Pyricularia graminis-tritici, a new Pyricularia species causing wheat blast.

Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice pathogen and in the last 30 years emerged as an important wheat pathogen in southern Brazil. We conducted phylogenetic analyses using 10 housekeeping loci for 128 isolates of P. oryzae sampled from sympatric populations of wheat, rice, and grasses growing in or near wheat fields. Phylogenetic analyses grouped the isolates into three major clades. Clade 1 comprised isolates associated only with rice and corresponds to the previously described rice blast pathogen P. oryzae pathotype Oryza (PoO). Clade 2 comprised isolates associated almost exclusively with wheat and corresponds to the previously described wheat blast pathogen P. oryzae pathotype Triticum (PoT). Clade 3 contained isolates obtained from wheat as well as other Poaceae hosts. We found that Clade 3 is distinct from P. oryzae and represents a new species, Pyricularia graminis-tritici (Pgt). No morphological differences were observed among these species, but a distinctive pathogenicity spectrum was observed. Pgt and PoT were pathogenic and highly aggressive on Triticum aestivum (wheat), Hordeum vulgare (barley), Urochloa brizantha (signal grass), and Avena sativa (oats). PoO was highly virulent on the original rice host (Oryza sativa), and also on wheat, barley, and oats, but not on signal grass. We conclude that blast disease on wheat and its associated Poaceae hosts in Brazil is caused by multiple Pyricularia species. Pyricularia graminis-tritici was recently found causing wheat blast in Bangladesh. This indicates that P. graminis-tritici represents a serious threat to wheat cultivation globally.

Fish assemblage in a semi-arid Neotropical reservoir: composition, structure and patterns of diversity and abundance.

The aim of this study was to analyse the composition, structure and spatial and temporal patterns of diversity and abundance of the ichthyofauna of the Santa Cruz Reservoir in semi-arid Brazil. Data were collected quarterly at eight sampling locations on the reservoir between February 2010 and November 2011 using gillnets from 12- to 70-mm mesh that were left in the water for 12h00min during the night. We evaluated the composition, structure and assemblage descriptors (Shannon-Wiener diversity index and equitability, respectively) and catch per unit effort by the number (CPUEn) and biomass (CPUEb) of the ichthyofauna. The 6,047 individuals (399,211.6 g) captured represented three orders, ten families and 20 species, of which four belonged to introduced species. The family Characidae was the most abundant with a total of 2,772 (45.8%) individuals captured. The species-abundance curve fit the log-normal model. In the spatial analysis of diversity, there were significant differences between sampling sites in the lacustrine and fluvial regions, and the highest values were found in the lacustrine region. In the temporal analysis of diversity, significant differences were also observed between the rainy and dry seasons, and the higher values were found during the dry season. Equitability followed the same spatiotemporal pattern as diversity. The Spearman correlation was significantly negative between diversity and rainfall. A cluster analysis spatially separated the ichthyofauna into two groups: one group formed by sampling sites in the fluvial region and another group formed by the remainder of the points in the lacustrine region. Both the CPUEn and CPUEb values were higher at point 8 (fluvial region) and during the rainy season. A two-way ANOVA showed that the CPUEn and CPUEb values were spatially and temporally significant. We conclude that the spatial and temporal trends of diversity in the Santa Cruz reservoir differ from those of other Brazilian reservoirs but that the fish community composition and spatiotemporal patterns of abundance were similar.

Seguridad y eficacia de la biopsia renal percutánea / Safety and efficacy of percutaneous renal biopsy

Se realizó una evaluación de la seguridad y eficacia del procedimiento de la biopsia renal percutánea BRP de riñones nativos bajo control ecográfico simultáneo. Se revisaron las historias clínicas de todos los pacientes que fueron biopsiados en el período comprendido entre enero de 2005 y diciembre de 2008 en el Servicio de Nefrología del Hospital de Pediatría Juan P. Garrahan. Se excluyeron del análisis los procedimientos realizados bajo anestesia general y en riñón transplantado. Se evaluaron 117 procedimientos realizados en 114 pacientes: 59 varones (50.4%) y 55 mujeres (49.6%). Las indicaciones más frecuentes de BRP fueron: proteinuria masiva o significativa con o sin hematuria 45 (38,6%), Lupus Eritematoso Sistémico 32 (27.4%) y síndrome nefrótico cortico-resistente 23 (20%); otras menos frecuentes estuvieron representadas por: Púrpura de Schönlein-Henoch 7 (6%), insuficiencia renal aguda (IRA) 5 (4%) e insuficiencia renal crónica (IRC) 5 (4%). No se produjeron eventos adversos (EA) en 97 (83%) procedimientos. En 20 (17%), se produjeron EA. Los EA no serios fueron 9: microhematuria (n=3), macrohematuria (n=3) y dolor lumbar (n=3). Los 11 restantes fueron EAS (serios) que correspondieron a hematomas perirrenales de los cuales 2 requirieron transfusión de glóbulos rojos. Las muestras obtenidas fueron suficientes para el diagnóstico en 113 procedimientos (97%), con un número de glomérulos de 30 ± 11. Los resultados demostraron que el procedimiento de BRP con disparador automático, anestesia local y control ecográfico simultáneo es seguro y eficaz. El número de EAS registrados en este estudio es similar o menor según las series analizadas. A diferencia de la publicación internacional en nuestro centro se realiza el procedimiento con el paciente despierto (AU)

In this study we evaluated the safety and efficacy of ultrasound-guided percutaneous renal biopsy (PRB) of native kidneys. The clinical charts of all patients that underwent PRB between January 2005 and December 2008 at the Department of Nephrology of the Pediatric Hospital Juan P. Garrahan were reviewed. Procedures performed under general anesthesia and in transplanted kidneys were excluded from the analysis. We evaluated 117 procedures performed in 114 patients: 59 were male (50.4%) and 55 female (49.6%). The most frequent indications for PRB were: massive or significant proteinuria with or without hematuria 45 (38,6%), systemic lupus erythematosus 32 (27.4%), and steroid-resistant nephrotic syndrome 23 (20%); other less frequent indications were: Henoch-Schönlein purpura 7 (6%), acute renal insufficiency (ARI) 5 (4%), and chronic renal insufficiency (CRI) 5 (4%). No adverse events (AE) were observed in 97 (83%) procedures. AE were seen in 20 (17%). There were 9 minor AE: microhematuria (n=3), gross hematuria (n=3), and lumbar pain (n=3). Serious AE observed were perinephric hematoma in 11 patients of whom 2 required red blood cell transfusions. The sample size was sufficient for diagnosis in 113 procedures (97%), with a number of glomeruli of 30 ± 11. The results show that ultrasoundguided PRB with an automatic trigger and local anesthesia is a safe and effective procedure. The number of serious AE in this study is similar to or lower than reported in previous series. Unlike other international series, at our center the procedure is performed while the patient is awake (AU)