An assessment to pathogenicity of Streptococcus iniae obtained from rainbow trout fish in Fars Province

In order to evaluating Streptoccocus iniae pathogenicity recovered from trout in Fars province a total number of 400 healthy (15-20g) fingerling fish specimens which were kept in 1000 liters ponds and after spending compatibility (adaptation) period in new environment and desired condition as aspect of temperature, pH, food and density relative to accomplish disease experiments in interamusclar injection method with 3 × 10 3 , 3 × 10 4, 3 × 10 5, 3 × 10 6 ,3 × 10 7 bacterium cell dilutions per each fish, interaperitonal method with 2 × 10 3 , 2 × 10 4, 2 × 10 5, 2 × 10 6 ,2 × 10 7 dilutions of bacterium cell and in water bath method with 2 × 10 3 , 2 × 10 4, 2 × 10 5, 2 × 10 6 2 × 107 dilutions in 20 degree centigrade temperature were used. Control groups according to above (mentioned) method with 0.1cc sterile physiological serum per each fish were injected. Clinical and autopsy signs that observed in injected groups were includes: body darkness, swelling of abdomen, exophthalmy sometime with eye ocular haemorrhagy, anal (rectal) prolaps, blood congestion and petechia in muscles and congestion and haemorrhagy in intestines. Infectious results in interamusclar injection shown that, mortality 22 hours after injection begans and in 3 × 107 cells dilution per each fish 30 hours pass the injection was reached above 50 percent, so that the amount of LD50/ 30h in 3 × 10 7 cells per each fish was estimated. In interaperitonal injection method was shown those 20 hours after injection mortality begins and up to maximum 80 hours after continued and 32 hours after injection in 2 × 10 7 cells dilution mortality was reached above 50 percent, so that LD50 /32 hour in 2 × 10 7 cell dilution per each fish estimated. In water bath method even after sparing 15 days mortality had been too low which indicating long process of disease. By microscopic study of tissues, dilatation of bowman capsule, shrinkage of glomerols, increasing of melano macrophage centers, degeneration, necrosis of urine tubules in kidney tissue, dilatation of sinusoids, congestion of hepatic vessels, increasing of melanoma macrophages and hepatocite vacuolization in liver tissue, spleen congestion, heart pericardit, ocular haemorrhagy, congestion, edema and separating of basement membrane from gill secondary lamellae can be referred.

Intestinal ameliorative effects of traditional Ogi-tutu, Vernonia amygdalina and Psidium guajava in mice infected with Vibrio cholera.

Background: Cholera, a severe acute watery diarrhea caused by Vibrio cholerae is endemic in Nigeria with most cases occurring in the rural areas. In South West Nigeria, some individuals resort to alternative treatments such as Ogi-tutu, Psidium guajava and Vernonia amygdalina during infections. The effectiveness of these alternatives in the prevention and treatment of V. cholerae infection requires experimental investigation. Objective: This study was designed to investigate the ameliorative effects of Ogi-tutu, Vernonia amygdalina and Psidium guajava on intestinal histopathology of experimental mice infected with V. cholerae. Methods: Preliminary investigation of in vitro vibriocidal activities of these alternatives were carried out using agar cup diffusion assay. For ameliorative effects, adult mice were inoculated with 100 μl (106 cells) of Vibrio cholerae and dosed at 0 h (immediate prevention) and 4 h (treatment of infection) and their intestines were histopathologically evaluated. Results: The histopathological changes were the same irrespective of the treated groups, but the lesions varied in extent and severity. The ameliorative effects in decreasing order were V. amygdalina > P. guajava > Ogi-tutu. Conclusion: V. amygdalina gave the best ameliorative effects in the prevention and treatment of V. cholerae infection.

Bacterial community characterization of water and intestine of the shrimp Litopenaeus stylirostris in a biofloc system

Background Biofloc technology (BFT), a rearing method with little or no water exchange, is gaining popularity in aquaculture. In the water column, such systems develop conglomerates of microbes, algae and protozoa, together with detritus and dead organic particles. The intensive microbial community presents in these systems can be used as a pond water quality treatment system, and the microbial protein can serve as a feed additive. The current problem with BFT is the difficulty of controlling its bacterial community composition for both optimal water quality and optimal shrimp health. The main objective of the present study was to investigate microbial diversity of samples obtained from different culture environments (Biofloc technology and clear seawater) as well as from the intestines of shrimp reared in both environments through high-throughput sequencing technology. Results Analyses of the bacterial community identified in water from BFT and “clear seawater” (CW) systems (control) containing the shrimp Litopenaeus stylirostris revealed large differences in the frequency distribution of operational taxonomic units (OTUs). Four out of the five most dominant bacterial communities were different in both culture methods. Bacteria found in great abundance in BFT have two principal characteristics: the need for an organic substrate or nitrogen sources to grow and the capacity to attach to surfaces and co-aggregate. A correlation was found between bacteria groups and physicochemical and biological parameters measured in rearing tanks. Moreover, rearing-water bacterial communities influenced the microbiota of shrimp. Indeed, the biofloc environment modified the shrimp intestine microbiota, as the low level (27 %) of similarity between intestinal bacterial communities from the two treatments. Conclusion This study provides the first information describing the complex biofloc microbial community, which can help to understand the environment-microbiota-host relationship in this rearing system.

Parasitology of juvenile mullet (Mugil liza) and effect of formaldehyde on parasites and host

Few studies have been performed with parasites of marine and estuarine fish in southern Brazil. In the present study, unpublished results show the ways of parasitism of juvenile mullet by parasites. The toxicity of formaldehyde and the effectiveness of this chemotherapy in controlling parasites in reared juvenile mullet Mugil liza were also studied. Juvenile mullets (1 +/- 0.26 g; 4.1 +/- 0.4 cm) were exposed to different concentrations of 37% formaldehyde: control group and five formaldehyde concentrations which were tested: T1 (13.5), T2 (21.6), T3 (40.5), T4 (81) and T5 (135) mg L-1 with 8 fish per repetition in triplicate. To verify the drug effectiveness in parasitic control, juvenile mullets were exposed to 1 h prophylactic bath of 37% formaldehyde with a control group and five formaldehyde concentrations: T1 (67.5), T2 (135), T3 (270), T4 (405) and T5 (540) mg L-1, 8 fish per repetition in triplicate. Ligophorus cf. uruguayensis (Monogenoidea: Ancyrocephalidae) and Solostamenides cf. platyorchis (Monogenoidea: Microcotylidae) were identified in the gills. Digenea and Nematoda were observed in the intestines. This is the first occurrence of S. cf. platyorchis in Brazil. During the toxicity test, the LC50-96 h was estimated at 20.77 mg L-1 of formaldehyde. During the 1 h formaldehyde prophylactic bath, all parasites were eliminated in formaldehyde concentrations between 135 and 540 mg L-1. High survival rate was observed in all treatments. Values of prevalence and intensity of infestation observed in this study showed the potential damage caused by Monogenoidea to mullet. Formaldehyde baths with 135 mg L-1 are recommended to control Monogenoidea in mullet and the safe limits for formaldehyde use were presented. Besides, the endoparasites were tolerant to formaldehyde exposure. (C) 2012 Elsevier B.V. All rights reserved.

La perturbation du locus Nr2f1-K12 entraine une différenciation gliale précoce dans un nouveau modèle murin de mégacôlon aganglionnaire

La maladie de Hirschsprung est une affection congénitale de la motilité intestinale caractérisée par un segment aganglionnaire dans le côlon terminal. Un criblage génétique par mutation insertionnelle aléatoire chez la souris nous a permis d’identifier la lignée transgénique Spot dont les homozygotes souffrent de mégacôlon aganglionnaire. L’analyse d’intestins d’embryons mutants a révélé une baisse de prolifération et un délai de migration des cellules de la crête neurale entériques (CCNe) progénitrices dus à leur différenciation gliale précoce, entrainant un défaut de colonisation de l’intestin et une aganglionose du côlon. Le séquençage du génome Spot indique que le transgène s’est inséré à l’intérieur du locus K12-Nr2f1 sur le chromosome 13, une région dépourvue de gènes préalablement associés à la maladie, perturbant également une séquence non-codante très conservée dans l’évolution. K12 est un gène d’ARN long non codant (ARNlnc) et antisens du gène Nr2f1, lui-même impliqué dans la gliogénèse du système nerveux central. Le séquençage du transcriptome des CCN a montré une surexpression de Nr2f1 et des formes courtes de K12 chez Spot et des essais luciférase ont révélé l’activité répressive de l’élément conservé. Nous avons observé l’expression de K12 dans les CCNe et sa localisation subcellulaire dans des zones transcriptionnellement actives du noyau. Avec l’émergence des ARNlnc régulateurs, ces données nous permettent de pointer deux nouveaux gènes candidats associés à une différenciation gliale prématurée du SNE menant au mégacôlon aganglionnaire, en supposant que la régulation de Nr2f1 se fait par son antisens, K12.

La perturbation du locus Nr2f1-K12 entraine une différenciation gliale précoce dans un nouveau modèle murin de mégacôlon aganglionnaire

La maladie de Hirschsprung est une affection congénitale de la motilité intestinale caractérisée par un segment aganglionnaire dans le côlon terminal. Un criblage génétique par mutation insertionnelle aléatoire chez la souris nous a permis d’identifier la lignée transgénique Spot dont les homozygotes souffrent de mégacôlon aganglionnaire. L’analyse d’intestins d’embryons mutants a révélé une baisse de prolifération et un délai de migration des cellules de la crête neurale entériques (CCNe) progénitrices dus à leur différenciation gliale précoce, entrainant un défaut de colonisation de l’intestin et une aganglionose du côlon. Le séquençage du génome Spot indique que le transgène s’est inséré à l’intérieur du locus K12-Nr2f1 sur le chromosome 13, une région dépourvue de gènes préalablement associés à la maladie, perturbant également une séquence non-codante très conservée dans l’évolution. K12 est un gène d’ARN long non codant (ARNlnc) et antisens du gène Nr2f1, lui-même impliqué dans la gliogénèse du système nerveux central. Le séquençage du transcriptome des CCN a montré une surexpression de Nr2f1 et des formes courtes de K12 chez Spot et des essais luciférase ont révélé l’activité répressive de l’élément conservé. Nous avons observé l’expression de K12 dans les CCNe et sa localisation subcellulaire dans des zones transcriptionnellement actives du noyau. Avec l’émergence des ARNlnc régulateurs, ces données nous permettent de pointer deux nouveaux gènes candidats associés à une différenciation gliale prématurée du SNE menant au mégacôlon aganglionnaire, en supposant que la régulation de Nr2f1 se fait par son antisens, K12.

Fiber, a component for health gastrointestinal endocrine system

Dietary fiber was classified according to its solubility in an attempt to relate physiological effects to chemical types of fiber. Soluble fibers (B-glucans, gums, wheat dextrin, psyllium, pectin, inulin) were considered to have benefits on serum lipids, while insoluble fibers (cellulose, lignin, pectins, hemicelluloses) were linked with laxation benefits. More important characteristics of fiber in terms of physiological benefits are viscosity and fermentability. Viscous fibers (pectins, B-glucans, gums, psyllium) are those that have gel-forming properties in the intestinal tract, and fermentable fibers (wheat dextrin, pectins, B-glucans, gum, inulin) are those that can be metabolized by colonic bacteria. Objective: To summarize the beneficial effects of dietary fiber, as nutraceuticals, in order to maintain a healthy gastrointestinal system. Methods: Our study is a systematic review. Electronic databases, including PubMed, Medline, with supplement of relevant websites, were searched. We included randomized and non-randomized clinical trials, epidemiological studies (cohort and case-control). We excluded case series, case reports, in vitro and animal studies. Results: The WHO, the U.S. Food and Drug Administration (FDA), the Heart Foundation and the Romanian Dietary Guidelines recommends that adults should aim to consume approximately 25–30 g fiber daily. Dietary fiber is found in the indigestible parts of cereals, fruits and vegetables. There are countries where people don’t eat enough food fibers, these people need to take some kind of fiber supplement. Evidence has been found that dietary fiber from whole foods or supplements may (1) reduce the risk of cardiovascular disease by improving serum lipids and reducing serum total and low-density lipoprotein (LDL) cholesterol concentrations, (2) decreases the glycaemic index of foods, which leads to an improvement in glycemic response, positive impact on diabetes, (3) protect against development of obesity by increasing satiety hormone leptin concentrations, (4) reduced risk of developing colorectal cancer by normalizes bowel movements, improve the integrity of the epithelial layer of the intestines, increase the resistance against pathogenic colonization, have favorable effects on the gut microbiome, wich is the second genomes of the microorganisms, (5) have a positive impact on the endocrine system by gastrointestinal polypeptide hormonal regulation of digestion, (6) have prebiotic effect by short-chain fatty acids (SCFA) production; butyrate acid is the preferred energy source for colonic epithelial cells, promotes normal cell differentiation and proliferation, and also help regulate sodium and water absorption, and can enhance absorption of calcium and other minerals. Although all prebiotics are fiber, not all fiber is prebiotic. This generally refers to the ability of a fiber to increase the growth of bifidobacteria and lactobacilli, which are beneficial to human health, and (7) play a role in improving immune function via production of SCFAs by increases T helper cells, macrophages, neutrophils, and increased cytotoxic activity of natural killer cells. Conclusion: Fiber consumption is associated with high nutritional value and antioxidant status of the diet, enhancing the effects on human health. Fibers with prebiotic properties can also be recommended as part of fiber intake. Due to the variability of fiber’s effects in the body, it is important to consume fiber from a variety of sources. Increasing fiber consumption for health promotion and disease prevention is a critical public health goal.