Pantoea agglomerans-Induced Dieback in Pistachio in Chile

Pistachio crops have a great economic potential, as their global production has increased dramatically over the past few decades. Therefore, it is important to maintain the healthy phytosanitary status of pistachio crops. In a Chilean pistachio orchard, a dieback of the trees was observed, with blighting of twigs and severe necrosis in the trunk and twigs. Bacterial isolation, pathogenicity tests and molecular characterization were conducted to determine the causal agent of the observed disease. The bacterial isolation and analysis of 16S rRNA gene led to the identification of Pantoea genus bacteria. Pathogenicity tests carried out on fruits inoculated with Pantoea isolates induced large necrosis seven days post-inoculation. Further inoculations were carried out on pruning cuttings and on the trunk of 18-month-old pistachio plants. Thirty-one weeks after inoculation, necrotic lesions were observed in the wood of pistachio plants. Sequence analysis of housekeeping genes enabled the isolated bacterium to be identified as Pantoa agglomerans, and to verify its role as the causal agent of the pistachio dieback with necrotic lesions. This is the first report of an occurrence of P. agglomerans inducing dieback in pistachio

Complete genome sequence of <i>Vibrio anguillarum</i> phage CHOED successfully used for phage therapy in aquaculture

Vibrio anguillarum phage CHOED was isolated from Chilean mussels. It is a virulent phage showing effective inhibition of V. anguillarum. CHOED has potential in phage therapy, because it can protect fish from vibriosis in fish farms. Here, we announce the completely sequenced genome of V. anguillarum phage CHOED

Aluminium depletion in NiCrAlY bond coatings by hot corrosion as a function

12 figures, 2 tablesThree different projection system are used to prepare NiCrAlY bond coats over metallic substrates: atmospheric plasma spray (APS), high velocity oxyfuel (HVOF) and high frequency pulse detonation (HFPD). These coatings were tested in hot corrosion experiments with sprayed Na2SO4 at 1000ºC for 20 and 100 hours experiments in air. Coatings surface composition after thermal treatment was characterised by XRD and SEM. Cross section of coatings were analysed by SEM-EDX. A relationship between microstructural characteristics of initial coatings and final performance in hot corrosion was found in terms of porosity percentage: plasma sprayed coatings present higher percentage of porosity compared to HVOF and HFPD projection systems for the same composition and Al is heavily consumed in interparticle oxidation. This Al depletion in turn involves intrinsic chemical failure and surface layer is comprised by a porous spinel of mixed oxides. On the other hand, high energy projection systems produce dense coatings allowing the Al migration to external alumina layer, particularly in the case of HVOF coating.The authors want to express their gratitude to the Spanish Ministry of Education and Science for the financial support of the work, project MAT2004-02921, and to the Diputación General de Aragón, for the project PM0252004Peer reviewe

Virtual screening of gene expression regulatory sites in non-coding regions of the infectious salmon anemia virus

© 2014 Díaz et al.; licensee BioMed Central Ltd.Background: Members of the Orthomyxoviridae family, which contains an important fish pathogen called the infectious salmon anemia virus (ISAV), have a genome consisting of eight segments of single-stranded RNA that encode different viral proteins. Each of these segments is flanked by non-coding regions (NCRs). In other Orthomyxoviruses, sequences have been shown within these NCRs that regulate gene expression and virulence; however, only the sequences of these regions are known in ISAV, and a biological role has not yet been attributed to these regions. This study aims to determine possible functions of the NCRs of ISAV. Results: The results suggested an association between the molecular architecture of NCR regions and their role in the viral life cycle. The available NCR sequences from ISAV isolates were compiled, alignments were performed to obtain a consensus sequence, and conserved regions were identified in this consensus sequence.

Study of sulphidation and chlorination on oxidized SS310 and plasma-sprayed Ni–Cr coatings as simulation of hot corrosion in fouling and slagging in combustion

The behaviour of two thermal sprayed Ni–Cr coatings compared to conventional SS310 was studied under pyrite, potassium sulphate and potassium chloride attack in inert atmosphere at 900 °C, as simulation of fouling and slagging in co-firing coal with biomass. The morphologic description of chemical attack by S, K and Cl and depth of penetration is performed using SEM, and EDX for chemical composition of scales. Sulphur from molten iron sulphide is able to penetrate through the coatings forming chromium and nickel sulphides, but in a less extent than in the preoxidised austenitic steel. The coatings proved to be resistant to molten potassium sulphate attack, which was catastrophic in the case of not-coated preoxidised SS310. The resistance of these materials against chlorination was tested and although both coatings were corroded by KCl salt, coating 1, with higher chromium content, hindered corrosion progression and protected steel matrix under coating.Peer reviewe

Bacteriophages in the control of pathogenic vibrios

Vibrios are common inhabitants of marine and estuarine environments. Some of them can be pathogenic to humans and/or marine animals using a broad repertory of virulence factors. Lately, several reports have indicated that the incidence of Vibrio infections in humans is rising and also in animals constitute a continuing threat for aquaculture. Moreover, the continuous use of antibiotics has been accompanied by an emergence of antibiotic resistance in Vibrio species, implying a necessity for efficient treatments. One promising alternative that emerges is the use of lytic bacteriophages; however, there are some drawbacks that should be overcome to make phage therapy a widely accepted method. In this work, we discuss about the major pathogenic Vibrio species and the progress, benefits and disadvantages that have been detected during the experimental use of bacteriophages to their control.Fondecyt 11140412 11140257 Proyecto PUCV DI Investigacion Innovadora Interdisciplinaria 039.461/201

Amplification of tlh gene in other Vibrionaceae specie by specie-specific multiplex PCR of Vibrio parahaemolyticus

Background: The surveillance of Vibrio parahaemolyticus in the Chilean coast has been mainly performed by multiplex PCR amplification of three different hemolysin genes, which are specie-specific virulence factors. These genes are also employed in the determination of V. parahaemolyticus pathogenic load in seafood and for characterization of pathogenic strains associated to diarrhea cases in human. During environmental surveillance that we performed every summer, we occasionally observed a thermolabile hemolysin (tlh) PCR product of a slightly smaller size than expected, which was coincident with low loads of V. parahaemolyticus in the environment. In order to understand this observation, we probed the specificity of tlh primers for the detection of V. parahaemolyticus at different bacterial loads and DNA concentrations. Results: Primers used for the detection of V. parahaemolyticus specific tlh amplified a slightly smaller tlh gene, which is found in Vibrio alginolyticus and other related strains. These amplicons were observed when V. parahaemolyticus was absent or in undetectable loads in the environment. Conclusions: Surveillance of V. parahaemolyticus using tlh primers can be imprecise because amplification of a V. parahaemolyticus specific marker in V. alginolyticus and other related strains occurs. This situation complicates potentially the estimation of bacterial load in seafood, because do not ensure the correct identification of V. parahaemolyticus when his load is low. Additionally, it could complicate the tracking of outbreaks of V. parahaemolyticus infections, considering the genetic markers used would not be specie-specific

Yttria stabilized zirconia corrosion destabilization followed by Raman mapping

The incidence of V2O5 corrosion on yttria stabilized zirconia (YSZ) thermal barrier coatings has been studied as a function of application methods and powder initial granulometry. Commercial fused-and-crushed 8 wt.% yttria-stabilized zirconia was sprayed by Atmospheric Plasma Spraying (APS) and High Frequency Pulse Detonation. Hollow Spherical Powder (HOSP™) with the same composition was sprayed by APS. The coatings where covered with V2O5 powder and treated at 1000 °C for different times. The extent of corrosion was followed by X-ray diffraction, scanning electron microscopy and Raman micro-spectrometry. A relationship between coating porosity and corrosion resistance is explored: the HOSP coating presented deeper penetration of corrosion than the other coatings. The authors present the extended capabilities of Raman semi-quantitative phase analysis to describe the depth and density of yttria leaching by vanadia leading to YSZ destabilization.The authorswant to express their gratitude to the Spanish Ministry of Education and Science for the financial support of the work, project MAT2004-02921, and to the Diputación General de Aragón, for the project PM0252004.Peer reviewe

Old and New Aphid-Borne Viruses in Coriander in Chile: An Epidemiological Approach

In Chile, edible herbs are mainly grown by small farmers. This type of horticultural crop typically requires intensive management because it is highly susceptible to insects, some of which transmit viruses that severely affect crop yield and quality. In 2019, in coriander plants tested negative for all previously reported viruses, RNA-Seq analysis of one symptomatic plant revealed a plethora of viruses, including one virus known to infect coriander, five viruses never reported in coriander, and a new cytorhabdovirus with a 14,180 nucleotide RNA genome for which the species name Cytorhabdovirus coriandrum was proposed. Since all the detected viruses were aphid-borne, aphids and weeds commonly growing around the coriander field were screened for viruses. The results showed the occurrence of the same seven viruses and the alfalfa mosaic virus, another aphid-borne virus, in aphids and weeds. Together, our findings document the presence of multiple viruses in coriander and the potential role of weeds as virus reservoirs for aphid acquisition