Zimevit: un biofungicida que combina la acción de una bacteria y una levadura para el control del moho gris de la vid ocasionado por Botrytis cinerea.

Botrytis cinerea, provoca pérdidas importantes en la producción de vid. Zimevit, un biofungicida desarrollado en Uruguay que combina la acción de una bacteria (Bacillus subtilis, UYBC38) y una levadura (Metschnikowia pulcherrima, M26) fue evaluado a campo en las variedades Cabernet Franc y Gewurztraminer. Los tratamientos fueron: Zimevit; iprodione como tratamiento convencional y agua como testigo. En los tres ensayos efectuados la aplicación de Zimevit resultó en una menor incidencia y severidad del moho gris en los racimos al momento de la cosecha sin diferenciarse del fungicida iprodione. El hecho de que Zimevit haya logrado reducir tanto la incidencia como la severidad de la enfermedad estaria demostrando la existencia de un doble efecto inhibitorio, tanto sobre la germinación de esporas como sobre el desarrollo posterior de la enfermedad. Si bien se recomienda realizar nuevas evaluaciones para conocer su comportamiento en años con clima favorable al desarrollo de la enfermedad, puede afirmarse que Zimevit aparece como una herramienta potencial a ser usada en sistemas de manejo integrado del moho gris de la vid en Uruguay

Grapevine nursery propagation material as source of fungal trunk disease pathogens in Uruguay

Grapevine fungal trunk diseases (GTDs) have become a serious problem for grapevines worldwide. Nursery vines infected during the propagation process are considered one of the main ways of dissemination of GTD pathogens. In this study, we examined the status of GTDs in grapevine planting material, from rootstocks and scion mother cuttings to grafted rooted vines ready to plant, according to the local nursery propagation process. During 2018-2019, internal symptoms of GTDs were examined in 2400 propagation materials and fungal isolations were carried out from a subsample of 1026 selected materials. Our results revealed that nursery grapevine plants produced in Uruguay have a high incidence of GTDs, regardless of the scion/rootstock combination. Typical brown to black streaks and sectorial wood necrosis were observed in materials on all propagation stages, with a markedly increasing incidence throughout the nursery process, reaching almost 100% in grafted rooted vines ready to plant. Botryosphaeria dieback, Petri disease and black-foot disease were the main GTDs found. The results showed that Botryosphaeria dieback and Petri disease pathogens infect materials from the early stages of the process, with a marked increase towards the end of the plant production process, whereas black-foot disease pathogens were found exclusively in vines ready to plant. Diaporthe dieback pathogens were also detected in materials in all stages but in a low proportion (less than 10% of infected material). Based on single locus analysis, the 180 isolates selected were placed into eight genera and 89% identified within 22 fungal species associated with GTDs, with Phaeoacremonium oleae and Diaporthe terebinthifolii as new records on grapevine worldwide. Our results have concluded that locally produced vines are one of the main ways of dissemination of GTD pathogens and showed that a nursery sanitation programme is required to reduce the incidence of these diseases

Apraxia severa por atrapamiento del nervio radial en el brazo: “síndrome de Lotem”. Presentación de un caso

Se presenta el caso de un hombre de 57 años que consulta por parálisis alta del nervio radial, con dolor y prueba de Tinel positiva en la cara lateral del brazo dominante, de inicio súbito, luego de grandes esfuerzos musculares repetitivos, sin mejoría clínica al tercer mes de evolución. Se realizó un tratamiento quirúrgico descompresivo. El paciente tuvo una rápida recuperación a partir del séptimo día, y remisión completa a los 25 días de la cirugía. Conclusión: El atrapamiento del nervio radial en el brazo es un cuadro poco frecuente. Según los estudios publicados, la evolución clínica es variada, pero si no hay remisión o la evolución de la parálisis no es favorable en 3 meses, creemos que la cirugía es el tratamiento de elección

First report of Colletotrichum siamense causing apple bitter rot in central Argentina

The introduction of low-chill apple cultivars in Argentina allowed the expansion of production into warmer northern and central areas. Bitter rot, caused by Colletotrichum species, is one of the prevalent apple diseases worldwide (Baroncelli et al. 2014, Munir et al. 2016, Velho et al. 2015). In December 2014, bitter rot symptoms were observed on apple fruits cvs. ?Eva?, ?Caricia? and ?Princesa? in four orchards of Santa Fe province. The rot began as brown, 1-2 mm circular spots which enlarged rapidly and became sunken and extended toward the fruit core in a V-shaped pattern. Under high humidity conditions concentric rings of pinhead-size salmon acervuli formed in the lesions. Causal agent was isolated by touching acervuli with a sterile needle and monosporic cultures were obtained on PDA after 7 days at 25°C, with a 12-h light period. Colonies were white to gray on the top and pink on the underside, where concentric rings of salmon acervuli were clearly distinguished. The width and length of one hundred conidia were examined in three isolates (E3, E8 and E9), ranging from 3.37 to 5.54 μm (avg. 4.46), and from 11 to 17.85 μm (avg. 14.58), respectively. Conidia were mainly cylindrical, with rounded ends. After germination, conidia formed oval appressoria ranging from 9.17 to 10.31 μm (avg. 9.65), and from 6.88 to 7.81 μm (avg. 7.39). These morphological characteristics correspond to species belonging to C. gloesporioides complex (Weir et al. 2012). To accurately identify the species, DNA was extracted from isolates and genes corresponding to glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ß-tubulin (TUB2) and calmodulin (CAL) were partially amplified and sequenced. CAL and GAPDH sequences presented a 100% of identity with species of Colletotrichum siamense, whereas TUB2 sequences showed between 99 and 100 % of identity with the same species. The nucleotides sequences were deposited in GenBank (KY656675-KY656677, GAPDH; KY656678-KY656680, TUB2; and MF476801-MF476803, CAL). Multilocus phylogenetic analyses performed with references sequences (Weir et al. 2012) showed that the three isolates clustered with C. siamense, in accordance with BLAST results. To confirm pathogenicity, each isolate was inoculated in eight fruits of the cultivar from which it was originally obtained. Two drops of 10 μl of conidial suspension (1x105 conidia per ml) were deposited in wounded and non-wounded areas on fruits previously disinfested with 1% sodium hypochlorite solution for 1 min and rinsed twice with sterile distilled water. Drops of sterile water were deposited in eight fruits as control. Pathogenicity tests were repeated twice. Fruits were kept under high humidity conditions at 25°C for ten days. First symptoms appeared 3 days after inoculation (DAI) in wounded areas and 5 DAI in non-wounded areas. After that, all of the isolates produced symptoms identical to those previously described, whereas the controls remain symptomless. The pathogen was re-isolated from lesions, and identified as C. siamense by morphological characteristics and based on the CAL sequences, as previously described. To our knowledge, this is the first report of C. siamense in Argentina causing bitter rot on apple. C. siamense was previously reported to be more aggressive than other Colletotrichum species, but it is also more sensitive to fungicides (Munir et al. 2016), which encourages the development of species-specific management strategies for this pathogen in central Argentina.Fil: Fernandez, Laura Noemí. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Alaniz, Sandra. Universidad de la Republica. Facultad de Agricultura; UruguayFil: Mondino, Pedro. Universidad de la Republica. Facultad de Agricultura; UruguayFil: Roeschlin, Roxana Andrea. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Reconquista; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Maumary, Roxana Lorena. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Gariglio, Norberto Francisco. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Favaro, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentin

Global analysis of the apple fruit microbiome: are all apples the same?

We present the first worldwide study on the apple (Malus × domestica) fruit microbiome that examines questions regarding the composition and the assembly of microbial communities on and in apple fruit. Results revealed that the composition and structure of the fungal and bacterial communities associated with apple fruit vary and are highly dependent on geographical location. The study also confirmed that the spatial variation in the fungal and bacterial composition of different fruit tissues exists at a global level. Fungal diversity varied significantly in fruit harvested in different geographical locations and suggests a potential link between location and the type and rate of postharvest diseases that develop in each country. The global core microbiome of apple fruit was represented by several beneficial microbial taxa and accounted for a large fraction of the fruit microbial community. The study provides foundational information about the apple fruit microbiome that can be utilized for the development of novel approaches for the management of fruit quality and safety, as well as for reducing losses due to the establishment and proliferation of postharvest pathogens. It also lays the groundwork for studying the complex microbial interactions that occur on apple fruit surfaces.info:eu-repo/semantics/publishedVersio

Targeting of host organelles by pathogenic bacteria: a sophisticated subversion strategy.

International audienceMany bacterial pathogens have evolved the ability to subvert and exploit host functions in order to enter and replicate in eukaryotic cells. For example, bacteria have developed specific mechanisms to target eukaryotic organelles such as the nucleus, the mitochondria, the endoplasmic reticulum and the Golgi apparatus. In this Review, we highlight the most recent advances in our understanding of the mechanisms that bacterial pathogens use to target these organelles. We also discuss how these strategies allow bacteria to manipulate host functions and to ultimately enable bacterial infection

Extracellular enzymes of Colletotrichum fructicola isolates associated to Apple bitter rot and Glomerella leaf spot

Colletotrichum fructicola causes two important diseases on apple in Southern Brazil, bitter rot (ABR) and Glomerella leaf spot (GLS). In this pathosystem, the Colletotrichum ability to cause different symptoms could be related to differences of extracellular enzymes produced by the fungi. Thus, the objectives of this study were to compare the production of these enzymes between ABR- and GLS-isolate in vitro and to evaluate their involvement on infected apple leaves with C. fructicola. In agar plate enzymatic assay, ABR- showed significantly higher amylolytic and pectolytic activity than GLS-isolate. In contrast, for lipolytic and proteolytic no significant differences were observed between isolates. In culture broth, ABR-isolate also had higher activity of pectin lyase (PNL), polygalacturonase (PG) and laccase (LAC). Notably, LAC was significantly five-fold higher in ABR- than GLS-isolate. On the other hand, in infected apple leaves no significant difference was observed between isolates for PNL, PG and LAC. Although differences in extracellular enzymes of ABR- and GLS-isolate have not been observed in vivo, these results contributed to highlight the importance to investigate such enzymes in depth

Cannabis Intoxication in Small Animals. Review

El Cannabis es una de las drogas más consumidas a nivel mundial, Uruguay en particular es el décimo país con mayor consumo per cápita. Dado que en el país se ha regulado legalmente el mercado y consumo de Cannabis tanto de uso recreativo como medicinal y ya que es posible tener acceso a productos medicinales y flores de Cannabis en las farmacias de nuestro país, es esperable que exista mayor exposición accidental de los animales domésticos a estos productos. Así mismo, la legalización ayuda a que los propietarios se sientan seguros a la hora de reconocer que sus mascotas pueden haber tenido acceso a productos a base de Cannabis. Por lo tanto, resulta menester conocer detalladamente la toxicodinamia, toxicocinética, signos clínicos, diagnóstico y tratamiento de la intoxicación por Cannabis en pequeños animales.Cannabis is one of the most consumed drugs worldwide, being Uruguay the tenth country with higher consume per capita. Due to the legally regulation of the medical and recreational Cannabis market and consume and the possibility to buy medicinal products and Cannabis flowers in the pharmacies of our country, the enhancement of accidental exposure to Cannabis products in small animals is expected. Furthermore, the legalization helps pets’ owners to feel confident to recognize that their animals could have ingested Cannabis products. Hence, it is fundamental to be aware in the toxicodynamic, toxicokinetic, clinical signs, diagnosis and treatment of Cannabis intoxication in small animals.Facultad de Ciencias Veterinaria

Ascospore Infection and Colletotrichum Species Causing Glomerella Leaf Spot of Apple in Uruguay

Glomerella leaf spot (GLS) caused by Colletotrichum spp. is a destructive disease of apple restricted to a few regions worldwide. The distribution and evolution of GLS symptoms were observed for two years in Uruguay. The recurrent ascopore production on leaves and the widespread randomized distribution of symptoms throughout trees and orchard, suggest that ascospores play an important role in the disease dispersion. The ability of ascospores to produce typical GLS symptom was demonstrated by artificial inoculation. Colletotrichum strains causing GLS did not result in rot development, despite remaining alive in fruit lesions. Based on phylogenetic analysis of actin, β-tubulin and glyceraldehyde-3-phosphate dehydrogenase gene regions of 46 isolates, 25 from fruits and 21 from leaves, C. karstii was identified for the first time causing GLS in Uruguay and C. fructicola was found to be the most frequent (89%) and aggressive species. The higher aggressiveness of C. fructicola and its ability on to produce abundant fertile perithecia could help to explain the predominance of this species in the field

Legionnaires’ Disease: State of the Art Knowledge of Pathogenesis Mechanisms of Legionella

International audienceLegionella species are environmental gram-negative bacteria able to cause a severe form of pneumonia in humans known as Legionnaires' disease. Since the identification of Legionella pneumophila in 1977, four decades of research on Legionella biology and Legionnaires' disease have brought important insights into the biology of the bacteria and the molecular mechanisms that these intracellular pathogens use to cause disease in humans. Nowadays, Legionella species constitute a remarkable model of bacterial adaptation, with a genus genome shaped by their close coevolution with amoebae and an ability to exploit many hosts and signaling pathways through the secretion of a myriad of effector proteins, many of which have a eukaryotic origin. This review aims to discuss current knowledge of Legionella infection mechanisms and future research directions to be taken that might answer the many remaining open questions. This research will without a doubt be a terrific scientific journey worth taking