Genetic characterization of porcine circovirus type 2 in captive wild boars in southern Brazil

Tropical Animal Health and Production - Porcine circovirus type 2 (PCV2) has been identified in pig population in Brazil since 2000, but scarce studies involving wild boars with PCV2 infection are...     

Control of brown spot of pear by reducing the overwintering inoculum through sanitation

Stemphylium vesicarium, the causal agent of brown spot of pear, overwinters in the leaf residues of pear and herbaceous plants of the orchard floor. Pseudothecia of the teleomorph, Pleospora allii, are formed on these residues where they produce ascospores. New methods were tested aimed at reducing this overwintering inoculum and increasing the efficacy of control of brown spot of pear. Sanitation methods were evaluated in nine trials in Girona (Spain) and Ferrara (Italy) over a 4-year period. The sanitation methods were leaf litter removal in December to February, and application of biological control agents (commercial formulates of Trichoderma spp.) to the orchard ground cover from February to May. Fungicides were also applied to the trees during the pear-growing season, scheduled according to the BSPcast model. The different methods were tested as stand-alone applications or in combination. All methods consistently reduced the disease incidence at harvest on fruit with an efficacy between 30 to 60% for leaf litter removal and more than 60% for the combination of leaf litter removal and biological control. Efficacy of sanitation alone (leaf litter removal and biological control) in reducing the brown spot level on fruit was similar in most of the trials to the efficacy obtained when fungicides were applied alone. However, integration of sanitation methods and fungicides did not improve the efficacy of disease control over the level provided by fungicides alone.     

Local and regional environmental variation influences the growth of tropical trees in selection trials in the Republic of Panama

Native Neotropical trees are being increasingly planted for restoration purposes and timber production, but we lack species-specific data on growth responses to different regional climates and local environmental variation. We used regression trees and variance components to quantify the effects of within- and among-site environmental variation on the basal area (BA) of 21 Neotropical and two exotic tree species at three selection trials in the Republic of Panama. Sites represented distinct regional climates in which annual rainfall varied from 1100 to 2226 mm, with dry seasons of 4.1–6.7 months. Local environmental variables included measures of slope steepness and position, soil texture, soil color, and indicators of soil condition, such as subsoil rockiness.     

Antioxidant activity of uruguayan propolis. In vitro and cellular assays

The antioxidant capacity of propolis from the southern region of Uruguay was evaluated using in vitro as well as cellular assays. Free radical scavenging capacity was assessed by ORAC, obtaining values significantly higher than those of other natural products (8000 μmol Trolox equiv/g propolis). ORAC values correlated well with total polyphenol content (determined by Folin-Ciocalteu method) and UV absorption. Total polyphenol content (150 mg gallic acid equiv/g propolis) and flavonoids (45 mg quercetin equiv/g propolis) were similar to values reported for southern Brazilian (group 3) and Argentinean propolis. Flavonoid composition determined by RP-HPLC indicates a strong poplar-tree origin. Samples high in polyphenols efficiently inhibit low-density lipoprotein lipoperoxidation and tyrosine nitration. In addition, Uruguayan propolis was found to induce the expression of endothelial nitric oxide synthase and inhibit endothelial NADPH oxidase, suggesting a potential cardiovascular benefit by increasing nitric oxide bioavailability in the endothelium.     

Vaccination of one-day-old broiler chicks against infectious coryza

In order to evaluate the protection conferred by an experimental inactivated vaccine against infectious coryza, three challenge trials were undertaken using 112 1-day-old broilers. The vaccine "Hepa Inmuno NC" included bacterial antigens of Avibacterium paragallinarum (serogroups A, B, variant B, and C) as well as antigens of Newcastle virus and hepatitis virus. Fifty-six broiler chicks were vaccinated at the first day of life at the hatchery while another 56 chicks were left unvaccinated. Three infection trials were conducted simultaneously using each of the three serogroups A, B, or C of Av. paragallinarum. In each trial, 17 vaccinated and 17 unvaccinated broilers were used. Challenge was performed at day 31 of life by injection, into the left infraorbital sinus, of approximately 1 x 10(5) colony forming units of the corresponding Av. paragallinarum strain. Clinical signs were recorded on day 2 postchallenge. All broilers were euthanatized and both infraorbital sinuses were bacteriologically examined for the presence of Av. paragallinarum on day 5 postchallenge. In comparison with the unvaccinated broilers, the vaccine significantly reduced the number of broilers with clinical signs after challenge with serogroup B, and significantly fewer vaccinated broilers were positive for the presence of Av. paragallinarum after challenge with serogroup C. On the other hand, no significant protection was observed when broilers were challenged with Av. paragallinarum from serogroup A. Despite the high infection rates in vaccinated chicks after an experimental infection with Av. paragallinarum, it was possible to reduce colonization of Av. paragallinarum (serogroup B) and clinical signs (serogroup C) in broiler chicks by vaccination at the first day of life. Further cross-protection trials should be done, including other Av. paragallinarum strains in the vaccine, especially those from serogroup A.     

Chemical characterization of an aqueous extract and the essential oil of Tithonia diversifolia and their biocontrol activity against seed-borne pathogens of rice

Journal of Plant Diseases and Protection - The high cost of chemical pesticides and their negative impact on the environment prompted the search for natural pesticides from plants. The objective of...     

Antiradical Capacity and Induction of Apoptosis on HeLa Cells by a <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> Extract

Jamapa bean is a black Phaseolus vulgaris variety rich in condensed tannins, anthocyanins and flavonols with interesting biological activities. The objective of this work was to evaluate the antiradical capacity (ARC) of a Jamapa bean methanolic extract (BME) and some of the proanthocyanidin-rich fractions derived from it, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The effect of the BME on some proteins involved in apoptosis on HeLa cells was also evaluated. A strong correlation between proanthocyanidin concentration in BME and antiradical capacity was found, suggesting that these compounds contribute significantly to antiradical activity. BME was a better radical scavenger than butylated hydroxytoluene (45.6 and 33.9% ARC at 400 μM, respectively). Two proanthocyanidin-rich fractions obtained after a preliminary separation of the BME using Toyopearl (TP4 and TP6) exhibited a higher antiradical activity than the parent extract. The treatment of HeLa cells with 35 μg BME/ml/24 h increased the expression of Bax and Caspase-3, pro-apoptotic proteins (6.13 and 1.2 times for Caspase-3 and Bax, respectively). The mechanism of action of some proteins involved in apoptosis was also evaluated, and the results suggest that black Jamapa bean could be an important source of polyphenolic compounds with potential biological use as antioxidant and anticancer agents.     

An Indigenous Virulent Strain of Erwinia amylovora Lacking the Ubiquitous Plasmid pEA29

ABSTRACT An atypical strain of Erwinia amylovora was isolated near an outbreak of fire blight at a nursery in Spain in 1996. It was obtained from a Crataegus plant showing typical symptoms and was identified as E. amy-lovora by biochemical tests and enrichment-enzyme-linked immuno-sorbent assay, but not by polymerase chain reaction using primers based on the pEA29 sequence. Nevertheless, with primers from chromosomal regions, the isolate gave the expected amplification band. This strain carries one plasmid of approximately 70 kb, with no homology with the 29-kb plasmid common to all pathogenic strains, or with a large plasmid present in some E. amylovora strains. Growth of the strain in minimal medium without thiamine was slower compared with cultures in the same medium with thiamine, a characteristic typical of strains cured of the 29-kb plasmid. Nevertheless, aggressiveness assays on pear, apple, and Pyracantha plants and in immature pear fruit showed that this strain exhibited a virulence level similar to other strains containing pEA29. To the best of our knowledge, this is the first report of the isolation from naturally infected plant material of a pathogenic strain of E. amylovora without pEA29, but with a plasmid of approximately 70 kb not previously described.