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Montevideo, Uruguay

Coutinho T.A.,University of Pretoria | Brady C.L.,University of Pretoria | Vaart M.V.D.,University of Pretoria | Venter S.N.,University of Pretoria | And 4 more authors.
Australasian Plant Pathology | Year: 2011

A serious disease of green, actively expanding stems of young Eucalyptus grandis, E. dunnii, E. globulus and E. globulus subsp. maidenii has been observed in plantations in Uruguay and Argentina during the course of the past 10 years. The symptoms of the disease are unlike those previously observed on any species of Eucalyptus. In this study, we describe the symptoms of this new disease and determine its cause. A diagnostic feature of the disease is a red discolouration of the young host tissue and blistering of the young bark leading to rapid shoot death. A bacterium was consistently isolated from the stem blisters on to nutrient agar, purified and a selection of six strains were subjected to standard phenotypic tests and 16S rRNA-, gyrB- and rpoB-gene sequencing. The ability of these strains to induce a hypersensitive reaction (HR) was tested on tobacco and a pathogenicity tests were undertaken on a E. grandis clone. The bacterium was found to be identical to Erwinia psidii. Strains inoculated into tobacco produced a HR within 36 h and discolouration of internal shoot tissue was observed in the inoculated E. grandis clone. E. psidii is known to cause die-back of guava (Psidium guajava) which is closely related to Eucalyptus, also belonging to the Myrtaceae. Results of this study suggest that E. psidii has undergone a host shift to become an important pathogen of Eucalyptus spp. that are widely planted in South America to sustain important paper and pulp industries. © Australasian Plant Pathology Society Inc. 2010.

Ramos N.,University of the Republic of Uruguay | Mirazo S.,University of the Republic of Uruguay | Castro G.,Ministerio de Ganaderia | Arbiza J.,University of the Republic of Uruguay
Infection, Genetics and Evolution | Year: 2015

Porcine Circovirus Type 2 (PCV2) is a worldwide distributed virus and is considered an important emerging pathogen related to several distinct disease syndromes in pigs.PCV2 strains are classified into three genotypes: PCV2a, with five subtypes (2A-2E), PCV2b with three subtypes (1A-1C) and PCV2c, only found in Denmark.Recently, several reports suggested the circulation of newly emerging PCV2b mutants (mPCV2b) isolated from pigs with PCVAD in cases of suspected vaccine failure.In this work, we report for the first time the identification of mPCV2b in pigs from Uruguay, providing an additional evidence of a global circulation. Complete genome characterization and phylogenetic analysis reveal that Uruguayan strains, as well as mPCV2b previously reported are closely related to other sequences already classified as PCV2b-1C. Furthermore, results showed that mPCV2b presented different genetic markers in the capsid protein compared with classical PCV2a/b strains. Further investigation about antigenic shift of the mPCV2b strains including the Uruguayan isolates is needed. © 2015.

Rojas A.,University of the Republic of Uruguay | Verde M.,University of the Republic of Uruguay | Urteaga D.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Scarabino F.,Ministerio de Ganaderia | Martinez S.,University of the Republic of Uruguay
Palaios | Year: 2014

Drillholes represent direct evidence of ecological interactions in the fossil record. Most of them have been interpreted as predatory in origin and enable the analysis of behavioral information of both predator and prey. Drillholes have been found in a variety of fossil organisms, but this is the first report of a bored fossil chiton plate. It was found in the La Coronilla deposit, a Late Pleistocene invertebrate assemblage from southeastern Uruguay. The drillhole belongs to the ichnospecies Oichnus simplex and is attributed to a muricid gastropod, which could likely have been the ocenebrinid Urosalpinx haneti, recorded in the fossil assemblage. The drillhole features all traits for a predatory origin. However, the rareness of this particular interaction between chitons and gastropods in the fossil record and in the recent, could signify an event of arbitrary drilling. The reported occurrence here raises the question as to whether this behavior represents an understudied ecological interaction between polyplacophorans and gastropods. Copyright © 2014, SEPM (Society for Sedimentary Geology)

Ramos N.,University of the Republic of Uruguay | Mirazo S.,University of the Republic of Uruguay | Castro G.,Ministerio de Ganaderia | Arbiza J.,University of the Republic of Uruguay
Infection, Genetics and Evolution | Year: 2013

Porcine Circovirus Type 2 (PCV2) is a worldwide distributed virus and is considered an important emerging pathogen related to several distinct disease syndromes in pigs.Genomic structure consists of three major open reading frames (ORFs). ORF1 (rep gene) encodes replication-related proteins, ORF2 (cap gene) encodes the capsid protein and ORF3 encodes a protein putatively involved in virus-induced apoptosis.Based on cap gene sequences, PCV2 strains are classified into two main genotypes, PCV2a with five clusters (2A-2E) and PCV2b with three clusters (1A-1C).According to previous theorical studies, PCV2 strains can eventually undergo intra and inter-genotype recombination, mainly within the rep gene. Ever since, several evidences of recombination in the field have been reported and confirmed this hypothesis.In South America, data regarding molecular characterization of PCV2 strains is still scant. Genotyping studies in the region have concluded that PCV2b is the predominant circulating genotype in the region and till now, no recombinant strains have ever been reported.In this work we thoroughly characterized at the molecular level Uruguayan PCV2 strains by extensive sequence data analysis. Moreover, recombination software tools were applied to explore and characterize eventual occurrence of natural recombination events.Two recombinant PCV2 strains were detected in this study, as a consequence of an inter-genotype recombination event between PCV2b-1A and PCV2a-2D, as the major and minor parent, respectively. According to recombination software analysis, in both cases the event occurred within the ORF1.Herein, extensive viral sequence dataset is provided, including the characterization of the first PCV2 recombinant strains ever reported in South America. Additionally, our results suggested a multi-centered source of PCV2 infection in Uruguay, which probably involved Brazilian and European origins. © 2013 Elsevier B.V.

Beretta A.N.,Instituto Nacional Of Investigacion Agropecuaria | Silbermann A.V.,Ministerio de Ganaderia | Paladino L.,Ministerio de Ganaderia | Torres D.,Instituto Nacional Of Investigacion Agropecuaria | And 3 more authors.
Ciencia e Investigacion Agraria | Year: 2014

The Robinson pipette method (Pipette) is accurate and precise but time consuming. Bouyoucos (1936) proposed a more rapid and simpler procedure called the hydrometer method. Both analytical techniques are sedimentation procedures accepted as standard techniques for particle-size analysis. The sand, silt, and clay contents of several soil samples were determined using the Pipette method as a control and compared with the Bouyoucus, the Bouyoucos Modified (Bouyoucos_M) and the Bouyoucos Modified with gravimetric determination of the sand content (Bouyoucos_M-T) methods. Data obtained from these procedures was used to assess soil textural class, the soil erodibility coefficient (K), the water retained at field capacity (FC) and the permanent wilting point (PWP). In the Bouyoucos_M method, the soil organic matter (SOM) was destroyed and the dispersingagent concentration was increased. In the Bouyoucos_M-T method, the sand was quantified gravimetrically by sieving samples through a 53 µm mesh. The hydrometer and Pipette methods measurements correlated well. The Bouyoucos and the Bouyoucus-M methods overestimated the sand content. The performance of the Bouyoucos_M-T method did not differ from that of the Pipette method. Compared with the Pipette method, the Bouyoucus method underestimated the clay content, and the Bouyoucos_M method did not differ from the Pipette method. The values obtained with the Bouyoucos_M and the Bouyoucos methods underestimated the FC and the PWP, and Bouyoucos_M-T method did not differ from estimations based on the Pipette method data. The assessed K value was underestimated with the Bouyoucos_M method. The Bouyoucos and the Bouyoucos_M-T methods estimated the K values similar to the Pipette method. The Bouyucus_M-T method is suitable for determining the soil texture and inferring soil properties but is unacceptable for assessing the class texture for soil taxonomic classification. © 2014 Pontificia Universidad Catolica de Chile, Facultad de Agronomia e Ingenieria Forestal. All rights reserved.

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