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Benjamin R. Lafrentz - One of the best experts on this subject based on the ideXlab platform.
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lack of association between flavobacterium columnare genomovar and virulence in hybrid tilapia Oreochromis niloticus l Oreochromis aureus steindachner
Journal of Fish Diseases, 2015Co-Authors: Craig A Shoemaker, Benjamin R. LafrentzAbstract:: Columnaris disease can be problematic in tilapia (Oreochromis spp.) production. An understanding of the pathogenesis and virulence of Flavobacterium columnare is needed to develop prevention strategies. The objective of this study was to determine the virulence of genetically defined isolates of F. columnare in sex-reversed hybrid tilapia, Oreochromis niloticus (L.)×O. aureus (Steindachner). A series of immersion challenge trials were performed using isolates of the five established genomovars of F. columnare: I, II, II-B, III and I/II. The mean per cent mortality of fish challenged with genomovar I, II and III isolates ranged from 0 to 100, 3.3-78 and 3.3-75%, respectively. The mean per cent mortality of fish challenged with genomovar II-B ranged from 35 to 96.7%, and the only genomovar I/II isolate tested caused no mortality. Contrary to previous work in other fish species, there did not appear to be an association between F. columnare genomovar and virulence in tilapia. The challenge model used resulted in acute mortality. An alternative challenge model was tested by cohabitating healthy fish with dead fish infected with F. columnare. This method resulted in rapid appearance of clinical signs and mortality, suggesting the potential for F. columnare to increase in virulence upon growth on/in a fish host.
Zhigang Zhou - One of the best experts on this subject based on the ideXlab platform.
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effects of dietary bacillus subtilis c 3102 on the production intestinal cytokine expression and autochthonous bacteria of hybrid tilapia Oreochromis niloticus Oreochromis aureus
Aquaculture, 2013Co-Authors: Yu Zhang, Zhigang Zhou, Yalin Yang, Toshihiro Marubashi, Bin YaoAbstract:Abstract Bacillus spp. are widely used in aquafeeds as probiotics for enhanced growth performance, innate immune responses, and disease resistance. The present study aimed to evaluate the effects of low doses of dietary Bacillus subtilis C-3102 on the production, intestinal cytokine expression and adhesive bacteria of hybrid tilapia Oreochromis niloticus ♀ × Oreochromis aureus ♂. Juvenile hybrid tilapia were fed B. subtilis C-3102 at doses of 0 (CK), 2.5 × 105 (Ta) and 5.0 × 105 (Tb) CFU g− 1 of diets for 56 days. The results showed that different diets had no effects on fish growth performance. The B. subtilis supplement was detected in the gut wall of fish treated with 5.0 × 105 CFU g− 1 at 28 days and 56 days by both plate culture and PCR-DGGE methods, while it was only identified in fish treated with 2.5 × 105 CFU g− 1 at 56 days by PCR-DGGE. Supplementation of dietary B. subtilis C-3102 altered the autochthonous gut bacterial communities, significantly increased (P
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lactobacillus planarum subsp plantarum jcm 1149 vs aeromonas hydrophila nj 1 in the anterior intestine and posterior intestine of hybrid tilapia Oreochromis niloticus Oreochromis aureus an ex vivo study
Fish & Shellfish Immunology, 2013Co-Authors: Pengfei Ren, Yaling Yang, Wenshu Liu, Einar Ringo, Zhigang ZhouAbstract:To investigate the ex vivo interactions of probiotic-pathogen-host in warm-water fish, hybrid tilapia (Oreochromis niloticus♀ × Oreochromis aureus♂) were sacrificed to isolate anterior and posterior intestine for incubation with phosphate-buffered saline (PBS; pH 7.2) as the control, Lactobacillus plantarum JCM 1149 at 1.0 × 10(9) CFU/ml, Aeromonas hydrophila NJ-1 at 1.0 × 10(8) CFU/ml, or the both combination. Denaturing Gradient Gel Electrophoresis (DGGE) fingerprint and consequent sequence analysis confirmed anterior intestine sac was more prone to the colonization of L. plantarum JCM 1149 and A. hydrophila NJ-1 than the posterior part. L. plantarum JCM 1149 and A. hydrophila NJ-1 inhibited the population each other in anterior or posterior sac, indicating their competition for the colonization. The induced expression of HSP70, IL-1β and TNF-α in the anterior sac by the addition of L. plantarum JCM 1149 or A. hydrophila NJ-1 demonstrated the activity and a local immune response of ex vivo anterior sac. Compared with posterior intestine, higher population colonization and more sensitive immune response of anterior sac indicated differential patterns for the probiotic-pathogen-host interactions. Scanning electronic microscopy (SEM) observation showed that pathogen A. hydrophila NJ-1 damaged the anterior intestine, which was alleviated by the pretreatment of L. plantarum JCM 1149, showing its probiotic effect.
Yonggang Tan - One of the best experts on this subject based on the ideXlab platform.
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the effect of chromium picolinate on growth and carbohydrate utilization in tilapia Oreochromis niloticus x Oreochromis aureus
Aquaculture, 2003Co-Authors: Qing Pan, Sheng Liu, Yonggang TanAbstract:A growth trial was conducted to investigate the effect of chromium on growth and carbohydrate utilization of hybrid tilapia, Oreochromis niloticus X Oreochromis aureus. Fish (average initial body weight = 1.3 g) were fed four experimental diets formulated to 45% glucose or dextrin, with or without 2 mg chromium/kg as chromium picolinate (Cr-Pic), for 8 weeks in a flow-through system. The results showed no significant differences in final weight gain and feed efficiency (FE) among treatments ( P>0.05). There were also no significant differences in the proximate composition of the carcass of the fish fed the various diets. Significantly higher (P<0.05) liver glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) activities were observed in fish fed the dextrin than those fed glucose. Results suggest no significant effect of Cr-Pic supplementation at 2 mg/kg diet on growth and carbohydrate utilization in tilapia. (C) 2003 Elsevier Science B.V. All right reserved.
Chenghui Wang - One of the best experts on this subject based on the ideXlab platform.
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complete mitochondrial genome of blackchin tilapia sarotherodon melanotheron perciformes cichlidae
Mitochondrial DNA, 2011Co-Authors: Shou Jie Tang, Ying Ting Jiang, Chenghui WangAbstract:Blackchin tilapia, Sarotherodon melanotheron, is a highly salt-tolerant species in tilapias. In this paper, the complete mitochondrial genome of S. melanotheron was determined first. The mitogenome (16,627 bp) had the typical vertebrate mitochondrial gene arrangement, including 13 protein-coding, 22 tRNA, 2 rRNA genes, and 1 putative control region. It shared 95.1%, 93.2%, and 92.2% mitogenome sequence with Oreochromis aureus, Oreochromis niloticus, and Oreochromis mossambicus, respectively.
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complete mitochondrial dna sequences of the nile tilapia Oreochromis niloticus and blue tilapia Oreochromis aureus genome characterization and phylogeny applications
Molecular Biology Reports, 2011Co-Authors: Anyuan He, Hong Yang, Sifa Li, Chenghui WangAbstract:Cichlid fishes have played an important role in evolutionary biology and aquaculture industry. Nile tilapia (Oreochromis niloticus), blue tilapia (Oreochromis aureus) and Mozambique tilapia (Oreochromis mossambicus), the useful models in studying evolutionary biology within Cichlid fishes, are also mainly cultured species in aquaculture with great economic importance. In this paper, the complete nucleotide sequence of the mitochondrial genome for O. niloticus and O. aureus were determined and phylogenetic analyses from mitochondrial protein-coding genes were conducted to explore their phylogenetic relationship within Cichlids. The mitogenome is 16,625 bp for O. niloticus and 16,628 bp for O. aureus, containing the same gene order and an identical number of genes or regions with the other Cichlid fishes, including 13 protein-coding genes, two rRNA genes, 22 tRNA genes and one putative control region. Phylogenetic analyses using three different computational algorithms (maximum parsimony, maximum likelihood and Bayesian method) show O. niloticus and O. mossambicus are closely related, and O. aureus has remotely phylogenetic relationship from above two fishes.
Shiyen Shiau - One of the best experts on this subject based on the ideXlab platform.
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optimal dietary lipid level for growth of juvenile hybrid tilapia Oreochromis niloticus x Oreochromis aureus
Aquaculture, 1996Co-Authors: Benshan Chou, Shiyen ShiauAbstract:A growth experiment was conducted to determine the optimal dietary lipid level of juvenile hybrid tilapia, Oreochromis niloticus X Oreochromis aureus. Five isoenergetic and isonitrogenous purified diets containing 0–20% lipid (corn oil/cod liver oil/lard, 1:1:1) in 5% increments were fed for 8 weeks to triplicate groups of tilapia in a recirculated filtered rearing system maintained at 21 °C. Weight gain was higher in fish fed the 10 and 15% lipid diets, followed by the 5% lipid diet, then by the 20% lipid diet and was lowest in fish fed the lipid-free control diet. Protein efficiency ratio (PER) and protein deposition in fish generally followed the same pattern of weight gain. Feed conversion ratios (FCR) were better (P < 0.05) for fish fed the lipid diets than those fed the control diet. Body lipid content was highest (P < 0.05) in fish fed the 20% lipid diet, followed by those fed the 10 and 15% lipid diets, and lowest in fish fed the 5% lipid diet and the control diet. Liver malic enzyme, glucose-6-phosphate dehydrogenase and phosphogluconate dehydrogenase activities were higher in fish fed the lipid-free control diet and generally decreased as the lipid content in the diet increased. Second-order regression of weight gain on concentrations of dietary lipid indicates that the optimal dietary lipid for maximal growth of O. Niloticus X O. aureus is about 12%. Five percent of dietary lipid appears to meet the minimal requirement for this species.