Host status of selected cultivated fruit crops to <Emphasis Type="Italic">Meloidogyne enterolobii</Emphasis>

Meloidogyne enterolobii (syn. M. mayaguensis) has been reported to cause severe damage in commercial guava orchards and other plants in Central and South American countries. Considering the risk of introduction and dissemination of this pest in the European region, M. enterolobii was placed on the EPPO A2 list in 2010. The use of non-host fruit species is a recommended strategy to manage root-knot nematodes in infested guava orchards. This study screened 89 plant genotypes from 25 fruit plants of economic importance, plus two susceptible controls (guava and tomato) for its host status to M. enterolobii. Three to eight months after inoculation, nematode reproduction factor (RF) was used to characterize host suitability of fruit crops to this nematode. Ten banana genotypes, six Barbados cherries, one fig, two grape rootstocks and six melons were rated as good hosts for this nematode. Sixteen fruit plants behaved either as non-hosts or poor hosts to M. enterolobii, including assaí, atemoya, avocado, cashew nut, citrus, coconut, grape, jabuticaba, mango, mulberry, papaya, passion fruit, sapodilla, soursop, starfruit and strawberry. For the future, field experiments in areas infested by this nematode are essential to confirm the greenhouse results. These non-host fruit species can replace in the future eradicated guava trees in fields severely infested by this nematode and become an economic option for growers where M. enterolobii is considered a serious problem.     

Reaeration Coefficient Estimate: New Parameter for Predictive Equations

The reaeration coefficient (K _a) is an essential parameter to predict the dissolved-oxygen concentration in different aquatic ecosystems. The techniques applied to K _a estimates require considerable efforts, since measuring this coefficient is a laborious and expensive task. Thus, the use of predictive equations wherein K _a is found through hydraulic flow parameters is common. However, the available prediction equations lead to estimates often different from each other. A new predictive equation is addressed in the present study. The insertion of a dimensionless number resulting from the relation between the RMS (Root Mean Square) of the free-surface vertical velocity and the surface flow velocity is the great innovation of the study. The reaeration experiments and the surface vertical velocity mapping were performed in a circular hydraulic channel. The flow velocity varied from 0.25 to 0.64 m s^?1, and depth varied from 0.09 to 0.15 m. The new equation led to more accurate results than the equations based on traditional hydraulic parameters such as the Reynolds and Froude numbers, mainly when it comes to K _a values higher than 40 day^?1. The sensitivity analysis has shown that the new dimensionless number is the most sensitive parameter of the herein proposed predictive equation and that the influence from the Reynolds and Froude numbers on K _a weakens as turbulence gets more intense.     

Fructooligosaccharide supplementation in diets for tropical gar (Atractosteus tropicus) juvenile: Effects on morphophysiology and intestinal barrier function

Supplementary fructooligosaccharides (FOS) were evaluated on growth, survival, gut morphology, digestive enzyme activity and expression of intestinal barrier genes in tropical gar (Atractosteus tropicus). Four treatments were designed to include FOS (5, 10, 15 and 20 g/Kg) and were compared with a control (0 g/Kg) and the current commercial trout diet. Ten fish were stocked (0.25 ± 0.01 g and 4.2 ± 0.4 cm total length) per experimental unit by triplicate in a 45‐day experiment. Fish fed with 5 and 10 g/Kg of FOS had the highest average weight and total average length. Fish fed 5 g/Kg FOS showed the best growth indexes (absolute weight gain: 2.16; specific growth rate: 4.96; and feed conversion rate: 1.23) and survival (96.66%) and also had the highest acid protease, chymotrypsin and leucine aminopeptidase activities. Fish fed 5 g/Kg FOS had a high absorption area and accumulation of lipids in the liver. Finally, relative overexpression of occluding (occ), nucleotide‐binding oligomerization domain‐2 (nod2) and mucin 2 (muc2) was detected in fish fed 10 and 15 g/Kg FOS. The supplementation between 5 and 10 g/Kg FOS in diets for A. tropicus juveniles could be beneficial for growth, digestive enzyme activities, gut morphology and intestinal barrier function.     

Cultivable microbiota of Lithobates catesbeianus and advances in the selection of lactic acid bacteria as biological control agents in raniculture

The cultivable microbiota of skin and cloaca of captive Lithobates catesbeianus includes microorganisms generally accepted as beneficial and potentially pathogenic bacteria. In order to select a group of potentially probiotic bacteria, 136 isolates were evaluated for their surface properties and production of antagonistic metabolites. Then, 11 lactic acid bacteria (LAB) strains were selected and identified as Lactobacillus plantarum, Lb. brevis, Pediococcus pentosaceus, Lactococcus lactis, L. garvieae and Enterococcus gallinarum. Studies of compatibility indicate that all the strains could be included in a multi-strain probiotic, with the exception of Ent. gallinarum CRL 1826 which inhibited LAB species through a bacteriocin-like metabolite. These results contribute to the design of a probiotic product to improve the sanitary status of bullfrogs in intensive culture systems, to avoid the use of antibiotics and thus to reduce production costs. It could also be an alternative to prevent infectious diseases during the ex situ breeding of amphibian species under threat of extinction.     

Uptake of milk with and without solid feed during the monogastric phase: Effect on fibrolytic and methanogenic microorganisms in the gastrointestinal tract of calves

Microbial communities are affected by diet and play a role in the successful transition from milk to a solid diet. The response of microorganisms in the gastrointestinal tract of Holstein bull calves to the uptake of milk with solid feed (control treatment; CT), or milk without solid feed (milk‐only treatment; MT) during the first 3 weeks of life was investigated. Samples were collected from the rumen (fluid and tissue), abomasum (fluid), cecum (fluid and tissue) and feces at 7, 14 and 20 days of age. Calf weight was higher on days 14 and 20 in the MT than the CT. In the rumen at 14 days, the fibrolytic bacteria Fibrobacter succinogenes and Prevotella ruminicola increased in the CT and Ruminococcus flavefaciens increased in the MT. This suggests that R. flavefaciens is not strictly fibrolytic and that it might use milk as a substrate or other microbial species might supply a substrate. Diet affected methanogens, but this may have been due to an indirect effect via an association with Geobacter spp. or other syntrophic partners. The treatments also affected microorganisms in the abomasum, cecum and feces. Our results contribute to an understanding of diet, microbes in the gastrointestinal tract and weaning.     

Maltodextrin and Gum Arabic-Based Microencapsulation Methods for Anthocyanin Preservation in Juçara Palm (<Emphasis Type="Italic">Euterpe edulis</Emphasis> Martius) Fruit Pulp

The juçara fruits (Euterpe edulis Martius), native to the Atlantic Forest, are rich in anthocyanins. To preserve the anthocyanins in juçara fruit pulp, this study aimed to evaluate the effectiveness of microencapsulation by spray drying and freeze drying with maltodextrin (dextrose equivalent 16.5 to 19.5) and gum arabic in different proportions. The obtained microparticles were characterized by quantifying the total polyphenol and anthocyanin contents, by performing differential scanning calorimetry, thermogravimetry, and infrared spectroscopy and by using scanning electron microscopy to analyze the morphology of the particles. The total amount of polyphenols in the fruit pulp was 750?±?16.7 mg GAE/100 g of the freeze-dried sample. The total anthocyanins in the fruit pulp was 181.25?±?5.36 (mg/100 g). The microparticles were formed by employing maltodextrin and gum arabic in a 1:1 proportion as the polymeric matrix; the mixtures of pulp and polymeric matrix were prepared in proportions of 2:3 and 2:1, preserving up to 83.69% of the anthocyanin content. Lyophilization of the 2:1 mixture resulted in an anthocyanin content of 116.89?±?4.43 (mg/100 g), whereas lyophilization of the 2:3 mixture resulted in 151.68?±?1.39 (mg/100 g) anthocyanin content, which did not differ from the value obtained by spray drying the 2:3 mixture (150.76?±?5.79 (mg/100 g)). Thermal analyses showed that the microparticles obtained by freeze drying at a ratio of 2:3 presented greater resistance to degradation with increasing temperature. The incorporation of the pulp in the polymeric matrix was demonstrated by IR analyses. Microparticles obtained by freeze drying showed the formation of various-sized flakes, whereas those obtained by spray drying were spherical in shape. Microencapsulation is a possible alternative for improving the stability of the anthocyanins in this fruit.     

Oxidative stress in the erythrocytes of cattle intoxicated with Senecio sp

BACKGROUND: Intoxication caused by Senecio sp is characterized by irreversible damage to liver cells and may be associated with oxidative stress. OBJECTIVES: The aim of this study was to evaluate the effects of intoxication by Senecio sp on lipoperoxidation, antioxidant defenses, and the osmotic resistance of erythrocytes in cattle. METHODS: Blood samples from 30 intoxicated animals (group 1) and 30 healthy animals (group 2) were analyzed. The diagnosis of poisoning by Senecio sp was based on histopathologic lesions verified through hepatic biopsy. The following biochemical parameters of oxidative stress in the erythrocytes were determined: thiobarbituric acid-reactive substances (TBARS), copper-zinc superoxide dismutase (CuZnSOD) activity, and nonprotein sulfhydryl (NPSH) groups. Erythrocyte osmotic fragility also was evaluated. RESULTS: TBARS concentration and CuZnSOD activity were significantly (P <.001) higher in group 1 when compared with group 2. The concentration of erythrocyte NPSH groups was significantly (P <.03) lower in group 1 when compared with group 2. Osmotic fragility was more pronounced in the erythrocytes of group 1 when compared with group 2 (P < .001). CONCLUSIONS: The results of this study indicate that poisoning by Senecio sp causes an increase in lipoperoxidation, oxidation of NPSH groups, and consequently, oxidative stress in bovine erythrocytes that may contribute to hemolysis. These findings may contribute to a better understanding of the mechanisms involved in cell damage in animals intoxicated by Senecio sp.     

Biochemical intestinal parameters in germ-free minipigs and rats and in ex-germ-free minipigs and rats monoassociated with Escherichia coli

Intestinal contents of newborn and young germ-free minipigs and germ-free rats were investigated for the following biochemical parameters - conversion of cholesterol to coprostanol, degradation of beta-aspartylglycine, level of tryptic activity, formation of urobilinogen and the profile of short-chain fatty acids. Additionally, germ-free minipigs and germ-free rats were monoassociated with non-pathogenic strains of Escherichia coli and were investigated for the same biochemical parameters. The conversion of cholesterol to coprostanol, degradation of beta-aspartylglycine, tryptic activity and the short-chain fatty acid profile were similar to those found in previous studies in germ-free animals. Slightly higher amounts of urobilinogen than in the other species investigated so far were found in samples from germ-free and monoassociated minipigs. Except for the total amount of short-chain fatty acids in rats, monoassociation with E. coli did not alter any of the parameters either in the minipigs or in the rats.     

The genome of Brucella melitensis

The genome of Brucella melitensis strain 16M was sequenced and contained 3,294,931 bp distributed over two circular chromosomes. Chromosome I was composed of 2,117,144 bp and chromosome II has 1,177,787 bp. A total of 3198 ORFs were predicted. The origins of replication of the chromosomes are similar to each other and to those of other -proteobacteria. Housekeeping genes such as those that encode for DNA replication, protein synthesis, core metabolism, and cell-wall biosynthesis were found on both chromosomes. Genes encoding adhesins, invasins, and hemolysins were also identified.     

Haemoproteus lophortyx infection in bobwhite quail

This report chronicles recurring outbreaks of Haemoproteus lophortyx infection in captive bobwhite quail. Clinically, the signs of infection included reluctance to move, ruffled appearance, prostration, and death. These signs were associated with parasitemia, anemia, and the presence of large megaloschizonts in skeletal muscles, particularly those of the thighs and back. The average cumulative mortality for flocks experiencing outbreaks was over 20%. In a typical outbreak, mortality rose when the birds were 5-6 wk of age, peaked in 8-to-10-wk-old quail, and declined rapidly when the quail were 9-11 wk old. Outbreaks occurred exclusively between the months of May and October, and warm weather was determined to be a risk factor for H. lophortyx mortality. This protozoan most likely overwinters in native California quail in the area and is transmitted to quail on the ranch by an insect vector that emerges in warm weather. Infection of the large population of na?ve bobwhite quail on the ranch leads to amplification of H. lophortyx, resulting in epidemics in successive flocks.