-observed-adverse-effect level (NOAEL). Recovery data showed that the effects produced by lower concentration of methomyl at 20 μg/L were reversible but not at the higher 200 μg/L concentration.

  5. Draft Genome Sequence of an Attenuated Streptococcus agalactiae Strain Isolated from the Gut of a Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Yu, Angen; Lan, Jiangfeng; Zhang, Yulei; Zhang, Hua; Li, Yuhui; Hu, Minqiang; Cheng, Jiewei

    2017-01-01

    ABSTRACT Streptococcus agalactiae is a pathogen that causes severe anthropozoonosis within a broad range of hosts from aquatic animals to mammals, including human beings. Here, we describe the draft genome of S. agalactiae HZAUSC001, a low-virulent strain isolated from the gut of a moribund tilapia (Oreochromis niloticus) in China. PMID:28183773

  6. Evaluation of reference genes for quantitative real-time RT-PCR analysis of gene expression in Nile tilapia (Oreochromis niloticus).

    PubMed

    Yang, Chang Geng; Wang, Xian Li; Tian, Juan; Liu, Wei; Wu, Fan; Jiang, Ming; Wen, Hua

    2013-09-15

    Quantitative real-time reverse-transcriptase polymerase chain reaction (RT-qPCR) has been used frequently to study gene expression related to fish immunology. In such studies, a stable reference gene should be selected to correct the expression of the target gene. In this study, seven candidate reference genes (glyceraldehyde-3-phosphate dehydrogenase (GADPH), ubiquitin-conjugating enzyme (UBCE), 18S ribosomal RNA (18S rRNA), beta-2-microglobulin (B2M), elongation factor 1 alpha (EF1A), tubulin alpha chain-like (TUBA) and beta actin (ACTB)), were selected to analyze their stability and normalization in seven tissues (liver, spleen, kidney, brain, heart, muscle and intestine) of Nile tilapia (Oreochromis niloticus) challenged with Streptococcus agalactiae or Streptococcus iniae, respectively. The results showed that all the candidate reference genes exhibited tissue-dependent transcriptional variations. With PBS injection as a control, UBCE was the most stable and suitable single reference gene in the intestine, liver, brain, kidney, and spleen after S. iniae infection, and in the liver, kidney, and spleen after S. agalactiae infection. EF1A was the most suitable in heart and muscle after S. iniae or S. agalactiae infection. GADPH was the most suitable gene in intestine and brain after S. agalactiae infection. In normal conditions, UBCE and 18S rRNA were the most stably expressed genes across the various tissues. These results showed that for RT-qPCR analysis of tilapia, selecting two or more reference genes may be more suitable for cross-tissue analysis of gene expression.

  7. Dispersion of the Vancomycin Resistance Genes vanA and vanC of Enterococcus Isolated from Nile Tilapia on Retail Sale: A Public Health Hazard

    PubMed Central

    Osman, Kamelia M.; Ali, Mohamed N.; Radwan, Ismail; ElHofy, Fatma; Abed, Ahmed H.; Orabi, Ahmed; Fawzy, Nehal M.

    2016-01-01

    Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC) as well as the presence of enterococcal surface protein (esp) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight Enterococcus isolates from the 80 fish samples (10%) to be further identified as E. faecalis (6/8, 75%) and E gallinarum (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the

  8. A Tandem Duplicate of Anti-Müllerian Hormone with a Missense SNP on the Y Chromosome Is Essential for Male Sex Determination in Nile Tilapia, Oreochromis niloticus

    PubMed Central

    Li, Minghui; Sun, Yunlv; Zhao, Jiue; Shi, Hongjuan; Zeng, Sheng; Ye, Kai; Jiang, Dongneng; Zhou, Linyan; Sun, Lina; Tao, Wenjing; Nagahama, Yoshitaka; Kocher, Thomas D.; Wang, Deshou

    2015-01-01

    Variation in the TGF-β signaling pathway is emerging as an important mechanism by which gonadal sex determination is controlled in teleosts. Here we show that amhy, a Y-specific duplicate of the anti-Müllerian hormone (amh) gene, induces male sex determination in Nile tilapia. amhy is a tandem duplicate located immediately downstream of amhΔ-y on the Y chromosome. The coding sequence of amhy was identical to the X-linked amh (amh) except a missense SNP (C/T) which changes an amino acid (Ser/Leu92) in the N-terminal region. amhy lacks 5608 bp of promoter sequence that is found in the X-linked amh homolog. The amhΔ-y contains several insertions and deletions in the promoter region, and even a 5 bp insertion in exonVI that results in a premature stop codon and thus a truncated protein product lacking the TGF-β binding domain. Both amhy and amhΔ-y expression is restricted to XY gonads from 5 days after hatching (dah) onwards. CRISPR/Cas9 knockout of amhy in XY fish resulted in male to female sex reversal, while mutation of amhΔ-y alone could not. In contrast, overexpression of Amhy in XX fish, using a fosmid transgene that carries the amhy/amhΔ-y haplotype or a vector containing amhy ORF under the control of CMV promoter, resulted in female to male sex reversal, while overexpression of AmhΔ-y alone in XX fish could not. Knockout of the anti-Müllerian hormone receptor type II (amhrII) in XY fish also resulted in 100% complete male to female sex reversal. Taken together, these results strongly suggest that the duplicated amhy with a missense SNP is the candidate sex determining gene and amhy/amhrII signal is essential for male sex determination in Nile tilapia. These findings highlight the conserved roles of TGF-β signaling pathway in fish sex determination. PMID:26588702

  9. Effect of acute exposure to nonylphenol on biochemical, hormonal, and hematological parameters and muscle tissues residues of Nile tilapia; Oreochromis niloticus

    PubMed Central

    Ismail, Hager Tarek H.; Mahboub, Heba Hassan H.

    2016-01-01

    Aim: This study was aimed to evaluate some biochemical, hormonal, hematological, and histopathological changes in Nile tilapia, Oreochromis niloticus, after acute exposure to nonylphenol (NP). In addition to detection of NP residues in the fish, muscle tissues for human health concern. Materials and Methods: A total of 90 apparently healthy Nile tilapia, O. niloticus, were randomly divided into three equal groups; each containing 30 fish (three replicates). Groups 1 and 2 kept as a control and solvent control (acetone), respectively, and Group 3 exposed to NP at a dose level of 500 µg/L water for 7 successive days. Blood and tissue samples were collected 2 times randomly from each group after 7 days from fish exposure to NP and 10 days from exposure stopping. Results: Fish exposed to NP Group 3 showed anorexia, sluggish movement, erythema of the skin, areas of scales loss, and hemorrhagic ulcers in some areas of body region leading to exposing the viscera. Biochemical results revealed a significant increase in serum total proteins and globulins levels, a highly significant increase in serum alanine aminotransferase and aspartate aminotransferase activities, triglycerides, cholesterol, and creatinine levels, insignificant increase in serum uric acid level, and a highly significant decrease in serum testosterone and estradiol-β17 levels in Group 3 in compare with the control group. Histopathological finding confirms these results. While hematological results of the same group revealed a significant increase in red blood cells count and packed cell volume value, insignificant increase in hemoglobin concentration, leukopenia, lymphopenia, and monocytopenia in compared with the control group. All of these changes appeared after 7 days from fish exposure to NP. Most of these alterations returned toward the normal level after 10 days from stopping exposure to NP. NP residues detected in fish muscle tissues of Group 3 during exposure and after stopping exposure to it

  10. Morphology and muscle gene expression in GIFT and Supreme Nile tilapia varieties reared in two cultivation systems.

    PubMed

    Lima, E C S; Povh, J A; Otonel, R A A; Leonhardt, J H; Alfieri, A A; Headley, S A; Souza, F P; Poveda-Parra, A R; Furlan-Murari, P J; Lopera-Barrero, N M

    2017-03-16

    Tissue growth in most fishes occurs by muscular hyperplasia and hypertrophy, which are influenced by different regulatory factors, such as myostatin. The current study evaluated the influence of cultivation in hapas and earthen ponds on the diameter of white muscle fibers and on the myostatin (MSTN-1) gene in GIFT and Supreme varieties of tilapia. Fish of both varieties were reared for 204 days and then divided into four developmental stages. White muscle samples, corresponding to 100 fibers per slide, were collected from the middle region of fish of each variety and cultivation system, and were measured and divided into two classes representing hyperplasia and hypertrophy. Samples were subjected to real-time PCR to analyze gene expression. Hyperplasia decreased during the developing stages, coupled with increased hypertrophy. There was a higher rate of hypertrophy in fish raised in earthen ponds when compared to those raised in hapas, during juvenile and developing phases, and greater hypertrophic growth was observed in GIFT specimens when compared to Supreme specimens in earthen ponds. Since increased MSTN-1 gene expression was observed in GIFT specimens during the developing phase in pond cultivations, and in Supreme tilapia in hapas, MSTN-1 expression is related to greater hypertrophy. These results demonstrate the capacity for increased muscle growth in earthen pond cultivation in which the GIFT variety developed best. How the environment affects the growth of different tilapia varieties may be employed to optimize culture management and genetic improvement programs. Further investigations should aim to describe mechanisms affecting muscle growth and development.

  11. Assessment of the immune-modulatory and antimicrobial effects of dietary chitosan on Nile tilapia (Oreochrmis niloticus) with special emphasis to its bio-remediating impacts.

    PubMed

    Abu-Elala, Nermeen M; Mohamed, Samah H; Zaki, Manal M; Eissa, Alaa Eldin

    2015-10-01

    Fish, pathogen and environment are three counterparts who are sharing the same circle of life. To keep fish up to their optimal health, environment should be competently improved and pathogen count/virulence should be seized. Using of bioactive immunostimulants to achieve these objectives is the hypothesis under assessment. Thus, the present study was performed to evaluate the use of shrimp shells derived chitosan as an immunostimulant as well as preventive regime against Aeromonas hydrophila infection of Nile tilapia and to assess its antibacterial/aquatic bio-remediating effects. Results achieved by feeding 1% chitosan as preventive/therapeutic regimes have revealed a remarkably enhanced several innate immunological parameters (e.g., Phagocytic activity/index, NBT, Lysozyme activity and ACH50), increased resistance against A. hydrophila and strikingly improved water quality compared to the 0.5 and 2% chitosan containing diets. Conclusively, experimental results suggest the commercial usage of chitosan as an efficient immunostimulant and bio-remediating agent in aquaculture.

  12. Histopathological alterations in the liver and intestine of Nile tilapia Oreochromis niloticus exposed to long-term sublethal concentrations of cadmium chloride

    NASA Astrophysics Data System (ADS)

    Younis, Elsayed; Abdel-Warith, Abdel-Wahab; Al-Asgah, Nasser; Ebaid, Hossam

    2015-07-01

    Fingerlings of Nile tilapia Oreochromis niloticus were exposed to 1.68, 3.36, and 5.04 mg/L cadmium (as CdCl2), which represent 10%, 20%, and 30% of their previously determined 96-h LC50. After exposure for 20 days, sections of the liver and intestine of treated fish were examined histologically. Histopathological changes varied from slight to severe structural modification, depending on the exposure concentration. The hepatic tissues of fish exposed to 10% LC50 showed markedly increased vacuolation of the hepatocytes and coarse granulation of their cytoplasm. Abundant erythrocytic infiltration among the hepatocytes was observed in fish exposed to 20% LC50. In the intestinal tissues of fish exposed to all doses, goblet cells proliferated and were greatly increased in size, the longitudinal muscularis mucosa was disturbed and, in the crypts of the sub-mucosal layer, apoptosis increased, indicated by large numbers of degenerated nuclei. Large numbers of inflammatory cells and dilated blood vessels were observed in the intestine of the group treated with 30% LC50.

  13. Retinoic acid homeostasis through aldh1a2 and cyp26a1 mediates meiotic entry in Nile tilapia (Oreochromis niloticus)

    PubMed Central

    Feng, Ruijuan; Fang, Lingling; Cheng, Yunying; He, Xue; Jiang, Wentao; Dong, Ranran; Shi, Hongjuan; Jiang, Dongneng; Sun, Lina; Wang, Deshou

    2015-01-01

    Meiosis is a process unique to the differentiation of germ cells. Retinoic acid (RA) is the key factor controlling the sex-specific timing of meiotic initiation in tetrapods; however, the role of RA in meiotic initiation in teleosts has remained unclear. In this study, the genes encoding RA synthase aldh1a2, and catabolic enzyme cyp26a1 were isolated from Nile tilapia (Oreochromis niloticus), a species without stra8. The expression of aldh1a2 was up-regulated and expression of cyp26a1 was down-regulated before the meiotic initiation in ovaries and in testes. Treatment with RA synthase inhibitor or disruption of Aldh1a2 by CRISPR/Cas9 resulted in delayed meiotic initiation, with simultaneous down-regulation of cyp26a1 and up-regulation of sycp3. By contrast, treatment with an inhibitor of RA catabolic enzyme and disruption of cyp26a1 resulted in earlier meiotic initiation, with increased expression of aldh1a2 and sycp3. Additionally, treatment of XY fish with estrogen (E2) and XX fish with fadrozole led to sex reversal and reversion of meiotic initiation. These results indicate that RA is indispensable for meiotic initiation in teleosts via a stra8 independent signaling pathway where both aldh1a2 and cyp26a1 are critical. In contrast to mammals, E2 is a major regulator of sex determination and meiotic initiation in teleosts. PMID:25976364

  14. Metals concentrations in Nile tilapia Oreochromis niloticus () from illegal fish farm in Al-Minufiya Province, Egypt, and their effects on some tissues structures.

    PubMed

    Authman, Mohammad M N; Abbas, Wafaa T; Gaafar, Alkhateib Y

    2012-10-01

    This study clarified the suitability of fishes caught from illegal fish farms to human consumption and their hazards to public health. For this purpose, the concentrations of some metals (Al, Cd, Pb, Hg and Ni) in water and Nile tilapia (Oreochromis niloticus) fish samples collected from an illegal fish farm, in addition to pathological conditions of the fish tissues, were examined. The illegal farm water was found to be heavily polluted with metals which far exceeded the permissible limits. It was found that metals accumulated in tissues of O. niloticus in concentrations higher than those of farm water. Kidney of O. niloticus contained the highest concentrations of the detected metals, while muscle and skin contained the lowest concentrations. The examination of fish tissues revealed various histopathological lesions which related directly to the pollution of the illegal farm water. Moreover, metals levels in O. niloticus muscle were higher than the maximum permissible levels for human consumption. Consequently, the flesh of fishes from the illegal farms could be considered hazardous to human health. Therefore, warning against eating fish caught from the illegal fish farms should be announced. Moreover, removal of such illegal fish farms is necessary for the public health protection.

  15. Growth, nutrient utilization and parameters of mineral metabolism in Nile tilapia Oreochromis niloticus (Linnaeus, 1758) fed plant-based diets with graded levels of microbial phytase.

    PubMed

    Portz, L; Liebert, F

    2004-10-01

    Diets with graded levels of the experimental microbial phytase SP1002 (0, 500, 1000, 2000 and 4000 FTU/kg) were fed to juvenile Nile tilapia (average BW = 68.8 g) for 60 days (n = 4). A digestibility trial ran parallel to the growth trial using 0.3 g TiO2/100 g as an indigestible marker. The efficiency of phytase supplementation was evaluated by parameters of growth response, crude protein and mineral utilization (using body composition data), apparent nutrient digestibility, mineral content in scale and vertebra and inorganic phosphorus in blood plasma. Data were submitted to ANOVA and Tukey-test using SAS-program. Significant improvements (p < 0.01) were found for growth, FCR and SGR, mainly for diets with 1000 and 2000 FTU/kg phytase supplementation. Protein utilization was significantly increased and maximized between 1000 and 2000 FTU/kg. Phosphorus utilization increased significantly up to 4000 FTU/kg. Digestibility of protein and phosphorus was also significantly improved. Phosphorus concentration in the blood, vertebra and scale increased significantly after phytase addition. Similarly, calcium and magnesium concentration in vertebra and scale were increased. Generally, phytase supplementation between 1000 and 2000 FTU/kg resulted in growth rates and mineralization parameters similar to a control diet with inorganic phosphorus.

  16. Effects of the pharmaceuticals diclofenac and metoprolol on gene expression levels of enzymes of biotransformation, excretion pathways and estrogenicity in primary hepatocytes of Nile tilapia (Oreochromis niloticus).

    PubMed

    Gröner, Frederike; Ziková, Andrea; Kloas, Werner

    2015-01-01

    The expression levels of key enzymes of the xenobiotic metabolism and excretion pathways concerning biotransformation phases I (cytochrome P4501A), II (glutathione S-transferase) and III (multidrug resistance protein) and of the estrogenic biomarker vitellogenin (vtg) were investigated in primary hepatocytes isolated from male Nile tilapia (Oreochromis niloticus) after exposure to diclofenac and metoprolol, two pharmaceuticals prevalent in the aquatic environment worldwide. The lowest test concentration (4×10(-9) M) was chosen to reflect an environmentally relevant exposure situation. Furthermore concentration dependent effects were investigated. Therefore a series of concentrations higher than the environmentally relevant range were used (10- and 100-fold). Diclofenac significantly induced all chosen biomarkers already at the environmentally relevant concentration indicating that biotransformation and elimination occur via the pathways under investigation. Estrogenic potential of this substance was demonstrated by VTG up-regulation as well. Metoprolol was either less effective than diclofenac or metabolized using different pathways. Key enzymes of the xenobiotic metabolism were less (CYP1A, GST) or not (MDRP) induced and a mild increase in vtg mRNA was detected only for 4×10(-8) M. No concentration-dependency for metoprolol was found.

  17. Retinoic acid homeostasis through aldh1a2 and cyp26a1 mediates meiotic entry in Nile tilapia (Oreochromis niloticus).

    PubMed

    Feng, Ruijuan; Fang, Lingling; Cheng, Yunying; He, Xue; Jiang, Wentao; Dong, Ranran; Shi, Hongjuan; Jiang, Dongneng; Sun, Lina; Wang, Deshou

    2015-05-15

    Meiosis is a process unique to the differentiation of germ cells. Retinoic acid (RA) is the key factor controlling the sex-specific timing of meiotic initiation in tetrapods; however, the role of RA in meiotic initiation in teleosts has remained unclear. In this study, the genes encoding RA synthase aldh1a2, and catabolic enzyme cyp26a1 were isolated from Nile tilapia (Oreochromis niloticus), a species without stra8. The expression of aldh1a2 was up-regulated and expression of cyp26a1 was down-regulated before the meiotic initiation in ovaries and in testes. Treatment with RA synthase inhibitor or disruption of Aldh1a2 by CRISPR/Cas9 resulted in delayed meiotic initiation, with simultaneous down-regulation of cyp26a1 and up-regulation of sycp3. By contrast, treatment with an inhibitor of RA catabolic enzyme and disruption of cyp26a1 resulted in earlier meiotic initiation, with increased expression of aldh1a2 and sycp3. Additionally, treatment of XY fish with estrogen (E2) and XX fish with fadrozole led to sex reversal and reversion of meiotic initiation. These results indicate that RA is indispensable for meiotic initiation in teleosts via a stra8 independent signaling pathway where both aldh1a2 and cyp26a1 are critical. In contrast to mammals, E2 is a major regulator of sex determination and meiotic initiation in teleosts.

  18. Ontogenetic changes in location and morphology of chloride cells during early life stages of the Nile tilapia Oreochromis niloticus adapted to fresh and brackish water.

    PubMed

    Fridman, S; Bron, J E; Rana, K J

    2011-09-01

    Ontogenetic changes in the location, size, density and morphology of chloride cells in the Nile tilapia Oreochromis niloticus adapted to fresh and brackish water are described using Na(+) /K(+) -ATPase immunohistochemistry, light microscopy (LM), scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM). The pattern of chloride cell distribution changed during development under both treatments, with chloride cell density decreasing significantly from hatch to 7 days post-hatch, but appearing on the inner opercular area at 3 days post-hatch and increasing significantly thereafter (P < 0·05). Chloride cells were always denser in fresh- than in brackish-water larvae. In both treatments, chloride cells located on the outer operculum and tail showed a marked increase in size with age, but cells located on the abdominal epithelium of the yolk sac and the inner operculum showed a significant decrease in size (P < 0·05). Chloride cells from brackish-water adapted larvae from 1 day post-hatch onwards were always significantly larger (P < 0·05) than those from freshwater-adapted larvae. SEM revealed structural differences in chloride cell apical morphology according to environmental conditions. There appears to be clearly defined temporal staging of the appearance of adaptive mechanisms that confer an ability to cope with varying environmental conditions during early development.

  19. Effects of chronic exposure of methomyl on the antioxidant system in liver of Nile tilapia (Oreochromis niloticus).

    PubMed

    Meng, Shun Long; Chen, Jia Zhang; Hu, Geng Dong; Song, Chao; Fan, Li Min; Qiu, Li Ping; Xu, Pao

    2014-03-01

    The chronic effect of methomyl on the antioxidant system in tilapia (Oreochromis niloticus) was investigated. Fish were exposed to sub-lethal concentrations of 0.2, 2, 20 and 200μgL(-1) for 30 days, and then transferred to methomyl-free water for 18 days. Hepatic antioxidant parameters, including Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Glutathione reductase (GR), Reduced glutathione (GSH) and oxidized glutathione (GSSG), were measured at 10min (day 0), 6, 12, 18, 24 and 30 days after starting the experiment and at 18 days after transferring to methomyl-free water. There were no significant changes in enzymatic activity and content of antioxidants in liver of tilapia exposed to 0.2μgL(-1) methomyl compared to controls. However, the results showed significant increases in activities of GST, GR, GPx and levels of GSSG accompanied by a decrease in GSH levels following methomyl exposure in tilapia to 2, 20 or 200μgL(-1) over the 30-day exposure period and the highest induction rates in GST, GR, GPx and GSSG were 150.87%, 163.21%, 189.76%, and 179.56% of the control respectively, and the highest inhibition rate in GSH was 50.67% of the control, suggesting the presence of oxidative stress. Thus it would appear that the 0.2μgL(-1) methomyl might be considered as the no observed adverse effect level (NOAEL). Recovery data showed that the effects produced by lower concentration of methomyl 20μgL(-1) were reversible but not at the higher 200μgL(-1) concentration.

  20. Acute aerocystitis in Nile tilapia bred in net cages and supplemented with chromium carbochelate and Saccharomyces cerevisiae.

    PubMed

    Castro, Marcello P; Claudiano, Gustavo S; Petrillo, Thalita R; Shimada, Marina Tie; Belo, Marco A A; Marzocchi-Machado, Cleni M; Moraes, Julieta R E; Manrique, G Wilson; Moraes, Flávio R

    2014-01-01

    Oreochromis niloticus bred in net cages were supplemented with cell wall of Saccharomyces cerevisiae (Sc) (0.3%) or chromium carbochelate (Cr) (18 mg/kg of feed) or in association (Sc + Cr), for 90 days. After this period, acute inflammation was induced in the swim bladder by inoculation of 3 × 10(8) CFU of inactivated Streptococcus agalactiae, and another group received 0.65% saline solution (control). Twelve, 24, and 48 h after stimulation, the inflammation was evaluated through total and differential counting of accumulated cells, and through leukocyte respiratory burst in the blood, cortisolemia, glycemia and serum lysozyme concentration. The results showed that there were greater total numbers of cells in the exudate of fish inoculated with inactivated bacterium than in those injected with saline solution, with predominance of lymphocytes, thrombocytes, macrophages and granulocytes. Tilapia supplemented with Cr presented increased total numbers of cells with significant accumulation of lymphocytes and reductions in cortisolemia and glycemia, but the different treatments did not have any influence on leukocyte respiratory burst or serum lysozyme concentration. Tilapia supplemented with Sc and the Cr + Sc association did not present significant changes to the variables evaluated, despite higher accumulation of lymphocytes in the inflammatory exudate from fish treated with Sc. The results indicate that tilapia bred in net cages and supplemented with Cr presented higher total accumulation of cells at the inflammatory focus, thus indicating an increase in the inflammatory response induced by the bacterium, probably due to the reduction in cortisolemia and higher glucose consumption. Thus, supplementation with Cr had beneficial action, which facilitated development of acute inflammation induced by the bacterium, but did not affect neither leukocyte respiratory burst in the blood nor serum lysozyme concentration.

  1. Additive genetic variation in resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae and S. agalactiae capsular type Ib: is genetic resistance correlated?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus (S.) iniae and S. agalactiae are both economically important Gram positive bacterial pathogens affecting the globally farmed tilapia (Oreochromis spp.). Historically control of these bacteria in tilapia culture has included biosecurity, therapeutants and vaccination strategies. Genet...

  2. Molecular and cytogenetic analysis of the telomeric (TTAGGG)n repetitive sequences in the Nile tilapia, Oreochromis niloticus (Teleostei: Cichlidae).

    PubMed

    Chew, Joyce S K; Oliveira, Claudio; Wright, Jonathan M; Dobson, Melanie J

    2002-03-01

    The majority of chromosomes in Oreochromis niloticus, as with most fish karyotyped to date, cannot be individually identified owing to their small size. As a first step in establishing a physical map for this important aquaculture species of tilapia we have analyzed the location of the vertebrate telomeric repeat sequence, (TTAGGG)n, in O. niloticus. Southern blot hybridization analysis and a Bal31 sensitivity assay confirm that the vertebrate telomeric repeat is indeed present at O. niloticus chromosomal ends with repeat tracts extending for 4-10 kb on chromosomal ends in erythrocytes. Fluorescent in situ hybridization revealed that (TTAGGG)n is found not only at telomeres, but also at two interstitial loci on chromosome 1. These data support the hypothesis that chromosome 1, which is significantly larger than all the other chromosomes in the karyotype, was produced by the fusion of three chromosomes and explain the overall reduction of chromosomal number from the ancestral teleost karyotype of 2n=48 to 2n=44 observed in tilapia.

  3. Cultivation of Monoraphidium sp., Chlorella sp. and Scenedesmus sp. algae in Batch culture using Nile tilapia effluent.

    PubMed

    Guerrero-Cabrera, Luis; Rueda, José A; García-Lozano, Hiram; Navarro, A Karin

    2014-06-01

    Monoraphidium sp., Chlorella sp. and Scenedesmus sp. algae were cultured in three volumes of Tilapia Effluent Medium (TEM) in comparison with the Bold Basal Medium (BBM) (Nichols and Bold, 1965). Specific growth rate (μ'), biomass dry productivity (Q), volumetric productivity (Qv) as well as lipid and protein content were measured. Then, volumetric productivities for both lipids and proteins were calculated (QVL and QVP). In Scenedesmus sp., BBM produced higher μ' and Qv than TEM in 1.5L volume. Chlorella sp. showed a higher QVL for BBM than TEM. Any observed difference in protein or lipid productivities among volumes was in favor of a greater productivity for 1.5L volume. Even when TEM had a larger protein content in Chlorella sp. than BBM, QVP was not different. Current results imply that TEM can be used as an alternative growth medium for algae when using Batch cultures, yet productivity is reduced.

  4. Major surfome and secretome profile of Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus): Insight into vaccine development.

    PubMed

    Li, Wei; Wang, Hai-Qing; He, Run-Zhen; Li, Yan-Wei; Su, You-Lu; Li, An-Xing

    2016-08-01

    Streptococcus agalactiae is a major piscine pathogen that is responsible for huge economic losses to the aquaculture industry. Safe recombinant vaccines, based on a small number of antigenic proteins, are emerging as the most attractive, cost-effective solution against S. agalactiae. The proteins of S. agalactiae exposed to the environment, including surface proteins and secretory proteins, are important targets for the immune system and they are likely to be good vaccine candidates. To obtain a precise profile of its surface proteins, S. agalactiae strain THN0901, which was isolated from tilapia (Oreochromis niloticus), was treated with proteinase K to cleave surface-exposed proteins, which were identified by liquid chromatography-tandem spectrometry (LC-MS/MS). Forty surface-associated proteins were identified, including ten proteins containing cell wall-anchoring motifs, eight lipoproteins, eleven membrane proteins, seven secretory proteins, three cytoplasmic proteins, and one unknown protein. In addition, culture supernatant proteins of S. agalactiae were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and all of the Coomassie-stained bands were subsequently identified by LC-MS/MS. A total of twenty-six extracellular proteins were identified, including eleven secretory proteins, seven cell wall proteins, three membrane proteins, two cytoplasmic proteins and three unknown proteins. Of these, six highly expressed surface-associated and secretory proteins are putative to be vaccine candidate of piscine S. agalactiae. Moreover, immunogenic secreted protein, a highly expressed protein screened from the secretome in the present study, was demonstrated to induce high antibody titer in tilapia, and it conferred protection against S. agalactiae, as evidenced by the relative percent survival (RPS) 48.61± 8.45%. The data reported here narrow the scope of screening protective antigens, and provide guidance in the development of a novel

  5. Effects of sub-lethal and chronic lead concentrations on blood and liver ALA-D activity and hematological parameters in Nile tilapia.

    PubMed

    Dos Santos, Carlucio Rocha; Cavalcante, Ana Luiza Michel; Hauser-Davis, Rachel Ann; Lopes, Renato Matos; Mattos, Rita De Cássia Oliveira Da Costa

    2016-07-01

    Liver and blood δ-aminolevulinic acid dehydratase (ALA-D) inhibition by exposure to sub-lethal lead concentrations over time in Nile tilapia (Oreochromis niloticus) were investigated. All three lead concentrations (1mgkg(-1), 10mgkg(-1) and 100mgkg(-1)) significantly inhibited ALA-D activity in blood (319±29.2; 180±14.6 and 172±19µmols(-1)h(-1)L(-1) respectively) and liver (302±5.84; 201±41.4 and 93±22.1µmols(-1)h(-1)L(-1)) 24h after injection relative to controls (blood: 597±37.0µmols(-1)h(-1)L(-1); liver: 376±23.1µmols(-1)h(-1)L(-1)). Blood ALA-D was greatly inhibited in all but the highest lead dose. Fish were then exposed to 1mgkg(-1) lead for 9 days, and presented short-term hyperglycemia, decreased hemoglobin and hematocrit values and time-dependent blood ALA-D activity inhibition, corroborating blood ALA-D activity as being more suitable for investigating lead effects, showing dose and time-dependent ALA-D inhibition after lead exposure. The results of the present study also demonstrated that fish size affects blood ALA-D activity, as fish from the 24-h assay, which were slightly smaller (approximately 200g), showed higher ALA-D inhibition in response to lead exposure when compared to the fish from the 9-day assay (approximately 500g). Thus, fish size should always be taken into account both in the field and in laboratory settings, and efforts should be made to obtain uniform fish size samples for biomarker studies.

  6. Correlated changes in body shape after five generations of selection to improve growth rate in a breeding program for Nile tilapia Oreochromis niloticus in Brazil.

    PubMed

    de Oliveira, Carlos Antonio Lopes; Ribeiro, Ricardo Pereira; Yoshida, Grazyella Massako; Kunita, Natali Miwa; Rizzato, Gabriel Soriani; de Oliveira, Sheila Nogueira; Dos Santos, Alexandra Inês; Nguyen, Nguyen Hong

    2016-11-01

    Body shape is a commercial trait of great interest as it impacts profit and productivity of aquaculture enterprises. In the present study, we examined correlated changes in two measures of body shape (depth to length ratio, DL-R and ellipticity of mid sagittal plane, EL-H) from a selection program for high daily weight gain in a Nile tilapia population reared in freshwater cages in Brazil. Genetic parameters for body shape and its genetic association with growth traits (body weight and daily gain) were also estimated from 8,725 individuals with growth performance recorded over five generations from 2008 to 2013. Mixed model analysis showed that the selection program resulted in substantial improvement in growth performance (about 4 % genetic gain per generation or per year) and also brought about trivial changes in body shape. The heritabilities ranged from 0.470 to 0.564 for growth traits and 0.180 to 0.289 for body shape. The common family effects were low for all traits studied, accounting for only 3-11 % of total phenotypic variance. The genetic correlations between body shape and growth traits were weak, i.e., -0.385 between EL-H and growth traits and 0.28 between DL-R and body weight or daily gain. Strong and negative genetic association was found between the two body shape traits (rg = --0.955). Harvest body weight and daily gain are essentially the same traits, as indicated by the close to one genetic correlations between the two characters. Our results demonstrated that the selection process to increase growth rate had small, but slowly constant effect in body shape traits; and in the long term, the fish would have become rotund.

  7. MicroRNA-499 Expression Distinctively Correlates to Target Genes sox6 and rod1 Profiles to Resolve the Skeletal Muscle Phenotype in Nile Tilapia

    PubMed Central

    Carvalho, Robson F.; Martins, Cesar; Pinhal, Danillo

    2015-01-01

    A class of small non-coding RNAs, the microRNAs (miRNAs), has been shown to be essential for the regulation of specific cell pathways, including skeletal muscle development, maintenance and homeostasis in vertebrates. However, the relative contribution of miRNAs for determining the red and white muscle cell phenotypes is far from being fully comprehended. To better characterize the role of miRNA in skeletal muscle cell biology, we investigated muscle-specific miRNA (myomiR) signatures in Nile tilapia fish. Quantitative (RT-qPCR) and spatial (FISH) expression analyses revealed a highly differential expression (forty-four-fold) of miR-499 in red skeletal muscle compared to white skeletal muscle, whereas the remaining known myomiRs were equally expressed in both muscle cell types. Detailed examination of the miR-499 targets through bioinformatics led us to the sox6 and rod1 genes, which had low expression in red muscle cells according to RT-qPCR, FISH, and protein immunofluorescence profiling experiments. Interestingly, we verified that the high expression of miR-499 perfectly correlates with a low expression of sox6 and rod1 target genes, as verified by a distinctive predominance of mRNA destabilization and protein translational decay to these genes, respectively. Through a genome-wide comparative analysis of SOX6 and ROD1 protein domains and through an in silico gene regulatory network, we also demonstrate that both proteins are essentially similar in vertebrate genomes, suggesting their gene regulatory network may also be widely conserved. Overall, our data shed light on the potential regulation of targets by miR-499 associated with the slow-twitch muscle fiber type phenotype. Additionally the results provide novel insights into the evolutionary dynamics of miRNA and target genes enrolled in a putative constrained molecular pathway in the skeletal muscle cells of vertebrates. PMID:25793727

  8. Adult-onset opsoclonus-myoclonus syndrome due to West Nile Virus treated with intravenous immunoglobulin.

    PubMed

    Hébert, Julien; Armstrong, David; Daneman, Nick; Jain, Jennifer Deborah; Perry, James

    2017-02-01

    A 63-year-old female with no significant past medical history was presented with a 5-day history of progressive opsoclonus-myoclonus, headaches, and fevers. Her workup was significant only for positive West-Nile Virus serum serologies. She received a 2-day course of intravenous immunoglobulin (IvIG). At an 8-week follow up, she had a complete neurological remission. Adult-onset opsoclonus-myoclonus syndrome is a rare condition for which paraneoplastic and infectious causes have been attributed. To our knowledge, this is the first case reported of opsoclonus-myoclonus secondary to West-Nile Virus treated with intravenous immunoglobulin monotherapy.

  9. Chronic diclofenac exposure affects gill integrity and pituitary gene expression and displays estrogenic activity in nile tilapia (Oreochromis niloticus).

    PubMed

    Gröner, Frederike; Höhne, Christin; Kleiner, Wibke; Kloas, Werner

    2017-01-01

    Oreochromis niloticus has been exposed to diclofenac (DCF), a nonsteroidal anti-inflammatory drug prevalent in the aquatic environment, for 80 days post-hatch (dph). Concentrations ranged from environmentally relevant (0.1 μg L(-1) and 1 μg L(-1) DCF) up to 100-fold thereof. Population relevant endpoints (hatching, survival, growth) as well as gill histopathology were analyzed. On this level of examination only gills exhibited mild to moderate alterations. On the contrary, biomarkers associated with reproduction were affected due to DCF exposure, indicating the potential to affect sexual differentiation and gametogenesis by acting as an estrogenic endocrine disrupting compound (EDC) in tilapia. Vitellogenin (VTG) gene expression was significantly induced at 1 μg L(-1) DCF. In order to find an explanation, gene expression patterns of key enzymes of the biotransformation phases I, II, and III have been analyzed. It seems very likely that the detoxification metabolism is induced in a dose dependent manner at higher concentrations of DCF leading to the expression pattern of VTG mRNA. Our results suggest that DCF at environmentally relevant concentrations adversely affects O. niloticus gill histopathology and pituitary gene expression, and has the potential to act as an estrogenic EDC. The sensitivity of various endpoints, however, differs and therefore these endpoints should be linked.

  10. A revised description of Gyrodactylus cichlidarum Paperna, 1968 (Gyrodactylidae) from the Nile tilapia, Oreochromis niloticus niloticus (Cichlidae), and its synonymy with G. niloticus Cone, Arthur et Bondad-Reantaso, 1995.

    PubMed

    García-Vásquez, Adriana; Hansen, Haakon; Shinn, Andrew P

    2007-06-01

    A recent infestation of Gyrodactylus cichlidarum Paperna, 1968 on yolk sac fry of Nile tilapia, Oreochromis niloticus niloticus (L.), in an isolated aquarium system in the U.K. resulted in high mortalities and provided an opportunity to study this species in greater detail. A tentative identification was made using the measurements and drawings of the ventral bar and hamuli provided in the original description; however, details on the morphology of the marginal hooks were lacking. A comparison of the gyrodactylid material collected from O. n. niloticus with the holotype of G. cichlidarum, the only known available specimen, from Mango tilapia, Sarotherodon galilaeus galilaeus (L.), confirmed its identity. Proteolytic digestion and image analysis of the opisthaptoral hard parts were used to obtain tissue-free, accurate measurements as part of a complete revised description of G. cichlidarumn. Further, a comparison of G. cichlidarum from both hosts with the holotype and several paratypes of Gyrodactylus niloticus Cone, Arthur et Bondad-Reantaso, 1995 cited as parasitizing captive stocks of Nile tilapia in the Philippines revealed the two species to be synonymous. An 803 bp fragment of the ribosomal internal transcribed spacers 1 and 2 and the 5.8S was obtained and is provided with the revised description. This is the first DNA sequence from a Gyrodactylus species originating from the African continent. The sequence is very divergent from other species in the genus and only the 5.8S sequence places it unambiguously in the genus Gyrodactylus. In addition to G. cichlidarum, two specimens of another morphological similar species of Gyrodactylus were also found on the UK held stock of O. n. niloticus. These latter specimens, Gyrodacrylus sp., differed from G. cichlidarum in having a longer hamulus point with a smaller hamulus aperture and possessing marginal hook sickles that had a shorter shaft with a longer point giving the sickles a more rounded, closed appearance.

  11. Evaluation of the dairy/yeast prebiotic, GroBiotic-A, in the diet of the juvenile Nile tilapia, Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tilapia production ranks among the highest worldwide due to their fast growth and ability to thrive under various culture conditions. However, tilapias are still susceptible to outbreaks of systemic disease caused by opportunistic bacterial pathogens such as Streptococcus inaie. These epizootic ev...

  12. Tilapia: profile and economic importance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nile tilapia’s various attributes and an increasing global demand for this fish make it one of the most cultured species, with a global production estimated at nearly 2.5 million tonnes in 2010, and an estimated value of approximately $5 billion. Increased demand in the U.S. market for tilapia produ...

  13. First records of Ambiphrya and Vorticella spp. (Protozoa, Ciliophora) in cultured Nile tilapia (Oreochromis niloticus) in the central region of Saudi Arabia

    PubMed Central

    Abdel-Baki, Abdel-Azeem S.; Gewik, Mohamed M.; Al-Quraishy, Saleh

    2014-01-01

    The present study was carried out as part of an ongoing general survey seeking to uncover protozoan parasites infecting cultured tilapia in the central region of Saudi Arabia. In the sample of 400 specimens of tilapia (Oreochromis niloticus) 30 were infested with Ambiphrya ameiuri simultaneously with Vorticella sp. Morphometric criteria were used to describe and identify these species and this study presents the first records of these species among cultured fish in Saudi Arabia. PMID:25473359

  14. First records of Ambiphrya and Vorticella spp. (Protozoa, Ciliophora) in cultured Nile tilapia (Oreochromis niloticus) in the central region of Saudi Arabia.

    PubMed

    Abdel-Baki, Abdel-Azeem S; Gewik, Mohamed M; Al-Quraishy, Saleh

    2014-12-01

    The present study was carried out as part of an ongoing general survey seeking to uncover protozoan parasites infecting cultured tilapia in the central region of Saudi Arabia. In the sample of 400 specimens of tilapia (Oreochromis niloticus) 30 were infested with Ambiphrya ameiuri simultaneously with Vorticella sp. Morphometric criteria were used to describe and identify these species and this study presents the first records of these species among cultured fish in Saudi Arabia.

  15. Comprehensive identification and profiling of Nile tilapia (Oreochromis niloticus) microRNAs response to Streptococcus agalactiae infection through high-throughput sequencing.

    PubMed

    Wang, Bei; Gan, Zhen; Cai, Shuanghu; Wang, Zhongliang; Yu, Dapeng; Lin, Ziwei; Lu, Yishan; Wu, Zaohe; Jian, Jichang

    2016-07-01

    MicroRNAs are a kind of small non-coding RNAs that participate in various biological processes. Deregulated microRNA expression is associated with several types of diseases. Tilapia (Oreochromis niloticus) is an important commercial fish species in China. To identify miRNAs and investigate immune-related miRNAs of O. niloticus, we applied high-throughput sequencing technology to identify and analyze miRNAs from tilapia infected with Streptococcus agalactiae at a timescale of 72 h divided into six different time points. The results showed that a total of 3009 tilapia miRNAs were identified, including in 1121 miRNAs which have homologues in the currently available databases and 1878 novel miRNAs. The expression levels of 218 tilapia miRNAs were significantly altered at 6 h-72 h post-bacterial infection (pi), and these miRNAs were therefore classified as differentially expressed tilapia miRNAs. For the 1121 differentially expressed tilapia miRNAs target 41961 genes. GO and KEGG enrichment analysis revealed that some target genes of tilapia miRNAs were grouped mainly into the categories of apoptotic process, signal pathway, and immune response. This is the first report of comprehensive identification of O. niloticus miRNAs being differentially regulated in spleen in normal conditions relating to S. agalactiae infection. This work provides an opportunity for further understanding of the molecular mechanisms of miRNA regulation in O. niloticus host-pathogen interactions.

  16. Myo-inositol phosphate synthase expression in the European eel (Anguilla anguilla) and Nile tilapia (Oreochromis niloticus): effect of seawater acclimation.

    PubMed

    Kalujnaia, Svetlana; Hazon, Neil; Cramb, Gordon

    2016-08-01

    A single MIPS gene (Isyna1/Ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (MIPS) transcript identified in all eel tissues, although two MIPS spliced variants [termed MIPS(s) and MIPS(l)] are found in all tilapia tissues. The larger tilapia transcript [MIPS(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. In most tilapia tissues, the MIPS(s) transcript exhibits much higher abundance (generally >10-fold) with the exception of white skeletal muscle and oocytes, in which the MIPS(l) transcript predominates. SW acclimation resulted in large (6- to 32-fold) increases in mRNA expression for both MIPS(s) and MIPS(l) in all tilapia tissues tested, whereas in the eel, changes in expression were limited to a more modest 2.5-fold increase and only in the kidney. Western blots identified a number of species- and tissue-specific immunoreactive MIPS proteins ranging from 40 to 67 kDa molecular weight. SW acclimation failed to affect the abundance of any immunoreactive protein in any tissue tested from the eel. However, a major 67-kDa immunoreactive protein (presumed to be MIPS) found in tilapia tissues exhibited 11- and 54-fold increases in expression in gill and fin samples from SW-acclimated fish. Immunohistochemical investigations revealed specific immunoreactivity in the gill, fin, skin, and intestine taken from only SW-acclimated tilapia. Immunofluorescence indicated that MIPS was expressed within gill chondrocytes and epithelial cells of the primary filaments, basal epithelial cell layers of the skin and fin, the cytosol of columnar intestinal epithelial and mucous cells, as well as unknown entero-endocrine-like cells.

  17. Myo-inositol phosphate synthase expression in the European eel (Anguilla anguilla) and Nile tilapia (Oreochromis niloticus): effect of seawater acclimation

    PubMed Central

    Kalujnaia, Svetlana; Hazon, Neil

    2016-01-01

    A single MIPS gene (Isyna1/Ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (MIPS) transcript identified in all eel tissues, although two MIPS spliced variants [termed MIPS(s) and MIPS(l)] are found in all tilapia tissues. The larger tilapia transcript [MIPS(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. In most tilapia tissues, the MIPS(s) transcript exhibits much higher abundance (generally >10-fold) with the exception of white skeletal muscle and oocytes, in which the MIPS(l) transcript predominates. SW acclimation resulted in large (6- to 32-fold) increases in mRNA expression for both MIPS(s) and MIPS(l) in all tilapia tissues tested, whereas in the eel, changes in expression were limited to a more modest 2.5-fold increase and only in the kidney. Western blots identified a number of species- and tissue-specific immunoreactive MIPS proteins ranging from 40 to 67 kDa molecular weight. SW acclimation failed to affect the abundance of any immunoreactive protein in any tissue tested from the eel. However, a major 67-kDa immunoreactive protein (presumed to be MIPS) found in tilapia tissues exhibited 11- and 54-fold increases in expression in gill and fin samples from SW-acclimated fish. Immunohistochemical investigations revealed specific immunoreactivity in the gill, fin, skin, and intestine taken from only SW-acclimated tilapia. Immunofluorescence indicated that MIPS was expressed within gill chondrocytes and epithelial cells of the primary filaments, basal epithelial cell layers of the skin and fin, the cytosol of columnar intestinal epithelial and mucous cells, as well as unknown entero-endocrine-like cells. PMID:27252471

  18. An outbreak of disease caused by Francisella sp. in Nile tilapia Oreochromis niloticus at a recirculation fish farm in the UK.

    PubMed

    Jeffery, Keith R; Stone, David; Feist, Stephen W; Verner-Jeffreys, David W

    2010-09-02

    This study details the first diagnosis of Francisella sp. in tilapia in the United Kingdom. Losses of tilapia fry at a recirculation fish farm in England were investigated, giving a presumptive positive diagnosis of infection with Francisella sp. by histopathological examination. Most fish sampled showed moderate to marked pathology of the major organs, with lesions being present in most tissues. The most obvious host response was granuloma formulation. A subsequent follow-up visit provided further evidence for the presence of a Francisella species. PCR amplicons were obtained using Francisella spp.-specific primers that shared 100% sequence identity with the 16S rRNA gene of the type strain of the species F. asiatica previously described as the cause of disease in tilapia in Southeast Asia and Central America. This outbreak and the subsequent investigation emphasise the importance of strict biosecurity at fish farms and the care that needs to be taken when using a new supplier of fish.

  19. Responses and recovery pattern of sex steroid hormones in testis of Nile tilapia (Oreochromis niloticus) exposed to sublethal concentration of methomyl.

    PubMed

    Meng, Shun Long; Qiu, Li Ping; Hu, Geng Dong; Fan, Li Min; Song, Chao; Zheng, Yao; Wu, Wei; Qu, Jian Hong; Li, Dan Dan; Chen, Jia Zhang; Xu, Pao

    2016-12-01

    Tilapia were exposed to sublethal methomyl concentrations of 0, 0.2, 2, 20 or 200 μg/L for 30 days, and then transferred to methomyl-free water for 18 days. The sexual steroid hormones 17β-estradiol (E2), testosterone (T), and 11-ketotestosterone (11-KT) in tilapia testes were examined at 0, 6, 12, 18, 24 and 30 days after methomyl exposure, and at 18 days after fish were transferred to methomyl-free water. There were no significant changes in the hormone parameters in testes of tilapia exposed to low concentration 0.2 and 2 μg/L methomyl compared with the controls. However, high concentration 20 and 200 μg/L methomyl had the potential to disrupt the endocrine system of male tilapia, as shown by an increase in E2 and a decrease in T and 11-KT in the testes. Thus, it would appear that the 2 μg/L methomyl might be considered the no-observed-adverse-effect level. Recovery data showed that the effects produced by the lower concentration of 20 μg/L were reversible but the effects were not reversible at the higher concentration of 200 μg/L.

  20. Successful production of Nile and blue tilapia fry - findings based on degree days and demonstrated for earthen ponds in subtropical climates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Degree-days can be used to adjust for seasonal variation in water temperature when planning tilapia fingerling production strategies and are calculated by subtracting a threshold temperature ("biological zero") from the mean daily water temperature; the threshold temperature is the temperature below...

  1. A Comparison of the Beneficial Effects of Live and Heat-Inactivated Baker’s Yeast on Nile Tilapia: Suggestions on the Role and Function of the Secretory Metabolites Released from the Yeast

    PubMed Central

    Liu, Zhi; Xu, Li; Yang, Yalin; Tacon, Philippe; Auclair, Eric; Zhou, Zhigang

    2015-01-01

    Yeast is frequently used as a probiotic in aquaculture with the potential to substitute for antibiotics. In this study, the involvement and extent to which the viability of yeast cells and thus the secretory metabolites released from the yeast contribute to effects of baker’s yeast was investigated in Nile tilapia. No yeast, live yeast or heat-inactivated baker’s yeast were added to basal diets high in fishmeal and low in soybean (diet A) or low in fishmeal and high in soybean (diet B), which were fed to fish for 8 weeks. Growth, feed utilization, gut microvilli morphology, and expressions of hsp70 and inflammation-related cytokines in the intestine and head kidney were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Gut alkaline phosphatase (AKP) activity was measured after challenging the fish with Aeromonas hydrophila. Results showed that live yeast significantly improved FBW and WG (P < 0.05), and tended to improve FCR (P = 0.06) of fish compared to the control (no yeast). No significant differences were observed between inactivated yeast and control. Live yeast improved gut microvilli length (P < 0.001) and density (P < 0.05) while inactivated yeast did not. The hsp70 expression level in both the intestine and head kidney of fish was significantly reduced by live yeast (P < 0.05) but not inactivated yeast. Live yeast but not inactivated yeast reduced intestinal expression of tnfα (P < 0.05), tgfβ (P < 0.05 under diet A) and il1β (P = 0.08). Intestinal Lactococcus spp. numbers were enriched by both live and inactivated yeast. Lastly, both live and inactivated yeast reduced the gut AKP activity compared to the control (P < 0.001), indicating protection of the host against infection by A. hydrophila. In conclusion, secretory metabolites did not play major roles in the growth promotion and disease protection effects of yeast. Nevertheless, secretory metabolites were the major contributing factor towards improved gut

  2. A Comparison of the Beneficial Effects of Live and Heat-Inactivated Baker's Yeast on Nile Tilapia: Suggestions on the Role and Function of the Secretory Metabolites Released from the Yeast.

    PubMed

    Ran, Chao; Huang, Lu; Liu, Zhi; Xu, Li; Yang, Yalin; Tacon, Philippe; Auclair, Eric; Zhou, Zhigang

    2015-01-01

    Yeast is frequently used as a probiotic in aquaculture with the potential to substitute for antibiotics. In this study, the involvement and extent to which the viability of yeast cells and thus the secretory metabolites released from the yeast contribute to effects of baker's yeast was investigated in Nile tilapia. No yeast, live yeast or heat-inactivated baker's yeast were added to basal diets high in fishmeal and low in soybean (diet A) or low in fishmeal and high in soybean (diet B), which were fed to fish for 8 weeks. Growth, feed utilization, gut microvilli morphology, and expressions of hsp70 and inflammation-related cytokines in the intestine and head kidney were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Gut alkaline phosphatase (AKP) activity was measured after challenging the fish with Aeromonas hydrophila. Results showed that live yeast significantly improved FBW and WG (P < 0.05), and tended to improve FCR (P = 0.06) of fish compared to the control (no yeast). No significant differences were observed between inactivated yeast and control. Live yeast improved gut microvilli length (P < 0.001) and density (P < 0.05) while inactivated yeast did not. The hsp70 expression level in both the intestine and head kidney of fish was significantly reduced by live yeast (P < 0.05) but not inactivated yeast. Live yeast but not inactivated yeast reduced intestinal expression of tnfα (P < 0.05), tgfβ (P < 0.05 under diet A) and il1β (P = 0.08). Intestinal Lactococcus spp. numbers were enriched by both live and inactivated yeast. Lastly, both live and inactivated yeast reduced the gut AKP activity compared to the control (P < 0.001), indicating protection of the host against infection by A. hydrophila. In conclusion, secretory metabolites did not play major roles in the growth promotion and disease protection effects of yeast. Nevertheless, secretory metabolites were the major contributing factor towards improved gut

  3. First record of three African trichodinids (Ciliophora: Peritrichida) in cultured Nile tilapia (Oreochromis niloticus) in Saudi Arabia with re-evaluation of their host specificity.

    PubMed

    Abdel-Baki, Abdel-Azeem Sh; Al Ghamdi, Ali; Al-Quraishy, Saleh

    2017-02-18

    Saudi Arabia has a developing aquaculture industry that farms primarily tilapia. Although trichodinids are presumably the most usually encountered protozoan parasites in these cultured fish, they have rarely been studied in this context, and there is no data on the species that might infect cultured tilapia in Saudi Arabia. The present study was therefore carried out as a general survey to investigate the occurrence and identify the species of trichodinids that can infect cultured tilapia (Oreochromis niloticus) in Saudi Arabia. A total of 500 tilapia fish were collected from fish farms in Riyadh city and examined in order to determine the species of trichodinids present in the positive specimens. Three species of trichodinids (Trichodina maritinkae, T. centrostrigeata and T. frenata) were isolated and described as new records in Saudi Arabia. These trichodinids were found simultaneously in the same fish with overall prevalence of 20% (100/500). The identification and characterization of these three species are documented based on Riyadh specimens, for the first time. Additionally, the present paper confirms the existence of T. frenata for the second time globally and establishes this trichodinid as a new parasite for O. niloticus. T. maritinkae is highly specific to clariids, and previously, it has not been reported from any fish species other than clariids. The present work also confirmed that T. centrostrigeata can also infest cichlid fish. The list of host records of these species is expanded and their host specificity re-evaluated based on the results of this study in addition to the previously published data. We conclude that there is a need for further study of the impacts of these Trichodina spp. on Saudi Arabian fishery sector.

  4. Responses of glutathione-related antioxidant defense system in serum of Nile tilapia (Oreochromis niloticus) exposed to sublethal concentration of methomyl and recovery pattern.

    PubMed

    Meng, Shun-Long; Qu, Jian-Hong; Fan, Li-Min; Qiu, Li-Ping; Chen, Jia-Zhang; Xu, Pao

    2015-04-01

    Tilapia were exposed to sublethal concentrations of 0, 0.2, 2, 20, or 200 μg/L for 30 days, and then transferred to methomyl-free water for 18 days. GST, GPx, GR, GSH, and GSSG in tilapia serum were examined at 0, 6, 12, 18, 24, and 30 days after methomyl exposure and at 18 days after transferring to methomyl-free water. There were no significant changes in antioxidants activities and contents in serum of tilapia exposed to 0.2 μg/L. Significant increases in GST, GR, GPx, and GSSG accompanied by a decrease in GSH were observed following methomyl exposure to 2, 20, or 200 μg/L, suggesting the presence of oxidative stress. Thus, it would appear the 0.2 μg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that the effects produced by lower concentration of 20 μg/L were reversible but not at the higher 200 μg/L concentration.

  5. Effects of dietary Bacillus licheniformis on growth performance, immunological parameters, intestinal morphology and resistance of juvenile Nile tilapia (Oreochromis niloticus) to challenge infections.

    PubMed

    Han, Biao; Long, Wei-Qing; He, Ju-Yun; Liu, Yong-Jian; Si, Yu-Qi; Tian, Li-Xia

    2015-10-01

    The effects of oral administration of Bacillus licheniformis on growth performance, immunity, intestinal morphology and disease resistance of juvenile tilapia were investigated. Six experimental diets supplemented with different concentrations of B. licheniformis (0%, 0.02%, 0.04%, 0.06%, 0.08% and 0.1% of AlCare(®), containing live germ 2 × 10(10) CFU/g) were formulated, viz. control, T1, T2, T3, T4 and T5. Each diet was randomly assigned to triplicate groups of 30 fishes (3.83 ± 0.03 g). After 10 weeks of feeding trial, weight gain (WG), final body wet weight (FBW) and specific growth rate (SGR) increased significantly in groups T2, T3, T4 and T5 compared with control and T1 (p < 0.05). However, survival rate and feed conversion ratio (FCR) were not found to be significantly affected (P > 0.05). Compared with control, dietary B. licheniformis supplementation increased the content of complement C3 in serum significantly (P < 0.05). The lysozyme activity was observed to be highest in T2 (P < 0.05) without differences among other groups. However, SOD activity was not affected by B. licheniformis supplementation (P > 0.05). When tilapia were challenged against Streptococcus iniae, survival rate improved significantly when tilapia fed with T2, T3, T4 and T5 (P < 0.05). Although there was no significant differences in villi length and muscular layer thickness of anterior intestinal among the treatments, intestinal villi of fish fed with higher concentrations of B. licheniformis (T2, T3, T4, T5) tended to be regularly arranged and exhibited less exfoliation, twist and fusion. These results indicated that dietary supplementation of B. licheniformis not only increased the growth, immune response and disease resistance of juvenile tilapia, but also influenced anterior intestinal development and integrity. Furthermore, in our study, the optimal concentration of B. licheniformis in diets for tilapia was greater than or equal to 4.4 × 10(6) CFU/g.

  6. Safety and immunogenicity of an oral DNA vaccine encoding Sip of Streptococcus agalactiae from Nile tilapia Oreochromis niloticus delivered by live attenuated Salmonella typhimurium.

    PubMed

    Huang, L Y; Wang, K Y; Xiao, D; Chen, D F; Geng, Y; Wang, J; He, Y; Wang, E L; Huang, J L; Xiao, G Y

    2014-05-01

    Attenuated Salmonella typhimurium SL7207 was used as a carrier for a reconstructed DNA vaccine against Streptococcus agalactiae. A 1.02 kb DNA fragment, encoding for a portion of the surface immunogenic protein (Sip) of S. agalactiae was inserted into pVAX1. The recombinant plasmid pVAX1-sip was transfected in EPC cells to detect the transient expression by an indirect immunofluorescence assay, together with Western blot analysis. The pVAX1-sip was transformed by electroporation into SL7207. The stability of pVAX1-sip into Salmonella was over 90% after 50 generations with antibiotic selection in vitro while remained stable over 80% during 35 generations under antibiotic-free conditions. The LD50 of SL/pVAX1-sip was 1.7 × 10(11) CFU/fish by intragastric administration which indicated a quite low virulence. Tilapias were inoculated orally at 10(8) CFU/fish, the recombinant bacteria were found present in intestinal tract, spleens and livers and eventually eliminated from the tissues 4 weeks after immunization. Fish immunized at 10(7), 10(8) and 10(9) CFU/fish with different immunization times caused various levels of serum antibody and an effective protection against lethal challenge with the wild-type strain S. agalactiae. Integration studies showed that the pVAX1-sip did not integrate with tilapia chromosomes. The DNA vaccine SL/pVAX1-sip was proved to be safe and effective in protecting tilapias against S. agalactiae infection.

  7. Variation in adult longevity of Culex pipiens f. pipiens, vector of the West Nile Virus.

    PubMed

    Andreadis, S S; Dimotsiou, O C; Savopoulou-Soultani, M

    2014-11-01

    The common house mosquito, Culex pipiens (Diptera: Culicidae), which is considered the primary bridge vector of West Nile Virus (WNV) to humans, is a wide spread insect pest with medical importance and consists of two distinct bioforms, Cx. pipiens f. pipiens and Cx. pipiens f. molestus. Here, we consider the adult lifespan of male and female Cx. pipiens f. pipiens under controlled conditions at five constant temperature regimes (15, 20, 25, 27.5, and 30 °C). Our results show that adult longevity was affected by temperature, as it significantly decreased with increase in temperature. At the highest tested temperature, mean adult longevity did not exceed 12 days for both sexes and thus makes impossible the risk of WNV transmission. On the other hand at the lowest temperature, longevity was extremely high with some individuals surviving up to 129 and 132 days, males and females, respectively, and thus enable them to function as potential vectors of WNV for a prolonged period of time. As far as sex is concerned, adult females displayed a 1.2-1.4-fold longer longevity compared to the male ones. However, this difference was significant only at the lowest and highest tested temperature regime. This information is useful in determining the critical temperatures which may affect the distribution of Cx. pipiens and consequently the risk of WNV transmission. Moreover, the effect of environmental temperature should be considered when evaluating the abundance of these species.

  8. Overwintering of Uranotaenia Unguiculata Adult Females in Central Europe: A Possible Way of Persistence of the Putative New Lineage of West Nile Virus?

    PubMed

    Rudolf, Ivo; Šebesta, Oldřich; Straková, Petra; Betášová, Lenka; Blažejová, Hana; VEnclíková, Kristýna; Seidel, Bernhard; Tóth, Sandor; Hubálek, Zdeněk; Schaffner, Francis

    2015-12-01

    We report the overwintering of Uranotaenia unguiculata adult females in Central Europe (Czech Republic, Hungary, Austria). This finding suggests a potential mode of winter persistence of putative novel lineage of West Nile virus in the temperate regions of Europe.

  9. SNP marker detection and genotyping in tilapia.

    PubMed

    Van Bers, N E M; Crooijmans, R P M A; Groenen, M A M; Dibbits, B W; Komen, J

    2012-09-01

    We have generated a unique resource consisting of nearly 175 000 short contig sequences and 3569 SNP markers from the widely cultured GIFT (Genetically Improved Farmed Tilapia) strain of Nile tilapia (Oreochromis niloticus). In total, 384 SNPs were selected to monitor the wider applicability of the SNPs by genotyping tilapia individuals from different strains and different geographical locations. In all strains and species tested (O. niloticus, O. aureus and O. mossambicus), the genotyping assay was working for a similar number of SNPs (288-305 SNPs). The actual number of polymorphic SNPs was, as expected, highest for individuals from the GIFT population (255 SNPs). In the individuals from an Egyptian strain and in individuals caught in the wild in the basin of the river Volta, 197 and 163 SNPs were polymorphic, respectively. A pairwise calculation of Nei's genetic distance allowed the discrimination of the individual strains and species based on the genotypes determined with the SNP set. We expect that this set will be widely applicable for use in tilapia aquaculture, e.g. for pedigree reconstruction. In addition, this set is currently used for assaying the genetic diversity of native Nile tilapia in areas where tilapia is, or will be, introduced in aquaculture projects. This allows the tracing of escapees from aquaculture and the monitoring of effects of introgression and hybridization.

  10. Coordinated microRNA and messenger RNA expression profiles for understanding sexual dimorphism of gonads and the potential roles of microRNA in the steroidogenesis pathway in Nile tilapia (Oreochromis niloticus).

    PubMed

    Wang, Weiwei; Liu, Wenzhong; Liu, Qing; Li, Baojun; An, Lixia; Hao, Ruirong; Zhao, Jinliang; Liu, Shaozhen; Song, Jing

    2016-03-15

    Sexual dimorphism is a widespread phenomenon in animals. However, the potential role of microRNAs (miRNAs) in regulating this dimorphism is not fully understood. In our study, we used an integrated approach to identify functional targets of miRNA by combining the paired expression profiles of miRNAs and messenger RNAs (mRNAs) in ovaries and testes of young Nile tilapia, Oreochromis niloticus. The results revealed that 67 upregulated and nine downregulated miRNAs and 2299 upregulated and 3260 downregulated genes were identified in the ovary compared with those in the testis (P < 0.01). The target genes of differentially expressed miRNAs were predicted and overlapped with the differentially expressed mRNAs. Furthermore, Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted in these coincident genes. By correlating miRNA-mRNA and predicting computational target, two types of negatively regulatory miRNA-mRNA correlations (upregulated or downregulated miRNA and downregulated or upregulated mRNA) were obtained. Seven functional miRNA-target gene pairs, miR-17-5p/DMRT1, miR-20a/DMRT1, miR-138/CYP17A2, miR-338/CYP17A2, miR-200a/CYP17A2, miR-456/AMH, and miR-138/AMH, were predicted at the sequence level and further detected by real-time polymerase chain reaction on the basis of the significantly negative relationships. Our results suggest that the integrated analysis of miRNA and mRNA expression profiling can provide novel insights into the molecular mechanism of sexual dimorphism.

  11. Molecular characterization and expression of a granzyme of an ectothermic vertebrate with chymase-like activity expressed in the cytotoxic cells of Nile tilapia (Oreochromis niloticus).

    PubMed

    Praveen, Kesavannair; Leary, John H; Evans, Donald L; Jaso-Friedmann, Liliana

    2006-02-01

    We have identified the gene coding for a novel serine protease with close similarities to mammalian granzymes from nonspecific cytotoxic cells of a teleost fish Oreochromis niloticus. The genomic organization of tilapia granzyme-1 (TLGR-1) has the signature five-exon-four-intron structure shared by all granzymes and similar hematopoietic Ser proteases. Molecular modeling studies suggested a granzyme-like structure for this protein with four disulfide linkages and two additional Cys residues. The expression of this gene is found to be restricted to cytotoxic cell populations with a low level of constitutive expression when compared to similar granzymes in other teleost species. High levels of transcriptional activation of TLGR-1 with different stimuli suggested that this gene is highly induced during immune reactions. Triplet residues around the active site Ser of TLGR, which determines the primary substrate specificity of granzymes, differ significantly from that of other granzymes. Recombinant TLGR-1 was expressed in the mature and proenzyme forms using pPICZ-alpha vector in the Pichia pastoris expression system. Recombinant TLGR-1 was used to determine the primary substrate specificity of this protease using various synthetic thiobenzyl ester substrates. In vitro enzyme kinetics assays suggested a preference for residues with bulky side chains at the P1 site, indicating a chymase-like activity for this protease. These results indicate the presence of novel granzymes in cytotoxic cells from ectothermic vertebrates.

  12. Pubertal effects of 17α-methyltestosterone on GH-IGF-related genes of the hypothalamic-pituitary-liver-gonadal axis and other biological parameters in male, female and sex-reversed Nile tilapia.

    PubMed

    Phumyu, Nonglak; Boonanuntanasarn, Surintorn; Jangprai, Araya; Yoshizaki, Goro; Na-Nakorn, Uthairat

    2012-06-01

    The influence of 17α-methyltestosterone (MT) on growth responses, biological parameters and the expression of genes involved in the GH-IGF pathway of the hypothalamic-pituitary-liver-gonadal axis were investigated in female, male, and sex-reversed Nile tilapia to evaluate the relationship between sex and MT-induced changes in these parameters. Female fish had a lower growth rate than male and sex-reversed fish, and MT increased growth performance and duodenal villi in females. Most but not all biological parameters of sex-reversed fish were similar to those of male fish. Male fish had higher red blood cell counts and hemoglobin levels than female and sex-reversed fish, suggesting that these hematological indices reflect a higher metabolic rate in male fish. Greater blood triglyceride levels indicated the vitellogenin process in female fish. MT increased the alternative complement activity in female fish (P<0.05). Sex and MT had no significant effects on the hypothalamic mRNAs of GHRH and PACAP. Although not statistically significant, females tended to have higher GH mRNA levels than male and sex-reversed fish. Additionally, MT tended to decrease and increase GH mRNA levels in female and male fish, respectively. There were significant differences among sexes in the expression of GHR, and IGF mRNAs at the peripheral level in the liver and gonads. Females had lower hepatic GHRs and higher ovarian GHRs than male and sex-reversed fish. While the mRNA levels of IGF-1 were lower in the ovary, the levels of IGF-2 were higher compared with those in testes. A significant correlation between GHRs and IGFs was demonstrated in the liver and gonad (except for IGF-1). Multiple regression analysis showed a significant relationship between GH mRNA and both GHRs and IGFs in the liver and gonad. MT exerted androgenic and, to some extent, estrogenic effects on several physiological parameters and GH-IGF action.

  13. Nile Delta

    Atmospheric Science Data Center

    2013-04-15

    article title:  The Nile River Delta     View Larger Image ... of eastern Africa. At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids ...

  14. A Live Attenuated Chimeric West Nile Virus Vaccine, rWN/DEN4Δ30, Is Well Tolerated and Immunogenic in Flavivirus-Naive Older Adult Volunteers.

    PubMed

    Pierce, Kristen K; Whitehead, Stephen S; Kirkpatrick, Beth D; Grier, Palmtama L; Jarvis, Adrienne; Kenney, Heather; Carmolli, Marya P; Reynolds, Cynthia; Tibery, Cecilia M; Lovchik, Janece; Janiak, Anna; Luke, Catherine J; Durbin, Anna P; Pletnev, Alexander G

    2017-01-01

    West Nile virus (WNV) is a major cause of mosquito-borne illness in the United States. Human disease ranges from mild febrile illness to severe fatal neurologic infection. Adults aged >60 years are more susceptible to neuroinvasive disease accompanied by a high mortality rate or long-lasting neurologic sequelae. A chimeric live attenuated West Nile virus vaccine, rWN/DEN4Δ30, was shown to be safe and immunogenic in healthy adults aged 18-50 years. This study evaluated rWN/DEN4Δ30 in flavivirus-naive adults aged 50-65 years and found it to be safe and immunogenic. Outbreaks of WNV infection tend to be unpredictable, and a safe and effective vaccine will be an important public health tool.

  15. Shewanella putrefaciens in cultured tilapia detected by a new calcein-loop-mediated isothermal amplification (Ca-LAMP) method.

    PubMed

    Suebsing, Rungkarn; Kampeera, Jantana; Sirithammajak, Sarawut; Pradeep, Padmaja Jayaprasad; Jitrakorn, Sarocha; Arunrut, Narong; Sangsuriya, Pakkakul; Saksmerprome, Vanvimon; Senapin, Saengchan; Withyachumnarnkul, Boonsirm; Kiatpathomchai, Wansika

    2015-12-09

    Shewanella putrefaciens is being increasingly isolated from a wide variety of sources and is pathogenic to many marine and freshwater fish. For better control of this pathogen, there is a need for the development of simple and inexpensive but highly specific, sensitive, and rapid detection methods suitable for application in field laboratories. Our colorogenic loop-mediated isothermal amplification (LAMP) assay combined with calcein (Ca-LAMP) for unaided visual confirmation of LAMP amplicons is a simple method for fish pathogen detection in cultured tilapia. Here, we describe the detection of S. putrefaciens using the same platform. As before, the method gave positive results (orange to green color change) in 45 min at 63°C with sensitivity 100 times higher than that of a conventional PCR assay, with no cross-amplification of other known fish bacterial pathogens tested. Using the assay with 389 samples of gonads, fertilized eggs, and fry of farmed Nile and red tilapia Oreochromis spp., 35% of samples were positive for S. putrefaciens. The highest prevalence was found in samples of gonads (55%) and fertilized eggs (55%) from adult breeding stocks, indicating that S. putrefaciens could be passed on easily to fry used for stocking production ponds. Tissue tropism assays revealed that the spleen showed the highest colonization by S. putrefaciens in naturally infected tilapia and that it would be the most suitable organ for screening and monitoring fish stocks for presence of the bacteria.

  16. Population dynamics of Enterogyrus cichlidarum (Monogenea: Ancyrocephalinae) from the stomach of Tilapia spp. in Egypt.

    PubMed

    Khidr, A A

    1990-10-01

    In a 1-year seasonal study of the numbers of the stomach-inhabiting monogenean Enterogyrus cichlidarum in Tilapia nilotica in the River Nile, Egypt, prevalence and intensity reached a height in spring and infection levels were surprisingly high in winter. T. zillii harboured fewer parasites but seasonal changes were similar. No parasites were found in T. galilaea. The prevalence and intensity of the infection with E. cichlidarum rose significantly with increasing size of the host. Some of the possible reasons for these fluctuations are discussed. Immature enterogyrids were more abundant in the posterior sector of the stomach and adult enterogyrids showed a preference for the anterior sector. No significant difference was found in the numbers of enterogyrids in male and female hosts.

  17. Effectiveness of Aquaflor (50% florfenicol) administered in feed to control mortality associated with Streptococcus iniae in tilapia at a commercial tilapia production facility

    USGS Publications Warehouse

    Gaikowski, Mark P.; Schleis, Susan M.; Leis, Eric; Lasee, Becky A.; Endris, Richard G.

    2014-01-01

    The efficacy of Aquaflor (florfenicol; FFC) to control mortality caused by Streptococcus iniae in tilapia was evaluated under field conditions. The trial was initiated following presumptive diagnosis of S. iniae infection in a mixed group of fingerling (mean, 4.5 g) Nile Tilapia Oreochromis niloticus and a hybrid of Nile Tilapia×Blue Tilapia O. aureus. Diagnoses included mortality in source tank; examination of clinical signs and presence or absence of gram-positive cocci in brain, and collection of samples for microbiological review and disease confirmation of 60 moribund fish. Following presumptive diagnosis, tilapia (83/tank) were randomly transferred to each of 20 test tanks receiving the same water as the source tank (test tank water was not reused). Tilapia were offered either nonmedicated control feed or FFC-medicated feed (FFC at 15 mg/kg body weight/d; 10 tanks per regimen) for 10 consecutive days followed by a 14-d observation period during which only the nonmedicated control feed was offered. Streptococcus iniae was presumptively identified during pretreatment necropsy and confirmed by polymerase chain reaction assay; S. iniae was confirmed in samples taken during the dosing period but was not detected during the postdosing period. The FFC disk diffusion zone of inhibition ranged from 29 to 32 mm, while the minimum inhibitory concentration of FFC ranged from 2 to 4 μg/mL for the S. iniae isolates collected. Survival of tilapia assigned to the FFC-dose group was significantly greater at 14 d posttreatment than that of the nonmedicated controls. The odds of tilapia assigned to the FFC-dose group surviving to the end of the postdosing period were 1.34 times the odds of survival of tilapia assigned to the nonmedicated control group. There were no clinically apparent adverse effects associated with the administration of FFC-medicated feed in this study.

  18. The Nile

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image of the northern portion of the Nile River was captured by MISR's nadir camera on January 30, 2001 (Terra orbit 5956). The Nile is the longest river in the world, extending for about 6700 kilometers from its headwaters in the highlands of eastern Africa.

    At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids of Giza. North of here the Nile branches into two distributaries, the Rosetta to the west and the Damietta to the east.

    Also visible in this image is the Suez Canal, a shipping waterway connecting Port Said on the Mediterranean Sea with the Gulf of Suez. The Gulf is an arm of the Red Sea, and is located on the righthand side of the picture.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  19. Nile River

    Atmospheric Science Data Center

    2013-04-15

    ... extent of the Nile waters before and after the onset of the rainy seasons of 2000 (top pair) and 2001 (bottom pair). The images are ... poor prior to the flooding due to a late start of the rainy season in parts of the country. Following two consecutive years of serious ...

  20. Prevalence of Francisella noatunensis subsp. orientalis in cultured tilapia on the island of Oahu, Hawaii.

    PubMed

    Soto, Esteban; McGovern-Hopkins, Kathleen; Klinger-Bowen, Ruth; Fox, Bradley K; Brock, James; Antonio, Nathene; Waal, Zelda van der; Rushton, Stephen; Mill, Aileen; Tamaru, Clyde S

    2013-06-01

    Francisellosis is an emergent disease in cultured and wild aquatic animals. The causative agent, Francisella noatunensis subsp. orientalis (Fno), is a gram-negative bacterium recognized as one of the most virulent pathogens of warmwater fish. The main objective of this project was to investigate the prevalence of Fno in cultured tilapia (specifically, Mozambique Tilapia Oreochromis mossambicus, Koilapia [also known as Wami Tilapia] O. hornorum, Blue Tilapia O. aureus, and Nile Tilapia O. niloticus hybrids) on the island of Oahu, Hawaii, using conventional and real-time PCR assays followed by statistical modeling to compare the different diagnostic methods and identify potential risk factors. During 2010 and 2012, 827 fish were collected from different geographical locations throughout the island of Oahu. Upon collection of fish, the water temperature in the rearing system and the length of individual fish were measured. Extraction of DNA from different tissues collected aseptically during necropsy served as a template for molecular diagnosis. High correlation between both molecular methods was observed. Moreover, the bacterium was isolated from infected tilapia on selective media and confirmed to be Fno utilizing a species-specific Taqman-based real-time PCR assay. Although a direct comparison of the prevalence of Fno between the different geographical areas was not possible, the results indicate a high prevalence of Fno DNA in cultured tilapia throughout the farm sites located on Oahu. Of the different tilapia species and hybrids currently cultured in Hawaii, Mozambique Tilapia were more susceptible to infection than Koilapia. Water temperature in the rearing systems and fish size also had a strong effect on the predicted level of infection, with fish held at lower temperatures and smaller fish being more susceptible to piscine francisellosis.

  1. Ichthyophthirius multifiliis infection induces apoptosis in different species of Tilapia.

    PubMed

    El-Dien, Abdel Hakim S; Abdel-Gaber, Rewaida A

    2009-08-01

    The parasitic ciliate Ichthyophthirius multifiliis (Ich) is one of the most important protozoan pathogens of freshwater fish worldwide. Examination of 4 species of Tilapia from the River Nile recorded highest rate infection in Oreochromis niloticus, followed by Oreochromis aureus, Sarotherodon galilaeus and Tilapia zilli. By electron microscopy, apoptotic cells collected from Tilapia species infected with "Ich" showed an aggregation on the apical and basal parts of the ciliated and non-ciliated endothelial lining the gill epithelium. Ultrastructural analysis showed that the chromatin in the liver of Ich-infected O. niloticus was highly condensed and massed at the center of the nucleus. UItrastructural analysis of "Ich" infected O. aureus showed that the nuclear membrane of hepatocytes was also shrunken. In S. galilaeus, chromatin was highly condensed, fragmented and massed at the nuclear center, occasionally forming crescent-shaped masses. Ultrastructural of O. niloticus spleen showed that the macrophage number was comparatively high as compared to control. In O. aureus, damaged splenic cell number did not change, and phagocytic capacity of macrophages was not very high. In Ich-infected S. galilaeus, a marked decrease in splenic cells number was seen. Analysis of DNA by agarose gel electrophoresis on gill, liver and spleen cells showed a ladder of DNA fragments in multiple of 180bp in length, pointing to an internucleosomal DNA cleavage.

  2. Colorimetric Method of Loop-Mediated Isothermal Amplification with the Pre-Addition of Calcein for Detecting Flavobacterium columnare and its Assessment in Tilapia Farms.

    PubMed

    Suebsing, Rungkarn; Kampeera, Jantana; Sirithammajak, Sarawut; Withyachumnarnkul, Boonsirm; Turner, Warren; Kiatpathomchai, Wansika

    2015-03-01

    Flavobacterium columnare, the causative agent of columnaris disease in fish, affects many economically important freshwater fish species. A colorimetric method of loop-mediated isothermal amplification with the pre-addition of calcein (LAMP-calcein) was developed and used to detect the presence of F. columnare in farmed tilapia (Nile Tilapia Oreochromis niloticus and red tilapia [Nile Tilapia × Mozambique Tilapia O. mossambicus]) and rearing water. The detection method, based on a change in color from orange to green, could be performed within 45 min at 63°C. The method was highly specific, as it had no cross-detections with 14 other bacterial species, including other fish pathogens and two Flavobacterium species. The method has a minimum detection limit of 2.2 × 10(2) F. columnare CFU; thus, it is about 10 times more sensitive than conventional PCR. With this method, F. columnare was detected in gonad, gill, and blood samples from apparently healthy tilapia broodstock as well as in samples of fertilized eggs, newly hatched fry, and rearing water. The bacteria isolated from the blood were further characterized biochemically and found to be phenotypically identical to F. columnare. The amplified products from the LAMP-calcein method had 97% homology with the DNA sequence of F. columnare.

  3. Phase II, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Investigate the Immunogenicity and Safety of a West Nile Virus Vaccine in Healthy Adults

    PubMed Central

    Biedenbender, Rex; Bevilacqua, Joan; Gregg, Anne M.; Watson, Mike

    2011-01-01

    Background. ChimeriVax-WN02 is a live, attenuated chimeric vaccine for protection against West Nile virus. This Phase II, randomized, double-blind, placebo–controlled, multicenter study assessed the immunogenicity, viremia, and safety of the ChimeriVax-WN02 vaccine. Methods. The 2-part study included adults in general good health. In part 1, subjects aged 18–40 years were randomized to 1 of 4 treatment groups: ChimeriVax–WN02 3.7- × -105 plaque-forming units (PFU), 3.7 × 104 PFU, 3.7 × 103 PFU, or placebo. In part 2, subjects aged 41–64 and ≥65 years were randomized to receive ChimeriVax-WN02 3.7 × 105 PFU or placebo. Results. In both part 1 and part 2, seroconversion was achieved at day 28 by >96% of subjects in active treatment groups. In part 1, neutralizing antibody titers at day 28 were higher and viremia levels lower with the highest dose, whereas the adverse event profile was similar between the dose groups. In part 2, antibody titers and viremia levels were higher in subjects aged ≥65 years, and more subjects in the 41–64 years cohort experienced adverse events. Conclusions. The ChimeriVax-WN02 vaccine was highly immunogenic in younger adults and the elderly, and it was well tolerated at all dose levels and in all age groups investigated. Clinical Trials.gov identifier: NCT00442169. PMID:21148499

  4. Tilapia: environmental and nutritional requirements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tilapia are an important species to global aquaculture production. Their adaptability to a wide range of environmental and nutritional conditions and their ability to grow and reproduce make them a prime species for aquaculture. Nonetheless, to achieve maximum performance in culture, tilapia requir...

  5. Behaviours Associated with Acoustic Communication in Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Longrie, Nicolas; Poncin, Pascal; Denoël, Mathieu; Gennotte, Vincent; Delcourt, Johann; Parmentier, Eric

    2013-01-01

    Background Sound production is widespread among fishes and accompanies many social interactions. The literature reports twenty-nine cichlid species known to produce sounds during aggressive and courtship displays, but the precise range in behavioural contexts is unclear. This study aims to describe the various Oreochromis niloticus behaviours that are associated with sound production in order to delimit the role of sound during different activities, including agonistic behaviours, pit activities, and reproduction and parental care by males and females of the species. Methodology/Principal Findings Sounds mostly occur during the day. The sounds recorded during this study accompany previously known behaviours, and no particular behaviour is systematically associated with sound production. Males and females make sounds during territorial defence but not during courtship and mating. Sounds support visual behaviours but are not used alone. During agonistic interactions, a calling Oreochromis niloticus does not bite after producing sounds, and more sounds are produced in defence of territory than for dominating individuals. Females produce sounds to defend eggs but not larvae. Conclusion/Significance Sounds are produced to reinforce visual behaviours. Moreover, comparisons with O. mossambicus indicate two sister species can differ in their use of sound, their acoustic characteristics, and the function of sound production. These findings support the role of sounds in differentiating species and promoting speciation. They also make clear that the association of sounds with specific life-cycle roles cannot be generalized to the entire taxa. PMID:23620756

  6. Human Streptococcus agalactiae isolate in Nile tilapia (Oreochromis niloticus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, the Lancefield group B Streptococcus (GBS), long recognized as a mammalian pathogen, is an emerging pathogen to fish. We show that a GBS serotype Ia, multilocus sequence type ST-7 isolate from a human neonatal meningitis clinical case causes disease signs and mortality in N...

  7. Screening of multiple hormonal activities in water and sediment from the river Nile, Egypt, using in vitro bioassay and gonadal histology.

    PubMed

    Osman, Alaa G M; AbouelFadl, Khaled Y; Krüger, Angela; Kloas, Werner

    2015-06-01

    In Egypt, until yet no records are available regarding possible multiple hormonal activities in the aquatic systems and especially in the river Nile. In this paper, in vitro yeast estrogen screen (YES) and yeast androgen screen (YAS) were used to assess (for the first time) the multiple hormonal activities in surface waters and sediments of the river Nile. This study aimed to determine whether river Nile water can cause changes in gonadal histology of Nile tilapia (Oreochromis niloticus niloticus). All water samples exhibited extremely low levels of estrogenicity. Estrogenicity was nearly not detected in any of the sediment samples. Unlike the estrogenicity, significant androgenic activities were recorded in the water and sediment samples along the course of the river Nile. The present study reports for the first time quantification anti-estrogenic and anti-androgenic activities with high levels in both water and sediment of the river Nile. The greatest anti-estrogenic and anti-androgenic activities were observed in samples from downstream river Nile. These results indicated that the anti-estrogenic and anti-androgenic activities along the Nile course were great and the pollution of the sites at downstream was more serious than the upstream sites due to industrial and anthropogenic activities at these sites. Good correlations were observed among some hormonal activities, suggesting coexistence of these contaminants in the environmental matrices. There were no signs of sexual disruption in any of the gonads analyzed from either male or female Nile tilapia, demonstrating that no hormonal activity present along the Nile course was sufficient to induce adverse effects on reproductive development. Further investigation is necessary to identify the compounds responsible for the hormonal activities in the river Nile and to examine effects of very low levels of hormonally active compounds on gonadal histology, as well as in the development of more sensitive biomarkers.

  8. West Nile Virus: Review of the Literature

    PubMed Central

    Petersen, Lyle R.; Brault, Aaron C.; Nasci, Roger S.

    2015-01-01

    IMPORTANCE Since its introduction in North America in 1999,West Nile virus has produced the 3 largest arboviral neuroinvasive disease outbreaks ever recorded in the United States. OBJECTIVE To review the ecology, virology, epidemiology, clinical characteristics, diagnosis, prevention, and control of West Nile virus, with an emphasis on North America. EVIDENCE REVIEW PubMed electronic database was searched through February 5, 2013. United States national surveillance data were gathered from the Centers for Disease Control and Prevention. FINDINGS West Nile virus is now endemic throughout the contiguous United States, with 16 196 human neuroinvasive disease cases and 1549 deaths reported since 1999. More than 780 000 illnesses have likely occurred. To date, incidence is highest in the Midwest from mid-July to early September. West Nile fever develops in approximately 25% of those infected, varies greatly in clinical severity, and symptoms may be prolonged. Neuroinvasive disease (meningitis, encephalitis, acute flaccid paralysis) develops in less than 1% but carries a fatality rate of approximately 10%. Encephalitis has a highly variable clinical course but often is associated with considerable long-term morbidity. Approximately two-thirds of those with paralysis remain with significant weakness in affected limbs. Diagnosis usually rests on detection of IgM antibody in serum or cerebrospinal fluid. Treatment is supportive; no licensed human vaccine exists. Prevention uses an integrated pest management approach, which focuses on surveillance, elimination of mosquito breeding sites, and larval and adult mosquito management using pesticides to keep mosquito populations low. During outbreaks or impending outbreaks, emphasis shifts to aggressive adult mosquito control to reduce the abundance of infected, biting mosquitoes. Pesticide exposure and adverse human health events following adult mosquito control operations for West Nile virus appear negligible. CONCLUSIONS AND

  9. Photic and circadian regulation of melatonin production in the Mozambique tilapia Oreochromis mossambicus.

    PubMed

    Nikaido, Yoshiaki; Ueda, Satomi; Takemura, Akihiro

    2009-01-01

    Diverse circadian systems related to phylogeny and ecological adaptive strategies are proposed in teleosts. Recently, retinal photoreception was reported to be important for the circadian pacemaking activities of the Nile tilapia Oreochromis niloticus. We aimed to confirm the photic and circadian responsiveness of its close relative-the Mozambique tilapia O. mossambicus. Melatonin production in cannulated or ophthalmectomized fish and its secretion from cultured pineal glands were examined under several light regimes. Melatonin production in the cannulated tilapias was measured at 3-h intervals; it fluctuated daily, with a nocturnal increase and a diurnal decrease. Exposing the cannulated fish to several light intensities (1500-0.1 lx) and to natural light (0.1 and 0.3 lx) suppressed melatonin levels within 30 min. Static pineal gland culture under light-dark and reverse light-dark cycles revealed that melatonin synthesis increased during the dark periods. Rhythmic melatonin synthesis disappeared on pineal gland culture under constant dark and light conditions. After ophthalmectomy, plasma melatonin levels did not vary with light-dark cycles. These results suggest that (1) Mozambique tilapias possess strong photic responsiveness, (2) their pineal glands are sensitive to light but lack circadian pacemaker activity, and (3) they require lateral eyes for rhythmic melatonin secretion from the pineal gland.

  10. FAQ: General Questions about West Nile Virus

    MedlinePlus

    ... Public Service Videos General Questions About West Nile Virus Recommend on Facebook Tweet Share Compartir On This ... West Nile virus cases? What is West Nile virus? West Nile virus is an arthropod-borne virus ( ...

  11. The Nile River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of the northern portion of the Nile River was captured by MISR's nadir camera on January 30, 2001 (Terra orbit 5956). The Nile is the longest river in the world, extending for about 6700 kilometers from its headwaters in the highlands of eastern Africa. At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids of Giza. North of here the Nile branches into two distributaries, the Rosetta to the west and the Damietta to the east. Also visible in this image is the Suez Canal, a shipping waterway connecting Port Said on the Mediterranean Sea with the Gulf of Suez. The Gulf is an arm of the Red Sea, and is located on the righthand side of the picture. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

  12. West Nile Virus

    MedlinePlus

    ... you'll be infected with West Nile virus, mosquito bites can still be an itchy nuisance. The CDC advises people to protect themselves from mosquito bites by using mosquito repellent, especially at times ...

  13. West Nile Virus

    MedlinePlus

    ... West Nile virus has been found in animals, birds, and humans in all continental states in the ... picked up the virus after feeding on infected birds. Pets and other animals can also become infected ...

  14. Agonistic and reproductive behaviors in males of red hybrid tilapia, Oreochromis niloticus (Linnaeus, 1758) x O. mossambicus (Peters, 1852) (Osteichthyes: Cichlidae).

    PubMed

    Medeiros, A P T; Chellappa, S; Yamamoto, M E

    2007-11-01

    The red hybrid tilapia, Oreochromis niloticus (Linnaeus, 1758) x O. mossambicus (Peters, 1852) is a fertile hybrid used in the semi-intensive level of fish culture in the Northeast of Brazil. It is a territorial cichlid and is highly aggressive towards conspecifics during the breeding season. The purpose of this study was to investigate and describe the aggressive behaviour displayed by the males of this hybrid in non-reproductive and reproductive contexts. Behavioural observations revealed that aggression displayed by the reproductive males of red hybrid tilapia included threatening, undulation, parallel, lateral and frontal attacks, chasing, escape and submission. Possession of a territory influenced male aggressiveness, which was more intense in their own territory than that observed in a neutral situation. The males built nests, irrespective of female presence. All the behavioural patterns were in accordance with those previously described for one parental species, the Nile tilapia, O. niloticus.

  15. Nile River Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The Nile River Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population. The capital city of Cairo is at the apex of the delta. Just across the river from Cairo can be seen the ancient three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

  16. Francisella Infection in Cultured Tilapia in Thailand and the Inflammatory Cytokine Response.

    PubMed

    Jantrakajorn, Sasibha; Wongtavatchai, Janenuj

    2016-06-01

    Francisella infections developed in freshwater Nile Tilapia Oreochromis niloticus and red tilapia Oreochromis spp. farms in Thailand during 2012-2014. The diseased fish were lethargic and pale in color and showed numerous white nodules in their enlarged spleens. Histopathological examination and electron microscopy suggested that the white nodules were multifocal granulomas consisting of coccobacilli within vacuolated cells. Isolation of Francisella-like bacteria was achieved from 42 of 100 samples, while polymerase chain reaction confirmed Francisella infections in all samples. Analysis of the 16S rRNA gene from samples obtained from three different geographical culture areas revealed more than 99% similarity with F. noatunensis subsp. orientalis. The influence of Francisella infection on inflammatory cytokines was determined on splenic cells of fish intraperitoneally injected with the bacteria (0.8 × 10(5) colony-forming units per fish). Infected tilapia showed significantly greater expression of the pro-inflammatory genes interleukin-1β (IL-1β) and tumor necrotic factor-α (TNF-α) within 24 h postinjection (hpi) and for up to 96 hpi. However, down-regulation of an anti-inflammatory gene, transforming growth factor-β (TGF-β) was observed as early as 24 hpi. This investigation demonstrates that an imbalance between pro- and anti-inflammatory cytokines in response to the infection may account for the substantial number of granulomas in fish hematopoietic tissues that was found in the later stage of the disease. Received September 9, 2015; accepted December 13, 2015.

  17. Induced alkoxyresorufin-O-dealkylases in tilapias (Oreochromis niloticus) from Guandu river, Rio de Janeiro, Brazil.

    PubMed

    Parente, Thiago E M; De-Oliveira, Ana C A X; Silva, Igor B; Araujo, Francisco G; Paumgartten, Francisco J R

    2004-03-01

    The activity of fish monooxygenases has been extensively used as a monitoring tool to detect contamination of water bodies by cytochrome P450-inducing agents. In this study we evaluated the activities of ethoxy- (EROD), methoxy- (MROD) and pentoxy- (PROD) resorufin-O-dealkylases in the liver of Nile tilapias (Oreochromis niloticus) collected at the Guandu river, at a reference clean site (Lake 1) and at two other sampling sites (Lakes 2 and 3) in Rio de Janeiro state, Brazil. Alkoxyresorufin-O-dealkylases were measured fluorimetrically in the hepatic S9 fraction. EROD (17.7-fold), MROD (14.2-fold) as well as PROD activities were considerably higher in tilapias from Guandu river. A moderate increase of EROD (5.0-fold) and MROD (5.4-fold) was also found in tilapias from Lake 3. These findings suggest that Guandu river watershed, the main source of urban drinking water supply in Rio de Janeiro, is polluted with CYP1A-inducing xenobiotics. Furthermore, we also found a good linear relationship between EROD and MROD, a finding that agrees with the hypothesis that the two reactions are catalysed by the same CYP1A isoform in O. niloticus.

  18. Discover the Nile River

    ERIC Educational Resources Information Center

    Project WET Foundation, 2009

    2009-01-01

    Bordering on the Fantastic. As the longest river on earth, the Nile passes through 10 countries. Presented through a wide range of activities and a winning array of games, it's also unsurpassed at taking young minds into exploring the world of water, as well as natural and man made wonders.

  19. West Nile Virus

    MedlinePlus

    ... spread by mosquitoes. Mosquitoes become infected by biting birds that carry the virus. People can get West Nile virus when an infected mosquito bites them. This happens most often in the warm-weather months of spring, summer and early fall. You ...

  20. FAQ: West Nile Virus and Dead Birds

    MedlinePlus

    ... Education Public Service Videos West Nile Virus & Dead Birds Recommend on Facebook Tweet Share Compartir On This ... dead bird sightings to local authorities. How do birds get infected with West Nile virus? West Nile ...

  1. Skin and subcutaneous mycoses in tilapia (Oreochromis niloticus) caused by Fusarium oxysporum in coinfection with Aeromonas hydrophila.

    PubMed

    Cutuli, M Teresa; Gibello, Alicia; Rodriguez-Bertos, Antonio; Blanco, M Mar; Villarroel, Morris; Giraldo, Alejandra; Guarro, Josep

    2015-09-01

    Subcutaneous mycoses in freshwater fish are rare infections usually caused by oomycetes of the genus Saprolegnia and some filamentous fungi. To date, Fusarium infections in farmed fish have only been described in marine fish. Here, we report the presence of Fusarium oxysporum in subcutaneous lesions of Nile tilapia (Oreochromis niloticus). Histopathologic evaluation revealed granuloma formation with fungal structures, and the identity of the etiological agent was demonstrated by morphological and molecular analyses. Some of the animals died as a result of systemic coinfection with Aeromonas hydrophila.

  2. Dietary supplementation with Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus oryzae enhance immunity and disease resistance against Aeromonas hydrophila and Streptococcus iniae infection in juvenile tilapia Oreochromis niloticus.

    PubMed

    Iwashita, Marina Keiko P; Nakandakare, Ivan B; Terhune, Jeffery S; Wood, Theresa; Ranzani-Paiva, Maria José T

    2015-03-01

    A feeding trial was conducted to investigate the effects of dietary administration of probiotic with Bacillus subtilis, Aspergillus oryzae and Saccharomyces cerevisiae on growth, innate immune response, Hemato-immunological parameters and disease resistance of Nile tilapia, Oreochromis niloticus. Animals were distributed in three equal groups, each of five replicates and received one of the following experimental diets for four weeks: Control, non-supplemented diet; 5 g kg(-1) probiotic mixture (B. subtilis 1.5 × 10(9) CFU g(-1), S. cerevisiae 10(9) CFU g(-1) and A. oryzae 2 × 10(9) CFU g(-1)); and 10 g kg(-1) probiotic mixture (B. subtilis 3.0 × 10(9) CFU g(-1), S. cerevisiae 2.0 × 10(9) CFU g(-1) and A. oryzae 4.0 × 10(9) CFU g(-1)). The respiratory burst activity, white blood cells and hematological parameters were evaluated after four, five and six weeks of feeding. At the end of the growth trial, fish were sampled for intestinal microbiology and challenged by intraperitoneal injection of LD50 concentration of Aeromonas hydrophila and Streptococcus iniae. Mortality was recorded for the following 3 weeks. Results showed that administration of the probiotic had no significant effect on the growth rates of Nile tilapias, although the fish fed probiotics had better feed conversion. Respiratory burst activity, erythrocyte fragility and levels of white blood cells were significantly improved in tilapias fed diet supplemented with probiotic levels (P < 0.05), which may exhibit up-regulating effects on tilapia immune parameters. The cumulative mortality after A. hydrophila and S. iniae challenge decreased in tilapias fed with probiotic (P < 0.05). The present study demonstrated the potential of B. subtilis, S. cerevisiae and A. oryzae combined as beneficial dietary probiotic in juvenile O. niloticus.

  3. Shelf life of air and modified atmosphere-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled conditions

    PubMed Central

    Cyprian, Odoli; Lauzon, Hélène L; Jóhannsson, Ragnar; Sveinsdóttir, Kolbrún; Arason, Sigurjón; Martinsdóttir, Emilía

    2013-01-01

    Optimal packaging and storage conditions for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and −1°C. Sensory analysis of cooked samples revealed a shelf life of 13–15 days for air-packaged fillets during storage at 1°C and 20 days at −1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g−1. In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (tilapia fillets quality and a major factor in influencing retail purchase decisions. In view of that, air packaged at −1°C storage temperature was the optimal condition for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study. PMID:24804022

  4. Mental Status after West Nile Virus Infection

    PubMed Central

    Sadek, Joseph; Pergam, Steven; Echevarria, Leonor A.; Davis, Larry E.; Goade, Diane; Harnar, Joanne; Nofchissey, Robert A.; Sewel, C. Mack; Ettestad, Paul

    2006-01-01

    Mental status after acute West Nile virus infection has not been examined objectively. We compared Telephone Interview for Cognitive Status scores of 116 patients with West Nile fever or West Nile neuroinvasive disease. Mental status was poorer and cognitive complaints more frequent with West Nile neuroinvasive disease (p = 0.005). PMID:16965710

  5. Environmental and cortisol-mediated control of Ca(2+) uptake in tilapia (Oreochromis mossambicus).

    PubMed

    Lin, Chia-Hao; Kuan, Wei-Chun; Liao, Bo-Kai; Deng, Ang-Ni; Tseng, Deng-Yu; Hwang, Pung-Pung

    2016-04-01

    Ca(2+) is a vital element for many physiological processes in vertebrates, including teleosts, which live in aquatic environments and acquire Ca(2+) from their surroundings. Ionocytes within the adult gills or larval skin are critical sites for transcellular Ca(2+) uptake in teleosts. The ionocytes of zebrafish were found to contain transcellular Ca(2+) transporters, epithelial Ca(2+) channel (ECaC), plasma membrane Ca(2+)-ATPase 2 (PMCA2), and Na(+)/Ca(2+) exchanger 1b (NCX1b), providing information about the molecular mechanism of transcellular Ca(2+) transports mediated by ionocytes in fish. However, more evidence is required to establish whether or not a similar mechanism of transcellular Ca(2+) transport also exists in others teleosts. In the present study, ecac, pmca2, and ncx1 were found to be expressed in the branchial ionocytes of tilapia, thereby providing further support for the mechanism of transcellular Ca(2+) transport through ionocytes previously proposed for zebrafish. In addition, we also reveal that low Ca(2+) water treatment of tilapia stimulates Ca(2+) uptake and expression of ecac and cyp11b (the latter encodes a cortisol-synthesis enzyme). Treatment of tilapia with exogenous cortisol (20 mg/l) enhanced both Ca(2+) influx and ecac expression. Therefore, increased cyp11b expression is suggested to enhance Ca(2+) uptake capacity in tilapia exposed to low Ca(2+) water. Furthermore, the application of cortisol receptor antagonists revealed that cortisol may regulate Ca(2+) uptake through glucocorticoid and/or mineralocorticoid receptor (GR and/or MR) in tilapia. Taken together, the data suggest that cortisol may activate GR and/or MR to execute its hypercalcemic action by stimulating ecac expression in tilapia.

  6. Pheromone signaling: a pissing contest in tilapia.

    PubMed

    Li, Weiming; Buchinger, Tyler

    2014-09-22

    In many species, males produce elaborate signals used by females in the evaluation of potential mates. Two urinary steroid epimers have now been shown to be components of a courtship display by male Mozambique tilapia that promotes female maturation.

  7. Depletion of florfenicol amine, marker residue of florfenicol, from the edible fillet of tilapia (Oreochromis niloticus x O. niloticus and O. niloticus x O. aureus) following florfenicol administration in feed

    USGS Publications Warehouse

    Gaikowski, M.P.; Mushtaq, M.; Cassidy, P.; Meinertz, J.R.; Schleis, S.M.; Sweeney, D.; Endris, R.G.

    2010-01-01

    Aquaflor??, a 50% feed premix containing the broad spectrum antibacterial agent florfenicol is available globally to control mortality associated with economically significant systemic bacterial diseases of fish. Florfenicol (FFC) is effective in controlling mortality associated with Streptococcus iniae in tilapia Oreochromis sp. when administered in medicated feed at a dose of 15 mg/kg bodyweight (BW)/d for 10 consecutive days. Our objective was to characterize the depletion of the FFC marker residue, florfenicol amine (FFA), from the edible tissue of market-weight Nile tilapia O. niloticus x O. niloticus and hybrid tilapia O. niloticus x O. aureus offered feed medicated with FFC at a nominal dose rate of 15 mg/kg BW/d for 12 days. Near market-weight tilapia were obtained from a commercial tilapia farm, distributed to 2 single pass (one for Nile tilapia and one for hybrid tilapia), flow-through systems and maintained at 27 ??C under a 15 h light:9 h dark photoperiod over a 41-d pre-dosing period. During the dosing period, tilapia were offered feed medicated with FFC at a concentration of 1.479 g/kg at 1% BW daily divided in three equal offerings. The initial 10-d dosing period was extended to 12 d because one tank did not consume > 75% of the feed offered during the first two dosing days. The total dose consumed by fish in each of the 2 tanks ranged from 147 to 167 mg/kg. Once during the pre-dose period and on days 1, 2, 4, 7, 14, 21, and 28 of the post-dose period, groups of fish were indiscriminately removed from each tank, measured for weight and length, scaled, filleted, and the skin-on fillets stored at <-70 ??C. Frozen fillets were individually homogenized, extracted, and FFA concentration was determined by high-performance liquid chromatography with UV detection. Florfenicol amine is rapidly eliminated from tilapia fillet after withdrawal from medication and depletion followed first-order kinetics with an estimated half-life of 2.32 d. The FFA tolerance

  8. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor®-medicated feed therapy

    USGS Publications Warehouse

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2015-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  9. Mechanical and thermal properties of irradiated films based on Tilapia ( Oreochromis niloticus) proteins

    NASA Astrophysics Data System (ADS)

    Sabato, S. F.; Nakamurakare, N.; Sobral, P. J. A.

    2007-11-01

    Proteins are considered potential material in natural films as alternative to traditional packaging. When gamma radiation is applied to protein film forming solution it resulted in an improvement in mechanical properties of whey protein films. The objective of this work was the characterization of mechanical and thermal properties of irradiated films based on muscle proteins from Nile Tilapia ( Oreochromis niloticus). The films were prepared according to a casting technique with two levels of plasticizer: 25% and 45% glycerol and irradiated in electron accelerator type Radiation Dynamics, 0.550 MeV at dose range from 0 to 200 kGy. Thermal properties and mechanical properties were determined using a differential scanning calorimeter and a texture analyzer, respectively. Radiation from electron beam caused a slightly increase on its tensile strength characteristic at 100 kGy, while elongation value at this dose had no reduction.

  10. Mosquito, adult (image)

    MedlinePlus

    This illustration shows an adult southern house mosquito. This mosquito feeds on blood and is the carrier of many diseases, such as encephalitis, West Nile, dengue fever, yellow fever, and others. ( ...

  11. Safety Evaluation of Transgenic Tilapia with Accelerated Growth.

    PubMed

    Guillén; Berlanga; Valenzuela; Morales; Toledo; Estrada; Puentes; Hayes; de la Fuente J

    1999-01-01

    Recent advances in modern marine biotechnology have permitted the generation of new strains of economically important fish species through the transfer of growth hormone genes. These transgenic fish strains show improved growth performance and therefore constitute a better alternative for aquaculture programs. Recently, we have obtained a transgenic tilapia line with accelerated growth. However, before introducing this line into Cuban aquaculture, environmental and food safety assessment was required by national authorities. Experiments were performed to evaluate the behavior of transgenic tilapia in comparison to wild tilapia as a way to assess the environmental impact of introducing transgenic tilapia into Cuban aquaculture. Studies were also conducted to evaluate, according to the principle of substantial equivalence, the safety of consuming transgenic tilapia as food. Behavior studies showed that transgenic tilapia had a lower feeding motivation and dominance status than controls. Food safety assessment indicated that tilapia growth hormone has no biological activity when administered to nonhuman primates. Furthermore, no effects were detected in human healthy volunteers after the consumption of transgenic tilapia. These results showed, at least under the conditions found in Cuba, no environmental implications for the introduction of this transgenic tilapia line and the safety in the consumption of tiGH-transgenic tilapia as an alternative feeding source for humans. These results support the culture and consumption of these transgenic tilapia.

  12. Effects of Prunella vulgaris labiatae extract on specific and non-specific immune responses in tilapia (Oreochromis niloticus).

    PubMed

    Park, Kwan-Ha; Choi, Sanghoon

    2014-01-01

    We examined the effects of Prunella vulgaris Labiatae (P. vulgaris L.) on specific and non-specific immune responses of Nile tilapia, Oreochromis niloticus. The optimal concentration without toxicity of P. vulgaris was determined to 30-40 μg/ml in vitro and 120 μg/100 g of fish in vivo. P. vulgaris significantly elicited an antibody titer compared to FCA or β-glucan. β-glucan plus P. vulgaris group synergistically enhanced antibody production. No significant difference in antibody production was observed between P. vulgaris and P. vulgaris plus β-glucan group. A respiratory burst activity of head kidney (HK) leucocytes of tilapia administered with 300 or 500 μg P. vulgaris was significantly (p < 0.05) enhanced compared with the PBS-injected control group and FCA-treated group. Maximum increase in the NBT reduction value was observed in 500 μg P. vulgaris group but no significant difference was found between 300 and 500 μg P. vulgaris group. The level of serum lysozyme activity was significantly (p < 0.05) higher in the 300 and 500 μg P. vulgaris than 100 μg P. vulgaris and FCA group. The phagocytic activities of HK leucocytes from tilapia administered with 300 and 500 μg P. vulgaris were significantly (p < 0.05) higher than 100 μg P. vulgaris and the control group. P. vulgaris was revealed with a good immunoadjuvant evoking the specific and non-specific immune responses of tilapia.

  13. The tilapias' chromosomes influencing sex determination.

    PubMed

    Cnaani, A

    2013-01-01

    The sex chromosomes of tilapias (family Cichlidae; genera Oreochromis, Sarotherodon and Tilapia) have been studied for over 50 years, which has gained interest from both agricultural and basic scientific perspectives. Several closely related tilapia species which can interbreed have been studied, and it has been repeatedly demonstrated that there is variation within and between species in the chromosomal sex-determination mechanism. Both male and female heterogametic sex-determination systems have been characterized, as well as epistatic and environmental influences on sex determination. Three different linkage groups (LG1, LG3 and LG23) have been identified as sex-associated chromosomes and have been subjected to further cytogenetic research and analyses of the genes located around the sex-determining region. Variation in the genetic and physical characteristics of the sex chromosomes makes tilapias an excellent model system for studying the evolution of vertebrate sex chromosomes. This review summarizes the progress made along 5 decades of research and the current knowledge of the tilapias' sex chromosomes.

  14. West Nile Virus: Symptoms and Treatment

    MedlinePlus

    ... Form Controls Search The CDC submit West Nile virus Note: Javascript is disabled or is not supported ... visit this page: About CDC.gov . West Nile Virus Home Frequently Asked Questions General Questions Preguntas frecuentes ...

  15. Nile River, Lake Nasser, Aswan Dam, Egypt

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Egypt's High Aswan Dam on the Nile River at the first cataracts, Nile River, (24.0N, 33.0E) was completed in 1971 to provide cheap hydroelectric power and to regulate the historically uneven flow of the Nile River. The contrast between the largely base rock desert east of the Nile versus the sand covered desert west of the river and the ancient irrigated floodplain downstream from the damsite is clearly shown.

  16. Control Over the Nile: Implications across Nations

    DTIC Science & Technology

    2010-06-01

    Declaration...................................................................50 3. The Hydro-Meteorological Survey of the Equatorial Lakes ( HYDROMET ...Eastern Nile Subsidiary Action Program HYDROMET Hydro-Meteorological Survey of the Equatorial Lakes IMF International Monetary Fund NBI Nile...The Hydro-Meteorological Survey of the Equatorial Lakes ( HYDROMET ) Led by Egypt, the Nile basin countries of Kenya, Uganda, Tanzania, and Sudan

  17. [West Nile virus infection].

    PubMed

    Pérez Ruiz, Mercedes; Gámez, Sara Sanbonmatsu; Clavero, Miguel Angel Jiménez

    2011-12-01

    West Nile virus (WNV) is an arbovirus usually transmitted by mosquitoes. The main reservoirs are birds, although the virus may infect several vertebrate species, such as horses and humans. Up to 80% of human infections are asymptomatic. The most frequent clinical presentation is febrile illness, and neuroinvasive disease can occur in less than 1% of cases. Spain is considered a high-risk area for the emergence of WNV due to its climate and the passage of migratory birds from Africa (where the virus is endemic). These birds nest surrounding wetlands where populations of possible vectors for the virus are abundant. Diagnosis of human neurological infections can be made by detection of IgM in serum and/or cerebrospinal fluid samples, demonstration of a four-fold increase in IgG antibodies between acute-phase and convalescent-phase serum samples, or by detection of viral genome by reverse transcription-polymerase chain reaction (especially useful in transplant recipients). Since WNV is a biosafety level 3 agent, techniques that involve cell culture are restricted to laboratories with this level of biosafety, such as reference laboratories. The National Program for the Surveillance of WNV Encephalitis allows the detection of virus circulation among birds and vectors in areas especially favorable for the virus, such as wetlands, and provides information for evaluation of the risk of disease in horses and humans.

  18. Use of probiotics in diets of Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    AAquaculture is one of the fastest growing sectors of agriculture globally. Production in freshwater and marine fisheries has plateaued, and the continued demand for seafood and need for affordable protein sources in third world countries will ensure growth of aquaculture in the future. Tilapia are ...

  19. The White Nile sedimentary system

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo; Andò, Sergio; Padoan, Marta; Resentini, Alberto; Vezzoli, Giovanni; Villa, Igor

    2014-05-01

    The Nile River flows for ~6700 km from south of the Equator to finally reach the Mediterranean Sea at northern subtropical latitudes (Woodward et al. 2007). This is the longest sedimentological laboratory on Earth, a unique setting in which we are investigating changes in sediment composition associated with diverse chemical and physical processes, including weathering and hydraulic sorting. The present study focuses on the southern branch of the Nile across 20° of latitude, from hyperhumid Burundi and Rwanda highlands in central Africa to Khartoum, the capital city of Sudan at the southern edge of the Sahara. Our study of the Kagera basin emphasizes the importance of weathering in soils at the source rather than during stepwise transport, and shows that the transformation of parent rocks into quartzose sand may be completed in one sedimentary cycle (Garzanti et al. 2013a). Micas and heavy minerals, less effectively diluted by recycling than main framework components, offer the best key to identify the original source-rock imprint. The different behaviour of chemical indices such as the CIA (a truer indicator of weathering) and the WIP (markedly affected by quartz dilution) helps us to distinguish strongly weathered first-cycle versus polycyclic quartz sands (Garzanti et al. 2013b). Because sediment is efficiently trapped in East African Rift lakes, the composition of Nile sediments changes repeatedly northwards across Uganda. Downstream of both Lake Kyoga and Lake Albert, quartzose sands are progressively enriched in metamorphiclastic detritus supplied from tributaries draining amphibolite-facies basements. The evolution of White Nile sediments across South Sudan, a scarcely accessible region that suffered decades of civil war, was inferred from the available information (Shukri 1950), integrated by original petrographic, heavy-mineral and geochemical data (Padoan et al. 2011). Mineralogical and isotopic signatures of Bahr-el-Jebel and Sobat sediments, derived

  20. A review of piscine islet xenotransplantation using wild-type tilapia donors and the production of transgenic tilapia expressing a "humanized" tilapia insulin.

    PubMed

    Wright, James R; Yang, Hua; Hyrtsenko, Olga; Xu, Bao-You; Yu, Weiming; Pohajdak, Bill

    2014-01-01

    Most islet xenotransplantation laboratories have focused on porcine islets, which are both costly and difficult to isolate. Teleost (bony) fish, such as tilapia, possess macroscopically visible distinct islet organs called Brockmann bodies which can be inexpensively harvested. When transplanted into diabetic nude mice, tilapia islets maintain long-term normoglycemia and provide human-like glucose tolerance profiles. Like porcine islets, when transplanted into euthymic mice, they are rejected in a CD4 T-cell-dependent manner. However, unlike pigs, tilapia are so phylogenetically primitive that their cells do not express α(1,3)Gal and, because tilapia are highly evolved to live in warm stagnant waters nearly devoid of dissolved oxygen, their islet cells are exceedingly resistant to hypoxia, making them ideal for transplantation within encapsulation devices. Encapsulation, especially when combined with co-stimulatory blockade, markedly prolongs tilapia islet xenograft survival in small animal recipients, and a collaborator has shown function in diabetic cynomolgus monkeys. In anticipation of preclinical xenotransplantation studies, we have extensively characterized tilapia islets (morphology, embryologic development, cell biology, peptides, etc.) and their regulation of glucose homeostasis. Because tilapia insulin differs structurally from human insulin by 17 amino acids, we have produced transgenic tilapia whose islets stably express physiological levels of humanized insulin and have now bred these to homozygosity. These transgenic fish can serve as a platform for further development into a cell therapy product for diabetes.

  1. A review of piscine islet xenotransplantation using wild-type tilapia donors and the production of transgenic tilapia expressing a “humanized” tilapia insulin

    PubMed Central

    Wright, James R; Yang, Hua; Hyrtsenko, Olga; Xu, Bao-You; Yu, Weiming; Pohajdak, Bill

    2014-01-01

    Most islet xenotransplantation laboratories have focused on porcine islets, which are both costly and difficult to isolate. Teleost (bony) fish, such as tilapia, possess macroscopically visible distinct islet organs called Brockmann bodies which can be inexpensively harvested. When transplanted into diabetic nude mice, tilapia islets maintain long-term normoglycemia and provide human-like glucose tolerance profiles. Like porcine islets, when transplanted into euthymic mice, they are rejected in a CD4 T-cell-dependent manner. However, unlike pigs, tilapia are so phylogenetically primitive that their cells do not express α(1,3)Gal and, because tilapia are highly evolved to live in warm stagnant waters nearly devoid of dissolved oxygen, their islet cells are exceedingly resistant to hypoxia, making them ideal for transplantation within encapsulation devices. Encapsulation, especially when combined with co-stimulatory blockade, markedly prolongs tilapia islet xenograft survival in small animal recipients, and a collaborator has shown function in diabetic cynomolgus monkeys. In anticipation of preclinical xenotransplantation studies, we have extensively characterized tilapia islets (morphology, embryologic development, cell biology, peptides, etc.) and their regulation of glucose homeostasis. Because tilapia insulin differs structurally from human insulin by 17 amino acids, we have produced transgenic tilapia whose islets stably express physiological levels of humanized insulin and have now bred these to homozygosity. These transgenic fish can serve as a platform for further development into a cell therapy product for diabetes. PMID:25040337

  2. Influence of good manufacturing practices on the shelf life of refrigerated fillets of tilapia (Oreochromis niloticus) packed in modified atmosphere and gamma-irradiated

    PubMed Central

    Monteiro, Maria Lúcia Guerra; Mársico, Eliane Teixeira; Mano, Sérgio Borges; Teixeira, Claudia Emília; da Cruz Silva Canto, Anna Carolina Vilhena; de Carvalho Vital, Helio; Conte-Júnior, Carlos Adam

    2013-01-01

    This study evaluated the influence of good manufacturing practices (GMP) on the shelf life of refrigerated fillets of Nile tilapia (Oreochromis niloticus) packed in modified atmosphere packaging (MAP) and irradiated. In a first series of experiments, 120 tilapia fillets kept under controlled sanitary conditions were purchased from a fish market managed by a cooperative. A second lot totaling 200 tilapia fillets was obtained under controlled storage conditions from a pilot plant. The combined effects of MAP (40% CO2 and 60% N2) and irradiation (1.5 kGy) were investigated by monitoring physical and chemical (total volatile bases and pH), bacteriological (aerobic heterotrophic mesophilic and psychrophilic bacteria) and sensory (acceptance test) changes in the samples. The quality of samples decreased with storage time regardless of the treatment, remaining higher in fillets produced in the pilot plant in comparison with the commercially produced fillets. The observed shelf life of nonirradiated commercially produced fillets was only 3 days, compared to 8 days for those produced in the pilot plant, probably due to GMP in the latter. It was concluded that, even with a combination of proven conservation methods for meats, the adoption of good manufacturing practices still remains essential before, during, and after the filleting process in order to ensure the effectiveness of the entire treatment. PMID:24804034

  3. Influence of good manufacturing practices on the shelf life of refrigerated fillets of tilapia (Oreochromis niloticus) packed in modified atmosphere and gamma-irradiated.

    PubMed

    Monteiro, Maria Lúcia Guerra; Mársico, Eliane Teixeira; Mano, Sérgio Borges; Teixeira, Claudia Emília; da Cruz Silva Canto, Anna Carolina Vilhena; de Carvalho Vital, Helio; Conte-Júnior, Carlos Adam

    2013-07-01

    This study evaluated the influence of good manufacturing practices (GMP) on the shelf life of refrigerated fillets of Nile tilapia (Oreochromis niloticus) packed in modified atmosphere packaging (MAP) and irradiated. In a first series of experiments, 120 tilapia fillets kept under controlled sanitary conditions were purchased from a fish market managed by a cooperative. A second lot totaling 200 tilapia fillets was obtained under controlled storage conditions from a pilot plant. The combined effects of MAP (40% CO2 and 60% N2) and irradiation (1.5 kGy) were investigated by monitoring physical and chemical (total volatile bases and pH), bacteriological (aerobic heterotrophic mesophilic and psychrophilic bacteria) and sensory (acceptance test) changes in the samples. The quality of samples decreased with storage time regardless of the treatment, remaining higher in fillets produced in the pilot plant in comparison with the commercially produced fillets. The observed shelf life of nonirradiated commercially produced fillets was only 3 days, compared to 8 days for those produced in the pilot plant, probably due to GMP in the latter. It was concluded that, even with a combination of proven conservation methods for meats, the adoption of good manufacturing practices still remains essential before, during, and after the filleting process in order to ensure the effectiveness of the entire treatment.

  4. Human food safety and environmental hazards associated with the use of methyltestosterone and other steroids in production of all-male tilapia.

    PubMed

    Mlalila, Nichrous; Mahika, Charles; Kalombo, Lonji; Swai, Hulda; Hilonga, Askwar

    2015-04-01

    In recent years, all-male cultures of Nile tilapia (Oreochromis niloticus) have been the most preferred mode of production in aquaculture industry. All-male individuals achieve higher somatic growth rate and shut high energy losses associated with gonadal development and reproduction. The economic advantages of culturing all-male tilapia have led to the development of procedures for producing unisex cultures, using 17α-methyltestosterone (MT). Despite widespread use of the MT in tilapia farming, the implications of hormone treatment in relation to human health and the environment have raised a number of concerns in the scientific community. In this review, the hormonal application processes, economic and ecological significance of MT, food safety and residual MT, comparative uses of steroids in aquaculture, animal husbandry, and medicine have been briefly reviewed for regulatory guidelines, and finally, future research perspectives have been addressed. The review can be used as policy-making guidelines in aquaculture framework development as can be emphasized in African continent, among others. The most important conclusion to draw is that the quantity of MT used in conventional practice is large compared to the actual dose required for sex reversal, fish produced are safe for human consumptions, and the environmental hazards should be further emphasized.

  5. Tilapia Piscidin 4 (TP4) Stimulates Cell Proliferation and Wound Closure in MRSA-Infected Wounds in Mice

    PubMed Central

    Huang, Hang-Ning; Chan, Yi-Lin; Wu, Chang-Jer; Chen, Jyh-Yih

    2015-01-01

    Antimicrobial peptides (AMPs) are endogenous antibiotics that directly affect microorganisms, and also have a variety of receptor-mediated functions. One such AMP, Tilapia piscidin 4 (TP4), was isolated from Nile tilapia (Oreochromis niloticus); TP4 has antibacterial effects and regulates the innate immune system. The aim of the present study was to characterize the role of TP4 in the regulation of wound closure in mice and proliferation of a keratinocyte cell line (HaCaT) and fibroblast cell line (Hs-68). In vitro, TP4 stimulated cell proliferation and activated collagen I, collagen III, and keratinocyte growth factor (KGF) gene expression in Hs-68 cells, which induces keratin production by HaCaT cells. This effect was detectable at TP4 concentrations of 6.25 µg/mL in both cell lines. In vivo, TP4 was found to be highly effective at combating peritonitis and wound infection caused by MRSA in mouse models, without inducing adverse behavioral effects or liver or kidney toxicity. Taken together, our results indicate that TP4 enhances the survival rate of mice infected with the bacterial pathogen MRSA through both antimicrobial and wound closure activities mediated by epidermal growth factor (EGF), transforming growth factor (TGF), and vascular endothelial growth factor (VEGF). The peptide is likely involved in antibacterial processes and regulation of tissue homeostasis in infected wounds in mice. Overall, these results suggest that TP4 may be suitable for development as a novel topical agent for wound dressing. PMID:25955756

  6. Tilapia Piscidin 4 (TP4) Stimulates Cell Proliferation and Wound Closure in MRSA-Infected Wounds in Mice.

    PubMed

    Huang, Hang-Ning; Chan, Yi-Lin; Wu, Chang-Jer; Chen, Jyh-Yih

    2015-05-06

    Antimicrobial peptides (AMPs) are endogenous antibiotics that directly affect microorganisms, and also have a variety of receptor-mediated functions. One such AMP, Tilapia piscidin 4 (TP4), was isolated from Nile tilapia (Oreochromis niloticus); TP4 has antibacterial effects and regulates the innate immune system. The aim of the present study was to characterize the role of TP4 in the regulation of wound closure in mice and proliferation of a keratinocyte cell line (HaCaT) and fibroblast cell line (Hs-68). In vitro, TP4 stimulated cell proliferation and activated collagen I, collagen III, and keratinocyte growth factor (KGF) gene expression in Hs-68 cells, which induces keratin production by HaCaT cells. This effect was detectable at TP4 concentrations of 6.25 µg/mL in both cell lines. In vivo, TP4 was found to be highly effective at combating peritonitis and wound infection caused by MRSA in mouse models, without inducing adverse behavioral effects or liver or kidney toxicity. Taken together, our results indicate that TP4 enhances the survival rate of mice infected with the bacterial pathogen MRSA through both antimicrobial and wound closure activities mediated by epidermal growth factor (EGF), transforming growth factor (TGF), and vascular endothelial growth factor (VEGF). The peptide is likely involved in antibacterial processes and regulation of tissue homeostasis in infected wounds in mice. Overall, these results suggest that TP4 may be suitable for development as a novel topical agent for wound dressing.

  7. Assessment of Heavy-Metal Pollution in Sediments and Tilapia Fish Species in Kafue River of Zambia.

    PubMed

    Mbewe, Gezile; Mutondo, Moola; Maseka, Kenneth; Sichilongo, Kwenga

    2016-10-01

    We report results from an evaluation of the levels of heavy metals, i.e., copper (Cu), cadmium (Cd), lead (Pb), nickel (Ni), manganese (Mn), chromium (Cr), and iron (Fe) in sediment and tilapia fish samples from a wide stretch of the Kafue river of Zambia. In sediment samples, the highest Pb and Fe concentrations were recorded at Hippo Dam, i.e., 36.2 ± 0.1 mg/kg dw and 733 ± 37 mg/kg dw at Kafue Town, respectively. Other notably high metal concentrations in sediment were Cr at Kafue Bridge (42.5 ± 0.1 mg/kg dw [dw]), Cu at Mpongwe (233 ± 5 mg/kg dw), and Mn at Kafue Town (133 ± 1 mg/kg dw); it was highest at Ithezi Tezhi Dam at 166 ± 1 mg/kg d. Three fish species, i.e., three-spot bream Tilapia andersonii, red-breasted bream T. rendalli, and nile tilapia Oreochromis niloticus were evaluated for levels of the seven metals. The concentrations of the metals in these fish species afforded estimation of the biota sediment-accumulation factor, which is the ratio of the concentration of the metal in liver to that in the sediment. The coefficients of condition (K) values, which give an indication of the health of the fish, were also estimated. The K values ranged from 2.5 ± 0.5 to 5.1 ± 0.6 in all of the three fish species. Partial least squares analysis showed that heavy metals are generally sequestered evenly in all of the parts of all of the three fish species except for elevated levels of Mn, Cd, and Pb in the liver samples.

  8. Signatures of selection in tilapia revealed by whole genome resequencing.

    PubMed

    Xia, Jun Hong; Bai, Zhiyi; Meng, Zining; Zhang, Yong; Wang, Le; Liu, Feng; Jing, Wu; Wan, Zi Yi; Li, Jiale; Lin, Haoran; Yue, Gen Hua

    2015-09-16

    Natural selection and selective breeding for genetic improvement have left detectable signatures within the genome of a species. Identification of selection signatures is important in evolutionary biology and for detecting genes that facilitate to accelerate genetic improvement. However, selection signatures, including artificial selection and natural selection, have only been identified at the whole genome level in several genetically improved fish species. Tilapia is one of the most important genetically improved fish species in the world. Using next-generation sequencing, we sequenced the genomes of 47 tilapia individuals. We identified a total of 1.43 million high-quality SNPs and found that the LD block sizes ranged from 10-100 kb in tilapia. We detected over a hundred putative selective sweep regions in each line of tilapia. Most selection signatures were located in non-coding regions of the tilapia genome. The Wnt signaling, gonadotropin-releasing hormone receptor and integrin signaling pathways were under positive selection in all improved tilapia lines. Our study provides a genome-wide map of genetic variation and selection footprints in tilapia, which could be important for genetic studies and accelerating genetic improvement of tilapia.

  9. Parasite treatment reduced Flavobacterium columnare infection in tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterium Flavobacterium columnare and parasite Trichodina are common pathogens of cultured fish. The authors conducted a study to evaluate whether treatment of Trichodina parasitized tilapia with formalin would improve fish survival and reduce F. columnare infection in fish. Tilapia parasitized by...

  10. Risk assessment of polychlorinated biphenyls (PCBs) and trace metals in River Nile up- and downstream of a densely populated area.

    PubMed

    Omar, Wael A; Mahmoud, Hamada M

    2017-02-01

    Cairo city is the largest populated area along the whole course of River Nile with a wide range of anthropogenic activities. Efforts to restore fish habitat and recreational use of the river have raised concerns about its water, sediment and biota quality. This study provides a baseline data on the levels of PCBs and trace metals in River Nile along Cairo sector and implements the formulation of monitoring activities of the river's pollution status. Water, sediment and Nile tilapia (Oreochromis niloticus) samples were collected during summer season, 2013 from two sites, up- and downstream, for detection and determination of 11 PCB congeners (PCBs 28, 44, 52, 70, 101, 105, 118, 138, 152, 180 and 192) as well as six trace metals (Cu, Zn, Mn, Cd, Pb and Fe). Evidences of long- or short-term exposures to these contaminants as well as its accumulation tendency were assessed by integrating the obtained analytical results of biotic and abiotic components of this aquatic ecosystem. All calculated lifetime cancer risk values for PCBs showed unacceptable risk of cancer for human consumers at both normal and subsistence fish consumption rates. The calculated hazard index for total PCBs indicates that fish are not safe for human consumption except in site 1 at normal consumption rate. Meanwhile, trace metals do not pose unacceptable risks at both consumption rates except for Pb in site 1 at subsistence consumption rate.

  11. Safety of feed treated with 17a-methyltestosterone (17MT) to larval Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a synthetic androgen, 17 a-methyltestosterone (17MT) is frequently used to redirect the course of sex differentiation by exposing the undifferentiated gonad at sufficient dosage. This hormone has been widely accepted as a safe and effective treatment for sex-reversal in many fish species, and it...

  12. Genomic Diversity of Streptoccocus agalactiae Isolates from Multiple Hosts and Their Infectivity in Nile Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, the Lancefield group B Streptococcus (GBS), has a broad host range and can be pathogenic to numerous animals, including fish. GBS is most recognized for causing cattle mastitis and human neonatal meningitis, it also causes fatal meningo-encephalitis in fish. We investigat...

  13. Complete genome sequence of a virulent Streptococcus agalactiae strain 138P isolated from disease Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complete genome of a virulent Streptococcus agalactiae strain 138P is 1838701 bp in size, containing 1831 genes. The genome has 1593 coding sequences, 152 pseudo genes, 16 rRNAs, 69 tRNAs, and 1 non-coding RNA. The annotation of the genome is added by the NCBI Prokaryotic Genome Annotation Pipel...

  14. Lead poisoning in Nile tilapia (Oreochromis niloticus): oxidant and antioxidant relationship.

    PubMed

    Tanekhy, Mahmoud

    2015-04-01

    Selenium and vitamin E are very effective antioxidant agents which play important roles in improving and development of aquaculture sector. This study was conducted to determine the protective and treatment effects of vitamin E and selenium against lead toxicity. Administration of both vitamin E and selenium ameliorated the adverse effects of lead acetate toxicity through significant increase in hemoglobin, packed cell volume, RBC count, WBC count, and lymphocytes compared to lead acetate-exposed groups especially after the 10th week. Also, it is revealed that severe decrease of total protein, calcium, phosphorous, and magnesium in lead acetate intoxicated group. On contrary, significant increase of blood parameters upon addition of vitamin E and selenium combined with/without lead. On the other hand, insignificant decreases of sAST, sALT, urea, and creatinine in group fed on vitamin E and selenium, while increase in lead acetate intoxicated group. Lead acetate caused increasing of lipid peroxidation level (malondialdehyde) and decreasing of superoxide dismutase activity and reduced glutathione level. From these results, it is concluded that exposure to lead acetate is considered as hepatotoxic environmental pollutant. Exposure to lead acetate induced significant effects on antioxidant status. Antioxidants (vitamin E and selenium) showed important roles to protect body against lipid peroxidation, which considered as the first step of cell membrane damage, in addition to the improvement of the endogenous antioxidant enzyme activities.

  15. GENOMIC DIVERSITY OF STREPTOCCOCUS AGALACTIAE ISOLATES FROM MULTIPLE HOSTS AND THEIR INFECTIVITY IN NILE TILAPIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our laboratory has conducted multiple studies to investigate the genomic diversity of GBS isolates from different phylogenetic hosts and geographical regions. We have examined fish and dolphin GBS strains using phenotypic, serological typing and multilocus sequence typing (MLST) techniques and comp...

  16. Parasite fauna of farmed Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) in Uganda.

    PubMed

    Akoll, Peter; Konecny, Robert; Mwanja, Wilson W; Nattabi, Juliet K; Agoe, Catherine; Schiemer, Fritz

    2012-01-01

    An intensive parasite survey was conducted in 2008 to better understand the parasite fauna occurrence, distribution and diversity in the commercial aquaculture fish species in Uganda. A total of 265 fish collected from hatcheries and grow-out systems were examined for parasites using routine parasitological techniques. The survey yielded 17 parasite species: 11 from Oreochromis niloticus and ten from Clarias gariepinus. Four parasites-Amirthalingamia macracantha, Monobothrioides sp., Zoogonoides sp. and a member of the family Amphilinidae-were recorded for the first time in the country. The parasite diversity was similar between hosts; however, O. niloticus was dominated by free-living stage-transmitted parasites in lower numbers, whereas both trophically and free-living stage-transmitted parasites were equally represented in C. gariepinus in relatively high intensities. The patterns in parasite numbers and composition in the two hosts reflect differences in fish habitat use and diet. A shift in parasite composition from monoxenous species-dominated communities in small-sized fish to heteroxenous in large fishes was recorded in both hosts. This was linked to ontogenetic feeding changes and prolonged exposure to parasites. Polyculture systems showed no effect on parasite intensity and composition. The gills were highly parasitized, mainly by protozoans and monogeneans. Generally, the occurrence and diversity of parasites in these fish species highlight the likelihood of disease outbreak in the proposed intensive aquaculture systems. This calls for raising awareness in fish health management among potential farmers, service providers and researchers.

  17. Feeding motivation as a personality trait in Nile tilapia (Oreochromis niloticus): role of serotonergic neurotransmission.

    PubMed

    Silva, Patricia I M; Martins, Catarina I M; Höglund, Erik; Gjøen, Hans Magnus; Øverli, Øyvind

    2014-10-01

    Consistent individual variation in behaviour and physiology (i.e. animal personality or coping style) has emerged as a central topic in many biological disciplines. Yet, underlying mechanisms of crucial personality traits like feeding behaviour in novel environments remain unclear. Comparative studies, however, reveal a strong degree of evolutionary conservation of neural mechanisms controlling such behaviours throughout the vertebrate lineage. Previous studies have indicated duration of stress-induced anorexia as a consistent individual characteristic in teleost fishes. This study aims to determine to what degree brain 5-hydroxytryptamine (5-HT, serotonin) activity pertains to this aspect of animal personality, as a correlate to feed anticipatory behaviour and recovery of feed intake after transfer to a novel environment. Crucial to the definition of animal personality, a strong degree of individual consistency in different measures of feeding behaviour (feeding latency and feeding score), was demonstrated. Furthermore, low serotonergic activity in the hypothalamus was highly correlated with a personality characterized by high feeding motivation, with feeding motivation represented as an overall measure incorporating several behavioural parameters in a Principle Component Analyses (PCA). This study thus confirms individual variation in brain 5-HT neurotransmission as a correlate to complex behavioural syndromes related to feeding motivation.

  18. Nile Tilapia Infectivity by Genomically Diverse Streptoccocus agalactiae Isolates from Multiple Hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, Lancefield group B Streptococcus (GBS), is recognized for causing cattle mastitis, human neonatal meningitis, and fish meningo-encephalitis. We investigated the genomic diversity of GBS isolates from different phylogenetic hosts and geographical regions using serological t...

  19. The safety of 17a-methyltestosterone administered in feed to larval Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Techniques developed to control sexual differentiation in fishes have typically involved androgen or estrogen (i.e., steroid) treatment, which directs sexual differentiation toward males or females. Treatment regimens have included immersion of larval fish in water containing a steroid, incorporati...

  20. Alteration in gene expression in Nile tilapia (Oreochromis niloticus) juveniles submitted to fasting and refeeding.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most important biological processes in living organisms that are affected by environmental fluctuations is growth, and the skeletal muscle growth in fish is dependent on proliferation and differentiation of myogenic precursor cells that are activated by Myogenic Regulatory Factors or inhi...

  1. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor®-medicated feed therapy

    USGS Publications Warehouse

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2013-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  2. Physicochemical changes of tilapia (Oreochromis niloticus) muscle during salting.

    PubMed

    Chaijan, Manat

    2011-12-01

    The effect of wet and dry saltings on the physicochemical changes of tilapia (Oreochromis niloticus) muscle was investigated. Dry salting resulted in the higher rate of salt uptake into tilapia muscle facilitating the faster decrease in Aw (p<0.05). The pH of both dry and wet salted fish muscles tended to decrease throughout the salting time and the lower pH was found in dry salted fish (p<0.05). The increase in the protein content in the salting medium was found during wet salted tilapia production (p<0.05). The TCA-soluble peptide content tended to decrease with increasing the salting time in both salting methods (p<0.05), suggesting a leaching effect of the salting medium or the exudative loss occurred in salted tilapia. Wet salting caused the greater formation of metmyoglobin in tilapia muscle when compared to dry salting at all time points (p<0.05) and the content of metmyoglobin increased as salting time increased in both salting methods (p<0.05). A lowered metmyoglobin with a lowered redness index of dry salted tilapia muscle was found, indicating the continuous oxidation of metmyoglobin to other hypervalent derivatives and hence the discolouration of salted tilapia. Lipid hydrolysis and oxidation of tilapia meat occurred with varying degrees in both salting methods and these changes depended on salting time. Dry salting resulted in a higher oxidation of tilapia muscle lipid as indicated by the higher PV and TBARS throughout the salting period when compared with that of wet salting (p<0.05). In conclusion, the physicochemical changes of tilapia muscle during salting are governed by the salting method and the salting time applied.

  3. Climate-based models for West Nile Culex mosquito vectors in the Northeastern US

    NASA Astrophysics Data System (ADS)

    Gong, Hongfei; Degaetano, Arthur T.; Harrington, Laura C.

    2011-05-01

    Climate-based models simulating Culex mosquito population abundance in the Northeastern US were developed. Two West Nile vector species, Culex pipiens and Culex restuans, were included in model simulations. The model was optimized by a parameter-space search within biological bounds. Mosquito population dynamics were driven by major environmental factors including temperature, rainfall, evaporation rate and photoperiod. The results show a strong correlation between the timing of early population increases (as early warning of West Nile virus risk) and decreases in late summer. Simulated abundance was highly correlated with actual mosquito capture in New Jersey light traps and validated with field data. This climate-based model simulates the population dynamics of both the adult and immature mosquito life stage of Culex arbovirus vectors in the Northeastern US. It is expected to have direct and practical application for mosquito control and West Nile prevention programs.

  4. Climate-based models for West Nile Culex mosquito vectors in the Northeastern US.

    PubMed

    Gong, Hongfei; DeGaetano, Arthur T; Harrington, Laura C

    2011-05-01

    Climate-based models simulating Culex mosquito population abundance in the Northeastern US were developed. Two West Nile vector species, Culex pipiens and Culex restuans, were included in model simulations. The model was optimized by a parameter-space search within biological bounds. Mosquito population dynamics were driven by major environmental factors including temperature, rainfall, evaporation rate and photoperiod. The results show a strong correlation between the timing of early population increases (as early warning of West Nile virus risk) and decreases in late summer. Simulated abundance was highly correlated with actual mosquito capture in New Jersey light traps and validated with field data. This climate-based model simulates the population dynamics of both the adult and immature mosquito life stage of Culex arbovirus vectors in the Northeastern US. It is expected to have direct and practical application for mosquito control and West Nile prevention programs.

  5. West Nile virus and "poliomyelitis".

    PubMed

    Sejvar, James J

    2004-07-27

    West Nile virus (WNV) has recently been associated with a syndrome of acute flaccid paralysis. Most cases of WNV-associated weakness have clinical, histopathologic, and electrophysiologic characteristics indistinguishable from those of poliomyelitis caused by infection with poliovirus. There is debate about the nomenclature of this manifestation of WNV infection. An historical perspective of the term "poliomyelitis" suggests that the term "WNV poliomyelitis" seems appropriate, but members of the neurologic and infectious disease communities should engage in discussion regarding the terminology of this syndrome.

  6. West Nile Virus: an overview.

    PubMed

    Hale, Deborah

    2015-05-01

    West Nile Virus is the most frequent cause of arboviral disease in the United States. It was first identified in the United States in 1999. Since that time, each of the 48 contiguous states in the United States has seen the disease, and it has been found in 96% of the U.S. counties in infected humans, mosquitoes, birds, horses, or other mammals. Although most often the disease resolves on its own, patients can develop serious and life-threatening complications, and may need further monitoring and treatment. This article reviews the prevalence, transmission, signs and symptoms, complications, treatment, surveillance, and prevention of the disease.

  7. Resource recovery from septic tank effluent using duckweed-based tilapia aquaculture.

    PubMed

    El-Shafai, Saber A; Abdel-Gawad, Fagr Kh; Samhan, Farag; Nasr, Fayza A

    2013-01-01

    Two parallel duckweed ponds were deployed to utilize nutrients from the effluent of a septic tank treating domestic wastewater. The effluent and fresh biomass of duckweed pond were fed to two subsequent fish ponds stocked with Nile tilapia (Oreochromis niloticus). Fish ponds receiving freshwater and commercial feed were used as control. The results of specific growth rate and feed conversion ratio showed no significant difference between the control ponds and treatment ponds. On the other hand, the total and net fish yields were significantly higher in the control. Microbial analysis revealed contamination of gills, intestine and liver of fish in the treatment ponds. The activity of the immune response genes was up-regulated in the brain and liver of the treatment samples. A micronucleus assay revealed a similar percentage of micronuclei in the polychromatic erythrocytes of blood in the control and treatment samples, while the treatment samples a had higher incidence of micronuclei in the polychromatic erythrocytes of gills, compared with the control.

  8. The impact of rearing environment on the development of gut microbiota in tilapia larvae

    PubMed Central

    Giatsis, Christos; Sipkema, Detmer; Smidt, Hauke; Heilig, Hans; Benvenuti, Giulia; Verreth, Johan; Verdegem, Marc

    2015-01-01

    This study explores the effect of rearing environment on water bacterial communities (BC) and the association with those present in the gut of Nile tilapia larvae (Oreochromis niloticus, Linnaeus) grown in either recirculating or active suspension systems. 454 pyrosequencing of PCR-amplified 16S rRNA gene fragments was applied to characterize the composition of water, feed and gut bacteria communities. Observed changes in water BC over time and differences in water BCs between systems were highly correlated with corresponding water physico-chemical properties. Differences in gut bacterial communities during larval development were correlated with differences in water communities between systems. The correlation of feed BC with those in the gut was minor compared to that between gut and water, reflected by the fact that 4 to 43 times more OTUs were shared between water and gut than between gut and feed BC. Shared OTUs between water and gut suggest a successful transfer of microorganisms from water into the gut, and give insight about the niche and ecological adaptability of water microorganisms inside the gut. These findings suggest that steering of gut microbial communities could be possible through water microbial management derived by the design and functionality of the rearing system. PMID:26658351

  9. Shifting Sediment Sources in the Quaternary Nile

    NASA Astrophysics Data System (ADS)

    Woodward, Jamie; Macklin, Mark; Fielding, Laura; Millar, Ian; Williams, Martin

    2016-04-01

    Invited Paper The Nile basin contains the longest river channel system in the world and drains about one tenth of the African continent. A dominant characteristic of the modern Nile is the marked spatial and temporal variability in the flux of water and sediment. Because the major headwater basins of the Nile are linked to key elements of the global climate system, the sedimentary records in the basin have attracted good deal of attention from the Quaternary palaeoclimate and palaeohydrology communities. Various approaches (from heavy minerals to strontium isotopes) have been employed to examine present and past patterns of sediment yield in the basin. A good deal of work has been carried out on the long sediment records in the delta and offshore which provide high resolution archives of hydrological changes in the upstream basin as well fluctuations in the input of dust from the desert. The sediment load of the modern desert Nile (downstream of Khartoum) is dominated by sediment inputs from the Blue Nile (61 +/- 5%) and Atbara (35 +/- 4%), whilst the White Nile contribution is meagre (3 +/- 2%) (Padoan et al. 2011). Recent work has shown that these values were very different during humid phases of the Quaternary when stronger Northern Hemisphere summer insolation produced wetter conditions across North Africa. In the early Holocene, for example, the Nile floodplain in Northern Sudan shows a tributary wadi input of 40-50%. This paper will review three decades of work on the sediment delivery dynamics of the Quaternary Nile and explore their palaeoclimatic implications. Padoan, M., Garzanti, E., Harlavan, Y., Villa, I.M. (2011) Tracing Nile sediment sources by Sr and Nd isotope signatures (Uganda, Ethiopia, Sudan). Geochim. Cosmochim. Acta 75 (12), 3627-3644.

  10. The utilization of Vallisneria aethiopica, Brassica oleracea and Pennisetum clandestinum by Tilapia rendalli

    NASA Astrophysics Data System (ADS)

    Hlophe, S. N.; Moyo, N. A. G.

    A common lawn grass; kikuyu grass, an abundant vegetable; cabbage and vallisneria a common macrophyte were tested for utilisation by two size classes of a herbivorous fish, Tilapia rendalli held in glass aquarium tanks. The test feeds were given to sub-adult T. rendalli for 133 days at 8% body weight and juvenile fish for 84 days at 15% body weight. Sub-adult and juvenile fish fed kikuyu grass attained a higher specific growth rate, higher protein efficiency ratio and better food conversion ratio than those fed cabbage and vallisneria. This is explained by the differences in the protein content, higher levels of lysine and the sulphur-containing amino acid, methionine in kikuyu grass. Palatability studies of the juveniles also showed that kikuyu was most preferred. However, sub-adults preferred vallisneria, kikuyu and cabbage respectively. The possible reasons for the selection are discussed.

  11. West Nile virus and the climate.

    PubMed

    Epstein, P R

    2001-06-01

    West Nile virus is transmitted by urban-dwelling mosquitoes to birds and other animals, with occasional "spillover" to humans. While the means by which West Nile virus was introduced into the Americas in 1999 remain unknown, the climatic conditions that amplify diseases that cycle among urban mosquitoes, birds, and humans are warm winters and spring droughts. This information can be useful in generating early warning systems and mobilizing timely and the most environmentally friendly public health interventions. The extreme weather conditions accompanying long-term climate change may also be contributing to the spread of West Nile virus in the United States and Europe.

  12. West Nile Virus and wildlife

    USGS Publications Warehouse

    Marra, P.P.; Griffing, S.; Caffrey, C.; Kilpatrick, A.M.; McLean, R.; Brand, C.; Saito, E.; Dupuis, A.P.; Kramer, Laura; Novak, R.

    2004-01-01

    West Nile virus (WNV) has spread rapidly across North America, resulting in human deaths and in the deaths of untold numbers of birds, mammals, and reptiles. The virus has reached Central America and the Caribbean and may spread to Hawaii and South America. Although tens of thousands of birds have died, and studies of some bird species show local declines, few regionwide declines can be attributed to WNV. Predicting future impacts of WNV on wildlife, and pinpointing what drives epidemics, will require substantial additional research into host susceptibility, reservoir competency, and linkages between climate, mosquitoes, and disease. Such work will entail a collaborative effort between scientists in governmental research groups, in surveillance and control programs, and in nongovernmental organizations. West Nile virus was not the first, and it will not be the last, exotic disease to be introduced to the New World. Its spread in North America highlights the need to strengthen animal monitoring programs and to integrate them with research on disease ecology.

  13. Biological safety of fish (tilapia) collagen.

    PubMed

    Yamamoto, Kohei; Igawa, Kazunari; Sugimoto, Kouji; Yoshizawa, Yuu; Yanagiguchi, Kajiro; Ikeda, Takeshi; Yamada, Shizuka; Hayashi, Yoshihiko

    2014-01-01

    Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia) atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin) yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the Ministry of Health, Labour and Welfare of Japan. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine.

  14. Drought May Beckon Bigger West Nile Outbreaks

    MedlinePlus

    ... affect transmission of the virus between mosquitoes and birds by stressing birds or changing where they gather. Mosquitoes become infected ... West Nile virus when they feed on infected birds, according to the U.S. Centers for Disease Control ...

  15. West Nile virus: North American experience

    USGS Publications Warehouse

    Hofmeister, Erik K.

    2011-01-01

    West Nile virus, a mosquito-vectored flavivirus of the Japanese encephalitis serogroup, was first detected in North America following an epizootic in the New York City area in 1999. In the intervening 11 years since the arrival of the virus in North America, it has crossed the contiguous USA, entered the Canadian provinces bordering the USA, and has been reported in the Caribbean islands, Mexico, Central America and, more recently, South America. West Nile virus has been reported in over 300 species of birds in the USA and has caused the deaths of thousands of birds, local population declines of some avian species, the clinical illness and deaths of thousands of domestic horses, and the clinical disease in over 30 000 Americans and the deaths of over 1000. Prior to the emergence of West Nile virus in North America, St. Louis encephalitis virus and Dengue virus were the only other known mosquito-transmitted flaviviruses in North America capable of causing human disease. This review will discuss the North American experience with mosquito-borne flavivirus prior to the arrival of West Nile virus, the entry and spread of West Nile virus in North America, effects on wild bird populations, genetic changes in the virus, and the current state of West Nile virus transmission.

  16. West Nile Virus in California

    PubMed Central

    Lothrop, Hugh; Chiles, Robert; Madon, Minoo; Cossen, Cynthia; Woods, Leslie; Husted, Stan; Kramer, Vicki; Edman, John

    2004-01-01

    West Nile virus (WNV) was first isolated in California during July 2003 from a pool of Culex tarsalis collected near El Centro, Imperial County. WNV transmission then increased and spread in Imperial and Coachella Valleys, where it was tracked by isolation from pools of Cx. tarsalis, seroconversions in sentinel chickens, and seroprevalence in free-ranging birds. WNV then dispersed to the city of Riverside, Riverside County, and to the Whittier Dam area of Los Angeles County, where it was detected in dead birds and pools of Cx. pipiens quinquefasciatus. By October, WNV was detected in dead birds collected from riparian corridors in Los Angeles, west to Long Beach, and through inland valleys south from Riverside to San Diego County. WNV was reported concurrently from Arizona in mid-August and from Baja, Mexico, in mid-November. Possible mechanisms for virus introduction, amplification, and dispersal are discussed. PMID:15496236

  17. Heterozygous mutation of eEF1A1b resulted in spermatogenesis arrest and infertility in male tilapia, Oreochromis niloticus

    PubMed Central

    Chen, Jinlin; Jiang, Dongneng; Tan, Dejie; Fan, Zheng; Wei, Yingying; Li, Minghui; Wang, Deshou

    2017-01-01

    Eukaryotic elongation factor 1 alpha (eEF1A) is an essential component of the translational apparatus. In the present study, eEF1A1b was isolated from the Nile tilapia. Real-time PCR and Western blot revealed that eEF1A1b was expressed highly in the testis from 90 dah (days after hatching) onwards. In situ hybridization and immunohistochemistry analyses showed that eEF1A1b was highly expressed in the spermatogonia of the testis. CRISPR/Cas9 mediated mutation of eEF1A1b resulted in spermatogenesis arrest and infertility in the F0 XY fish. Consistently, heterozygous mutation of eEF1A1b (eEF1A1b+/−) resulted in an absence of spermatocytes at 90 dah, very few spermatocytes, spermatids and spermatozoa at 180 dah, and decreased Cyp11b2 and serum 11-ketotestosterone level at both stages. Further examination of the fertilization capacity of the sperm indicated that the eEF1A1b+/− XY fish were infertile due to abnormal spermiogenesis. Transcriptomic analyses of the eEF1A1b+/− testis from 180 dah XY fish revealed that key elements involved in spermatogenesis, steroidogenesis and sperm motility were significantly down-regulated compared with the control XY. Transgenic overexpression of eEF1A1b rescued the spermatogenesis arrest phenotype of the eEF1A1b+/− testis. Taken together, our data suggested that eEF1A1b is crucial for spermatogenesis and male fertility in the Nile tilapia. PMID:28266557

  18. N Isotopes in Nile Sediments (ethiopia, Sudan)

    NASA Astrophysics Data System (ADS)

    Padoan, M.; Villa, I. M.; Garzanti, E.; Galbusera, M.; Quistini, S.; Peruta, L.; El Kammar, A.

    2009-04-01

    The Nile is the most important river of the Eastern Mediterranean. Its water and sediment fluxes have greatly influenced marine circulation throughout the Quaternary, and are widely considered as possible causes for stagnation and formation of sapropel (Krom et al., 1999a; 2002; Talbot et al., 2000; Freydier et al., 2001; Weldeab et al., 2002; Scrivner et al., 2004). Variations in annual flooding and baseflow of the river Nile, controlled by climate changes, had major impact on the rise and demise of Egyptian dynasties (Stanley et al., 2003). In order to better define sedimentary sources of the Nile system and to obtain more robust results, we have analyzed Nd isotopes in sediments of all its major Sudanese and Ethiopian tributaries (Atbara, Gash, Abay, Didesa, Dabus, White Nile, Bahr Ez Zeraf) in several replicate samples. Analyses were carried out on distinct mud and sand fractions (<40 microns and 125-180 microns) of 30 samples, and systematic changes related to grain size and hydraulic-sorting processes could thus be investigated. On the same samples, companion studies are being carried out on Sr isotopes (Padoan et al., 2007) and on Pb isotopes at the Geological Survey of Israel (Harlavan et al., in preparation). Overall, isotopic signals are markedly different between the White Nile system, derived from largely Archean to Paleoproterozoic basement rocks, and Ethiopian tributaries, derived in diverse proportions from largely Neoproterozoic rift-shoulder basements and overlying Oligocene flood basalts. Isotopic signals of Main Nile sediments downstream of the Atbara confluence are close to those of Blue Nile sediments, indicating that detritus is mainly provided by the latter (Garzanti et al., 2006). In the White Nile branch, the 143Nd/144Nd ratio of the mud fraction is lower in the Bahr Ez Zeraf (0.51167) than in the White Nile downstrean of the Sobat confluence (0.51219), revealing significant sediment influx from the latter. In Blue Nile and Atbara branches

  19. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false West Nile virus serological reagents. 866.3940... virus serological reagents. (a) Identification. West Nile virus serological reagents are devices that consist of antigens and antisera for the detection of anti-West Nile virus IgM antibodies, in human...

  20. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false West Nile virus serological reagents. 866.3940... virus serological reagents. (a) Identification. West Nile virus serological reagents are devices that consist of antigens and antisera for the detection of anti-West Nile virus IgM antibodies, in human...

  1. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false West Nile virus serological reagents. 866.3940... virus serological reagents. (a) Identification. West Nile virus serological reagents are devices that consist of antigens and antisera for the detection of anti-West Nile virus IgM antibodies, in human...

  2. Water and Regional Stability: The Nile a Case Study

    DTIC Science & Technology

    2011-03-24

    of the Nile River basin include the Hydromet Survey (1967-1992) and Technical Cooperation Committee for the Promotion of the Development and...Environmental Protection of the Nile Basin (TECCONILE) (1992-1998) The Hydromet Survey was a mechanism for Riparians along the Nile River to receive

  3. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false West Nile virus serological reagents. 866.3940... virus serological reagents. (a) Identification. West Nile virus serological reagents are devices that consist of antigens and antisera for the detection of anti-West Nile virus IgM antibodies, in human...

  4. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false West Nile virus serological reagents. 866.3940... virus serological reagents. (a) Identification. West Nile virus serological reagents are devices that consist of antigens and antisera for the detection of anti-West Nile virus IgM antibodies, in human...

  5. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor(R)-medicated feed therapy (20 mg/kg BW/d for 10 days)

    USGS Publications Warehouse

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2013-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  6. Impacts of West Nile Virus on wildlife

    USGS Publications Warehouse

    Saito, E.K.; Wild, M.A.

    2004-01-01

    The recent epidemic of West Nile virus in the United States proved to be unexpectedly active and was the largest epidemic of the virus ever recorded. Much remains to be discovered about the ecology and epidemiology of West Nile virus in the United States, including which species are important in maintaining the virus in nature, why some species are more susceptible to lethal infection, and what environmental factors are important in predicting future epidemics. These factors will likely vary regionally, depending on local ecological characteristics. Until scientists better understand the virus and factors influencing its activity, predicting its effects for future seasons is impossible. However, experts are certain about one thing: West Nile virus is here to stay.

  7. Characterization of a piscirickettsiosis-like disease in Hawaiian tilapia.

    PubMed

    Mauel, Michael J; Miller, Debra L; Frazier, Kendall; Liggett, Alan D; Styer, L; Montgomery-Brock, Dee; Brock, James

    2003-02-27

    In 1994, tilapia (Oreochromis mossambicus and Sarotherodon melanotheron) in wild and farmed populations on Oahu, Hawaii, USA, began to die of an unknown disease that was similar but not identical to piscirickettsiosis in salmonids. Only tilapia were affected. Diseased tilapia often swam erratically and had trouble staying at depth. Scattered cutaneous haemorrhage and exophthalmia were often noted. In many cases, fish were found dead with no clinical signs. Gills exhibited epithelial hyperplasia with severe multifocal consolidation of secondary lamellae. Multiple granulomas were observed in the gills, spleen, kidney, choroid gland and testes, but not in the liver. Tilapia mortalities occurred only during the cooler months (October to April) of the year and were not recorded during the warmer months (May to September). The mortalities declined with each successive year, after the 1994 outbreak, and currently losses are sporadic. Oxytetracycline-medicated feed reduced mortality. Cytologic examination of blood smears revealed moderate to large numbers of Gram-negative, pleomorphic, intracellular bacteria in rare circulating monocytes. Histologically, some predilection for nervous tissue and brain was observed. When viewed with transmission electron microscopy, pleomorphic coccoid bacteria, measuring 0.56 +/- 0.14 x 0.7 +/- 0.20 microm, occurred free in the cytoplasm and within phagolysosomes. The organisms had a double cell wall, no defined nucleus and variable electron-dense and -lucent areas. Unlike Piscirickettsia salmonis, the agent of piscirickettsiosis, the Hawaiian tilapia Piscirickettsia-like organism (HTPLO) does not form craterform lesions in the liver and is active above 20 degrees C. HTPLO can be transmitted horizontally by cohabitation, and cold stress induces the syndrome in juvenile tilapia from farms where the disease is endemic.

  8. Use of Testing for West Nile Virus and Other Arboviruses

    PubMed Central

    Vanichanan, Jakapat; Salazar, Lucrecia; Wootton, Susan H.; Aguilera, Elizabeth; Garcia, Melissa N.; Murray, Kristy O.

    2016-01-01

    In the United States, the most commonly diagnosed arboviral disease is West Nile virus (WNV) infection. Diagnosis is made by detecting WNV IgG or viral genomic sequences in serum or cerebrospinal fluid. To determine frequency of this testing in WNV-endemic areas, we examined the proportion of tests ordered for patients with meningitis and encephalitis at 9 hospitals in Houston, Texas, USA. We identified 751 patients (567 adults, 184 children), among whom 390 (52%) experienced illness onset during WNV season (June–October). WNV testing was ordered for 281 (37%) of the 751; results indicated acute infection for 32 (11%). Characteristics associated with WNV testing were acute focal neurologic deficits; older age; magnetic resonance imaging; empirically prescribed antiviral therapy; worse clinical outcomes: and concomitant testing for mycobacterial, fungal, or other viral infections. Testing for WNV is underutilized, and testing of patients with more severe disease raises the possibility of diagnostic bias in epidemiologic studies. PMID:27537988

  9. Habitat associations, reproduction and diet of the Guinean tilapia Tilapia guineensis of the Gambia River floodplains.

    PubMed

    Louca, V; Lindsay, S W; Piyapong, C; Lucas, M C

    2010-06-01

    The ecology of the Guinean tilapia Tilapia guineensis a dominant species of the lower Gambia River floodplains and an important food source in parts of West Africa was studied to better understand the threat posed from construction of a barrage across the river. The catch per unit effort (CPUE) of T. guineensis was positively associated with conductivity and dissolved oxygen and negatively associated with water depth and the % vegetation cover. Diet studies indicated that the T. guineensis is primarily an iliophage. The peak of reproduction was at the beginning of the rainy season. CPUE peaked in May, just before the first rains, and subsequently declined, probably reflecting movement into newly flooded habitat. Median size at maturity was 11.6 cm total length, L(T), for females and 12.5 cm L(T) for males. L(T)-frequency analysis indicated several juvenile cohorts as well as very young fish on the floodplains each month, suggesting continuation of reproduction throughout the rainy season. The impending construction of a hydroelectric dam on the Gambia River is likely to affect T. guineensis negatively through anticipated changes in the hydrology of the river.

  10. Low-fat frankfurters from protein concentrates of tilapia viscera and mechanically separated tilapia meat

    PubMed Central

    Cavenaghi-Altemio, Angela D; Alcade, Lígia B; Fonseca, Gustavo G

    2013-01-01

    In order to develop a healthy low-fat frankfurter-type sausage, different formulations were developed with tilapia viscera surimi (T1) and two with mechanically separated tilapia meat (MSTM) surimi (T2 and T3), all without pig lard addition. Due to technological problems observed for T1 sausage during cooking, it was not further investigated. The functionality of the other two formulations was evaluated based on proximate composition, pH, water activity, and texture. Finally, microbiological and sensory analyses based on acceptance tests were performed. Listeria monocytogenes and Salmonella spp. were found to be absent. T2 showed higher frequencies for the attributes color (90.0%) and overall acceptability (86.7%), while T3 showed higher frequencies for taste (86.7%) and texture (96.7%). The surimi concentration was reflected in the physical properties of the sausages. It was found that the addition of MSTM surimi to sausage favored greater cutting strength (3.9 N for T2 and 4.9 N for T3). Beyond the surimi utilization, the total replacement of pig lard by cassava starch and soybean protein had also contributed with the texture properties. PMID:24804055

  11. Chemical restraint of the Nile hippopotamus (Hippopotamus amphibius) in captivity.

    PubMed

    Ramsay, E C; Loomis, M R; Mehren, K G; Boardman, W S; Jensen, J; Geiser, D

    1998-03-01

    This retrospective study describes 16 immobilizations performed on nine adult captive Nile hippopotamus (Hippopotamus amphibius). Animals were immobilized using intramuscular etorphine alone (1.0-5.0 micrograms/kg; n = 9) or in combination with xylazine (67-83 micrograms/kg; n = 6) or acepromazine (20 micrograms/kg; n = 1). Exact weights for the animals were unknown so drug dosages were based on estimated weights. Seven animals either were in good health or had minor or localized medical problems. Following etorphine and xylazine induction, one animal undergoing castration was anesthetized with isoflurane in oxygen delivered by endotracheal tube. Ten immobilizations occurred without complications, and eight of those procedures were rated as good or excellent. Complications, including bradypnea, cyanosis, and apnea, occurred during six immobilizations. One animal died following prolonged apnea, and the necropsy failed to find a specific cause of death. Immobilizations were reversed with diprenorphine alone (4.4-10.0 micrograms/kg; n = 13), diprenorphine (2.9 micrograms/kg) and naloxone (14.6 mu k/kg; n = 1), or naltrexone (146-180 micrograms/kg; n = 2). Mean time to reversal of immobilization for those animals given etorphine alone and reversed with diprenorphine alone was 21.6 min (n = 5). Time to reversal for the two immobilizations reversed with only naltrexone was 4 min. No renarcotizations were observed. Total doses of 2.0-6.0 mg etorphine i.m. should produce heavy sedation to surgical anesthesia in calm adult captive Nile hippopotamuses. Insufflation with oxygen during immobilization seems warranted.

  12. Determining the palaeodrainage of the Nile river from a provenance study of the Nile delta cone sediments

    NASA Astrophysics Data System (ADS)

    Fielding, Laura; Najman, Yani; Millar, Ian; Butterworth, Peter; Garzanti, Eduardo; Kneller, Ben

    2014-05-01

    This study documents the palaeodrainage history of the Nile River, in particular the time of its transition from a small locally sourced drainage network to the initiation of an extensive catchment. Today, the Nile drains as far south as Lake Victoria, with the White Nile draining largely cratonic rocks of Archean to Proterozoic age and the Blue Nile draining Cenozoic Ethiopian Continental Flood Basalts and Neoproterozoic basement. However, the timing of catchment expansion to the river's current extent is highly debated. Two end member models are: A) The Blue Nile did not connect with the lower Nile until the Late Messinian, and the White Nile not until 0.5 Ma. In this model, the pre-Messinian Nile delta sediments are locally derived from the Red Sea Hills (RSH) (Issawi and McCauley 1992). B) The Blue Nile has been connected to the lower Nile since the Oligocene (Burke and Wells 1989). Onshore fieldwork characterised each possible source area (Ethiopian flood basalts, Archean craton, and Neoproterozoic basement and Phanerozoic cover sequences of the RSH) using petrography, geochemistry and isotope studies. Tertiary-aged Nile delta sediments provide a unique archive of the river's palaeodrainage history, which were analysed from conventional core from exploration and appraisal wells in order to identify the occurrence (if any) of these sources in the delta geological record. Heavy mineral, petrographic, U/Pb rutile and Lu/Hf zircon analyses indicate Blue Nile and/or RSH input to the Nile delta since at least the Oligocene with very little input from the White Nile. Sr and Nd whole-rock analyses of mud samples allow discrimination between the Blue Nile and RSH sources and may, subject to further analyses, confirm Blue Nile input to the delta since the Oligocene. U-Pb zircon analyses reveal the presence of 20-30 Ma zircons in both the modern river sediments from the Ethiopian Highlands and the Nile Delta core from the early Miocene to present day indicating a

  13. Determining the Palaeodrainage of the Nile River from a Provenance Study of the Nile Delta Cone Sediments

    NASA Astrophysics Data System (ADS)

    Fielding, L.; Najman, Y.; Millar, I.; Butterworth, P.; Garzanti, E.; Kneller, B. C.

    2014-12-01

    This study documents the palaeodrainage history of the Nile River, in particular the time of its transition from a small locally sourced drainage network to the initiation of an extensive catchment. Today, the Nile drains as far south as Lake Victoria, with the White Nile draining largely cratonic rocks of Archean to Proterozoic age and the Blue Nile draining Cenozoic Ethiopian Continental Flood Basalts and Neoproterozoic basement. However, the timing of catchment expansion to the river's current extent is highly debated. Two end member models are: A) The Blue Nile did not connect with the lower Nile until the Late Messinian, and the White Nile not until 0.5 Ma. In this model, the pre-Messinian Nile delta sediments are locally derived from the Red Sea Hills (RSH) (Issawi and McCauley 1992). B) The Blue Nile has been connected to the lower Nile since the Oligocene (Burke and Wells 1989). Onshore fieldwork characterised each possible source area (Ethiopian flood basalts, Archean craton, and Neoproterozoic basement and Phanerozoic cover sequences of the RSH) using petrography, geochemistry and isotope studies. Tertiary-aged Nile delta sediments provide a unique archive of the river's palaeodrainage history, which were analysed from conventional core from exploration and appraisal wells in order to identify the occurrence (if any) of these sources in the delta geological record. Heavy mineral, petrographic, U/Pb rutile and Lu/Hf zircon analyses indicate Blue Nile and/or RSH input to the Nile delta since at least the Oligocene with very little input from the White Nile. Sr and Nd whole-rock analyses of mud samples allow discrimination between the Blue Nile and RSH sources and may, subject to further analyses, confirm Blue Nile input to the delta since the Oligocene. U-Pb zircon analyses reveal the presence of 20-30 Ma zircons in both the modern river sediments from the Ethiopian Highlands and the Nile Delta core from the early Miocene to present day indicating a

  14. The aquaculture potential of Tilapia rendalli in relation to its feeding habits and digestive capabilities

    NASA Astrophysics Data System (ADS)

    Hlophe, S. N.; Moyo, N. A. G.

    Tilapia rendalli is a predominately macrophagous fish. However, it was able to colonise an oligotrophic dam (Flag Boshielo) with limited macrophytes. Therefore, the diet of T. rendalli in this dam was investigated; its stomach contents were examined over 12 months. A size related dietary shift was evident. Juveniles fed mainly on zooplankton while sub-adult and adult fish grazed on both macrophytes and marginal vegetation. T. rendalli’s ability to strive in an environment with limited food resources led to a subsequent study to determine its aquaculture potential. Its growth performance was compared to that of the commonly cultured Oreochromis mossambicus. Juveniles of both species were fed a commercial tilapia diet for 60 days. Specific growth rate and protein efficiency ratio was comparable to that of O. mossambicus (P > 0.05, ANOVA). Feed conversion ratio was significantly higher (P < 0.05) in T. rendalli (1.43) than in O. mossambicus (1.25) indicating a better efficiency in feed utilisation by O. mossambicus. At a physiological level, protease, lipase and cellulase activities did not differ significantly between the two fish species (P > 0.05). Amylase activities were significantly higher (P < 0.05) in T. rendalli than in O. mossambicus. The highest amylase activities were recorded in the proximal intestines as 26.34 and 22.00 μmol/min/mg protein in T. rendalli and O. mossambicus respectively. This may be an indicator that T. rendalli is better equipped to digest plant diets. T. rendalli may be the aquaculture species of choice for emerging fish farmers who cannot afford the highly priced fishmeal as a protein source in fish diets.

  15. Evaluation of West Nile Virus Education Campaign

    PubMed Central

    Neuberger, John S.; Hansen, Gail; Fox, Michael H.

    2005-01-01

    We evaluated the 2003 Kansas West Nile virus public education campaign. Awareness was widespread but compliance was low. Spanish-speaking persons were poorly informed. Relevant factors included population segment variability, campaign content, media choice, and materials delivery methods. PMID:16318730

  16. Tracking Nile Delta vulnerability to Holocene change.

    PubMed

    Marriner, Nick; Flaux, Clément; Morhange, Christophe; Stanley, Jean-Daniel

    2013-01-01

    Understanding deltaic resilience in the face of Holocene climate change and human impacts is an important challenge for the earth sciences in characterizing the full range of present and future wetland responses to global warming. Here, we report an 8000-year mass balance record from the Nile Delta to reconstruct when and how this sedimentary basin has responded to past hydrological shifts. In a global Holocene context, the long-term decrease in Nile Delta accretion rates is consistent with insolation-driven changes in the 'monsoon pacemaker', attested throughout the mid-latitude tropics. Following the early to mid-Holocene growth of the Nile's deltaic plain, sediment losses and pronounced erosion are first recorded after ~4000 years ago, the corollaries of falling sediment supply and an intensification of anthropogenic impacts from the Pharaonic period onwards. Against the backcloth of the Saharan 'depeopling', reduced river flow underpinned by a weakening of monsoonal precipitation appears to have been particularly conducive to the expansion of human activities on the delta by exposing productive floodplain lands for occupation and irrigation agriculture. The reconstruction suggests that the Nile Delta has a particularly long history of vulnerability to extreme events (e.g. floods and storms) and sea-level rise, although the present sediment-starved system does not have a direct Holocene analogue. This study highlights the importance of the world's deltas as sensitive archives to investigate Holocene geosystem responses to climate change, risks and hazards, and societal interaction.

  17. Water balance dynamics in the Nile Basin

    USGS Publications Warehouse

    Senay, Gabriel B.; Asante, Kwabena; Artan, Guleid A.

    2009-01-01

    Understanding the temporal and spatial dynamics of key water balance components of the Nile River will provide important information for the management of its water resources. This study used satellite-derived rainfall and other key weather variables derived from the Global Data Assimilation System to estimate and map the distribution of rainfall, actual evapotranspiration (ETa), and runoff. Daily water balance components were modelled in a grid-cell environment at 0·1 degree (∼10 km) spatial resolution for 7 years from 2001 through 2007. Annual maps of the key water balance components and derived variables such as runoff and ETa as a percent of rainfall were produced. Generally, the spatial patterns of rainfall and ETa indicate high values in the upstream watersheds (Uganda, southern Sudan, and southwestern Ethiopia) and low values in the downstream watersheds. However, runoff as a percent of rainfall is much higher in the Ethiopian highlands around the Blue Nile subwatershed. The analysis also showed the possible impact of land degradation in the Ethiopian highlands in reducing ETa magnitudes despite the availability of sufficient rainfall. Although the model estimates require field validation for the different subwatersheds, the runoff volume estimate for the Blue Nile subwatershed is within 7·0% of a figure reported from an earlier study. Further research is required for a thorough validation of the results and their integration with ecohydrologic models for better management of water and land resources in the various Nile Basin ecosystems.

  18. Visualising DNA in Classrooms Using Nile Blue

    ERIC Educational Resources Information Center

    Milne, Christine; Roche, Scott; McKay, David

    2008-01-01

    Giving students the opportunity to extract, manipulate and visualise DNA molecules enhances a constructivist approach to learning about modern techniques in biology and biotechnology Visualisation usually requires agarose gel electrophoresis and staining. In this article, we report on an alternative DNA stain, Nile Blue A, that may be used in the…

  19. Nile perch: the great lake experiment.

    PubMed

    Ogutu-ohwayo, R

    1998-01-01

    In order to improve the fishery of Lake Victoria, a large predatory fish, the Nile perch (Lates niloticus), was introduced into the lake to feed on the smaller but abundant haplochromines, thereby producing a larger fish for food consumption. Originally the lake had a very high fish species diversity, dominated by more than 300 species of haplochromine cichlids; however, they were too small to be exploited for food. It took about 20 years for the population of the Nile perch in the lake to increase significantly. Although increased fish production has benefited riparian communities by providing revenue, employment, and food, the introduction of the Nile perch has also resulted in extinction and has transformed the lake ecosystem. In response to the concern caused by the introduction of the Nile perch, the deteriorating water quality, and the need to sustain the lucrative fishery, the governments of Uganda, Kenya, and Tanzania have initiated the multisectoral Lake Victoria Environment Management Programme. Its goals are to control the loading of nutrients and contaminants into the lake, manage land use in the catchment area, manage the introduced fish species, conserve biodiversity, and control the spread of water hyacinths.

  20. Does The Nile Reflect Solar Variability?

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Yung, Yuk

    2006-01-01

    Historical records of the Nile water level provide a unique opportunity to investigate the possibility that solar variability influences the Earth's climate. Particularly important are the annual records of the water level, which are uninterrupted for the years 622-1470 A.D. These records are non-stationary, so that standard spectral analyses cannot adequately characterize them. Here the Empirical Mode Decomposition technique, which is designed to deal with nonstationary, nonlinear time series, becomes useful. It allows the identification of two characteristic time scales in the water level data that can be linked to solar variability: the 88 year period and a time scale of about 200 years. These time scales are also present in the concurrent aurora data. Auroras are driven by coronal mass ejections and the rate of auroras is an excellent proxy for solar variability. Analysis of auroral data contemporaneous with the Nile data shows peaks at 88 years and about 200 years. This suggests a physical link between solar variability and the low frequency variations of the Nile water level. The link involves the influence of solar variability on the North Annual Mode of atmospheric variability and its North Atlantic and Indian Oceans patterns that affect rainfall over Eastern Equatorial Africa where the Nile originates.

  1. Molecular evolution of the Slc15 family and its response to waterborne copper and mercury exposure in tilapia.

    PubMed

    Huang, Qiansheng; Vera Delgado, Juan Manuel; Seni Pinoargote, Oscar David; Llaguno, Ricardo Avellán

    2015-06-01

    The solute carrier 15 family (Slc15), also called oligopeptide transporter family (Pept), was well-known for its role in the cellular uptake of di/tripeptides and peptide-like molecules. Our understanding of Slc15 family has already been enlarged since the rapid increasing of genome information; however, efforts are still expected to reveal the diversification of the family in an evolutionary manner. In the study, the sequence information were collected and analyzed through eleven eukaryotic organism representatives, especially in fish species. Gene expansion was observed through the evolution of the family. Further study was carried out with the representative species-Nile tilapia (Oreochromis niloticus). Tissue expression profiles were compared among members of the Slc15 family. Generally, they were all highly expressed both in the intestine and stomach, however, different members possessed its special tissue expression pattern. The mRNA levels of all the members (except Slc15a4) decreased after fasting while refeeding could restore the expression level. The recovery ability was impaired after exposure to environmental relevant concentration of copper (Cu(2+), 160 nmol/L). By contrast, mercury (Hg(2+), 25 nmol/L) did not exert significant impact on the recovery ability.

  2. Evaluating red-cockaded woodpeckers for exposure to West Nile Virus and blood parasites

    USGS Publications Warehouse

    Dusek, R.J.; Richardson, D.; Egstad, K.F.; Heisey, Dennis M.

    2006-01-01

    A marked decline in the Picoides borealis (Red-cockaded Woodpecker [RCW]) population at Noxubee National Wildlife Refuge, MS, was observed in 2002. Demographic changes - including absence of hatch-year birds, decreases in size of known groups, and loss of known groups-were identified during annual fall surveys and are uncharacteristic of RCW populations. In 2003, a serosurvey of 28 adult RCWs was conducted to investigate the presence of West Nile virus (WNV) exposure in the population, possibly providing insight into whether WNV may have been responsible for this decline. Blood smears were also examined from these birds for blood parasites. We found no evidence of West Nile virus exposure or blood parasites in any of the RCWs sampled. Further monitoring of the RCW population and WNV activity in other species at Noxubee NWR is recommended to further evaluate the potential role of WNV and blood parasites in their decline.

  3. Halogenated contaminants in farmed salmon, trout, tilapia, pangasius, and shrimp.

    PubMed

    van Leeuwen, S P J; van Velzen, M J M; Swart, C P; van der Veen, I; Traag, W A; de Boer, J

    2009-06-01

    Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDD/Fs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane diastereomers (HBCDs), and perfluorinated compounds (PFCs) were analyzed in popular farmed fish such as salmon, trout, tilapia, and pangasius and in farmed shrimp. The samples originated from southeast Asia, Europe, and South America. Results show the following: (i) Carnivorous species contained higher contaminant concentrations than omnivorous species. (ii) Contaminant concentrations generally decreased per species in the following order of salmon > trout > tilapia approximately equal to pangasius approximately equal to shrimp. (iii) Most contaminant concentrations decreased in the following order of PCBs approximately equal to dichloro-diphenyl-trichloroethanes (DDTs) > hexachlorobenzene approximately equal to pentachlorobenzene approximately equal to dieldrin approximately equal to PBDEs approximately equal to alpha-HBCD approximately equal to perfluorooctane sulfonate (PFOS) > World Health Organization toxic equivalents (WHO-TEQ) [PCDD/Fs and dioxin-like (dl)-PCBs]. (iv) Contaminant concentrations were very low (mostly <1 ng/g wet weight) and far below the European and Dutch legislative limits. (v) Contaminant concentrations in farmed shrimp, pangasius, and tilapia were lower than those in wild fish, whereas contaminant concentrations in farmed salmon and trout were higher than those in lean wild marine fish. From the five species investigated, salmon is predominantly responsible (97%) for human exposure to the sum of the investigated contaminants. The contribution of trout, tilapia, pangasius, and shrimp is small (3%) because contaminant concentrations and consumption volumes were much lower.

  4. Impacts of parasite infection on columnaris disease of tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is no information available on whether parasite infection will increase the susceptibility of tilapia to Flavobacterium columnare and whether parasite treatment could improve fish survival after F. columnare exposure. Two trials were conducted to evaluate 1) the susceptibility of hybrid tilapi...

  5. 20,000 years of Nile River dynamics and environmental changes in the Nile catchment area as inferred from Nile upper continental slope sediments

    NASA Astrophysics Data System (ADS)

    Revel, Marie; Ducassou, E.; Skonieczny, C.; Colin, C.; Bastian, L.; Bosch, D.; Migeon, S.; Mascle, J.

    2015-12-01

    Multi-proxy analysis of two marine sediment cores (MS27PT and MD04-2726) from the Nile continental slope provides evidence of changes in Nile sediment discharge related to changes in Ethiopian African Monsoon (EAM) precipitation, and allows us to reconstruct changes in Nile River runoff, vegetation and erosion in the Nile headwaters. Sediment element composition and neodymium isotopic composition reveal significant changes in clastic sediment provenance, with sources oscillating between a Saharan aeolian contribution during the Last Glacial Maximum/deglacial transition and during the Late Holocene, and a Blue/Atbara Nile fluvial contribution during the African Humid Period (AHP). This study provides a new understanding of past environmental changes. Between 14.6 and 14.13 ka there was a major input of sediments from the Ethiopian Highlands, consistent with a stronger EAM at that time. Climate in the Nile basin was wetter between 14.8 and 8.4 ka, with a corresponding increase in Blue Nile water and sediment discharge via the main Nile into the Eastern Mediterranean. The gradual climatic transition from the AHP to the present-day dry climate was reflected in a decrease in Blue Nile sediment deposition and flood discharge between 8.4 and 3.7 ka, with aridity at a maximum between 3.7 and 2.6 ka. The onset of drier conditions in the Blue Nile basin seems to have begun before the 8.2 ka cooling event in the North Atlantic. We speculate that the climatic change from the wet AHP to the dry late Holocene may have been a result of a break in the low latitude dynamic equilibrium between climate, vegetation and erosion, which may in turn have affected the climate in higher latitudes. Reduced Nile flow may also have had an impact on Levantine Intermediate Water originating in the Eastern Mediterranean through an increase in intermediate water formation.

  6. Geochemistry of sediments and surface soils from the Nile Delta and lower Nile valley studied by epithermal neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Arafa, Wafaa M.; Badawy, Wael M.; Fahmi, Naglaa M.; Ali, Khaled; Gad, Mohamed S.; Duliu, Octavian G.; Frontasyeva, Marina V.; Steinnes, Eiliv

    2015-07-01

    The distributions of 36 major and trace elements in 40 surface soil and sediment samples collected from the Egyptian section of the river Nile were determined by epithermal neutron activation analysis and compared with corresponding data for the Upper Continental Crust and North American Shale Composite. Their relative distributions indicate the presence of detrital material of igneous origin, most probably resulting from weathering on Ethiopian highlands and transported by the Blue Nile, the Nile main tributary. The distributions of the nickel, zinc, and arsenic contents suggest that the lower part of the Nile and its surroundings including the Nile Delta is not seriously polluted with metals from local human activity. The geographical distributions of Na, Cl, and I as well as results of principal component analysis suggest atmospheric supply of these elements from the ocean. In general the present data may contribute to a better understanding of the geochemistry of the Nile sediments.

  7. Blood lead concentrations in free-ranging Nile crocodiles (Crocodylus niloticus) from South Africa.

    PubMed

    Warner, Jonathan K; Combrink, Xander; Myburgh, Jan G; Downs, Colleen T

    2016-07-01

    Generally crocodilians have received little attention with regard to the effects of lead toxicity despite their trophic status as apex, generalist predators that utilize both aquatic and terrestrial habitats, thereby exposing them to a potentially wide range of environmental contaminants. During July-October 2010 we collected whole blood from 34 sub-adult and adult free-ranging Nile crocodiles (Crocodylus niloticus) from three separate populations in northeastern South Africa in order to analyze their blood lead concentrations (BPb). Concentrations ranged from below detectability (<3 μg/dL, n = 8) to 960 μg/dL for an adult male at the Lake St Lucia Estuary. Blood lead concentrations averaged 8.15 μg/dL (SD = 7.47) for females and 98.10 μg/dL (SD = 217.42) for males. Eighteen individuals (53 %) had elevated BPbs (≥10 μg/dL). We assessed 12 general linear models using Akaike's Information Criterion (AIC) and found no significant statistical effects among the parameters of sex, crocodile size and population sampled. On average, crocodiles had higher BPbs at Lake St Lucia than at Ndumo Game Reserve or Kosi Bay, which we attribute to lead sinker ingestion during normal gastrolith acquisition. No clinical effects of lead toxicosis were observed in these crocodiles, even though the highest concentration (960 μg/dL) we report represents the most elevated BPb recorded to date for a free-ranging vertebrate. Although we suggest adult Nile crocodiles are likely tolerant of elevated Pb body burdens, experimental studies on other crocodilian species suggest the BPb levels reported here may have harmful or fatal effects to egg development and hatchling health. In light of recent Nile crocodile nesting declines in South Africa we urge further BPb monitoring and ecotoxicology research on reproductive females and embryos.

  8. Molecular characterization of sdf1 and cxcr4 in the Mozambique tilapia, Oreochromis mossambicus.

    PubMed

    Amat-Fernandez, Jorge; Hammond, Michael J; Liang, Di; Wang, Tianfang; Ventura, Tomer; Elizur, Abigail; Cummins, Scott F

    2017-01-01

    Animal sexual reproduction relies on primordial germ cells (PGCs), the predecessors of the germ cell lineage, giving rise to either spermatogonia or oogonia after the completion of gonadal differentiation. There is limited information on the mechanism of PGC migration leading to the formation of the primordial gonad in Perciform fish. Oreochromis mossambicus, a tilapiine species, was investigated that is a commercially important aquaculture species in many parts of the world while in other areas it has become an invasive pest. Key components involved in PGC migration were identified, including the stromal-cell derived factor 1 (Om-sdf1a, Om-sdf1b) and the CXC receptor 4 (Om-cxcr4): both share conservation with existing model species. The spatial gene expression profiles were determined through transcript and protein analysis and displayed distinct localisation within the region of the developing gonad in larvae and within the adult gonads of certain cell populations. A recombinant Om-sdf1a was produced in Escherichia coli that activates Om-cxcr4 using a BRET-based yeast in vitro assay system, suggesting that it is structurally similar to the native Om-sdf1a and is appropriate for further structural studies. This study has improved understanding of the molecular basis of tilapia reproduction through investigation of gonad development, which may be important in the progression towards reproductive suppression methods to control tilapia populations in the wild. In addition, this research will facilitate developments in germ cell transplantation, an innovative technique that harnesses germ cell migration and allows the uptake of foreign germ cells, which differentiate to produce sperm or ova.

  9. West Nile Virus in Mosquitoes of Iranian Wetlands.

    PubMed

    Bagheri, Masoomeh; Terenius, Olle; Oshaghi, Mohammad Ali; Motazakker, Morteza; Asgari, Sassan; Dabiri, Farrokh; Vatandoost, Hassan; Mohammadi Bavani, Mulood; Chavshin, Ali Reza

    2015-12-01

    The West Nile virus (WNV) transmission cycle includes a wide range of migratory wetland birds as reservoirs, mosquitoes as biological vectors, and equines and humans as dead-end hosts. Despite the presence of potential vector species, there is no information about the existence of WNV in mosquito vectors in Iran. The Iranian West Azerbaijan Province is located in the northwestern part of Iran and has borders with Turkey, Iraq, Armenia, and the Republic of Azerbaijan. The current study was conducted to identify the wetland mosquitoes of the West Azerbaijan Province and their infection with WNV. In this study, 2143 specimens were collected, comprising 1541 adults and 602 larvae. Six species belonging to four genera were collected and identified: Anopheles maculipennis sensu lato (s.l.), Culex (Cx.) hortensis, Cx. pipiens s.l., Cx. theileri, Culiseta longiareolata, and Aedes (Ae.) (Ochlerotatus) caspius. In total, 45 pools of mosquitoes were examined. Two of the adult pools collected from the same location showed the presence of WNV in Ae. (Och.) caspius, from Sangar, Makoo County, as confirmed by PCR and sequencing. Due to the discovery of WNV in the mosquito population of the region, and the presence of wetlands and significant populations of migratory birds, the health sector should carefully monitor the factors involved in the cycle of this disease.

  10. The Carbon Cycle at the Nile Headwaters

    NASA Astrophysics Data System (ADS)

    Jones, Michael; Saunders, Matthew

    2014-05-01

    The carbon cycle at the Nile headwaters M B Jones, School of Natural Sciences, Trinity College, University of Dublin, Dublin 2, Ireland M Saunders, Environmental and Biochemical Sciences Group, The James Hutton Institute, Aberdeen, Scotland River systems play an integral role in the global carbon cycle by connecting the terrestrial biosphere, the atmosphere and the oceans. Extensive wetland systems, such as those found in the Amazon region, have been shown to export significant amounts of carbon to river waters as dissolved carbon dioxide (CO2) that can be transported and emitted hundreds of km downstream. The assessment of both regional and global carbon budgets could therefore be improved by quantifying these lateral carbon fluxes, especially from highly productive temporarily or permanently flooded areas where substantial CO2 evasion from inland waters can occur. The Nile is the longest river in the world and the headwaters are located in the extensive Papyrus dominated wetlands in central Africa that are associated with Lake Victoria. From its source the White Nile flows northwards through wetlands in Uganda and Sudan before it joins the Blue Nile. Papyrus wetlands have been shown to be some of the most productive global ecosystems, with recorded rates of aerial net primary productivity of up to 3.09 kg C m-2 yr-1. In addition, where anaerobic conditions occur they also accumulate large amounts of carbon in the form of peat, and under these circumstances they represent a significant carbon sink. However, as water moves through these wetlands and is exchanged with surrounding rivers and lakes significant quantities of dissolved organic and inorganic carbon as well as suspended particulate organic matter are exported, which are either released further downstream by degassing, decomposition or deposition. Information on such losses from these wetland ecosystems is extremely sparse but in order to better constrain ecosystem scale carbon dynamics more accurate

  11. Partial sodium replacement in tilapia steak without loss of acceptability.

    PubMed

    Monteiro, Maria Lúcia G; Mársico, Eliane T; Canto, Anna Carolina V C S; Costa-Lima, Bruno R C; Lázaro, César A; Cruz, Adriano G; Conte-Júnior, Carlos A

    2015-06-01

    The aim of this study was to evaluate physical and sensory characteristics of low-sodium tilapia steaks restructured with microbial transglutaminase. Polyphosphate (0.4%), condiment mixes-onion powder and garlic powder (2.5%), water (10.0%), transglutaminase (1.0%), and different types of salts (1.5%) were mixed with non-commercial sized fillets. Substitution of NaCl by KCl or MgCl2 (at 50% each) affected quality attributes and decreased (P < 0.05) consumer acceptability. The tri-salt steaks (KCl, MgCl2, and NaCl at 1:1:2 ratio) improved some attributes and increased (P < 0.05) acceptability and purchase intention. We conclude that potassium and magnesium chlorides are possible replacers of salt (NaCl) in restructured tilapia steaks and potentially decrease the risk factor for heart failure associated with high sodium consumption.

  12. Growth Performance and Resistance to Streptococcus iniae of Nile Tilapia, Oreochromis niloticus Fed Various Dietary Levels of Thiamin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thiamin or vitamin B1 functions in all cells as the coenzyme thiamin pyrophosphate that involves in the oxidative decarboxylation of an alpha-keto acids and the transketolase reactions in the pentose phosphate pathway. Thiamin has been demonstrated to be essential in diets of fish, and quantitative ...

  13. Response of AMP-activated protein kinase and energy metabolism to acute nitrite exposure in the Nile tilapia Oreochromis niloticus.

    PubMed

    Xu, Zhixin; Li, Erchao; Xu, Chang; Gan, Lei; Qin, Jian G; Chen, Liqiao

    2016-08-01

    Adenosine monophosphate-activated protein kinase (AMPK) is a prevalent mammalian energy metabolism sensor, but little is known about its role as an energy sensor in fish experiencing stress. We aimed to study AMPK in Oreochromis niloticus on both the molecular and the physical level. We found that the cDNAs encoding the AMPKα1 and AMPKα2 variants of the O. niloticus catalytic α subunit were 1753bp and 2563 bp long and encoded 571 and 557 amino acids, respectively. Both the AMPKα1 and the AMPKα2 isoform possess structural features similar to mammalian AMPKα, including a phosphorylation site at Thr172 in the N-terminus, and exhibit high homology with other fish and vertebrate AMPKα sequences (81.3%-98.1%). mRNA encoding the AMPKα isoforms was widely expressed in various tissues with distinctive patterns. AMPKα1 and AMPKα2 were primarily expressed in the intestines and brain, respectively. Under acute nitrite challenge, the mRNA encoding the AMPKα isoforms, as well as AMPK activity, changed over time. Its recovery period in freshwater, combined with the fact that it is highly conserved, suggests that fish AMPK, like its mammalian orthologues, acts as an energy metabolism sensor. Furthermore, subsequent decreases in AMPK mRNA levels and activity suggested that its action was transient but efficient. Physically, glucose, lactic acid and TGs in plasma, as well as energy materials in the hepatopancreas and muscle, were significantly altered over time, indicating changes in energy metabolism during the experimental period. These data have enabled us to characterize energy utilization in O. niloticus and further illustrate the role of fish AMPK as an energy sensor. This study provides new insight into energy metabolism and sensing by AMPK in teleost and necessitates further study of the multiple physiologic roles of AMPK in fish.

  14. Effects feeding zilpaterol hydrochloride on growth performance, fillet yeild, and body composition of rainbow trout, nile, tilapia, and channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zilpaterol hydrochloride (ZH) is a potent ß-adrenergic agonist (BAA) that has been used in feedlot cattle to increase average daily gain, feed efficiency, yield of trimmed cuts, and dress out percent. While positive effects of ZH have been observed in cattle, there have been no reports of this prod...

  15. Modulation of genotoxicity and endocrine disruptive effects of malathion by dietary honeybee pollen and propolis in Nile tilapia (Oreochromis niloticus)

    PubMed Central

    Kandiel, Mohamed M.M.; El-Asely, Amel M.; Radwan, Hasnaa A.; Abbass, Amany A.

    2013-01-01

    The present study aimed at verifying the usefulness of dietary 2.5% bee-pollen (BP) or propolis (PROP) to overcome the genotoxic and endocrine disruptive effects of malathion polluted water in Oreochromis niloticus (O. niloticus). The acute toxicity test was conducted in O. niloticus in various concentrations (0–8 ppm); mortality rate was assessed daily for 96 h. The 96 h-LC50 was 5 ppm and therefore 1/5 of the median lethal concentration (1 ppm) was used for chronic toxicity assessment. In experiment (1), fish (n = 8/group) were kept on a diet (BP/PROP or without additive (control)) and exposed daily to malathion in water at concentration of 5 ppm for 96 h “acute toxicity experiment”. Protective efficiency against the malathion was verified through chromosomal aberrations (CA), micronucleus (MN) and DNA-fragmentation assessment. Survival rate in control, BP and PROP groups was 37.5%, 50.0% and 100.0%, respectively. Fish in BP and PROP groups showed a significant (P < 0.05) reduction in the frequency of CA (57.14% and 40.66%), MN (53.13% and 40.63%) and DNA-fragmentation (53.08% and 30.00%). In experiment (2), fish (10 males and 5 females/group) were kept on a diet with/without BP for 21 days before malathion-exposure in water at concentration of 0 ppm (control) or 1 ppm (Exposed) for further 10 days “chronic toxicity experiment”. BP significantly (P < 0.05) reduced CA (86.33%), MN (82.22%) and DNA-fragmentation (93.11%), prolonged the sperm motility when exposed to 0.01 ppm of pollutant in vitro and increased the estradiol level in females comparing to control. In conclusion, BP can be used as a feed additive for fish prone to be raised in integrated fish farms or cage culture due to its potency to chemo-protect against genotoxicity and sperm-teratogenicity persuaded by malathion-exposure. PMID:25685536

  16. A microwave-irradiated Streptococcus agalactiae vaccine provides partial protection against experimental challenge in Nile tilapia, Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microwave irradiation, as opposed to formalin exposure, has not routinely been used in the preparation of killed vaccines despite the advantages of decreased chemical toxicity, ability to kill cells quickly, ease of completion requiring only a standard microwave, and potential increased protein cons...

  17. Development and efficacy of novobiocin and rifampicin-resistant Aeromonas hydrophila as novel vaccines in channel catfish and Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three attenuated Aeromonas hydrophila vaccines were developed from the virulent 2009 West Alabama isolates through selection for resistance to both novobiocin and rifampicin. When channel catfish (Ictalurus punctatus) were IP injected with 4×105 colony-forming units (CFU) of the mutants, no fish die...

  18. Effects of 11-ketotestosterone and fishmeal in the feed on growth of juvenile tilapia (Oreochromis mossambicus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of 11-ketotestosterone (11KT) and dietary fishmeal on growth of tilapia (Oreochromis mossambicus) were examined. Juvenile tilapia, weighing about 8g, were reared for 50 days with isonitrogenous and isocaloric diets containing fishmeal or all plant proteins, each with or without supplemen...

  19. The safety of 17a-Methyltestosterone medicated feed to tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    17a-Methyltestosterone (17MT) is used in U.S. aquaculture under an Investigational New Animal Drug exemption to produce male populations of tilapia. Efforts to gain FDA-approval include this Target Animal Safety study. A study was designed to determine its histological safety to tilapia when fed a...

  20. Primer prueba de desafio controlado en tilapia del Nilo Para Resistencia a Streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intensification of tilapia production has resulted in disease outbreaks that negatively affect commercial fish farmers. One bacterial pathogen that commonly causes losses in tilapia production is Streptococcus iniae. Control and prevention of S. iniae can be difficult and requires an integrated fish...

  1. 17a-Methyltestosterone - Medicated feed administered to Tilapia: Survival and pathologies.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    17a-Methyltestosterone (17MT) is used in U.S. aquaculture under an Investigational New Animal Drug exemption to produce male populations of tilapia. Efforts to gain FDA-approval include this Target Animal Safety study. A study was designed to determine its histological safety to tilapia when fed a...

  2. Treatment of Trichodina sp. reduced load of Flavobacterium colummnare and improved survival of hybrid tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasites and bacteria are common inhabitants in water of fish farms. The effect of parasite treatment on Flavobacterium columnare infection in tilapia is currently unknown. This study evaluated whether treatment of Trichodina sp. parasitized hybrid tilapia (Oreochromis niloticus × O. aureus) would...

  3. Characterization and functional analysis of hypoxia-inducible factor HIF1α and its inhibitor HIF1αn in tilapia

    PubMed Central

    Li, Hong Lian; Gu, Xiao Hui; Li, Bi Jun; Chen, Xiao; Lin, Hao Ran; Xia, Jun Hong

    2017-01-01

    Hypoxia is a major cause of fish morbidity and mortality in the aquatic environment. Hypoxia-inducible factors are very important modulators in the transcriptional response to hypoxic stress. In this study, we characterized and conducted functional analysis of hypoxia-inducible factor HIF1α and its inhibitor HIF1αn in Nile tilapia (Oreochromis niloticus). By cloning and Sanger sequencing, we obtained the full length cDNA sequences for HIF1α (2686bp) and HIF1αn (1308bp), respectively. The CDS of HIF1α includes 15 exons encoding 768 amino acid residues and the CDS of HIF1αn contains 8 exons encoding 354 amino acid residues. The complete CDS sequences of HIF1α and HIF1αn cloned from tilapia shared very high homology with known genes from other fishes. HIF1α show differentiated expression in different tissues (brain, heart, gill, spleen, liver) and at different hypoxia exposure times (6h, 12h, 24h). HIF1αn expression level under hypoxia is generally increased (6h, 12h, 24h) and shows extremely highly upregulation in brain tissue under hypoxia. A functional determination site analysis in the protein sequences between fish and land animals identified 21 amino acid sites in HIF1α and 2 sites in HIF1αn as significantly associated sites (α = 0.05). Phylogenetic tree-based positive selection analysis suggested 22 sites in HIF1α as positively selected sites with a p-value of at least 95% for fish lineages compared to the land animals. Our study could be important for clarifying the mechanism of fish adaptation to aquatic hypoxia environment. PMID:28278251

  4. Characterization and functional analysis of hypoxia-inducible factor HIF1α and its inhibitor HIF1αn in tilapia.

    PubMed

    Li, Hong Lian; Gu, Xiao Hui; Li, Bi Jun; Chen, Xiao; Lin, Hao Ran; Xia, Jun Hong

    2017-01-01

    Hypoxia is a major cause of fish morbidity and mortality in the aquatic environment. Hypoxia-inducible factors are very important modulators in the transcriptional response to hypoxic stress. In this study, we characterized and conducted functional analysis of hypoxia-inducible factor HIF1α and its inhibitor HIF1αn in Nile tilapia (Oreochromis niloticus). By cloning and Sanger sequencing, we obtained the full length cDNA sequences for HIF1α (2686bp) and HIF1αn (1308bp), respectively. The CDS of HIF1α includes 15 exons encoding 768 amino acid residues and the CDS of HIF1αn contains 8 exons encoding 354 amino acid residues. The complete CDS sequences of HIF1α and HIF1αn cloned from tilapia shared very high homology with known genes from other fishes. HIF1α show differentiated expression in different tissues (brain, heart, gill, spleen, liver) and at different hypoxia exposure times (6h, 12h, 24h). HIF1αn expression level under hypoxia is generally increased (6h, 12h, 24h) and shows extremely highly upregulation in brain tissue under hypoxia. A functional determination site analysis in the protein sequences between fish and land animals identified 21 amino acid sites in HIF1α and 2 sites in HIF1αn as significantly associated sites (α = 0.05). Phylogenetic tree-based positive selection analysis suggested 22 sites in HIF1α as positively selected sites with a p-value of at least 95% for fish lineages compared to the land animals. Our study could be important for clarifying the mechanism of fish adaptation to aquatic hypoxia environment.

  5. Identification of a Novel RNA Virus Lethal to Tilapia

    PubMed Central

    Eyngor, Marina; Zamostiano, Rachel; Kembou Tsofack, Japhette Esther; Berkowitz, Asaf; Bercovier, Hillel; Tinman, Simon; Lev, Menachem; Hurvitz, Avshalom; Galeotti, Marco; Eldar, Avi

    2014-01-01

    Tilapines are important for the sustainability of ecological systems and serve as the second most important group of farmed fish worldwide. Significant mortality of wild and cultured tilapia has been observed recently in Israel. The etiological agent of this disease, a novel RNA virus, is described here, and procedures allowing its isolation and detection are revealed. The virus, denominated tilapia lake virus (TiLV), was propagated in primary tilapia brain cells or in an E-11 cell line, and it induced a cytopathic effect at 5 to 10 days postinfection. Electron microscopy revealed enveloped icosahedral particles of 55 to 75 nm. Low-passage TiLV, injected intraperitoneally in tilapia, induced a disease resembling the natural disease, which typically presents with lethargy, ocular alterations, and skin erosions, with >80% mortality. Histological changes included congestion of the internal organs (kidneys and brain) with foci of gliosis and perivascular cuffing of lymphocytes in the brain cortex; ocular inflammation included endophthalmitis and cataractous changes of the lens. The cohabitation of healthy and diseased fish demonstrated that the disease is contagious and that mortalities (80 to 100%) occur within a few days. Fish surviving the initial mortality were immune to further TiLV infections, suggesting the mounting of a protective immune response. Screening cDNA libraries identified a TiLV-specific sequence, allowing the design of a PCR-based diagnostic test. This test enables the specific identification of TiLV in tilapines and should help control the spread of this virus worldwide. PMID:25232154

  6. Probiotic legacy effects on gut microbial assembly in tilapia larvae

    PubMed Central

    Giatsis, Christos; Sipkema, Detmer; Ramiro-Garcia, Javier; Bacanu, Gianina M.; Abernathy, Jason; Verreth, Johan; Smidt, Hauke; Verdegem, Marc

    2016-01-01

    The exposure of fish to environmental free-living microbes and its effect on early colonization in the gut have been studied in recent years. However, little is known regarding how the host and environment interact to shape gut communities during early life. Here, we tested whether the early microbial exposure of tilapia larvae affects the gut microbiota at later life stages. The experimental period was divided into three stages: axenic, probiotic and active suspension. Axenic tilapia larvae were reared either under conventional conditions (active suspension systems) or exposed to a single strain probiotic (Bacillus subtilis) added to the water. Microbial characterization by Illumina HiSeq sequencing of 16S rRNA gene amplicons showed the presence of B. subtilis in the gut during the seven days of probiotic application. Although B. subtilis was no longer detected in the guts of fish exposed to the probiotic after day 7, gut microbiota of the exposed tilapia larvae remained significantly different from that of the control treatment. Compared with the control, fish gut microbiota under probiotic treatment was less affected by spatial differences resulting from tank replication, suggesting that the early probiotic contact contributed to the subsequent observation of low inter-individual variation. PMID:27670882

  7. Nile behaviour and Upper Palaeolithic humans in Upper Egypt

    NASA Astrophysics Data System (ADS)

    Vermeersch, Pierre M.

    2014-05-01

    There is evidence of a decreasing human occupation of the Upper Egyptian Nile valley during the MIS 5 to MIS 3 period. Whereas very large extraction sites of the Middle Stone Age have been recorded, only very few sites of the Upper Palaeolithic have been found. The best explanation of this fact is that during the Late Middle Stone Age and the Upper Palaeolithc there was nearly no need for raw materials because there was only a very restricted population present in Upper Egypt. From about 22 ka BP an important population increase is registered by the presence of numerous Late Palaeolithic sites. During the whole LGM there is abundant presence of humans along the Nile Valley in Upper Egypt. This population was mainly living from fishing. There seems to be an abrupt end of the Palaeolithic occupation after 12.8 ka BP. Until now, no sites were found in the Valley until some rare Epipaleolithic sites occur about 8.0 ka BP. It will be suggested that these population changes are influenced by the river Nile behaviour. The best interpretation of the observations in the Upper Egyptian Nile Valley is the hypothesis that at the same time that Nile flow was reduced because of the dryness in its source area, the impact of aeolian activity was increased over Northeast Africa. The increased aeolian activity by northern winds in the Fayum and Wadi Ryan during the LGM resulted in the accumulation of aeolian sand in the valley. That aeolian sand was transported along the western Nile valley cliffs until it was accumulated when the Nile Valley change it S-N direction, such as at Nag'Hammadi. At other places sand was invading the Nile valley, directly from the Western Desert, creating a damming of the Nile at several places such as Armant and Aswan. As Nile flow was quite reduced, the Nile was unable to erode all the incoming sand and the Nile water with its important clay content was dammed. At several places large lakes were created in the Nile Valley. Those lakes were an ideal

  8. West Nile virus ecology in a tropical ecosystem in Guatemala.

    PubMed

    Morales-Betoulle, Maria E; Komar, Nicholas; Panella, Nicholas A; Alvarez, Danilo; López, María R; Betoulle, Jean-Luc; Sosa, Silvia M; Müller, María L; Kilpatrick, A Marm; Lanciotti, Robert S; Johnson, Barbara W; Powers, Ann M; Cordón-Rosales, Celia

    2013-01-01

    West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.

  9. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration.

    PubMed

    Chen, Shulin; Tang, Lanlan; Su, Wenjin; Weng, Wuyin; Osako, Kazufumi; Tanaka, Munehiko

    2015-12-01

    Alpha-chain subunits were separated from tilapia skin gelatin using ultrafiltration, and the physicochemical properties of obtained subunits were investigated. As a result, α1-subunit and α2-subunit could be successfully separated by 100 kDa MWCO regenerated cellulose membranes and 150 kDa MWCO polyethersulfone membranes, respectively. Glycine was the most dominant amino acid in both α1-subunit and α2-subunit. However, the tyrosine content was higher in α2-subunit than in α1-subunit, resulting in strong absorption near 280 nm observed in the UV absorption spectrum. Based on the DSC analysis, it was found that the glass transition temperatures of gelatin, α1-subunit and α2-subunit were 136.48 °C, 126.77 °C and 119.43 °C, respectively. Moreover, the reduced viscosity and denaturation temperature of α1-subunit were higher than those of α2-subunit, and the reduced viscosity reached the highest when α-subunits were mixed with α1/α2 ratio of approximately 2, suggesting that α1-subunit plays a more important role in the thermostability of gelatin than α2-subunit.

  10. Passive West Nile virus antibody transfer from maternal Eastern Screech-Owls (Megascops asio) to progeny

    USGS Publications Warehouse

    Hahn, D.C.; Nemeth, N.M.; Edwards, E.; Bright, P.R.; Komar, N.

    2006-01-01

    Transovarial antibody transfer in owls has not been demonstrated for West Nile virus (WNV). We sampled chicks from captive adult WNV-antibody-positive Eastern Screech-Owls (Megascops asio) to evaluate the prevalence of transovarial maternal antibody transfer, as well as titers and duration of maternal antibodies. Twenty-four owlets aged 1 to 27 days old circulated detectable antibodies with neutralizing antibody titers ranging from 20 to 1600 (median 1:40). Demonstrating that WNV antibodies are passively transferred transovarially is important for accurate interpretation of serologic data from young birds.

  11. Identifications of Captive and Wild Tilapia Species Existing in Hawaii by Mitochondrial DNA Control Region Sequence

    PubMed Central

    Wu, Liang; Yang, Jinzeng

    2012-01-01

    Background The tilapia family of the Cichlidae includes many fish species, which live in freshwater and saltwater environments. Several species, such as O. niloticus, O. aureus, and O. mossambicus, are excellent for aquaculture because these fish are easily reproduced and readily adapt to diverse environments. Historically, tilapia species, including O. mossambicus, S. melanotheron, and O. aureus, were introduced to Hawaii many decades ago, and the state of Hawaii uses the import permit policy to prevent O. niloticus from coming into the islands. However, hybrids produced from O. niloticus may already be present in the freshwater and marine environments of the islands. The purpose of this study was to identify tilapia species that exist in Hawaii using mitochondrial DNA analysis. Methodology/Principal Findings In this study, we analyzed 382 samples collected from 13 farm (captive) and wild tilapia populations in Oahu and the Hawaii Islands. Comparison of intraspecies variation between the mitochondrial DNA control region (mtDNA CR) and cytochrome c oxidase I (COI) gene from five populations indicated that mtDNA CR had higher nucleotide diversity than COI. A phylogenetic tree of all sampled tilapia was generated using mtDNA CR sequences. The neighbor-joining tree analysis identified seven distinctive tilapia species: O. aureus, O. mossambicus, O. niloticus, S. melanotheron, O. urolepies, T. redalli, and a hybrid of O. massambicus and O. niloticus. Of all the populations examined, 10 populations consisting of O. aureus, O. mossambicus, O. urolepis, and O. niloticus from the farmed sites were relatively pure, whereas three wild populations showed some degree of introgression and hybridization. Conclusions/Significance This DNA-based tilapia species identification is the first report that confirmed tilapia species identities in the wild and captive populations in Hawaii. The DNA sequence comparisons of mtDNA CR appear to be a valid method for tilapia species

  12. From non-covalent binding to irreversible DNA lesions: nile blue and nile red as photosensitizing agents

    NASA Astrophysics Data System (ADS)

    Gattuso, Hugo; Besancenot, Vanessa; Grandemange, Stéphanie; Marazzi, Marco; Monari, Antonio

    2016-06-01

    We report a molecular modeling study, coupled with spectroscopy experiments, on the behavior of two well known organic dyes, nile blue and nile red, when interacting with B-DNA. In particular, we evidence the presence of two competitive binding modes, for both drugs. However their subsequent photophysical behavior is different and only nile blue is able to induce DNA photosensitization via an electron transfer mechanism. Most notably, even in the case of nile blue, its sensitization capabilities strongly depend on the environment resulting in a single active binding mode: the minor groove. Fluorescence spectroscopy confirms the presence of competitive interaction modes for both sensitizers, while the sensitization via electron transfer, is possible only in the case of nile blue.

  13. From non-covalent binding to irreversible DNA lesions: nile blue and nile red as photosensitizing agents

    PubMed Central

    Gattuso, Hugo; Besancenot, Vanessa; Grandemange, Stéphanie; Marazzi, Marco; Monari, Antonio

    2016-01-01

    We report a molecular modeling study, coupled with spectroscopy experiments, on the behavior of two well known organic dyes, nile blue and nile red, when interacting with B-DNA. In particular, we evidence the presence of two competitive binding modes, for both drugs. However their subsequent photophysical behavior is different and only nile blue is able to induce DNA photosensitization via an electron transfer mechanism. Most notably, even in the case of nile blue, its sensitization capabilities strongly depend on the environment resulting in a single active binding mode: the minor groove. Fluorescence spectroscopy confirms the presence of competitive interaction modes for both sensitizers, while the sensitization via electron transfer, is possible only in the case of nile blue. PMID:27329409

  14. Microhabitat use, not temperature, regulates intensity of Gyrodactylus cichlidarum long-term infection on farmed tilapia--are parasites evading competition or immunity?

    PubMed

    Rubio-Godoy, Miguel; Muñoz-Córdova, Germán; Garduño-Lugo, Mario; Salazar-Ulloa, Martha; Mercado-Vidal, Gabriel

    2012-02-10

    Gyrodactylids (Monogenea) are ectoparasites of fish, some of which negatively affect commercially valuable fishes. Temperature strongly regulates population dynamics of these viviparous flatworms in farmed and wild fish populations, with most gyrodactylid species showing positive temperature-abundance associations. In agreement with epidemiological theory, numerous laboratory studies demonstrate that these parasites cannot persist in confined fish populations without periodic introduction of susceptible hosts. Extinction of gyrodactylid populations is due to host immunity, which develops in several fish species. In this one-year study, we followed populations of the recognized pathogen Gyrodactylus cichlidarum infecting four genetic groups of confined tilapia (wild type Nile tilapia Oreochromis niloticus niloticus, red O. n. niloticus, Mozambique tilapia O. mossambicus and a red synthetic population called Pargo-UNAM) kept under farming conditions and subject to natural environmental fluctuations. Based on the antecedents given, we postulated the following three hypotheses: (1) parasite abundance will be regulated by water temperature; (2) parasites will induce host mortality, particularly during periods of rapid infrapopulation growth; and (3) gyrodactylid populations will eventually become extinct on confined fish hosts. We disproved the three hypotheses: (1) parasite numbers fluctuated independently of temperature but were associated to changes in microhabitat use; (2) although gyrodactylid populations exhibited considerable growth, no evidence was found of negative effects on the hosts; and (3) infections persisted for one year on confined fish. Microhabitat use changed over time, with most worms apparently migrating anteriorly from the caudal fin and ending on the pectoral fins. Gyrodactylid populations followed similar trajectories in all fish, aggregating and dispersing repeatedly. Several instances were found where increased parasite dispersion coincided

  15. Dietary administration of Bacillus subtilis HAINUP40 enhances growth, digestive enzyme activities, innate immune responses and disease resistance of tilapia, Oreochromis niloticus.

    PubMed

    Liu, Haitian; Wang, Shifeng; Cai, Yan; Guo, Xiaohui; Cao, Zhenjie; Zhang, Yongzheng; Liu, Shubin; Yuan, Wei; Zhu, Weiwei; Zheng, Yu; Xie, Zhenyu; Guo, Weiliang; Zhou, Yongcan

    2017-01-01

    The probiotic properties of Bacillus subtilis HAINUP40 isolated from the aquatic environment, and the effects of dietary administration of B. subtilis HAINUP40 on the growth performance, intestinal probiotic recovery, digestive enzyme activities, innate immunity and disease resistance of tilapia (Oreochromis niloticus) were evaluated. The probiotic properties investigated include tolerance to simulated gastrointestinal stress, auto-aggregation, cell surface hydrophobicity and extracellular enzyme production. The cell number of B. subtilis changed little after 4 h in simulated gastric fluid at pH = 2.0, 3.0, 4.0 and simulated intestinal fluid at pH = 6.8.B.subtilis HAINUP40 revealed strong auto-aggregation property (34.6-87.0%) after 24 h incubation period. It exhibited significant cell surface hydrophobicity in xylene (28.8%) and chloroform (41.3%) and produced extracellular proteases and amylase. After tilapia (mean weight = 95 ± 8 g) were fed with a diet containing 10(8) cfu/g B. subtilis HAINUP40, their final body weight, percent weight gain (PWG), specific growth rate (SGR), total antioxidant capacity (T-AOC) and serum superoxide dismutase (SOD) increased significantly (p < 0.05) after 8 weeks; feed conversion rate (FCR) is significantly lower (p < 0.05) after 8 weeks; the protease and amylase activity in the digestive tract increased significantly (p < 0.05) after 4 and 8 weeks; and respiratory bursts and serum lysozyme activity increased significantly (p < 0.05) after 2 weeks. Moreover, being challenged with pathogenic Streptococcus agalactiae for 2 weeks, the relative percent survival (RPS%) is 52.94%. The results of this study strongly suggest that dietary supplement of B. subtilis HAINUP40 can effectively enhances the growth performance, immune response, and disease resistance of Nile tilapia.

  16. Nile Blue derivatives as lysosomotropic photosensitizers

    NASA Astrophysics Data System (ADS)

    Lin, Chi-Wei; Shulok, Janine R.; Kirley, S. D.; Cincotta, Louis; Foley, James W.

    1991-06-01

    The benzophenoxazines, including several Nile blue analogues, are a unique group of dyes that localize selectively in animal tumors. Chemical modifications of Nile blue A can yield derivatives with high 1O2 quantum yields. These derivatives represent a group of potentially effective photosensitizers for selective phototherapy of malignant tumors. In vitro evaluation of these derivatives has indicated that those with high 1O2 yields are very effective in mediating the photocytotoxicity of tumor cells. This photodynamic effect is most likely mediated through the action of 1O2, since photoirradiation under D2O enhanced and under hypoxic conditions diminished the photocytotoxic action. The subcellular localization of these photosensitizers in bladder tumor cells in culture was examined by light and fluorescence microscopies as well as by histochemical and biochemical studies. The results indicate that these dyes are localized primarily in the lysosome. The cellular uptake and retention of these dyes is energy- and pH-dependent. Agents such as nigericin, which alter the transmembrane pH gradient, reduced uptake and enhanced efflux of the dyes, while agents such as valinomycin, which reduce cellular membrane potential, had no effect on the uptake. These findings are consistent with having ion-trapping as the mechanism for the uptake of these dyes. Photoirradiation of sensitizer-treated cells obliterated lysosomes in a light-dose and drug-dose dependent fashion. Release of the hydrolytic enzymes may be the main cause for subsequent cell death since the cytolytic effect was reduced by a specific inhibitor of lysosomal proteolytic enzyme. A lysosomotropic photosensitization mechanism is therefore proposed for the photocytotoxic action of the Nile blue derivatives. This mechanism may provide an approach to the development of new photosensitizers for the effective and selective destruction of malignant tumors.

  17. Alligators as West Nile virus amplifiers.

    PubMed

    Klenk, Kaci; Snow, Jamie; Morgan, Katrina; Bowen, Richard; Stephens, Michael; Foster, Falicia; Gordy, Paul; Beckett, Susan; Komar, Nicholas; Gubler, Duane; Bunning, Michel

    2004-12-01

    Recent evidence suggests that American alligators (Alligator mississippiensis) may be capable of transmitting West Nile virus (WNV) to other alligators. We experimentally exposed 24 juvenile alligators to WNV parenterally or orally. All became infected, and all but three sustained viremia titers >5.0 log10 PFU/mL (a threshold considered infectious for Culex quinquefasciatus mosquitoes) for 1 to 8 days. Noninoculated tankmates also became infected. The viremia profiles and multiple routes of infection suggest alligators may play an important role in WNV transmission in areas with high population densities of juvenile alligators.

  18. Solar Forcings on Nile and Earthquakes

    NASA Astrophysics Data System (ADS)

    Al-Shehri, Saad Mohammed; Sabbah, Ismail; Yousef, Shahinaz Moustafa; Amin, Magdy Y.

    2013-03-01

    Nile and earthquake periodicities are examined in the light of solar and geomagnetic periodicities in order to uncover the role of the sun in initiating such terrestrial phenomena. The Nile periodicities under considerations covers the period 622-1420 AD. 1749- 1800 and 1870-1945 and are taken from an earlier paper by Yousef and El-Rae (1995). It is found that 11 yr and 21 yr solar periodicities affected the White Nile originating from the Equatorial plateau. On the other hand the Blue Nile arising mainly from Lake Tana in Ethiopia was affected mostly by the 3.3 yr, 2.9 yr, 2.7 yr, and the 2.52 yr periodicities. Such short periodicities are also present in cosmic rays. This is fairly true as during weak solar cycles series at the bottom of the 80-120 year Solar Wolf-Gleissberg Cycles, the level of the second to last of the weak cycles rise and fall coherently with full solar cycles with a correlation coefficient of about 0.9. Rain over Ethiopia is affected by the Monsoon precipitation which is related to the quasi biennial oscillations QBO of the equatorial zonal wind between the easterlies and the westerlies in the tropical stratosphere with a mean period of 29 months. We propose that the QBO are stimulated by the 2.52-2.48 yr solar periodicities. The 2.52 and 2.48 yr periodicity is strong in odd solar cycles 21 and 23. Generally speaking, it looks that different solar periodicities are space-time dependant and that they affect different regimes of terrestrial responses. In the case of earthquakes, we think that they are related to geomagnetic storms initiated by solar stimuli. Several solar periodicities are found in earthquakes. We postulate that electric currents in the ring current and in the ionosphere induce surface as well as deep electric currents in the magma thus produce motion and disturbances of the plates and the magma leading to earthquakes and volcanoes.

  19. Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt

    PubMed Central

    Megahed, Ayman Mohamed; Dahshan, Hesham; Abd-El-Kader, Mahdy A.; Abd-Elall, Amr Mohamed Mohamed; Elbana, Mariam Hassan; Nabawy, Ehab; Mahmoud, Hend A.

    2015-01-01

    Ten polychlorinated biphenyl (PCB) congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD). PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB congeners in the water revealed that highly chlorinated PCB technical mixtures such as Aroclor 1254 was the main PCB production historically used in Egypt. An increasing trend in PCB levels from the upper stream to the Nile estuaries was observed. The calculated flux of PCBs indicated that 6.8 tons of PCBs is dumped into the Mediterranean Sea each year from the River Nile. The hazard quotients and carcinogenic risk caused by PCB pollution in the River Nile were above the acceptable level indicating that PCBs in the River Nile water pose adverse health effects for all age groups. Our findings revealed that PCBs possess a serious risk to the Egyptian population that depends mainly on the River Nile as a source of water. Thus, stricter legislation and regulatory controls should be applied to reduce the risk of PCBs in Egypt. PMID:26798844

  20. Nile Delta vegetation response to Holocene climate variability

    USGS Publications Warehouse

    Bernhardt, Christopher E.; Horton, Benjamin P.; Stanley, Jean-Daniel

    2012-01-01

    A 7000 yr palynologic record from Burullus Lagoon, Nile Delta, Egypt, is assessed to investigate changes in terrestrial vegetation in response to Nile flow. Previous studies in this region have shown that sea-level rise in the early to mid-Holocene, and markedly increased human land use during the past several centuries, altered vegetation in and around the lagoon. The pollen record from this study documents changes in delta vegetation that likely reflect variations in Nile flow. We suggest that Cyperaceae pollen is a sensitive marker of precipitation over the Nile headwaters and the resultant Nile flow. Decreases in Cyperaceae pollen, interpreted as a marker for diminished Nile flow, as well as the increase in relative abundance of microscopic charcoal, occurred at ca. 6000–5500, ca. 5000, ca. 4200, and ca. 3000 cal. yr B.P. (calibrated years before present). These correspond to extreme regional and global aridity events associated with a more southerly mean position of the Intertropical Convergence Zone. These changes, also recorded by other proxy studies, indicate that several marked regional drought events affected the Nile Delta region and impacted ancient Egyptian and Middle Eastern civilizations.

  1. Endocrine-disruptor molecular responses, occurrence of intersex and gonado-histopathological changes in tilapia species from a tropical freshwater dam (Awba Dam) in Ibadan, Nigeria.

    PubMed

    Adeogun, Aina O; Onibonoje, Kolawole; Ibor, Oju R; Omiwole, Roseline A; Chukwuka, Azubuike V; Ugwumba, Alex O; Ugwumba, Adiaha A A; Arukwe, Augustine

    2016-05-01

    In the present study, the occurrence of endocrine disruptive responses in Tilapia species from Awba Dam has been investigated, and compared to a reference site (Modete Dam). The Awba Dam is a recipient of effluents from University of Ibadan (Nigeria) and several other anthropogenic sources. A total of 132 Tilapia species (Sarotherodon malenotheron (n=57 and 32, males and females, respectively) and Tilapia guineensis (n=23 and 20, males and females, respectively)) were collected from June to September 2014. At the reference site, samples of adult male and female S. melanotheron (48 males and 47 females) and T. guineensis (84 males and 27 females) were collected. Gonads were morphologically and histologically examined and gonadosomatic index (GSI) was calculated. Hepatic mRNA transcriptions of vitellogenin (Vtg) and zona radiata protein (Zrp) genes were analyzed using validated RT-qPCR. Significant increase in Vtg and Zrp transcripts were observed in male tilapias from Awba Dam, compared to males from the reference site. In addition, male tilapias from Awba Dam produced significantly higher Vtg and Zrp mRNA, compared to females in June and July. However, at the natural peak spawning period in August and September, females produced, significantly higher Vtg and Zrp mRNA, compared to males. Fish gonads revealed varying incidence of intersex with a striking presence of two (2) pairs of testes and a pair of ovary in S. melanotheron from Awba Dam. The entire fish population examined at Awba Dam showed a high prevalence of intersex (34.8%), involving phenotypic males and females of both species. Analysis of sediment contaminant levels revealed that As, Cd, Pb, Hg and Ni (heavy metals), monobutyltin cation, 4-iso-nonyphenol and PCB congeners (138, 153 and 180) were significantly higher in Awba Dam, compared to the reference site. Principal component analysis (PCA) showed that fish variables were positively correlated with sediment contaminant burden at Awba Dam, indicating

  2. Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

    PubMed

    Favaro, E G P; Sipaúba-Tavares, L H; Milstein, A

    2015-11-01

    In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

  3. A fatal neuroinvasive West Nile virus infection in a traveler returning from Madagascar: clinical, epidemiological and veterinary investigations.

    PubMed

    Larrieu, Sophie; Cardinale, Eric; Ocquidant, Philippe; Roger, Matthieu; Lepec, Richard; Delatte, Hélène; Camuset, Guillaume; Desprès, Philippe; Brottet, Elise; Charlin, Cyril; Michault, Alain

    2013-08-01

    Abstract. A 58-year-old woman living in Reunion Island and returning from Madagascar was hospitalized for neuroinvasive encephalitis and died 1 month later. West Nile virus (WNV) infection was biologically confirmed by detection of immunoglobulin M (IgM) reactive with WNV antigens in both cerebrospinal fluid and serum, and weak neutralizing activity was also detected. A veterinary survey performed in her traveling area showed a seroprevalence of WNV of 28.7% (95% confidence interval [CI] = 21.1-36.3) in adult poultry, confirming an active circulation of the virus. Development of a severe form could be related to a weak antibody response, because the patient presented low IgM and IgG titers. This case report underlines the constant risk of emergence of West Nile in Indian Ocean territories, including Reunion Island where competent vectors are widely present during the whole year.

  4. Mosquito-borne West Nile virus (WNV) surveillance in the Upper Rhine Valley, Germany.

    PubMed

    Timmermann, Ute; Becker, Norbert

    2010-06-01

    West Nile virus (WNV) could be introduced into Germany via migratory birds originating from Africa or southern Europe and subsequently transmitted to indigenous birds, humans, or horses by mosquitoes. Neither the virus itself nor antibodies against WNV have yet to be found in mosquitoes and horses, whereas antibodies have been detected in migrating birds and in humans that were in close contact with birds. At present, the West Nile virus itself has yet to be detected in Germany. This investigation was conducted primarily in major bird breeding, resting, and roosting habitats (hotspots) in the Upper Rhine Valley. Adult mosquitoes were trapped using CO2-baited Encephalitis Vector Surveillance (EVS)-traps and were tested for WNV by the VecTest WNV Antigen Assay. In 2007 and 2008, a total of 11,073 host-seeking adult female mosquitoes (13 species) were tested, and all tests were negative for WNV. Statistical calculations could be performed only where sufficient numbers of mosquitoes were trapped. For these sites, WNV infection among mosquitoes could be ruled out with 80% certainty. For the evaluation of the WNV situation in Germany, the results of this investigation are a further indication that the virus has not yet arrived.

  5. Conflicts of Shared Resources: A Case Study of River Nile

    DTIC Science & Technology

    2012-03-22

    as Lake Kivu. Rwanda joined the earlier Nile basin project, Hydromet , in 1967, with the support on the UNDP. 18 Although the country does not...operation Hydromet . In 1967, with the assistance of the United Nations Development Program (UNDP) and the World Meteorological Organization (WMO), Egypt...Kenya, Sudan, Tanzania and Uganda launched the Hydromet Survey project to regulate the water level of the Nile.”30 Rwanda joined later while Ethiopia

  6. Prevalence and effects of West Nile virus on wild American kestrel (Falco sparverius) populations in Colorado

    USGS Publications Warehouse

    Dusek, Robert J.; Iko, William M.; Hofmeister, Erik K.; Paul, Ellen

    2012-01-01

    To assess the potential impacts of West Nile virus (WNV) on a wild population of free-ranging raptors, we investigated the prevalence and effects of WNV on American Kestrels (Falco sparverius) breeding along the Front Range of the Rocky Mountains in northern Colorado. We monitored kestrel nesting activity at 131 nest boxes from March to August 2004. Of 81 nest attempts, we obtained samples from 111 adults and 250 young. We did not detect WNV in sera; however, 97.3% (108/111) of adults tested positive for WNV neutralizing antibodies, which possibly represented passive transfer of maternal antibodies. Clutch size, hatching, and fledging success in our study did not differ from that previously reported for this species, suggesting that previous WNV exposure in kestrels did not have an effect on reproductive parameters measured in the breeding populations we studied in 2004.

  7. Application of highly purified electrolyzed chlorine dioxide for tilapia fillet disinfection.

    PubMed

    Yu, Chen-Hsing; Huang, Tzou-Chi; Chung, Chao-Chin; Huang, Hao-Hsun; Chen, Ho-Hsien

    2014-01-01

    This research aimed to develop an electrolysis method to generate high-concentration chlorine dioxide (ClO2) for tilapia fillet disinfection. The designed generator produced up to 3500 ppm of ClO2 at up to 99% purity. Tilapia fillets were soaked in a 400 ppm ClO2 solution for 5, 10, and 25 min. Results show that total plate counts of tilapia, respectively, decreased by 5.72 to 3.23, 2.10, and 1.09 log CFU/g. In addition, a 200 ppm ClO2 solution eliminated coliform bacteria and Escherichia coli in 5 min with shaking treatment. Furthermore, ClO2 and trihalomethanes (THMs) residuals on tilapia fillets were analyzed by GC/MS and were nondetectable (GC-MS detection limit was 0.12 ppb). The results conform to Taiwan's environmental protection regulations and act governing food sanitation.

  8. Phosphorous digestibility and activity of intestinal phytase in hybrid tilapia, Oreochromis niloticus X O. aureus

    USGS Publications Warehouse

    La Vorgna, M.W.; Hafez, Y.; Hughes, S.G.; Handwerker, T.

    2003-01-01

    Experiments were conducted to determine the degree to which phytate-bound phosphorus from plant protein sources could be used by hybrid tilapia (Oreochromis niloticus X O. aureus). Utilizing an inert marker technique with chromic oxide, hybrid tilapia in our study were effective at utilizing both inorganic and phytate phosphorus as evidenced by average apparent digestibility values of 93.2% and 90.0% for total and phytate phosphorus, respectively. Analysis of the intestinal brush border membrane of the tilapia revealed enzyme activity that was capable of hydrolyzing phytic acid. The presence of phytic acid hydrolyzing enzyme activity in the intestinal brush border provides a probable mechanism by which these hybrid tilapia are able to utilize phytate phosphorus effectively. ?? 2003 by The Haworth Press, Inc. All rights reserved.

  9. Shelf life and quality study of minced tilapia with Nori and Hijiki seaweeds as natural additives.

    PubMed

    Ribeiro, Ingridy Simone; Shirahigue, Ligianne Din; Ferraz de Arruda Sucasas, Lia; Anbe, Lika; da Cruz, Pedro Gomes; Gallo, Cláudio Rosa; Carpes, Solange Teresinha; Marques, Marcos José; Oetterer, Marília

    2014-01-01

    The extraction of mechanically separated meat has emerged as an attractive process. However, it increases the incorporation of oxygen and, consequently, of flavors due to rancidity. Thus, preservatives must be added. The objective of this study was to evaluate the shelf life of minced tilapia to replace synthetic preservatives with Hijiki and Nori seaweeds extracts. The application of the extracts had no effect on the chemical composition of the minced tilapia. The seaweed extracts had inhibitory effect on total volatile base nitrogen. The minced tilapia complied with the microbiological standard set by Brazilin law. The panelists detected no differences in the rancid aroma and only minor differences were detected in the color of the products. It can be concluded that the minced tilapia with added seaweed extracts were within quality standards during frozen storage.

  10. Shelf Life and Quality Study of Minced Tilapia with Nori and Hijiki Seaweeds as Natural Additives

    PubMed Central

    Ribeiro, Ingridy Simone; Shirahigue, Ligianne Din; Ferraz de Arruda Sucasas, Lia; Anbe, Lika; da Cruz, Pedro Gomes; Gallo, Cláudio Rosa; Carpes, Solange Teresinha; Marques, Marcos José; Oetterer, Marília

    2014-01-01

    The extraction of mechanically separated meat has emerged as an attractive process. However, it increases the incorporation of oxygen and, consequently, of flavors due to rancidity. Thus, preservatives must be added. The objective of this study was to evaluate the shelf life of minced tilapia to replace synthetic preservatives with Hijiki and Nori seaweeds extracts. The application of the extracts had no effect on the chemical composition of the minced tilapia. The seaweed extracts had inhibitory effect on total volatile base nitrogen. The minced tilapia complied with the microbiological standard set by Brazilin law. The panelists detected no differences in the rancid aroma and only minor differences were detected in the color of the products. It can be concluded that the minced tilapia with added seaweed extracts were within quality standards during frozen storage. PMID:25478593

  11. Draft genome sequences of three Aeromonas hybrophila isolates from catfish and tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aeromonas hydrophila is a Gram-negative bacteria that is particularly adapted to freshwater environments and can cause severe infections in fish and humans. Here we report the draft genomes of three A. hydrophila catfish and tilapia isolates....

  12. Characterization of a Novel Orthomyxo-like Virus Causing Mass Die-Offs of Tilapia

    PubMed Central

    Bacharach, Eran; Mishra, Nischay; Briese, Thomas; Zody, Michael C.; Kembou Tsofack, Japhette Esther; Zamostiano, Rachel; Berkowitz, Asaf; Ng, James; Nitido, Adam; Corvelo, André; Toussaint, Nora C.; Abel Nielsen, Sandra Cathrine; Hornig, Mady; Del Pozo, Jorge; Bloom, Toby; Ferguson, Hugh

    2016-01-01

    ABSTRACT Tilapia are an important global food source due to their omnivorous diet, tolerance for high-density aquaculture, and relative disease resistance. Since 2009, tilapia aquaculture has been threatened by mass die-offs in farmed fish in Israel and Ecuador. Here we report evidence implicating a novel orthomyxo-like virus in these outbreaks. The tilapia lake virus (TiLV) has a 10-segment, negative-sense RNA genome. The largest segment, segment 1, contains an open reading frame with weak sequence homology to the influenza C virus PB1 subunit. The other nine segments showed no homology to other viruses but have conserved, complementary sequences at their 5′ and 3′ termini, consistent with the genome organization found in other orthomyxoviruses. In situ hybridization indicates TiLV replication and transcription at sites of pathology in the liver and central nervous system of tilapia with disease. PMID:27048802

  13. West Nile virus infection of birds, Mexico.

    PubMed

    Guerrero-Sánchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M; Trujillo-Olivera, María Teresa Jesús; Worwa, Gabriella; Dupuis, Alan; Brault, Aaron C; Kramer, Laura D; Komar, Nicholas; Estrada-Franco, José Guillermo

    2011-12-01

    West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006-2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths.

  14. Nutritional Profile and Chemical Stability of Pasta Fortified with Tilapia (Oreochromis niloticus) Flour

    PubMed Central

    Monteiro, Maria Lúcia G.; Mársico, Eliane T.; Soares, Manoel S.; Magalhães, Amanda O.; Canto, Anna Carolina V. C. S.; Costa-Lima, Bruno R. C.; Alvares, Thiago S.; Conte, Carlos A.

    2016-01-01

    Physicochemical parameters of pasta enriched with tilapia (Oreochromis niloticus) flour were investigated. Five formulations were prepared with different concentrations of tilapia flour as partial substitute of wheat flour: pasta without tilapia flour (PTF0%), pasta with 6% (PTF6%), 12% (PTF12%), 17% (PTF17%), and 23% (PTF23%) of tilapia flour. The formulations were assessed for proximate composition, fatty acid and amino acid profile on day 1 whereas, instrumental color parameters (L*, a* and b* values), pH, water activity (aw), and lipid and protein oxidation were evaluated on days 1, 7, 14, and 21 of storage at 25°C. Fortification with tilapia flour increased (p < 0.05) protein, lipid, ash, total essential amino acids, and total polyunsaturated fatty acids contents. In addition, supplementation of pasta with tilapia flour decreased (p < 0.05) lightness and water activity while redness, yellowness, pH values, and lipid oxidation were increased (p < 0.05) in a level-dependent manner. Nevertheless, all formulations were exhibited storage stability at 25°C. In general, protein oxidation was greater (p < 0.05) in the pasta containing 12%, 17%, and 23% of tilapia flour than their counterparts, and the storage promoted an increase (p < 0.05) on the carbonyl content in all formulations. Thus, pasta with 6% of tilapia flour has the potential to be a technological alternative to food industry for the nutritional enrichment of traditional pasta with negligible negative effects on the chemical stability of the final product during 21 days at 25°C. PMID:27973565

  15. Detection of Tilapia Lake Virus in Clinical Samples by Culturing and Nested Reverse Transcription-PCR.

    PubMed

    Kembou Tsofack, Japhette Esther; Zamostiano, Rachel; Watted, Salsabeel; Berkowitz, Asaf; Rosenbluth, Ezra; Mishra, Nischay; Briese, Thomas; Lipkin, W Ian; Kabuusu, Richard M; Ferguson, Hugh; Del Pozo, Jorge; Eldar, Avi; Bacharach, Eran

    2017-03-01

    Tilapia are an important group of farmed fish that serve as a significant protein source worldwide. In recent years, substantial mortality of wild tilapia has been observed in the Sea of Galilee and in commercial ponds in Israel and Ecuador. We have identified the etiological agent of these mass die-offs as a novel orthomyxo-like virus and named it tilapia lake virus (TiLV). Here, we provide the conditions for efficient isolation, culturing, and quantification of the virus, including the use of susceptible fish cell lines. Moreover, we describe a sensitive nested reverse transcription-PCR (RT-PCR) assay allowing the rapid detection of TiLV in fish organs. This assay revealed, for the first time to our knowledge, the presence of TiLV in diseased Colombian tilapia, indicating a wider distribution of this emerging pathogen and stressing the risk that TiLV poses for the global tilapia industry. Overall, the described procedures should provide the tilapia aquaculture industry with important tools for the detection and containment of this pathogen.

  16. Comparative Transcriptome Analysis Identifies Candidate Genes Related to Skin Color Differentiation in Red Tilapia

    PubMed Central

    Zhu, Wenbin; Wang, Lanmei; Dong, Zaijie; Chen, Xingting; Song, Feibiao; Liu, Nian; Yang, Hui; Fu, Jianjun

    2016-01-01

    Red tilapia is becoming more popular for aquaculture production in China in recent years. However, the pigmentation differentiation in genetic breeding is the main problem limiting its development of commercial red tilapia culture and the genetic basis of skin color variation is still unknown. In this study, we conducted Illumina sequencing of transcriptome on three color variety red tilapia. A total of 224,895,758 reads were generated, resulting in 160,762 assembled contigs that were used as reference contigs. The contigs of red tilapia transcriptome had hits in the range of 53.4% to 86.7% of the unique proteins of zebrafish, fugu, medaka, three-spined stickleback and tilapia. And 44,723 contigs containing 77,423 simple sequence repeats (SSRs) were identified, with 16,646 contigs containing more than one SSR. Three skin transcriptomes were compared pairwise and the results revealed that there were 148 common significantly differentially expressed unigenes and several key genes related to pigment synthesis, i.e. tyr, tyrp1, silv, sox10, slc24a5, cbs and slc7a11, were included. The results will facilitate understanding the molecular mechanisms of skin pigmentation differentiation in red tilapia and accelerate the molecular selection of the specific strain with consistent skin colors. PMID:27511178

  17. Sequence and expression analysis of the gene encoding inducible cAMP early repressor in tilapia.

    PubMed

    Chen, Ming; Wang, Rui; Gan, Xi; Lei, Aiying; Li, Chao; Yu, Xiaoli; Huang, Jun; Huang, Ting; Liang, Wanwen

    2010-06-01

    Suppression subtractive hybridization library was generated by comparison of cDNA populations isolated from peripheral leukocytes of pre- and post-immunized tilapia. One cDNA sequence encoding complete inducible cAMP early repressor was obtained from the library. The sequence was characterized by the presence of the basic structure of ICER IIgamma. Expression of ICER was in the tissues of four types of tilapia was decreased after infection with Streptococcus. After immunization, expression of ICER was initially decreased and then increased after 7 days. In addition, the order for the overall expression of ICER gene after infection and the increases of ICER expression later after immunization in these four types of tilapia was positively correlated to the disease resistance and productivity of these four species of tilapia. Our results provided molecular mechanisms for the different disease resistance capability in different species of tilapia. In addition, our results also provided reference molecular marker for breeding disease resistant tilapia, cAMP responsive element modulator.

  18. A White Nile megalake during the last interglacial period

    NASA Astrophysics Data System (ADS)

    Barrows, Timothy T.; Williams, Martin A. J.; Mills, Stephanie C.; Duller, Geoff A. T.; Fifield, L. Keith; Haberlah, David; Tims, Stephen G.; Williams, Frances M.

    2014-05-01

    The eastern Sahara Desert of Africa is one of the most climatically sensitive areas on Earth, varying from lake-studded savannah woodland to hyperarid desert over the course of a glacial-interglacial cycle. In currently semiarid Sudan there is widespread evidence that a very large freshwater lake once filled the White Nile River valley (Barrows et al., 2014). Here we present the first quantitative estimate for the dimensions of the lake and a direct age for the emplacement of its shoreline. Using a profile dating approach with the cosmogenic nuclide 10Be, we estimate an exposure age of 109 ± 8 ka for this megalake, indicating that it probably formed during the last interglacial period. This age is supported by optically stimulated luminescence dating of Blue Nile paleochannels associated with the lake. Using a high-resolution digital elevation model, we estimate that the lake was more than 45,000 km2 in area, making it comparable to the largest freshwater lakes on Earth today. We attribute the lake's existence to seasonal flood pulses as a result of local damming of the White Nile by a more southern position of the Blue Nile and greatly increased precipitation associated with an enhanced monsoon. References Barrows, T.T., Williams, M.A.J., Mills, S.C., Duller, G.A.T., Fifield, L.K., Haberlah, D., Tims, S.G., Williams, F.M., 2014. A White Nile megalake during the last interglacial period. Geology. 10.1130/g35238.1

  19. Safety of West Nile Virus vaccines in sandhill crane chicks

    USGS Publications Warehouse

    Olsen, G.H.; Miller, K.J.; Docherty, D.E.; Bochsler, V.S.; Folk, Martin J.; Nesbitt, Stephen A.

    2008-01-01

    West Nile virus arrived in North America in 1999 and has spread across the continent in the ensuing years. The virus has proven deadly to a variety of native avian species including sandhill cranes (Grus canadensis). In order to provide safe and efficacious protection for captive and released populations of whooping cranes (G. americana), we have conducted a series of four research projects. The last of these was a study of the effects of two different West Nile virus vaccines on young Florida sandhill crane (G. c. pratensis) chicks and subsequent challenge with the virus. We found that vaccinating crane chicks as early as day 7 post-hatch caused no adverse reactions or noticeable morbidity. We tested both a commercial equine vaccine West Nile - Innovator (Fort Dodge Laboratories, Fort Dodge, Iowa) and a new recombinant DNA vaccine (Centers for Disease Control). We had a 33% mortality in control chicks (n =6) from West Nile virus infection, versus 0% mortality in two groups of vaccinated chicks (n = 12), indicating the two vaccines tested were not only safe but effective in preventing West Nile virus.

  20. West Nile Virus Ecology in a Tropical Ecosystem in Guatemala

    PubMed Central

    Morales-Betoulle, Maria E.; Komar, Nicholas; Panella, Nicholas A.; Alvarez, Danilo; López, María R.; Betoulle, Jean-Luc; Sosa, Silvia M.; Müller, María L.; Kilpatrick, A. Marm; Lanciotti, Robert S.; Johnson, Barbara W.; Powers, Ann M.; Cordón-Rosales, Celia

    2013-01-01

    West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States. PMID:23149586

  1. Risks for fishborne zoonotic trematodes in tilapia production systems in Guangdong province, China.

    PubMed

    Li, Kang; Clausen, Jesper Hedegaard; Murrell, K Darwin; Liu, Liping; Dalsgaard, Anders

    2013-11-15

    Guangdong province is the most important region for tilapia culture in China. However, it is also an endemic region for fishborne zoonotic trematodes (FZT), which pose a risk to human food safety and health. A study was designed to assess the status of trematode parasite infections in tilapia aquaculture systems as an indicator of potential risks from FZT associated with consumption of tilapia. Tilapia from nursery and grow-out ponds were sampled from monoculture, polyculture and integrated aquaculture systems. The results from 388 tilapia examined revealed a very low prevalence (1.5%) of trematode infections (Heterophyidae and Echinostomatidae). Integrated systems using animal manure and latrine wastes as fertilizer did not show a higher prevalence of FZT. Because it was not clear whether the low risk of infection was attributable to existing effective pond management practices or a low risk of spillover of FZT from area sylvatic reservoir hosts, a survey of local wild-caught fish was conducted. Five species of FZT were discovered from a total of 271 wild-caught fish and a mean infection density of 4.0 metacercariae/100g; FZT discovered included intestinal flukes (Haplorchis spp., Procerovum varium, and Metagonimus spp.) and metacercariae tentatively identified as Clonorchis sinenesis. The common occurrence of FZT in wild-caught fish suggests that the presence of FZT in local wild animal reservoirs is substantial, and that although the current aquaculture management systems for tilapia are generally effective in preventing transmission of these parasites into tilapia production systems, the improvement of pond management practices and biosecurity must be maintained at a high level.

  2. Safety of florfenicol administered in feed to tilapia (Oreochromis sp.)

    USGS Publications Warehouse

    Gaikowski, Mark P.; Wolf, Jeffrey C.; Schleis, Susan M.; Tuomari, Darrell; Endris, Richard G.

    2013-01-01

    The safety of Aquaflor® (50% w/w florfenicol [FFC]) incorporated in feed then administered to tilapia for 20 days (2x the recommended duration) at 0, 15, 45, or 75 mg/kg body weight/day (0, 1, 3, or 5x the recommended dose of 15 mg FFC/kg BW/d) was investigated. Mortality, behavioral change, feed consumption, body size, and gross and microscopic lesions were determined. Estimated delivered doses were >96.9% of target. Three unscheduled mortalities occurred but were considered incidental since FFC-related findings were not identified. Feed consumption was only affected during the last 10 dosing days when the 45 and 75 mg/kg groups consumed only 62.5% and 55.3% of the feed offered, respectively. There were significant, dose-dependent reductions in body size in the FFC-dose groups relative to the controls. Treatment-related histopathological findings included increased severity of lamellar epithelial hyperplasia, increased incidence of lamellar adhesions, decreased incidence of lamellar telangiectasis in the gills, increased glycogen-type and lipid-type hepatocellular vacuolation in the liver, decreased lymphocytes, increased blast cells, and increased individual cell necrosis in the anterior kidney, and tubular epithelial degeneration and mineralization in the posterior kidney. These changes are likely to be of minimal clinical relevance, given the lack of mortality or morbidity observed. This study has shown that FFC, when administered in feed to tilapia at the recommended dose (15 mg FFC/kg BW/day) for 10 days would be well tolerated.

  3. Artificial masculinization in tilapia involves androgen receptor activation.

    PubMed

    Golan, Matan; Levavi-Sivan, Berta

    2014-10-01

    Estrogens have a pivotal role in natural female sexual differentiation of tilapia while lack of steroids results in testicular development. Despite the fact that androgens do not participate in natural sex differentiation, synthetic androgens, mainly 17-α-methyltestosterone (MT) are effective in the production of all-male fish in aquaculture. The sex inversion potency of synthetic androgens may arise from their androgenic activity or else as inhibitors of aromatase activity. The current study is an attempt to differentiate between the two alleged activities in order to evaluate their contribution to the sex inversion process and aid the search for novel sex inversion agents. In the present study, MT inhibited aromatase activity, when applied in vitro as did the non-aromatizable androgen dihydrotestosterone (DHT). In comparison, exposure to fadrozole, a specific aromatase inhibitor, was considerably more effective. Androgenic activity of MT was evaluated by exposure of Sciaenochromis fryeri fry to the substance and testing for the appearance of blue color. Flutamide, an androgen antagonist, administered concomitantly with MT, reduced the appearance of the blue color and the sex inversion potency of MT in a dose-dependent manner. In tilapia, administration of MT, fadrozole or DHT resulted in efficient sex inversion while flutamide reduced the sex inversion potency of all three compounds. In the case of MT and DHT the decrease in sex inversion efficiency caused by flutamide is most likely due to the direct blocking of the androgen binding to its cognate receptor. The negative effect of flutamide on the efficiency of the fadrozole treatment may indicate that the masculinizing activity of fadrozole may be attributed to excess, un-aromatized, androgens accumulated in the differentiating gonad. The present study shows that when androgen receptors are blocked, there is a reduction in the efficiency of sex inversion treatments. Our results suggest that in contrast to

  4. [West Nile virus: a reality in Mexico].

    PubMed

    Téllez, Ildefonso; Calderón, Oscar; Franco-Paredes, Carlos; del Río, Carlos

    2006-01-01

    West Nile virus (WNV) is a RNA virus of the Flaviridae, genus flavivirus family. It is a neuropathogenic virus causing disease in birds, horses and humans. WNVis transmitted by the vector mosquito Culex sp. The virus life 's cycle includes mosquitoes as vectors and birds as natural hosts. Humans are accidental hosts. Since the introduction of the Epidemiological Surveillance Program at the Ministry ofHealth. we have documented 90 positive test results among birds out of 1,223 cases studied in Mexico as of September IS. 2005. The incubation period in humans after a mosquito bite ranges from 3 to 14 days. Disease is characterized by early onset fever, general malaise, decreased appetite, nausea, vomiting, headaches, myalgias, enlarged lymph nodes andrash. Neurological manifestations include encephalitis andflaccid paralysis, which are present in less than 1% of subjects infected with WNV. Older patients display more adverse outcomes including death. The diagnosis is made by the determination of specific IgM and JgG antibodies in serum and/or cerebrospinal fluid. There is no antiviral treatment to date against WNV but interferon ?2b, and WNVspec4ic-immunoglobulin have been used Prevention is therefore the key to control the infection.

  5. Co-induction of hepatic IGF-I and progranulin mRNA by growth hormone in tilapia, Oreochromis mossambiccus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Like IGF-I, progranulin (pgrn) is a growth factor involved in tumorigenesis and wound healing. We report here the identification and characterization of pgrn cDNA in tilapia and the regulation of its expression by growth hormone(GH). The tilapia pgrn cDNA was cloned by RT-PCR ampliWcation, using g...

  6. Genetic Relatedness of Salmonella Serovars Isolated from Catfish (Clarias gariepinus) and Tilapia (Tilapia mossambica) Obtained from Wet Markets and Ponds in Penang, Malaysia.

    PubMed

    Budiati, Titik; Rusul, Gulam; Wan-Abdullah, Wan Nadiah; Chuah, Li-Oon; Ahmad, Rosma; Thong, Kwai Lin

    2016-04-01

    A total of 43 Salmonella enterica isolates belonging to different serovars (Salmonella Albany, Salmonella Agona, Salmonella Corvallis, Salmonella Stanley, Salmonella Typhimurium, Salmonella Mikawasima, and Salmonella Bovismorbificans) were isolated from catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from nine wet markets and eight ponds in Penang, Malaysia. Thirteen, 19, and 11 isolates were isolated from 9 of 32 catfish, 14 of 32 tilapia, and 11 of 44 water samples, respectively. Fish reared in ponds were fed chicken offal, spoiled eggs, and commercial fish feed. The genetic relatedness of these Salmonella isolates was determined by random amplified polymorphic DNA PCR (RAPD-PCR) using primer OPC2, repetitive extragenic palindromic PCR (REP-PCR), and pulsed-field gel electrophoresis (PFGE). Composite analysis of the RAPD-PCR, REP-PCR, and PFGE results showed that the Salmonella serovars could be differentiated into six clusters and 15 singletons. RAPD-PCR differentiated the Salmonella isolates into 11 clusters and 10 singletons, while REP-PCR differentiated them into 4 clusters and 1 singleton. PFGE differentiated the Salmonella isolates into seven clusters and seven singletons. The close genetic relationship of Salmonella isolates from catfish or tilapia obtained from different ponds, irrespective of the type of feed given, may be caused by several factors, such as the quality of the water, density of fish, and size of ponds.

  7. Use of Network Modeling Tools in the Nile System Design

    NASA Astrophysics Data System (ADS)

    Avery, Paul

    I discuss the relevance of network modeling tools to high energy physics experiments, particularly for understanding data flows and identifying possible bottlenecks during data analysis. The Nile collaboration is using these tools to model a fault-tolerant computing system distributed over geographically dispersed sites. I summarize Nile's evaluation of three commericial tools and our initial experience with OpNet Modeler from Mil3, Inc. These tools seem to offer an effective way of quantifying data movements from online acquisition to physics analysis, including how they are affected by storage mechanisms, distribution, and the characteristics of local and wide area networks.

  8. Liver functional metabolomics discloses an action of L-leucine against Streptococcus iniae infection in tilapias.

    PubMed

    Ma, Yan-Mei; Yang, Man-Jun; Wang, Sanying; Li, Hui; Peng, Xuan-Xian

    2015-08-01

    Streptococcus iniae seriously affects the intensive farming of tilapias. Much work has been conducted on prevention and control of S. iniae infection, but little published information on the metabolic response is available in tilapias against the bacterial infection, and no metabolic modulation way may be adopted to control this disease. The present study used GC/MS based metabolomics to characterize the metabolic profiling of tilapias infected by a lethal dose (LD50) of S. iniae and determined two characteristic metabolomes separately responsible for the survival and dying fishes. A reversal changed metabolite, decreased and increased l-leucine in the dying and survival groups, respectively, was identified as a biomarker which featured the difference between the two metabolomes. More importantly, exogenous l-leucine could be used as a metabolic modulator to elevate survival ability of tilapias infected by S. iniae. These results indicate that tilapias mount metabolic strategies to deal with bacterial infection, which can be regulated by exogenous metabolites such as l-leucine. The present study establishes an alternative way, metabolic modulation, to cope with bacterial infections.

  9. In vivo biological responses and bioresorption of tilapia scale collagen as a potential biomaterial.

    PubMed

    Sugiura, Hiroaki; Yunoki, Shunji; Kondo, Eiji; Ikoma, Toshiyuki; Tanaka, Junzo; Yasuda, Kazunori

    2009-01-01

    To date, collagen for biomedical uses has been obtained from mammalian sources. The purpose of this study was to evaluate the in vivo biological responses and bioresorption of collagen obtained from tilapia (Oreochromis niloticas) scales as compared to those of collagen from porcine dermis. Collagen sponges with micro-porous structures were fabricated from reconstituted collagen fibrils using freeze-drying and cross-linked by dehydrothermal treatment (DHT treatment) or additional treatment with a water-soluble carbodiimide (WSC treatment). The mechanical properties of the tilapia collagen sponges were similar to those of porcine collagen sponges with the same cross-linking methods, where WSC treatment remarkably improved the properties over DHT treatment alone. The pellet implantation tests into the paravertebral muscle of rabbits demonstrated that tilapia collagen caused rare inflammatory responses at 1- and 4-week implantations, statistically similar to those of porcine collagen and a high-density polyethylene as a negative control. The bioresorption rates of both the collagen implants were similar, except for the DHT-treated tilapia collagen sponges at 1-week implantation. These results suggest that tilapia collagen is a potential alternative to conventional mammalian collagens in biomedical uses.

  10. An Integrated Hydrological and Water Management Study of the Entire Nile River System - Lake Victoria to Nile Delta

    NASA Technical Reports Server (NTRS)

    Habib, Shahid; Zaitchik, Benjamin; Alo, Clement; Ozdogan, Mutlu; Anderson, Martha; Policelli, Fritz

    2011-01-01

    The Nile basin River system spans 3 million km(exp 2) distributed over ten nations. The eight upstream riparian nations, Ethiopia, Eretria, Uganda, Rwanda, Burundi, Congo, Tanzania and Kenya are the source of approximately 86% of the water inputs to the Nile, while the two downstream riparian countries Sudan and Egypt, presently rely on the river's flow for most of the their needs. Both climate and agriculture contribute to the complicated nature of Nile River management: precipitation in the headwaters regions of Ethiopia and Lake Victoria is variable on a seasonal and inter-annual basis, while demand for irrigation water in the arid downstream region is consistently high. The Nile is, perhaps, one of the most difficult trans-boundary water issue in the world, and this study would be the first initiative to combine NASA satellite observations with the hydrologic models study the overall water balance in a to comprehensive manner. The cornerstone application of NASA's Earth Science Research Results under this project are the NASA Land Data Assimilation System (LDAS) and the USDA Atmosphere-land Exchange Inverse (ALEXI) model. These two complementary research results are methodologically independent methods for using NASA observations to support water resource analysis in data poor regions. Where an LDAS uses multiple sources of satellite data to inform prognostic simulations of hydrological process, ALEXI diagnoses evapotranspiration and water stress on the basis of thermal infrared satellite imagery. Specifically, this work integrates NASA Land Data Assimilation systems into the water management decision support systems that member countries of the Nile Basin Initiative (NBI) and Regional Center for Mapping of Resources for Development (RCMRD, located in Nairobi, Kenya) use in water resource analysis, agricultural planning, and acute drought response to support sustainable development of Nile Basin water resources. The project is motivated by the recognition that

  11. LPXRFa, the piscine ortholog of GnIH, and LPXRF receptor positively regulate gonadotropin secretion in Tilapia (Oreochromis niloticus).

    PubMed

    Biran, Jakob; Golan, Matan; Mizrahi, Naama; Ogawa, Satoshi; Parhar, Ishwar S; Levavi-Sivan, Berta

    2014-11-01

    LPXRFamide (LPXRFa) peptides have been characterized for their ability to inhibit gonadotropin (GTH) release in birds and stimulate growth hormone (GH) release in frogs. However, their involvement in regulating the reproductive hypothalamo-pituitary-gonadal axis in mammals and fish is inconclusive. To study the role of LPXRFa peptides in the regulation of GTH secretion, we cloned tilapia LPXRFa and LPXRF receptor (LPXRF-R). Processing of the tilapia preproLPXRFa liberated three mature LPXRFa peptides that varied in size and post-translational modifications. Phylogenetic analysis of LPXRFa and the closely related RFamide peptide PQRFa showed clear clustering of each peptide sequence with its orthologs from various vertebrates. Signal-transduction analysis of the tilapia LPXRF-R in COS-7 cells showed clear stimulation of CRE-dependent luciferase activity, whereas the human NPFFR1 showed suppression of forskolin-induced CRE-dependent activity in this system. Administration of the tilapia pyroglutaminated LPXRFa-2 peptide to primary cell culture of tilapia pituitaries, or to reproductive female tilapia by ip injection, positively regulated both LH and FSH release in vivo and in vitro. Using double-labeled fluorescent in-situ hybridization and immunofluorescence, βLH cells were found to co-express both tilapia lpxrf and tilapia lpxrf-r mRNA, whereas some of the βFSH cells coexpressed only lpxrf-r mRNA. No coexpression of tilapia lpxrf-r was identified in GH-positive cells. These findings suggest that the LPXRFa system is a potent positive regulator of the reproductive neuroendocrine axis of tilapia.

  12. Neuromuscular Manifestations of West Nile Virus Infection

    PubMed Central

    Leis, A. Arturo; Stokic, Dobrivoje S.

    2012-01-01

    The most common neuromuscular manifestation of West Nile virus (WNV) infection is a poliomyelitis syndrome with asymmetric paralysis variably involving one (monoparesis) to four limbs (quadriparesis), with or without brainstem involvement and respiratory failure. This syndrome of acute flaccid paralysis may occur without overt fever or meningoencephalitis. Although involvement of anterior horn cells in the spinal cord and motor neurons in the brainstem are the major sites of pathology responsible for neuromuscular signs, inflammation also may involve skeletal or cardiac muscle (myositis, myocarditis), motor axons (polyradiculitis), and peripheral nerves [Guillain–Barré syndrome (GBS), brachial plexopathy]. In addition, involvement of spinal sympathetic neurons and ganglia provides an explanation for autonomic instability seen in some patients. Many patients also experience prolonged subjective generalized weakness and disabling fatigue. Despite recent evidence that WNV may persist long-term in the central nervous system or periphery in animals, the evidence in humans is controversial. WNV persistence would be of great concern in immunosuppressed patients or in those with prolonged or recurrent symptoms. Support for the contention that WNV can lead to autoimmune disease arises from reports of patients presenting with various neuromuscular diseases that presumably involve autoimmune mechanisms (GBS, other demyelinating neuropathies, myasthenia gravis, brachial plexopathies, stiff-person syndrome, and delayed or recurrent symptoms). Although there is no specific treatment or vaccine currently approved in humans, and the standard remains supportive care, drugs that can alter the cascade of immunobiochemical events leading to neuronal death may be potentially useful (high-dose corticosteroids, interferon preparations, and intravenous immune globulin containing WNV-specific antibodies). Human experience with these agents seems promising based on anecdotal reports

  13. Prolonged fasting and cortisol reduce myostatin mRNA levels in tilapia larvae; short-term fasting elevates.

    PubMed

    Rodgers, Buel D; Weber, Gregory M; Kelley, Kevin M; Levine, Michael A

    2003-05-01

    Myostatin negatively regulates muscle growth and development and has recently been characterized in several fishes. We measured fasting myostatin mRNA levels in adult tilapia skeletal muscle and in whole larvae. Although fasting reduced some growth indexes in adults, skeletal muscle myostatin mRNA levels were unaffected. By contrast, larval myostatin mRNA levels were sometimes elevated after a short-term fast and were consistently reduced with prolonged fasting. These effects were specific for myostatin, as mRNA levels of glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphatase were unchanged. Cortisol levels were elevated in fasted larvae with reduced myostatin mRNA, whereas in addition immersion of larvae in 1 ppm (2.8 microM) cortisol reduced myostatin mRNA in a time-dependent fashion. These results suggest that larval myostatin mRNA levels may initially rise but ultimately fall during a prolonged fast. The reduction is likely mediated by fasting-induced hypercortisolemia, indicating divergent evolutionary mechanisms of glucocorticoid regulation of myostatin mRNA, since these steroids upregulate myostatin gene expression in mammals.

  14. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    SciTech Connect

    Sockalingam, K. Abdullah, H. Z.

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  15. Novel brain lesions caused by Edwardsiella tarda in a red tilapia (Oreochromis spp.).

    PubMed

    Iregui, Carlos A; Guarín, Marlly; Tibatá, Victor M; Ferguson, Hugh W

    2012-03-01

    The histological lesions caused by Edwardsiella tarda in a variety of fish species, including tilapia, have been well characterized. There are apparent differences in the type of inflammatory response manifested by these different species, which may be due to the fish species itself, the phase of infection, or the virulence factors produced by different strains of E. tarda. In catfish, systemic abscesses involving muscles of the flank or caudal peduncle are the most common lesions. By contrast, infection in tilapia and red sea bream is more likely to be associated with granulomatous inflammation. Necrotic meningitis, encephalitis, and vasculitis with fibrinoid necrosis of the blood vessels walls, as well as the formation of a plaque-like structure in the brain, are described in the current study. The presence of E. tarda was confirmed by microbiological isolation and a positive nested polymerase chain reaction in paraffin wax-embedded tilapia tissues.

  16. Research findings from the use of probiotics in tilapia aquaculture: A review.

    PubMed

    Hai, Ngo Van

    2015-08-01

    This study aims to present research findings from the use of probiotics in tilapia aquaculture. In omnivorous species of tilapia aquaculture, intestines and gonads, rearing water and sediments or even commercial products, can be sources for acquiring appropriate probiotics. Administration of probiotics varies from direct oral/water routine to feed additives, of which the latter is most commonly used. Probiotic applications can be either mono or multiple strains. Dosage and duration of time are significant factors in providing desired results. As probiotics have been proven to be either immune enhancers and/or growth promoters in aquatic animals, several modes of actions of probiotics in enhancement of immune responses, and an improvement of growth and survival rates of tilapia are presented, while the effects of others are not yet understood to the same degree as for other fish species. Some points extracted from the research findings are emphasised for further investigation and development.

  17. UV treatments on the physicochemical properties of tilapia skin and pig skin gelatin.

    PubMed

    Wu, C K; Tsai, J S; Chen, Z Y; Sung, W C

    2015-06-01

    Tilapia skin gelatin, pig skin gelatin, and their mousse premixes were exposed to UV irradiation for 103, 206, and 309 kJ/cm(2). All samples after 309 kJ/cm(2) exposure exhibited a significant increase in gel strength, gel forming ability as well as viscosity of solutions. It was shown that UV treatment could also improve the pig skin gelatin foam stability and foam formation ability compared to those of tilapia skin gelatin. Nevertheless, the panelists gave the lowest scores to mousse made with 309 kJ/cm(2) UV-irradiated premix mousse pig skin gelatin. Tilapia skin gelatin could be used as a substitute ingredient for premix mousse made from pig skin gelatin.

  18. Experimental early pathogenesis of Streptococcus agalactiae infection in red tilapia Oreochromis spp.

    PubMed

    Iregui, C A; Comas, J; Vásquez, G M; Verján, N

    2016-02-01

    Streptococcus agalactiae causes a severe systemic disease in fish, and the routes of entry are still ill-defined. To address this issue, two groups of 33 red tilapia Oreochromis spp. each of 10 g were orally infected with S. agalactiae (n = 30), and by immersion (n = 30), six individuals were control-uninfected fish. Three tilapias were killed at each time point from 30 min to 96 h post-inoculation (pi); controls were killed at 96 h. Samples from most tissues were examined by haematoxylin-eosin (H&E), indirect immunoperoxidase (IPI) and periodic acid-Schiff; only intestine from fish infected by gavage was evaluated by transmission electron microscopy. The results of both experiments suggest that the main entry site of S. agalactiae in tilapia is the gastrointestinal epithelium; mucus seems to play an important defensive role, and environmental conditions may be an important predisposing factor for the infection.

  19. West Nile Virus Seroprevalence, Connecticut, USA, 2000–2014

    PubMed Central

    Cahill, Megan E.; Yao, Yi; Nock, David; Armstrong, Philip M.; Andreadis, Theodore G.; Diuk-Wasser, Maria A.

    2017-01-01

    West Nile virus (WNV) infection is mainly asymptomatic but can be severe in elderly persons. As part of studies on immunity and aging in Connecticut, USA, we detected WNV seroconversion in 8.5% of nonimmunosuppressed and 16.8% of immunosuppressed persons. Age was not a significant seroconversion factor. Our findings suggest that immune factors affect seroconversion. PMID:28322715

  20. Outbreak of West Nile Virus Infection in Greece, 2010

    PubMed Central

    Papa, Anna; Theocharopoulos, George; Dougas, Georgios; Athanasiou, Maria; Detsis, Marios; Baka, Agoritsa; Lytras, Theodoros; Mellou, Kassiani; Bonovas, Stefanos; Panagiotopoulos, Takis

    2011-01-01

    During 2010, an outbreak of West Nile virus infection occurred in Greece. A total of 197 patients with neuroinvasive disease were reported, of whom 33 (17%) died. Advanced age and a history of heart disease were independently associated with death, emphasizing the need for prevention of this infection in persons with these risk factors. PMID:22000357

  1. West Nile virus infection in killer whale, Texas, USA, 2007.

    PubMed

    St Leger, Judy; Wu, Guang; Anderson, Mark; Dalton, Les; Nilson, Erika; Wang, David

    2011-08-01

    In 2007, nonsuppurative encephalitis was identified in a killer whale at a Texas, USA, marine park. Panviral DNA microarray of brain tissue suggested West Nile virus (WNV); WNV was confirmed by reverse transcription PCR and sequencing. Immunohistochemistry demonstrated WNV antigen within neurons. WNV should be considered in cases of encephalitis in cetaceans.

  2. West Nile Virus Infection in Killer Whale, Texas, USA, 2007

    PubMed Central

    Wu, Guang; Anderson, Mark; Dalton, Les; Nilson, Erika; Wang, David

    2011-01-01

    In 2007, nonsuppurative encephalitis was identified in a killer whale at a Texas, USA, marine park. Panviral DNA microarray of brain tissue suggested West Nile virus (WNV); WNV was confirmed by reverse transcription PCR and sequencing. Immunohistochemistry demonstrated WNV antigen within neurons. WNV should be considered in cases of encephalitis in cetaceans. PMID:21801643

  3. West Nile Virus Antibodies in Wild Birds, Morocco, 2008

    PubMed Central

    Baouab, Riad E.; Soriguer, Ramon; Fassi-Fihri, Ouafaa; Llorente, Francisco; Jímenez-Clavero, Miguel Angel

    2009-01-01

    To determine circulation of West Nile virus (WNV) during nonepidemic times, we serosurveyed wild birds of Morocco in 2008. We found antibodies against WNV in 12 (3.5%) birds, against Usutu virus in 1 (0.3%), and against both in 2 (0.6%). High WNV prevalence among juvenile birds suggests local virus circulation among resident birds. PMID:19861065

  4. Corvidae feather pulp and West Nile virus detection

    USGS Publications Warehouse

    Docherty, D.E.; Romaine Long, R.; Griffin, Katie M.; Saito, E.K.

    2004-01-01

    We evaluated cloacal swab, vascular pulp of flight feather, and kidney and spleen pool samples from carcasses of members of the family Corvidae as sources of West Nile virus (WNV). The cloacal swab, kidney and spleen pool, and feather pulp were the source of WNV in 38%, 43%, and 77%, respectively, of the carcasses.

  5. West Nile Virus Isolation from Equines in Argentina, 2006

    PubMed Central

    Barrandeguy, María; Fabbri, Cintia; Garcia, Jorge B.; Vissani, Aldana; Trono, Karina; Gutierrez, Gerónimo; Pigretti, Santiago; Menchaca, Hernán; Garrido, Nelson; Taylor, Nora; Fernandez, Fernando; Levis, Silvana; Enría, Delia

    2006-01-01

    West Nile virus (WNV) was isolated from the brains of 3 horses that died from encephalitis in February 2006. The horses were from different farms in central Argentina and had not traveled outside the country. This is the first isolation of WNV in South America. PMID:17176571

  6. West Nile Virus: Biology, Transmission, and Human Infection

    PubMed Central

    Colpitts, Tonya M.; Conway, Michael J.; Montgomery, Ruth R.

    2012-01-01

    Summary: West Nile Virus was introduced into the Western Hemisphere during the late summer of 1999 and has been causing significant and sometimes severe human diseases since that time. This article briefly touches upon the biology of the virus and provides a comprehensive review regarding recent discoveries about virus transmission, virus acquisition, and human infection and disease. PMID:23034323

  7. Agricultural Model for the Nile Basin Decision Support System

    NASA Astrophysics Data System (ADS)

    van der Bolt, Frank; Seid, Abdulkarim

    2014-05-01

    To analyze options for increasing food supply in the Nile basin the Nile Agricultural Model (AM) was developed. The AM includes state-of-the-art descriptions of biophysical, hydrological and economic processes and realizes a coherent and consistent integration of hydrology, agronomy and economics. The AM covers both the agro-ecological domain (water, crop productivity) and the economic domain (food supply, demand, and trade) and allows to evaluate the macro-economic and hydrological impacts of scenarios for agricultural development. Starting with the hydrological information from the NileBasin-DSS the AM calculates the available water for agriculture, the crop production and irrigation requirements with the FAO-model AquaCrop. With the global commodity trade model MAGNET scenarios for land development and conversion are evaluated. The AM predicts consequences for trade, food security and development based on soil and water availability, crop allocation, food demand and food policy. The model will be used as a decision support tool to contribute to more productive and sustainable agriculture in individual Nile countries and the whole region.

  8. West Nile virus antibody prevalence in wild mammals, southern Wisconsin

    USGS Publications Warehouse

    Docherty, D.E.; Samuel, M.D.; Nolden, C.A.; Egstad, Kristina F.; Griffin, K.M.

    2006-01-01

    Twenty percent prevalence of West Nile virus antibody was found in free-ranging medium-sized Wisconsin mammals. No significant differences were noted in antibody prevalence with regard to sex, age, month of collection, or species. Our results suggest a similar route of infection in these mammals.

  9. West Nile Virus–associated Flaccid Paralysis Outcome

    PubMed Central

    Bode, Amy V.; Marfin, Anthony A.; Campbell, Grant L.; Pape, John; Biggerstaff, Brad J.; Petersen, Lyle R.

    2006-01-01

    We report 1-year follow-up data from a longitudinal prospective cohort study of patients with West Nile virus–associated paralysis. As in the 4-month follow-up, a variety of recovery patterns were observed, but persistent weakness was frequent. Respiratory involvement was associated with considerable illness and death. PMID:16704798

  10. Increase in West Nile neuroinvasive disease after Hurricane Katrina.

    PubMed

    Caillouët, Kevin A; Michaels, Sarah R; Xiong, Xu; Foppa, Ivo; Wesson, Dawn M

    2008-05-01

    After Hurricane Katrina, the number of reported cases of West Nile neuroinvasive disease (WNND) sharply increased in the hurricane-affected regions of Louisiana and Mississippi. In 2006, a >2-fold increase in WNND incidence was observed in the hurricane-affected areas than in previous years.

  11. Increase in West Nile Neuroinvasive Disease after Hurricane Katrina

    PubMed Central

    Michaels, Sarah R.; Xiong, Xu; Foppa, Ivo; Wesson, Dawn M.

    2008-01-01

    After Hurricane Katrina, the number of reported cases of West Nile neuroinvasive disease (WNND) sharply increased in the hurricane-affected regions of Louisiana and Mississippi. In 2006, a >2-fold increase in WNND incidence was observed in the hurricane-affected areas than in previous years. PMID:18439367

  12. Domestic goose model for West Nile virus vaccine efficiency testing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    West Nile virus (WNV) is an emergent pathogen in the Americas, first reported in New York during 1999, and has since spread across the United States (USA), Central and South America causing neurological disease in humans, horses and some bird species, including domestic geese. No WNV vaccines are li...

  13. West Nile Virus Surveillance, Guadeloupe, 2003–2004

    PubMed Central

    Blitvich, Bradley J.; Pradel, Jennifer; Molia, Sophie; Vachiéry, Nathalie; Pallavicini, Guillaume; Marlenee, Nicole L.; Zientara, Stéphan; Petitclerc, Martial; Martinez, Dominique

    2005-01-01

    We conducted extensive surveillance for West Nile virus infection in equines and chickens in Guadeloupe in 2003–2004. We showed a high seroprevalence in equines in 2003 related to biome, followed by a major decrease in virus circulation in 2004. No human or equine cases were reported during the study. PMID:16022789

  14. STS-56 Earth observation of the northeastern Nile Delta

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-56 Earth observation of the northeastern Nile Delta was photographed from the Earth-orbiting Discovery, Orbiter Vehicle (OV) 103. The branch of the Nile featured in the frame is Daimietta. The Suez Canal marks the boundary of the Nile Delta agriculture and the Sinai Desert to the right. Lake Masada, the dark waterlogged area to the west (left) of Port Said is becoming more saline as the Aswan Dam has reduced sediment downstream. This sediment reduction, according to NASA scientists studying the STS-56 photography, has resulted in increased coastal erosion and the intrusion of a salt-water lens to the ground water, particularly in the northeastern portions of the delta. Center pivot irrigation fields are located along either side of the Ramses Canal, which connects the Daimietta Nile with Great Bitter Lake. This canal has been re-dug three or four times in the past 3,000 years. Historians note that the canal's most famous use was as the departure point of the fleet of Pharaoh Necho.

  15. Is Solar Variability Reflected in the Nile River?

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Yung, Yuk L.

    2006-01-01

    We investigate the possibility that solar variability influences North African climate by using annual records of the water level of the Nile collected in 622-1470 A.D. The time series of these records are nonstationary, in that the amplitudes and frequencies of the quasi-periodic variations are time-dependent. We apply the Empirical Mode Decomposition technique especially designed to deal with such time series. We identify two characteristic timescales in the records that may be linked to solar variability: a period of about 88 years and one exceeding 200 years. We show that these timescales are present in the number of auroras reported per decade in the Northern Hemisphere at the same time. The 11-year cycle is seen in the Nile's high-water level variations, but it is damped in the low-water anomalies. We suggest a possible physical link between solar variability and the low-frequency variations of the Nile water level. This link involves the influence of solar variability on the atmospheric Northern Annual Mode and on its North Atlantic Ocean and Indian Ocean patterns that affect the rainfall over the sources of the Nile in eastern equatorial Africa.

  16. Geochronology of wadi tushka: lost tributary of the nile.

    PubMed

    Haynes, C V

    1980-10-03

    The Sadat Canal, now under construction, is designed to drain excess water from Lake Nasser to the Western Desert by way of Wadi Tushka, a sand-filled, dry-wash tributary of the Nile 34 kilometers north of Abu Simbel. Core-drilling logs made by the Aswan High Dam Authority prior to excavation of the Sadat Canal and along 48 kilometers of its axis reveal as much as 33 meters of unconsolidated sand and gravel over Mesozoic bedrock and under surficial dune sand and playa muds of Holocene age. Excavation of the canal revealed Acheulean artifacts 6.7 meters below the surface in fluvial sediments capped by a buried, red calcic paleosol. These data are interpreted as evidence for the existence of a major tributary of the Nile during the late middle Pleistocene. The tributary drained the Kiseiba-Dungul Depression and possibly the Kharga Depression as well. Chalcedony-armored mudstones in the depressions are believed to be saline lake deposits possibly related to a lake that drained to the Nile by way of Wadi Tushka, thus entrenching the divide between the depression and the valley. Gross correlations with Pleistocene deposits of the Nile Valley and the Kharga Depression are based upon archeological evidence only until more precise geochronology can be applied to the problem.

  17. Transcriptomic profiling analysis of tilapia (Oreochromis niloticus) following Streptococcus agalactiae challenge.

    PubMed

    Zhu, Jiajie; Fu, Qiang; Ao, Qiuwei; Tan, Yun; Luo, Yongju; Jiang, Hesheng; Li, Chao; Gan, Xi

    2017-03-01

    Innate immune system is the primary defense mechanism against pathogen infection in teleost, which are living in pathogen-rich aquatic environment. It has been long hypothesized that the disease resistance in teleost are strongly correlated to the activities of innate immune genes. Tilapia is an important economical fish around the world, especially in China, where the production accounts for nearly half of the global production. Recently, S. agalactiae has become one of the most serious bacterial diseases in southern China, resulted in high cumulative mortality and economic loss to tilapia industry. Therefore, we sought here to characterize the expression profiles of tilapia against S. agalactiae infection at whole transcriptome level by RNA-seq technology. A total of 2822 genes were revealed significantly expressed in tilapia spleen with a general trend of induction. Notably, most of the genes were rapidly the most induced at the early timepoint. The significantly changed genes highlighted the function of pathogen attachment and recognition, antioxidant/apoptosis, cytoskeletal rearrangement, and immune activation. Collectively, the induced expression patterns suggested the strong ability of tilapia to rapidly recognize the invasive bacteria, and activation of downstream immune signaling pathways to clear the bacteria and prevent the tissue damage and bacteria triggered cell apoptosis. Our results heighted important roles of novel candidate genes which were often missed in previous tilapia studies. Further studies are needed to characterize the molecular relationships between key immune genes and disease resistance, and to identify the candidate genes for molecular-assistant selection of disease-resistant broodstock and evaluation of disease prevention and treatment measures.

  18. The osmoregulatory effects of rearing Mozambique tilapia in a tidally changing salinity.

    PubMed

    Moorman, Benjamin P; Inokuchi, Mayu; Yamaguchi, Yoko; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

    2014-10-01

    The native distribution of Mozambique tilapia, Oreochromis mossambicus, is characterized by estuarine areas subject to salinity variations between fresh water (FW) and seawater (SW) with tidal frequency. Osmoregulation in the face of changing environmental salinity is largely mediated through the neuroendocrine system and involves the activation of ion uptake and extrusion mechanisms in osmoregulatory tissues. We compared plasma osmolality, plasma prolactin (PRL), pituitary PRL mRNA, and mRNA of branchial ion pumps, transporters, channels, and PRL receptors in tilapia reared in FW, SW, brackish water (BW) and in tidally-changing salinity, which varied between FW (TF) and SW (TS) every 6h. Plasma PRL was higher in FW tilapia than in SW, BW, TF, and TS tilapia. Unlike tilapia reared in FW or SW, fish in salinities that varied tidally showed no correlation between plasma osmolality and PRL. In FW fish, gene expression of PRL receptor 1 (PRLR1), Na(+)/Cl(-) cotransporter (NCC), aquaporin 3 (AQP3) and two isoforms of Na(+)/K(+)-ATPase (NKA α1a and NKA α1b) was higher than that of SW, BW or tidally-changing salinity fish. Gene expression of the Na(+)/K(+)/2Cl(-) cotransporter (NKCC1a), and the cystic fibrosis transmembrane conductance regulator (CFTR) were higher in fish in SW, BW or a tidally-changing salinity than in FW fish. Immunocytochemistry revealed that ionocytes of fish in tidally-changing salinities resemble ionocytes of SW fish. This study indicated that tilapia reared in a tidally-changing salinity can compensate for large changes in external osmolality while maintaining osmoregulatory parameters within a narrow range closer to that observed in SW-acclimated fish.

  19. L-proline increases survival of tilapias infected by Streptococcus agalactiae in higher water temperature.

    PubMed

    Zhao, Xian-Liang; Han, Yi; Ren, Shi-Tong; Ma, Yan-Mei; Li, Hui; Peng, Xuan-Xian

    2015-05-01

    Streptococcosis causes massive tilapia kills, which results in heavy economic losses of tilapia farming industry. Out of the Streptococcosis, Streptococcus agalactiae is the major pathogen. The bacterium causes higher mortality of tilapias in higher than lower temperatures. However, effect of temperature on metabolic regulation which is related to the mortality is largely unknown. The present study showed 50% and 70% mortality of tilapias cultured in 25 °C and 30 °C, respectively, in comparison with no death in 20 °C following infection caused by S. agalactiae. Then, GC/MS based metabolomics was used to investigate a global metabolic response of tilapia liver to the two higher water temperatures compared to 20 °C. Thirty-six and forty-five varied abundance of metabolites were identified in livers of tilapias cultured at 25 °C and 30 °C, respectively. More decreasing abundance of amino acids and increasing abundance of carbohydrates were detected in 30 °C than 25 °C groups. On the other hand, out of the pathways enriched, the first five biggest impact pathways belong to amino acid metabolism. Decreasing abundance of l-proline was identified as a crucial biomarker for indexing higher water temperature and a potential modulator to reduce the high death. This was validated by engineering injection or oral addition of l-proline. Exogenous l-proline led to elevated amino acid metabolism, which contributes to the elevated survivals. Our findings provide a potential metabolic modulator for controlling the disease, and shed some light on host metabolic prevention to infectious diseases.

  20. The modern Nile sediment system: Processes and products

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo; Andò, Sergio; Padoan, Marta; Vezzoli, Giovanni; El Kammar, Ahmed

    2015-12-01

    We trace compositional changes of Nile sediments for 7400 km, from their sources in equatorial rift highlands of Burundi and Rwanda to their sink in the Mediterranean Sea. All chemical and physical controls on sediment petrography, mineralogy and geochemistry, including weathering, grain-size, hydraulic sorting, mechanical breakdown, anthropic impact, mixing and recycling are investigated in detail. The Nile course is controlled along its entire length by the East African-Red Sea Rift. In this anorogenic setting, detritus is derived in various proportions from volcanic fields associated with tectonic extension (Anorogenic Volcanic provenance) and from igneous, metamorphic and sedimentary rocks uplifted on the rift shoulders or exposed on the craton (Continental Block provenance). The entire spectrum of such detrital signatures is displayed in the Nile catchment. Volcaniclastic Atbara sand is generated by focused erosion of the Ethiopian basaltic plateau in semiarid climate, whereas quartzose White Nile sand reflects low erosion rates, extensive weathering and sediment trapping in lakes and swamps at equatorial to subequatorial latitudes. In the main Nile, as in its main tributary the Blue Nile, suspended load is volcaniclastic, whereas feldspatho-quartzose bedload is derived largely from basement sources, with fine to medium-grained eolian sand added along the lower course. Mixing of detrital populations with different provenance and grain size is reflected in diverse violations of settling-equivalence relationships in fluvial and deltaic sediments. Sediment delivery from Sudan has been cut off after closure of the Aswan High Dam and accelerated erosion of deltaic cusps is leading to local formation of placer lags dominated by ultradense Fe-Ti-Cr oxides, but mineralogical changes caused by man's radical modification of fluvial regimes have been minor so far. In beaches of Sinai, Gaza and Israel, the Nile volcaniclastic trace gets progressively diluted by quartzose

  1. Overwintering of West Nile virus in Southern California.

    PubMed

    Reisen, William K; Fang, Ying; Lothrop, Hugh D; Martinez, Vincent M; Wilson, Jennifer; Oconnor, Paul; Carney, Ryan; Cahoon-Young, Barbara; Shafii, Marzieh; Brault, Aaron C

    2006-03-01

    West Nile virus (family Flaviviridae, genus Flavivirus, WNV) invaded southern California during 2003, successfully overwintered, amplified to epidemic levels, and then dispersed to every county in the state. Although surveillance programs successfully tracked and measured these events, mechanisms that allowed the efficient overwintering and subsequent amplification of WNV have not been elucidated. Our current research provided evidence for three mechanisms whereby WNV may have persisted in southern California during the winters of 2003-2004 and 2004-2005: 1) continued enzootic transmission, 2) vertical transmission by Culex mosquitoes, and 3) chronic infection in birds. WNV was detected in 140 dead birds comprising 32 species, including 60 dead American crows, thereby verifying transmission during the November-March winter period. Dead American crows provide evidence of recent transmission because this species always succumbs rapidly after infection. However, WNV RNA was not detected concurrently in 43,043 reproductively active female mosquitoes comprising 11 species and tested in 1,258 pools or antibody in sera from 190 sentinel chickens maintained in 19 flocks. Although efficient vertical transmission by WNV was demonstrated experimentally for Culex tarsalis Coquillett infected per os, 369 females collected diapausing in Kern County and tested in 32 pools were negative for WNV. Vertical transmission was detected in Culex pipiens quinquefasciatus Say adults reared from field-collected immatures collected from Kern County and Los Angeles during the summer transmission period. Chronic infection was detected by finding WNV RNA in 34 of 82 birds that were inoculated with WNV experimentally, held for >6 wk after infection, and then necropsied. Frequent detection of WNV RNA in kidney tissue in experimentally infected birds >6 wk postinfection may explain, in part, the repeated detection of WNV RNA in dead birds recovered during winter, especially in species such as

  2. Protection of tilapia (Oreochromis mosambicus) from edwardsiellosis by vaccination with Edwardsiella tarda ghosts.

    PubMed

    Kwon, Se Ryun; Nam, Yoon Kwon; Kim, Sung Koo; Kim, Ki Hong

    2006-04-01

    The vaccine potential of Edwardsiella tarda ghosts produced by gene E mediated lysis was investigated using tilapia (Oreochromis mosambicus). Tilapia immunized with E. tarda ghosts (ETG) and formalin killed E. tarda (FKC) vaccines showed significantly higher serum agglutination titers than control fish. Fish immunized with ETG showed no significant differences with fish immunized with FKC in serum agglutination titers, but showed significantly higher bactericidal activity than fish immunized with FKC. Furthermore, fish immunized with ETG showed higher protection than fish immunized with FKC. As this promising type of a non-living whole cell envelope preparation seems to be favorable over conventional vaccines, we suggest E. tarda ghosts as a new vaccine candidate.

  3. Intersex Tilapia (Oreochromis spp.) from a Contaminated River in Taiwan: A Case Study

    PubMed Central

    Sun, Peter Lin; Tsai, Shinn-Shoung

    2009-01-01

    River pollution in Taiwan is rather serious, but so far there have been no reports of fish intersex problems. This report reveals that 50% male tilapia in the Era-Jiin River of southern Taiwan were found to be feminized in an October 8, 1994 collection from station EJ-2 of this river. After discounting all other possible causative factors, and correlating with endocrine disrupting chemicals found in this river, we suggest that there is a great possibility that the occurrence of intersex tilapia was caused by these chemicals. The above finding suggests that greater attention needs to be given to endocrine disrupting chemicals problems. PMID:22069529

  4. Blue tilapia (Oreochromis aureus) predation on fishes in the Muddy River system, Clark County, Nevada

    USGS Publications Warehouse

    Scoppettone, G.G.; Salgado, J.A.; Nielsen, M.B.

    2005-01-01

    Blue tilapia (Oreochromis aureus), native to North Africa and the Middle East (Courtenay and Robins 1973, Fuller et al. 1999), has been introduced around the world as a human food source, for vegetation control, and as a game fish (Costa-Pierce and Riedel 2000). Blue tilapia has been particularly successful in establishing and spreading in North American waters where it has been reported to change fish community structure and cause native fish decline (Courtenay and Robins 1973, Fuller et al. 1999). Because of these detrimental effects, it is now generally considered an unwelcome introduction into North American waters (Dill and Cordone 1997, Fuller et al. 1999).

  5. Streptococcus agalactiae isolates of serotypes Ia, III and V from human and cow are able to infect tilapia.

    PubMed

    Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping

    2015-10-22

    Recent studies have shown that group B streptococcus (GBS) may be infectious across hosts. The purpose of this study is to investigate the pathogenicity of clinical GBS isolates with serotypes Ia, III and V from human and cow to tilapia and the evolutionary relationship among these GBS strains of different sources. A total of 27 clinical GBS isolates from human (n=10), cow (n=2) and tilapia (n=15) were analyzed using serotyping, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Among them, 15 isolates were tested for their pathogenicity to tilapia. The results showed that five human GBS strains (2 serotype III, 2 serotype Ia and 1 serotype V) infected tilapia with mortality rate ranging from 56.67% to 100%, while the other five human GBS strains tested were unable to infect tilapia. In addition, two cow GBS strains C001 and C003 of serotype III infected tilapia. However, they had significantly lower pathogenicity than the five human strains. Furthermore, human GBS strains H005 and H008, which had very strong ability to infect tilapia, had the same PFGE pattern. MLST analysis showed that the five human and the two cow GBS strains that were able to infect tilapia belonged to clonal complexes CC19, CC23 and CC103. The study for the first time confirmed that human or cow GBS clonal complexes CC19, CC23 and CC103 containing strains with serotypes Ia, III and V could infect tilapia and induce clinical signs under experimental conditions.

  6. Prevalence and Pathology of West Nile Virus in Naturally Infected House Sparrows, Western Nebraska, 2008

    PubMed Central

    O'Brien, Valerie A.; Meteyer, Carol U.; Reisen, William K.; Ip, Hon S.; Brown, Charles R.

    2010-01-01

    Nestling birds are rarely sampled in the field for most arboviruses, yet they may be important in arbovirus amplification cycles. We sampled both nestling and adult house sparrows (Passer domesticus) in western Nebraska for West Nile virus (WNV) or WNV-specific antibodies throughout the summer of 2008 and describe pathology in naturally infected nestlings. Across the summer, 4% of nestling house sparrows were WNV-positive; for the month of August alone, 12.3% were positive. Two WNV-positive nestlings exhibited encephalitis, splenomegaly, hepatic necrosis, nephrosis, and myocarditis. One nestling sparrow had large mural thrombi in the atria and ventricle and immunohistochemical staining of WNV antigen in multiple organs including the wall of the aorta and pulmonary artery; cardiac insufficiency thus may have been a cause of death. Adult house sparrows showed an overall seroprevalence of 13.8% that did not change significantly across the summer months. The WNV-positive nestlings and the majority of seropositive adults were detected within separate spatial clusters. Nestling birds, especially those reared late in the summer when WNV activity is typically greatest, may be important in virus amplification. PMID:20439979

  7. Late Quaternary environments and prehistoric occupation in the lower White Nile valley, central Sudan

    NASA Astrophysics Data System (ADS)

    Williams, Martin A. J.; Usai, Donatella; Salvatori, Sandro; Williams, Frances M.; Zerboni, Andrea; Maritan, Lara; Linseele, Veerle

    2015-12-01

    Despite the major contributions provided over fifty years ago by A.J. Arkell and J.D. Tothill to our understanding of late Quaternary environments and prehistoric occupation near the confluence of the Blue and White Nile in central Sudan, three key questions have remained unresolved since then. (a) Was the decline in Nile flood levels from early Holocene times onwards caused by a reduction in Nile discharge, or by channel incision, or both? (b) Was the regional climate wetter during times of high Nile floods and drier during times of low Nile floods? (c) Given the high degree of disturbance of Mesolithic and later prehistoric sites, is it possible to identify primary-context, stratified and undisturbed occupation? Drawing upon dated evidence from three sites to the east of and three to the west of the lower White Nile, we provide a qualified answer to the first question and documented affirmative answers to the second and third questions.

  8. Causal links between Nile floods and eastern Mediterranean sapropel formation during the past 125 kyr confirmed by OSL and radiocarbon dating of Blue and White Nile sediments

    NASA Astrophysics Data System (ADS)

    Williams, M. A. J.; Duller, G. A. T.; Williams, F. M.; Woodward, J. C.; Macklin, M. G.; El Tom, O. A. M.; Munro, R. N.; El Hajaz, Y.; Barrows, T. T.

    2015-12-01

    It has long been hypothesised that beds of highly organic mud or sapropels seen in marine sediment cores retrieved from the floor of the eastern Mediterranean accumulated during times of high Nile fluvial discharge. Our recent fieldwork in the valleys of the Blue Nile, the White Nile and the main Nile has for the first time revealed a sequence of extreme flood episodes synchronous with sapropel units S5 (124 kyr), S4 (102 kyr), S3 (81 kyr), S2 (55 kyr) and S1 (13.5-6.5 kyr). There are more weakly defined links with Nile floods and sapropel units S9 (240 kyr), S8 (217 kyr), S7 (195 kyr), S6 (172 kyr), but the dating error terms are too large to allow us to be too definite. During times of extreme floods over the past 125 kyr, wide distributary channels of the Blue Nile flowed across the Gezira alluvial fan in central Sudan and transported a bed load of sand and gravel into the lower White Nile valley. The sands were reworked by wind to form source-bordering dunes, all of which contain heavy minerals of Ethiopian provenance. These source-bordering dunes were active at 115-105 kyr, 60 kyr and 12-7 kyr, all times of extreme Blue Nile floods. The flood and dune sediments were dated using a combination of optically stimulated luminescence (OSL) and radiocarbon analyses. The Quaternary record of Nile floods discussed here shows a precessional signal and reflects episodes of stronger summer monsoon and more northerly seasonal movement of the ITCZ, linked to times of higher insolation in northern tropical latitudes. Progressive aggradation of Holocene Nile channels in northern Sudan has had a profound influence upon human settlement in the last 8 kyr.

  9. Isolation of two strains of West Nile virus during an outbreak in southern Russia, 1999.

    PubMed Central

    Lvov, D. K.; Butenko, A. M.; Gromashevsky, V. L.; Larichev, V. P.; Gaidamovich, S. Y.; Vyshemirsky, O. I.; Zhukov, A. N.; Lazorenko, V. V.; Salko, V. N.; Kovtunov, A. I.; Galimzyanov, K. M.; Platonov, A. E.; Morozova, T. N.; Khutoretskaya, N. V.; Shishkina, E. O.; Skvortsova, T. M.

    2000-01-01

    From July to September 1999, a widespread outbreak of meningoencephalitis associated with West Nile virus (Flavivirus, Flaviviridae) occurred in southern Russia, with hundreds of cases and dozens of deaths. Two strains of West Nile virus isolated from patient serum and brain-tissue samples reacted in hemagglutination-inhibition and neutralization tests with patients' convalescent-phase sera and immune ascites fluid from other strains of West Nile virus. PMID:10905970

  10. Non-invasive assessment of adrenocortical function in captive Nile crocodiles (Crocodylus niloticus).

    PubMed

    Ganswindt, Stefanie B; Myburgh, Jan G; Cameron, Elissa Z; Ganswindt, Andre

    2014-11-01

    The occurrence of stress-inducing factors in captive crocodilians is a concern, since chronic stress can negatively affect animal health and reproduction, and hence production. Monitoring stress in wild crocodiles could also be beneficial for assessing the state of health in populations which are potentially threatened by environmental pollution. In both cases, a non-invasive approach to assess adrenocortical function as a measure of stress would be preferable, as animals are not disturbed during sample collection, and therefore sampling is feedback-free. So far, however, such a non-invasive method has not been established for any crocodilian species. As an initial step, we therefore examined the suitability of two enzyme-immunoassays, detecting faecal glucocorticoid metabolites (FGMs) with a 11β,21-diol-20-one and 5β-3α-ol-11-one structure, respectively, for monitoring stress-related physiological responses in captive Nile crocodiles (Crocodylus niloticus). An adrenocorticotropic hormone (ACTH) challenge was performed on 10 sub-adult crocodiles, resulting in an overall increase in serum corticosterone levels of 272% above the pre-injection levels 5h post-injection. Saline-treated control animals (n=8) showed an overall increase of 156% in serum corticosterone levels 5h post-administration. Faecal samples pre- and post-injection could be obtained from three of the six individually housed crocodiles, resulting in FGM concentrations 136-380% above pre-injection levels, always detected in the first sample collected post-treatment (7-15 days post-injection). FGM concentrations seem comparatively stable at ambient temperatures for up to 72 h post-defaecation. In conclusion, non-invasive hormone monitoring can be used for assessing adrenocortical function in captive Nile crocodiles based on FGM analysis.

  11. Le lupus systémique juvénile familial: à propos de deux familles

    PubMed Central

    Krich, Sanaa; Inani, Kawtar; Meziane, Mariame; Souilmi, Fatima Zohta; Atmani, Samir; Hida, Mustapha; Harmouch, Taoufik; Amarti, Afaf; Mernissi, Fatima Zohra

    2015-01-01

    Le lupus érythémateux systémique (LES) juvénile est une connectivite rare, d’évolution plus sévère que chez l'adulte. Les cas familiaux sont exceptionnels. Il s'agissait de deux familles (5 patients atteints), chez qui on a objectivé un LES juvénile chez deux sæurs âgées de 14 ans et 6 ans respectivement chez la première famille, deux frères, âgés de 20 ans et 6 ans respectivement plus une sæur âgée de 10 ans chez la deuxième famille. Dans tout les cas le diagnostic de lupus systémique a été posé selon les nouveaux critères du groupe du SLICC (Systemic Lupus International Collaborating Clinics). Tous les patients ont été mis sous photoprotection, dermocorticoïdes et antipaludéens de synthèse sauf dans deux cas où la corticothérapie a été administrée. L’évolution a été favorable après le traitement dans la majorité des cas. Nous rapportons ces cas afin de discuter les particularités épidémiologiques, physiopathologiques, cliniques, paracliniques et thérapeutiques. PMID:26301023

  12. Prevalence and effects of West Nile virus on wild American kestrel (Falco sparverius) populations in Colorado [Chapter 4

    USGS Publications Warehouse

    Dusek, R.J.; Iko, William M.; Hofmeister, E.K.

    2012-01-01

    To assess the potential impacts of West Nile virus (WNV) on a wild population of free-ranging raptors, we investigated the prevalence and effects of WNV on American Kestrels (Falco sparverius) breeding along the Front Range of the Rocky Mountains in northern Colorado. We monitored kestrel nesting activity at 131 nest boxes from March to August 2004. Of 81 nest attempts, we obtained samples from 111 adults and 250 young. We did not detect WNV in sera; however, 97.3% (108/111) of adults tested positive for WNV neutralizing antibodies, which possibly represented passive transfer of maternal antibodies. Clutch size, hatching, and fledging success in our study did not differ from that previously reported for this species, suggesting that previous WNV exposure in kestrels did not have an effect on reproductive parameters measured in the breeding populations we studied in 2004.

  13. Monitoring the Spread of West Nile Virus with Satellite Data

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA-funded study uses temperature and vegetation data from satellites to help track and predict where West Nile virus is spreading in North America. Scientists and public health officials hope one day to use near real-time maps to focus resources and stave off the disease more efficiently. This image is a composite of land surface temperatures (LST) recorded between 1997 and 2000 and was used to help monitor and predict the spread of West Nile virus in the United States. In the color figure above, the mean land surface temperatures are in red; annual amplitude-or the difference between low and high annual temperatures-is in blue; and annual phase-or the timing of annual temperature peaks-appears in green. Brighter colors mean higher values. The major north-south temperature difference (dull red in the upper part of the image to bright red in the lower part) is considerably affected by the Rockies in the west and to a much lesser extent by the Appalachians in the east. The brighter blue in the upper part of the image indicates the big difference between highest and lowest temperatures during the course of a year at higher latitudes. There is less variation in the timing of the annual peak of land surface temperatures, which occurs earlier in the south than in the north. Black dots superimposed on this image are the locations (county geo-centers) where birds infected with West Nile virus were reported between January and October 2001. Scientists working with the International Research Partnership for Infectious Diseases (INTREPID) program based at NASA are using such imagery to define and predict the conditions where mosquitoes transmit West Nile virus in the U.S. The conclusion reached about the importance of any single variable depends both upon its value and context. A temperature of 30o Celsius (86o Fahrenheit) might be fatal for a mosquito at low humidity but survivable at higher humidities. The work done here on West Nile virus and other diseases shows very

  14. Electrotransfer of the tilapia piscidin 3 and tilapia piscidin 4 genes into skeletal muscle enhances the antibacterial and immunomodulatory functions of Oreochromis niloticus.

    PubMed

    Lin, Wen-Chun; Chang, Hsiao-Yun; Chen, Jyh-Yih

    2016-03-01

    Tilapia piscidin 3 (TP3) and tilapia piscidin 4 (TP4) are antimicrobial peptides recently isolated from Oreochromis niloticus. We previously showed that synthetic TP3 and TP4 possessed antimicrobial activities. Here, we analyzed the bactericidal abilities and immunomodulatory properties of these AMPs following the electroporation of pCMV-GFP-TP3 or pCMV-GFP-TP4 plasmid into tilapia (O. niloticus) muscle and subsequent infection with Vibrio vulnificus or Streptococcus agalactiae. Prior overexpression of TP3 or TP4 in tilapia muscle tissues efficiently reduced bacterial numbers at 24 and 48 h after V. vulnificus infection and reduced bacterial numbers at 24 h after S. agalactiae infection compared to numbers in controls expressing pCMV-GFP (EGFP). Electroporation of pCMV-EGFP-TP3 (TP3) or pCMV-EGFP-TP4 (TP4) significantly increased expression of several immune-related genes in muscle (IL-1β (12 h, TP3), IL-8 (12 h, TP3), TGFβ (3 h, TP4), and IκB (48 h, TP3, TP4)) and decreased the expression of TLR5 (12 h and 24 h, TP3) after V. vulnificus infection. Following S. agalactiae infection, expression of the following genes was significantly decreased in muscle: IL-1β (12 h, TP3), IL-8 (12 h, TP3, TP4), TLR5 (3 h-24 h, TP3, TP4), TGFβ (3 h, TP4; 24 h, TP3, TP4), and IκB (3 h, TP3). These data suggest that TP3 and TP4 exert antimicrobial effects after overexpression in the O. niloticus muscle, and also play important roles in the regulation of immune-related gene expression.

  15. First molecular analysis of West Nile virus during the 2013 outbreak in Croatia.

    PubMed

    Kurolt, Ivan C; Krajinović, Vladimir; Topić, Antea; Kuzman, Ilija; Baršić, Bruno; Markotić, Alemka

    2014-08-30

    This is the second subsequent year of West Nile neuroinvasive disease (WNND) outbreak in Croatia. Between July and October 2013, 22 patients presented with symptoms of WNND: all with meningitis and 18 additionally with encephalitis. In contrast to 2012, where six autochthonous infections were confirmed in eastern Croatia, the majority of this year's cases occurred in and around the city of Zagreb, where no West Nile virus infections have been observed before. Viral RNA was recovered from two patients and phylogenetic analyses revealed West Nile virus lineage 2. This represents the first molecular characterization and phylogenetic analysis of the circulating West Nile virus strain in Croatia.

  16. Triple trouble? Invasive poeciliid fishes carry the introduced tilapia pathogen Gyrodactylus cichlidarum in the Mexican highlands.

    PubMed

    García-Vásquez, Adriana; Razo-Mendivil, Ulises; Rubio-Godoy, Miguel

    2017-02-15

    As part of ongoing surveys of the gyrodactylid parasite fauna of freshwater fishes in Mexico, we recorded the infection of three species of poeciliids (Poecilia mexicana, Poeciliopsis gracilis, and Pseudoxiphophorus bimaculatus [syn.=Heterandria bimaculata]) with Gyrodactylus cichlidarum, a monogenean parasite of cichlid fishes, which has been co-introduced globally with its translocated, African "tilapia" hosts. This tilapia pathogen was found on poeciliid fishes both within their native distribution range in the Gulf of Mexico slope, as well as on invasive species artificially introduced to the Mexican highlands, to rivers draining into the Pacific Ocean. Identity of G. cichlidarum was confirmed by morphological and molecular analyses. Prevalence and abundance of infection were low, but this is the first record of G. cichlidarum infecting poeciliids (Cyprinodontiformes), which are distantly related to this parasite's primary cichlid fish hosts (Perciformes). This study provides evidence that G. cichlidarum, a recognized pathogen which has been co-introduced globally with its cichlid fish hosts for aquacultural purposes, is able to infect non-related poeciliid fishes inhabiting water bodies adjacent to tilapia farms, thereby potentially increasing its ability to disperse between farms and different river basins. It is of particular concern that G. cichlidarum was found on poeciliids, as these invasive fishes have been introduced worldwide and could act as carriers for this parasite known to induce significant mortality of farmed tilapias - globally, the second most important freshwater aquaculture fish group, after the carps.

  17. Accumulation and toxic effects of microcystin in tilapia (Oreochromis niloticus) from an eutrophic Brazilian lagoon.

    PubMed

    Hauser-Davis, Rachel Ann; Lavradas, Raquel Teixeira; Lavandier, Ricardo Cavalcanti; Rojas, Edwin Gonzalo Azero; Guarino, Alcides Wagner Serpa; Ziolli, Roberta Lourenço

    2015-02-01

    Microcystin (MC) accumulation and depuration in environmentally exposed tilapia (Oreochromis niloticus) at a chronically contaminated eutrophic lagoon was studied. This is one of the scarce reports on microcystin accumulation in bile of environmentally exposed fish, and gonad MC accumulation in the field, in contrast to laboratory exposure experiments. Results show that preferential MC accumulation in the environment occurred in tilapia fish muscle, followed by gonads, liver and, finally, bile. Biliary MC excretion in in situ conditions indicates elimination from the body to a certain degree. High gonad MC bioaccumulation is of concern, since this could indicate potential reproductive problems in this species. This study also demonstrated that tilapia shows similar oxidative stress responses (in the form of reduced glutathione, GSH) in the environment as those observed in laboratory exposed fish. MC dietary intake values for tilapia muscle and liver were above the limits imposed by international legislations, indicating that the local human population should exercise care when ingesting this species as a part of their diet and that human ingestion of MC-contaminated samples should be carefully monitored.

  18. Genetic characterization of Vibrio vulnificus strains from tilapia aquaculture in Bangladesh.

    PubMed

    Mahmud, Zahid H; Wright, Anita C; Mandal, Shankar C; Dai, Jianli; Jones, Melissa K; Hasan, Mahmud; Rashid, Mohammad H; Islam, Mohammad S; Johnson, Judith A; Gulig, Paul A; Morris, J Glenn; Ali, Afsar

    2010-07-01

    Outbreaks of Vibrio vulnificus wound infections in Israel were previously attributed to tilapia aquaculture. In this study, V. vulnificus was frequently isolated from coastal but not freshwater aquaculture in Bangladesh. Phylogenetic analyses showed that strains from Bangladesh differed remarkably from isolates commonly recovered elsewhere from fish or oysters and were more closely related to strains of clinical origin.

  19. Complete Genome Sequence of Streptococcus iniae 89353, a Virulent Strain Isolated from Diseased Tilapia in Taiwan

    PubMed Central

    Wu, Sheng-Han; Chen, Chun-Yao; Huang, Chang-Wen; Lu, Jenn-Kan; Chou, Hsin-Yiu

    2017-01-01

    ABSTRACT Streptococcus iniae 89353 is a virulent strain isolated from diseased tilapia in Taiwan. The full-genome sequence of S. iniae 89353 is 2,098,647 bp. The revealed genome information will be beneficial for identification and understanding of potential virulence genes of Streptococcus iniae and possible immunogens for vaccine development against streptococcosis. PMID:28126946

  20. Complete Genome Sequence of a Virulent Strain, Streptococcus iniae ISET0901, Isolated from Diseased Tilapia

    PubMed Central

    Zhang, Dunhua; Zhang, Lee

    2014-01-01

    Streptococcus iniae ISET0901 is a virulent strain isolated in 2007 from diseased tilapia. Its full genome is 2,070,856 bp. The availability of this genome will allow comparative genomics to identify virulence genes important for the pathogenesis of streptococcosis caused by S. iniae, as well as possible immunogens for vaccine development. PMID:24903878

  1. Application of Highly Purified Electrolyzed Chlorine Dioxide for Tilapia Fillet Disinfection

    PubMed Central

    Yu, Chen-Hsing; Huang, Tzou-Chi; Chung, Chao-Chin; Huang, Hao-Hsun

    2014-01-01

    This research aimed to develop an electrolysis method to generate high-concentration chlorine dioxide (ClO2) for tilapia fillet disinfection. The designed generator produced up to 3500 ppm of ClO2 at up to 99% purity. Tilapia fillets were soaked in a 400 ppm ClO2 solution for 5, 10, and 25 min. Results show that total plate counts of tilapia, respectively, decreased by 5.72 to 3.23, 2.10, and 1.09 log CFU/g. In addition, a 200 ppm ClO2 solution eliminated coliform bacteria and Escherichia coli in 5 min with shaking treatment. Furthermore, ClO2 and trihalomethanes (THMs) residuals on tilapia fillets were analyzed by GC/MS and were nondetectable (GC-MS detection limit was 0.12 ppb). The results conform to Taiwan's environmental protection regulations and act governing food sanitation. PMID:24696651

  2. Draft Genome Sequences of Three Aeromonas hydrophila Isolates from Catfish and Tilapia

    PubMed Central

    Tekedar, Hasan C.; Kumru, Salih; Kalindamar, Safak; Karsi, Attila; Waldbieser, Geoffrey C.; Sonstegard, Tad; Schroeder, Steven G.; Liles, Mark R.; Griffin, Matt J.

    2017-01-01

    ABSTRACT Aeromonas hydrophila is a Gram-negative bacterium that is particularly adapted to freshwater environments and can cause severe infections in fish and humans. Here, we report the draft genomes of three A. hydrophila catfish and tilapia isolates. PMID:28104665

  3. Effect of transglutaminase on quality characteristics of a value-added product tilapia wastes.

    PubMed

    Monteiro, Maria Lúcia Guerra; Mársico, Eliane Teixeira; Lázaro, César Aquiles; da Silva Canto, Anna Carolina Vilhena Cruz; Lima, Bruno Reis Carneiro da Costa; da Cruz, Adriano Gomes; Conte-Júnior, Carlos Adam

    2015-05-01

    The aim of this work was to evaluate the physico-chemical, instrumental color and texture, and sensory qualities of restructured tilapia steaks elaborated with small sized (non-commercial) tilapia fillets and different levels of microbial transglutaminase (MTG). Four concentrations of MTG were used: CON (0 % MTG), T1 (0.1 % MTG), T2 (0.5 % MTG), and T3 (0.8 % MTG). In addition, bacterial content and pH shifts were also evaluated during 90 days of frozen storage. The different levels of MTG did not affect (P > 0.05) either the proximate composition of the restructured tilapia steaks or the bacterial growth during the frozen storage. MTG improved (P < 0.05) cooking yield and instrumental hardness and chewiness as well as sensory (salty taste, succulence and tenderness) attributes; strongly contributing to greater overall acceptance. Therefore, restructured tilapia steaks manufactured with MTG are potentially valued-added products with good consumer acceptance and better purchase-intention than steaks formulated with 0 % MTG.

  4. Enhanced susceptibility of hybrid tilapia to Flavobacterium columnare after parasitism by Ichthyophthirius multifiliis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterium Flavobacterium columnare and protozoan Ichthyophthirius multifiliis are two common pathogens of cultured fish. The objective of this study was to evaluate the susceptibility of hybrid tilapia (Oreochromis spp.) to the bacterium F. columnare, including fish mortality and bacterial loads in ...

  5. Absorbed Dose Rate Due to Intake of Natural Radionuclides by Tilapia Fish (Tilapia nilotica,Linnaeus, 1758) Estimated Near Uranium Mining at Caetite, Bahia, Brazil

    SciTech Connect

    Pereira, Wagner de S; Kelecom, Alphonse

    2008-08-07

    The uranium mining at Caetite (Uranium Concentrate Unit--URA) is in its operational phase. Aiming to estimate the radiological environmental impact of the URA, a monitoring program is underway. In order to preserve the biota of the deleterious effects from radiation and to act in a pro-active way as expected from a licensing body, the present work aims to use an environmental protection methodology based on the calculation of absorbed dose rate in biota. Thus, selected target organism was the Tilapia fish (Tilapia nilotica, Linnaeus, 1758) and the radionuclides were: uranium (U-238), thorium (Th-232), radium (Ra-226 and Ra-228) and lead (Pb-210). As, in Brazil there are no radiation exposure limits adopted for biota the value proposed by the Department of Energy (DOE) of the United States of 3.5x10{sup 3} {mu}Gy y{sup -1} has been used. The derived absorbed dose rate calculated for Tilapia was 2.51x10{sup 0} {mu}Gy y{sup -1}, that is less than 0.1% of the dose limit established by DOE. The critical radionuclide was Ra-226, with 56% of the absorbed dose rate, followed by U-238 with 34% and Th-232 with 9%. This value of 0.1% of the limit allows to state that, in the operational conditions analyzed, natural radionuclides do not represent a radiological problem to biota.

  6. Recent progress in West Nile virus diagnosis and vaccination

    PubMed Central

    2012-01-01

    West Nile virus (WNV) is a positive-stranded RNA virus belonging to the Flaviviridae family, a large family with 3 main genera (flavivirus, hepacivirus and pestivirus). Among these viruses, there are several globally relevant human pathogens including the mosquito-borne dengue virus (DENV), yellow fever virus (YFV), Japanese encephalitis virus (JEV) and West Nile virus (WNV), as well as tick-borne viruses such as tick-borne encephalitis virus (TBEV). Since the mid-1990s, outbreaks of WN fever and encephalitis have occurred throughout the world and WNV is now endemic in Africa, Asia, Australia, the Middle East, Europe and the Unites States. This review describes the molecular virology, epidemiology, pathogenesis, and highlights recent progress regarding diagnosis and vaccination against WNV infections. PMID:22380523

  7. Alexander the Great and West Nile Virus Encephalitis

    PubMed Central

    Marr, John S.

    2003-01-01

    Alexander the Great died in Babylon in 323 BC. His death at age 32 followed a 2-week febrile illness. Speculated causes of death have included poisoning, assassination, and a number of infectious diseases. One incident, mentioned by Plutarch but not considered by previous investigators, may shed light on the cause of Alexander’s death. The incident, which occurred as he entered Babylon, involved a flock of ravens exhibiting unusual behavior and subsequently dying at his feet. The inexplicable behavior of ravens is reminiscent of avian illness and death weeks before the first human cases of West Nile virus infection were identified in the United States. We posit that Alexander may have died of West Nile encephalitis. PMID:14725285

  8. Cloning and characterization of the gene for L-amino acid oxidase in hybrid tilapia.

    PubMed

    Shen, Yubang; Fu, Gui Hong; Liu, Feng; Yue, Gen Hua

    2015-12-01

    Tilapia is the common name for a group of cichlid fishes. Identification of DNA markers significantly associated with important traits in candidate genes may speed up genetic improvement. L-Amino acid oxidase (LAO) plays a crucial role in the innate immune defences of animals. Previously, whether LAO variants were associated with economic traits had not been studied in fish. We characterized the cDNA sequence of the LAO gene of hybrid tilapia (Oreochromis spp.). Its ORF was 1536 bp, encoding a flavoenzyme of 511 amino acids. This gene consisted of seven exons and six introns. Its expression was detected in the intestine, blood, kidney, skin, liver. It was highly expressed in the intestine. After a challenge with a bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the liver, intestine and spleen (P < 0.05). We identified one SNP in the genomic sequence of the gene and found that this SNP was associated significantly with body length (P < 0.05), but not with resistance to S. agalactiae. The results of this study suggest that the LAO gene plays an important role in innate immune responses to the bacterial pathogen in tilapia. The investigation of relationship between polymorphism of LAO gene and disease resistance and growth in tilapia showed that one SNP was associated significantly with body length. Further experiments on whether SNPs in the LAO gene are associated with growth in tilapia and other populations could be useful in understanding more functions of the LAO gene.

  9. Contrasting mercury accumulation patterns in tilapia (Oreochromis niloticus) and implications on somatic growth dilution.

    PubMed

    Wang, Rui; Wang, Wen-Xiong

    2012-06-15

    Dietary ingestion constitutes a major pathway for mercury (Hg) accumulation in freshwater fish, thus the ingestion rate (IR) may greatly influence the Hg bioaccumulation through its effect on Hg influx and other biokinetic processes. To explore the complex influence of IR, we conducted long-term bioaccumulation experiments by accurately controlling the IRs in the freshwater tilapia (Oreochromis niloticus). The dietary accumulation of both inorganic mercury (Hg[II]) and methylmercury (MeHg) in tilapia under different IRs was monitored over a period of 30 days by feeding the fish with uniformly radiolabeled crustaceans. The biokinetic parameters under various IRs were concurrently determined. With the increase of IR from 0.01 g g⁻¹ d⁻¹ to 0.12 g g⁻¹ d⁻¹, the dietary assimilation efficiency of Hg(II) in the tilapia decreased by 43% while the elimination rate increased by a factor of 1.8; both biokinetic changes slowed down the overall Hg(II) bioaccumulation at high IRs. In contrast to Hg(II), the biokinetics of MeHg was not significantly influenced, but its bioaccumulation increased disproportionally with increasing IR, showing slower increase at higher IR. We then employed a biokinetic model to simulate the long-term mercury bioaccumulation patterns in tilapia at various IRs. The modeling results indicated that the growth effect could not be ignored in long-term accumulation process. A rapid growth of fish driven by food availability could significantly reduce the MeHg concentrations in the tilapia. Our results demonstrated for the first time the contrasting influences of dietary ingestion on the long-term bioaccumulation of Hg(II) and MeHg. The somatic growth dilution was much more likely to occur for MeHg than for Hg(II).

  10. Direct Ionic Regulation of the Activity of Myo-Inositol Biosynthesis Enzymes in Mozambique Tilapia.

    PubMed

    Villarreal, Fernando D; Kültz, Dietmar

    2015-01-01

    Myo-inositol (Ins) is a major compatible osmolyte in many cells, including those of Mozambique tilapia (Oreochromis mossambicus). Ins biosynthesis is highly up-regulated in tilapia and other euryhaline fish exposed to hyperosmotic stress. In this study, enzymatic regulation of two enzymes of Ins biosynthesis, Ins phosphate synthase (MIPS) and inositol monophosphatase (IMPase), by direct ionic effects is analyzed. Specific MIPS and IMPase isoforms from Mozambique tilapia (MIPS-160 and IMPase 1) were selected based on experimental, phylogenetic, and structural evidence supporting their role for Ins biosynthesis during hyperosmotic stress. Recombinant tilapia IMPase 1 and MIPS-160 activity was assayed in vitro at ionic conditions that mimic changes in the intracellular milieu during hyperosmotic stress. The in vitro activities of MIPS-160 and IMPase 1 are highest at alkaline pH of 8.8. IMPase 1 catalytic efficiency is strongly increased during hyperosmolality (particularly for the substrate D-Ins-3-phosphate, Ins-3P), mainly as a result of [Na+] elevation. Furthermore, the substrate-specificity of IMPase 1 towards D-Ins-1-phosphate (Ins-1P) is lower than towards Ins-3P. Because MIPS catalysis results in Ins-3P this results represents additional evidence for IMPase 1 being the isoform that mediates Ins biosynthesis in tilapia. Our data collectively demonstrate that the Ins biosynthesis enzymes are activated under ionic conditions that cells are exposed to during hypertonicity, resulting in Ins accumulation, which, in turn, results in restoration of intracellular ion homeostasis. We propose that the unique and direct ionic regulation of the activities of Ins biosynthesis enzymes represents an efficient biochemical feedback loop for regulation of intracellular physiological ion homeostasis during hyperosmotic stress.

  11. Dopamine inhibits somatolactin gene expression in tilapia pituitary cells through the dopamine D2 receptors.

    PubMed

    Jiang, Quan; Lian, Anji; He, Qi

    2016-07-01

    Dopamine (DA) is an important neurotransmitter in the central nervous system of vertebrates and possesses key hypophysiotropic functions. Early studies have shown that DA has a potent inhibitory effect on somatolactin (SL) release in fish. However, the mechanisms responsible for DA inhibition of SL gene expression are largely unknown. To this end, tilapia DA type-1 (D1) and type-2 (D2) receptor transcripts were examined in the neurointermediate lobe (NIL) of the tilapia pituitary by real-time PCR. In tilapia, DA not only was effective in inhibiting SL mRNA levels in vivo and in vitro, but also could abolish pituitary adenylate cyclase-activating polypeptide (PACAP)- and salmon gonadotropin-releasing hormone (sGnRH)-stimulated SL gene expression at the pituitary level. In parallel studies, the specific D2 receptor agonists quinpirole and bromocriptine could mimic the DA-inhibited SL gene expression. Furthermore, the D2 receptor antagonists domperidone and (-)-sulpiride could abolish the SL response to DA or the D2 agonist quinpirole, whereas D1 receptor antagonists SCH23390 and SKF83566 were not effective in this respect. In primary cultures of tilapia NIL cells, D2 agonist quinpirole-inhibited cAMP production could be blocked by co-treatment with the D2 antagonist domperidone and the ability of forskolin to increase cAMP production was also inhibited by quinpirole. Using a pharmacological approach, the AC/cAMP pathway was shown to be involved in quinpirole-inhibited SL mRNA expression. These results provide evidence that DA can directly inhibit SL gene expression at the tilapia pituitary level via D2 receptor through the AC/cAMP-dependent mechanism.

  12. Derivation and Osmotolerance Characterization of Three Immortalized Tilapia (Oreochromis mossambicus) Cell Lines

    PubMed Central

    Gardell, Alison M.; Qin, Qin; Rice, Robert H.; Li, Johnathan; Kültz, Dietmar

    2014-01-01

    Fish cell cultures are becoming more widely used models for investigating molecular mechanisms of physiological response to environmental challenge. In this study, we derived two immortalized Mozambique tilapia (Oreochromis mossambicus) cell lines from brain (OmB) and lip epithelium (OmL), and compared them to a previously immortalized bulbus arteriosus (TmB) cell line. The OmB and OmL cell lines were generated without or with Rho-associated kinase (ROCK) inhibitor/3T3 feeder layer supplementation. Although both approaches were successful, ROCK inhibitor/feeder layer supplementation was found to offer the advantages of selecting for epithelial-like cell type and decreasing time to immortalization. After immortalization (≥ passage 5), we characterized the proteomes of the newly derived cell lines (OmB and OmL) using LCMS and identified several unique cell markers for each line. Subsequently, osmotolerance for each of the three cell lines following acute exposure to elevated sodium chloride was evaluated. The acute maximum osmotolerance of these tilapia cell lines (>700 mOsm/kg) was markedly higher than that of any other known vertebrate cell line, but was significantly higher in the epithelial-like OmL cell line. To validate the physiological relevance of these tilapia cell lines, we quantified the effects of acute hyperosmotic challenge (450 mOsm/kg and 700 mOsm/kg) on the transcriptional regulation of two enzymes involved in biosynthesis of the compatible organic osmolyte, myo-inositol. Both enzymes were found to be robustly upregulated in all three tilapia cell lines. Therefore, the newly established tilapia cells lines represent valuable tools for studying molecular mechanisms involved in the osmotic stress response of euryhaline fish. PMID:24797371

  13. The Holocene Geoarchaeology of the Desert Nile in Northern Sudan

    NASA Astrophysics Data System (ADS)

    Woodward, Jamie; Macklin, Mark; Spencer, Neal; Welsby, Derek; Dalton, Matthew; Hay, Sophie; Hardy, Andrew

    2016-04-01

    Invited Paper Forty years ago Colin Renfrew declared that "every archaeological problem starts as a problem in geoarchaeology" (Renfrew, 1976 p. 2). With this assertion in mind, this paper draws upon the findings from field research in two sectors of the Nile Valley of Northern Sudan dedicated to the exploration of human-environment interactions during the middle and late Holocene. This part of the Nile corridor contains a rich cultural record and an exceptionally well preserved Holocene fluvial archive. A distinctive feature of these records is the variety of evidence for interaction between desert and river over a range of spatial and temporal scales. This interaction presented both challenges and opportunities for its ancient inhabitants. This paper will present evidence for large-scale landscape changes driven by shifts in global climate. It will also show how we have integrated the archaeological and geological records in the Northern Dongola Reach and at Amara West - where long-term field projects led by archaeologists from the British Museum have recognised the importance of a sustained commitment to interdisciplinary research to achieve a fully integrated geoarchaeological approach across a range of scales. The former project is a large-scale landscape survey with multiple sites across an 80 km reach of the Nile whilst the latter has a strong focus on a single New Kingdom town site and changes in its environmental setting. By combining multiple archaeological and geological datasets - and pioneering the use of OSL dating and strontium isotope analysis in the Desert Nile - we have developed a new understanding of human responses to Holocene climate and landscape change in this region. Renfrew, C. (1976) Archaeology and the earth sciences. In: D.A. Davidson and M.I. Shackley (eds) Geoarchaeology: Earth Science and the Past, Duckworth, London, 1-5.

  14. Nile River, Lake Nasser, Aswan High Dam, Egypt, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Lake Nasser, (24.0N, 33.0E) at the Aswan High Dam on the Nile River, in Egypt is the world's second largest artificial lake, extending 500 km, in length and about 5000 sq. km. in area. The lake has a storage capacity sufficient to irrigate farms in Egypt and Sudan year round allowing up to three harvests per year. Other benefits include year round river navagation, hydroelectric power, more fish harvests, reduced flooding and more industrial employment. opportunites.

  15. West Nile virus infections in humans--focus on Greece.

    PubMed

    Papa, Anna

    2013-10-01

    West Nile virus is a mosquito-borne flavivirus causing to humans a variety of symptoms, from asymptomatic or mild infection, to severe, and often fatal, infection of the central nervous system. The present review aims to describe the main clinical characteristics of the disease, to provide the recent epidemiological data, including those from the recent outbreaks in Greece, and to discuss the environmental factors which might play a role in the virus emergence and its wider dispersal.

  16. Ecology of West Nile Virus in North America

    PubMed Central

    Reisen, William K.

    2013-01-01

    The introduction, dispersal and establishment of West Nile virus in North America were reviewed, focusing on factors that may have enhanced receptivity and enabled the invasion process. The overwintering persistence of this tropical virus within temperate latitudes was unexpected, but was key in the transition from invasion to endemic establishment. The cascade of temporal events allowing sporadic amplification to outbreak levels was discussed within a future perspective. PMID:24008376

  17. Infection with non-lethal West Nile virus Eg101 strain induces immunity that protects mice against the lethal West Nile virus NY99 strain.

    PubMed

    Kumar, Mukesh; O'Connell, Maile; Namekar, Madhuri; Nerurkar, Vivek R

    2014-06-06

    Herein we demonstrate that infection of mice with West Nile virus (WNV) Eg101 provides protective immunity against lethal challenge with WNV NY99. Our data demonstrated that WNV Eg101 is largely non-virulent in adult mice when compared to WNV NY99. By day 6 after infection, WNV-specific IgM and IgG antibodies, and neutralizing antibodies were detected in the serum of all WNV Eg101 infected mice. Plaque reduction neutralization test data demonstrated that serum from WNV Eg101 infected mice neutralized WNV Eg101 and WNV NY99 strains with similar efficiency. Three weeks after infection, WNV Eg101 immunized mice were challenged subcutaneously or intracranially with lethal dose of WNV NY99 and observed for additional three weeks. All the challenged mice were protected against disease and no morbidity and mortality was observed in any mice. In conclusion, our data for the first time demonstrate that infection of mice with WNV Eg101 induced high titers of WNV specific IgM and IgG antibodies, and cross-reactive neutralizing antibodies, and the resulting immunity protected all immunized animals from both subcutaneous and intracranial challenge with WNV NY99. These observations suggest that WNV Eg101 may be a suitable strain for the development of a vaccine in humans against virulent strains of WNV.

  18. The Nile Delta: climate pacing and vulnerability to Holocene change

    NASA Astrophysics Data System (ADS)

    Marriner, Nick; Flaux, Clément; Morhange, Christophe; Stanley, Jean-Daniel

    2014-05-01

    Deltas are potentially important sentinels to investigate climate-driven changes in palaeohydrology and human impacts, but, paradoxically, have often been overlooked as palaeoclimate records. In this paper, we present two time-series from the Nile Delta to probe both millennial and centennial-scale changes in deltaic hydrogeomorphology over the past 8000 years. In a global Holocene context, the long-term decrease in Nile Delta accretion rates is consistent with insolation-driven changes in the 'monsoon pacemaker', attested throughout the mid-latitude tropics. Using a second record we suggest that, at shorter timescales, many of the major phases of deltaic modification were mediated by climate events linked to El Niño Southern Oscillation- type (ENSO) variability. In the final part of the paper, we propose that following the early to mid-Holocene growth of the Nile's deltaic plain pronounced deltaic erosion is first recorded after ~4000 years ago, the corollaries of falling sediment supply and an intensification of anthropogenic impacts from the Pharaonic period onwards. The study highlights the importance of the world's deltas as sensitive archives to investigate Holocene geosystem responses to climate change, risks and hazards, and societal interaction.

  19. Specific serum antibody responses in channel catfish (Ictalurus punctatus) provide limited protection against Streptococcus ictaluri challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Passive immunization has been shown to provide a spectrum of protection against certain piscine pathogens, and studies were conducted to determine the role of specific antibodies in immunity to Streptococcus ictaluri. Adult Nile tilapia (Oreochromis niloticus) were injected i.p. with tryptic soy br...

  20. Evaluation of antibody response to vaccination against West Nile virus in thick billed parrots (Rhynchopsitta pachyrhyncha).

    PubMed

    Glavis, Jennifer; Larsen, R Scott; Lamberski, Nadine; Gaffney, Patricia; Gardner, Ian

    2011-09-01

    West Nile virus (WNV) was first documented in North America in New York City in 1999. Several deaths attributable to WNV have been reported in captive thick-billed parrots (Rhynchopsitta pachyrhyncha), an endangered psittacine native to North America. The serologic responses in 12 captive adult thick-billed parrots after a series of three initial WNV vaccine injections with annual boosters over 6 yr was evaluated. In addition, the serologic responses of 11 thick-billed parrot chicks following an initial vaccination series to determine if there were seroconversions were also reported. Most adults (67%) had seroconverted after 5 yr of annual vaccination, with a median titer of 1:80 (range 1:40-1:160) for those that seroconverted. After the first year, birds were likely naturally exposed to WNV, which limited interpretation of titers. None of the chicks seroconverted during the initial three-vaccine series; only two of four chicks (50%) had seroconverted when tested at the 1-yr yearly booster, and at 2 yr, three of four chicks had seroconverted. Although some birds had detectable antibody titers, it is unclear whether this vaccine can reliably provide protection against WNV in thick-billed parrots.