Phagocytotic activity and gene expression of leukocytes isolated from Astyanax lacustris.

The constant intensification of aquaculture has considerable increased the stress levels of farmed fish and, consequently, the number and intensity of diseases outbreaks. Thus, studies on fish immune response, especially regarding the interaction of fish leukocytes with potential pathogens and xenobiotics are of great importance in order to develop new prophylactic and curative strategies. We isolated leukocytes from the head kidney of Astyanax lacustris-an important Neotropical fish species for aquaculture and a potential model for Neotropical aquaculture research-using a Percoll centrifugation protocol. The isolated leukocytes were incubated with lipopolysaccharide (LPS), and the expression of genes IL-1ß, IL-8, LysC, and LysG were measured. We assessed the phagocytotic activity of leukocytes using Congo red-dyed yeast, a novel and cost-effective protocol that has been developed in this study. The isolated leukocytes responded to LPS induction, exhibiting strong IL-1ß and IL-8 upregulation, two of the most important pro-inflammatory interleukins for vertebrates immune reponse. The optimal concentration of yeast for the phagocytic assay was 106 cells mL-1, resulting in acceptable phagocytic capacity (PC) but without excess of yeasts during the counting process, ensuring a high precision and accuracy of the method. To the best of our knowledge, the present study is the first to investigate the in vitro gene expression and phagocytic activity of leukocytes isolated from A. lacustris. Our findings will serve as a reference for future studies on the immunology and toxicology of Neotropical fish.

Isolated and combined organic acids in diets of broiler chickens challenged with Eimeria acervulina / [Ácidos orgânicos isolados ou associados em dietas de frangos de corte desafiados com Eimeria acervulina]

This study aimed to evaluate the effect of isolated or combined citric and benzoic acids added to the diets of broiler chickens on performance, allometry of the digestive system organs, intestinal pH and quantity of microorganisms in the jejunum. A total of 840 male Cobb broiler chicks were utilized, distributed in a complete random design in 2 × 2 factorial scheme, supplemented or not with citric acid, and sodium benzoate, with seven replications. At 14 days old, 1mL of a solution containing 1 × 105 sporulated oocysts of Eimeria acervulina per bird was inoculated orally. There was no effect of the acids on the broiler's performance in the 1 to 21-day period. In the total period (1 to 42 days), the broilers fed with a blend of citric and benzoic acid presented greater feed intake, without increment in weight gain. The data of allometry of the digestive system organs and the jejunal pH values were not influenced by the treatments. The citric acid increased the bacterial quantity of gram-positive coccus and total anaerobes in the jejunum. Under the conditions of the present study, we conclude that the citric and benzoic acids, isolated or combined, do not benefit the nutrition of broilers challenged with E. acervulina.(AU)

O objetivo deste trabalho foi avaliar os efeitos da inclusão isolada ou associada dos ácidos cítrico e benzoico na alimentação de frangos de corte sobre o desempenho, a alometria de órgãos do sistema digestório, o pH intestinal e a quantidade de microrganismos no jejuno. Foram utilizados 840 pintos de corte, machos, da linhagem Cobb, distribuídos num delineamento inteiramente ao acaso, em esquema fatorial 2 × 2, com suplementação ou não de ácido cítrico e suplementação ou não de benzoato de sódio, com sete repetições. Aos 14 dias de idade, foi inoculado, via oral, 1mL de solução contendo 1 × 105 oocistos esporulados de Eimeria acervulina por ave. Não houve efeito dos ácidos sobre o desempenho dos frangos no período de um a 21 dias. No período total (um a 42 dias), os frangos alimentados com a mistura de ácidos cítrico e benzoico apresentaram maior consumo de ração, sem incremento no ganho de peso. Os dados de alometria dos órgãos do sistema digestório e os valores de pH do jejuno não foram influenciados pelos tratamentos. O ácido cítrico aumentou a quantidade de bactérias do gênero cocos Gram positivos e anaeróbios totais no jejuno. Nas condições do presente estudo, conclui-se que os ácidos cítrico e benzoico, isolados ou associados, não beneficiam a nutrição de frangos de corte desafiados com E. acervulina.(AU)

Detection and molecular characterisation of bovine Enterovirus in Brazil: four decades since the first report.

It is suggested that bovine enteroviruses (BEV) are involved in the aetiology of enteric infections, respiratory disease, reproductive disorders and infertility. In this study, bovine faecal samples collected in different Brazilian states were subjected to RNA extraction, reverse transcription-polymerase chain reaction analysis and partial sequencing of the 5'-terminal portion of BEV. One hundred and three samples were tested with an overall positivity of 14.5%. Phylogenetic analysis clustered these BEV Brazilian samples into the Enterovirus F clade. Our results bring an important update of the virus presence in Brazil and contribute to a better understanding of the distribution and characterisation of BEV in cattle.

Carryover of aflatoxins from feed to lambari fish (Astyanax altiparanae) tissues.

The aim of this study was to verify the carryover of aflatoxin B1 from feed to lambari fish. Aflatoxins (AF) were incorporated into feed, checking the levels by HPLC. Treatments were: Control, feed without toxin; A, feed + 10 µg AFB1 kg-1; B, feed + 20 µg AFB1 kg-1; and C, feed + 50 µg AFB1 kg-1. Juveniles of lambari fish were placed in 12 aquariums at a density of 50 fish/m2. Fish were fed twice a day with extruded feed, at 5% of animal biomass. The unit sample was constituted by a pool of 10 fish. AFs B1, B2, G1, G2 and M1 were quantified by HPLC in fish muscle and liver after 30, 60, 90 and 120 days of experiment. There was accumulation of AFs is fish liver and muscle, mainly after 90 days. Fish from treatment C had higher levels of AFB1 in muscle when compared with the others, and AFB1 in muscle at 120 days was similar to the levels in feed. Therefore, when lambari fish is exposed on a daily and long-term basis to AFs in feed, the regulation limits for AFs in animal feed do not guarantee safety for consumers.

Effects of lipid sources, lysophospholipids and organic acids in maize-based broiler diets on nutrient balance, liver concentration of fat-soluble vitamins, jejunal microbiota and performance.

Three experiments with a 2 × 2 × 2 factorial arrangement were conducted to evaluate maize-based diets for broilers containing different lipid sources [soybean oil (S) or beef tallow (T)] supplemented with or without lysophospholipids and organic acids on nutrient balance (Experiment I, evaluation period of 10-14 d), on liver concentration of fat-soluble vitamins, on jejunal microbiota (Experiment II, sampling at d 14) and on performance (Experiment III, accumulated periods of 1-14, 1-21 and 1-42 d). A total of 1344 male chicks were used. In each experiment, the birds were allotted in a completely randomised design with 8 replications. The lysophospholipids were mainly composed of lysolecithins and the organic acids blend was constituted by lactic (40%), acetic (7%) and butyric acids (1%). An interaction between lipid sources and lysophospholipids was observed on faecal apparent digestibility of lipid (ADL), which improved with lysophospholipids addition in T diets. Broilers fed on S had higher ADL and faecal apparent digestibility of nitrogen-corrected gross energy (ADGEN). It was not possible to demonstrate a significant treatment effect on the liver concentration of vitamins A and E, even with the differences in fatty acid profile between S and T. Enterobacteria values were below the detection threshold. Lysophospholipid supplementation reduced gram-positive cocci in T-fed birds. S diets promoted lower total anaerobe counts compared with T diets, independent of additives. S diets increased BW gain and feed:gain ratio in all evaluation periods. Lysophospholipids and organic acids improved feed:gain ratio at 1-21 d in T diets. Furthermore, main effects were observed for lysophospholipids and organic acids at 1-42 d, which increased BW gain and improved feed:gain ratio, respectively. No positive interactions between additives were found.

Controversial results of therapy with mesenchymal stem cells in the acute phase of canine distemper disease.

Distemper disease is an infectious disease reported in several species of domestic and wild carnivores. The high mortality rate of animals infected with canine distemper virus (CDV) treated with currently available therapies has driven the study of new efficacious treatments. Mesenchymal stem cell (MSC)-based therapy is a promising therapeutic option for many degenerative, hereditary, and inflammatory diseases. Therefore, the aim of this study was to characterize stem cells derived from the canine fetal olfactory epithelium and to assess the systemic response of animals infected with CDV to symptomatic therapy and treatment with MSCs. Eight domestic mongrel dogs (N = 8) were divided into two groups: support group (SG) (N = 5) and support group + cell therapy (SGCT) (N = 3), which were monitored over 15 days. Blood samples were collected on days 0, 6, 9, 12, and 15 to assess blood count and serum biochemistry (urea, creatinine, alanine transferase, alkaline phosphatase, gamma-glutamyl transferase, total protein, albumin, and globulin), and urine samples were obtained on days 0 and 15 for urinary evaluation (urine I). The results showed a high mortality rate (SG = 4 and SGCT = 2), providing inadequate data on the clinical course of CDV infection. MSC therapy resulted in no significant improvement when administered during the acute phase of canine distemper disease, and a prevalence of animals with high mortality rate was found in both groups due to the severity of symptoms.

First detection and molecular characterization of Nebovirus in Brazil.

Nebovirus is a new genus of viruses belonging to the Caliciviridae family recently characterized in cattle, and is associated with gastrointestinal disorders, such as diarrhoea, anorexia and intestinal lesions particularly in calves. The aim of this study was to investigate the prevalence of neboviruses in Brazilian cattle and analyse phylogenetically the virus strains detected. A prevalence of 4·8% of neboviruses in faecal samples from 62 head of cattle from different Brazilian states was detected. All positive animals were aged 96·0% nt (100% aa) sequence identity between the virus sequences in this study and >88·8% nt (>94·4% aa) identity with Newbury1/UK. Our results indicate, for the first time, the occurrence of neboviruses in Brazil as well as in South America, and the first Newbury1-like nebovirus found outside the UK.

Fumonisin B1 in cereal mixtures marketed in Brazil.

The aim of this study was to detect and quantify fumonisin B1 (FB1) in cereal mixtures marketed in Brazil. Fifteen samples from different lots were acquired each month by internet from supermarkets during seven months, adding up to 105 analysed samples. The unit sample constituted of an original package with a minimum of 250 g. Extraction and clean-up of samples for FB1 determination were carried out using immunoaffinity columns. Identification and quantification of FB1 were performed by high performance liquid chromatography. Eighty-eight (83.8%) samples were contaminated with FB1 and four (3.8%) presented levels above 500 µg kg(-1) (634, 703, 1269 and 1876 µg kg(-1)). Maximum FB1 + FB2 levels allowed by Brazilian regulations will reach 1500 µg kg(-1) for corn flour in 2016 and 1000 µg kg(-1) for others corn products. This study showed that even at levels below the legislative limits, human exposure to this toxin can occur constantly.