Antifungal Activity of Phyllospheric Bacteria Isolated from Coffea arabica against Hemileia vastatrix.

Peru is one of the leading countries that produce and export specialty coffees, favorably positioned in the international markets for its physical and organoleptic cup qualities. In recent years, yellow coffee rust caused by the phytopathogenic fungus Hemileia vastatrix stands out as one of the main phytosanitary diseases that affect coffee culture yields. Many studies have demonstrated bacteria antagonistic activity against a number of phytopathogen fungi. In this context, the aim of this work was to select and characterize phyllospheric bacteria isolated from Coffea arabica with antagonistic features against coffee rust to obtain biocontrollers. For that purpose, a total of 82 phyllospheric bacteria were isolated from two coffee leaf rust-susceptible varieties, typica and caturra roja, and one tolerant variety, catimor. Of all the isolates, 15% were endophytic and 85% were epiphytes. Among all the isolates, 14 were capable of inhibiting the mycelial radial growth of Mycena citricolor, and Colletotrichum sp. 16S rRNA gene sequence-based analysis showed that 9 isolates were related to Achromobacter insuavis, 2 were related to Luteibacter anthropi and 1 was related to Rodococcus ceridiohylli, Achromobacter marplatensis and Pseudomonas parafulva. A total of 7 representative bacteria of each group were selected based on their antagonistic activity and tested in germination inhibition assays of coffee rust uredinospores. The CRRFLT7 and TRFLT8 isolates showed a high inhibition percentage of urediniospores germination (81% and 82%, respectively), similar to that obtained with the chemical control (91%). An experimental field assay showed a good performance of both strains against rust damage too, making them a promising alternative for coffee leaf rust biocontrol.

Bioprospection of native psychrotolerant plant-growth-promoting rhizobacteria from Peruvian Andean Plateau soils associated with Chenopodium quinoa.

The Peruvian Andean Plateau, one of the main production areas of native varieties of Chenopodium quinoa, is exposed to abrupt decreases in environmental temperature, affecting crop production. Plant-growth-promoting rhizobacteria that tolerate low temperatures could be used as organic biofertilizers in this region. We aimed to bioprospect the native psychrotolerant bacteria of the quinoa rhizosphere in this region that show plant-growth-promoting traits. Fifty-one strains belonging to the quinoa rhizosphere were characterised; 73% of the total could grow at low temperatures (4, 6, and 15 °C), whose genetic diversity based on DNA amplification of interspersed repetitive elements (BOX) showed 12 different profiles. According to the 16S rRNA sequence, bacterial species belonging to the classes Beta- and Gammaproteobacteria were identified. Only three (6%) isolates identified as nonpathogenic bacteria exhibited plant-growth-promoting activities, like IAA production, phosphate solubilization, growth in a nitrogen-free medium, and ACC deaminase production at 6 and 15 °C. ILQ215 (Pseudomonas silesiensis) and JUQ307 (Pseudomonas plecoglossicida) strains showed significantly positive plant growth effects in aerial length (about 50%), radicular length (112% and 79%, respectively), and aerial and radicular mass (above 170% and 210%, respectively) of quinoa plants compared with the control without bacteria. These results indicate the potential of both psychrotolerant strains to be used as potential organic biofertilizers for quinoa in this region.

Dermoscopic features of acral melanocytic nevi in a case series from Mexico

Abstract: Background: Pigmented lesions on acral sites are common; clinical differentiation of nevi and early melanoma can be challenging. In these cases, dermoscopy can provide a more accurate diagnosis. Most dermoscopic patterns on acral skin have been described in Asian and European populations, while there are few studies in Latin American populations. Objectives: To determine the frequency of pigmented lesions in volar skin and their dermoscopic patterns in a Mexican population. Methods: An observational, descriptive, cross-sectional study was performed in Hispanic patients with the presence of at least one pigmented lesion on acral skin. Clinical and dermoscopic images were obtained. These were subsequently evaluated independently by two dermatologists trained and experienced in dermoscopy. Results: A total of 582 pigmented lesions on volar skin were diagnosed in 321 patients. Overall, prevalence of acral pigmented lesions on volar skin was 6.8%. For both observers, parallel furrows were the most frequent pattern described, but for observer 2, a lattice-like pattern was prevalent on the toes and a homogeneous pattern on the sides of the feet. There was lower inter-observer agreement, with a kappa index of 0.144. Study limitations: The lesions were not biopsied, so clinical-histological correlation could not be performed. The study did not correlate dermoscopic patterns with age. Conclusions. As previously reported by other authors, parallel furrows were the most frequently found dermoscopic pattern on palmoplantar skin.

Dermoscopic features of acral melanocytic nevi in a case series from Mexico.

BACKGROUND: Pigmented lesions on acral sites are common; clinical differentiation of nevi and early melanoma can be challenging. In these cases, dermoscopy can provide a more accurate diagnosis. Most dermoscopic patterns on acral skin have been described in Asian and European populations, while there are few studies in Latin American populations OBJECTIVES: To determine the frequency of pigmented lesions in volar skin and their dermoscopic patterns in a Mexican population. Methods: An observational, descriptive, cross-sectional study was performed in Hispanic patients with the presence of at least one pigmented lesion on acral skin. Clinical and dermoscopic images were obtained. These were subsequently evaluated independently by two dermatologists trained and experienced in dermoscopy RESULTS: A total of 582 pigmented lesions on volar skin were diagnosed in 321 patients. Overall, prevalence of acral pigmented lesions on volar skin was 6.8%. For both observers, parallel furrows were the most frequent pattern described, but for observer 2, a lattice-like pattern was prevalent on the toes and a homogeneous pattern on the sides of the feet. There was lower inter-observer agreement, with a kappa index of 0.144 STUDY LIMITATIONS: The lesions were not biopsied, so clinical-histological correlation could not be performed. The study did not correlate dermoscopic patterns with age CONCLUSIONS: As previously reported by other authors, parallel furrows were the most frequently found dermoscopic pattern on palmoplantar skin

Characterization and potential of plant growth promoting rhizobacteria isolated from native Andean crops.

Bacteria isolated from soil and rhizosphere samples collected in Peru from Andean crops were tested in vitro and in vivo to determine their potential as plant growth promoters and their ability to induce systemic resistance to Alternaria alternata in tomato plants. The isolates were identified by sequencing their 16S ribosomal RNA gene. Test for phosphate solubilization, and indolacetic acid were also carried out, together with in vitro antagonism assays in dual cultures towards the plant pathogens Fusarium solani, A. alternata and Curvularia lunata. The three most promising isolates (Pa15, Ps155, Ps168) belonged to the genus Pseudomonas. Further assays were carried out with tomato plants to assess their plant protection effect towards A. alternata and as growth promoters. Inoculation of tomato seeds with all isolates significantly enhanced seed germination, plantlets emergence and plant development. Bacterial inoculation also reduce damage level caused by A. alternata. The expression levels of three tomato genes involved in the jasmonate (AOS), ethylene responsive (ERF-2) and pathogenesis related (PR-P2) pathways were determined in plants challenged with A. alternata, alone or with each bacterial isolate, respectively. Results showed that at 24 h after infection, in absence of the pathogen, the expression level of the tested genes was very low. The presence of A. alternata alone and in combination with bacteria increased the transcripts of all genes. Data showed a potential of best performing isolate Ps168 to sustain tomato plants nutrition and activate defense-related genes for protection by pathogenic fungi.

[Skin diseases and obesity]. / Dermatosis en la obesidad.

Obesity is a public health problem worldwide. It predominates in industrialized countries; however, it is prevalent in all nations. It is defined as a condition of excess adipose tissue and is the result of changes in lifestyle, excessive consumption of energy-dense foods with poor nutritional value, physical inactivity and the reduction of open space where one can practice a sport. Although obesity is associated with multiple diseases, it is important to stress that the metabolic changes caused by it affect skin physiology and play a predisposing factor for the development of skin diseases. Very little has been studied on the impact of obesity on the skin. The purpose of this article is to review the most frequently skin diseases in obesity. Some skin pathologies in obesity are caused by changes in skin physiology, others are related to insulin resistance or constitute an exacerbating factor for dermatitis. This article covers the clinical features of obesity related skin disease and its management.

La obesidad, que se define como un estado patológico de exceso de tejido adiposo, se considera un problema de salud pública mundial. Esta enfermedad, que predomina en los países industrializados, es prevalente prácticamente en todas las naciones del mundo y es el resultado de los cambios en el estilo de vida, el consumo excesivo de alimentos con alto contenido energético y pobre valor nutricional, así como del sedentarismo y de la reducción de espacios al aire libre donde se puede practicar deporte. Aunque la obesidad se relaciona con múltiples enfermedades, es importante subrayar que los cambios metabólicos originados por la misma afectan la fisiología cutánea y juegan un factor predisponente para el desarrollo de algunas enfermedades dermatológicas. Hasta ahora ha sido poco analizado el impacto en la piel que genera la obesidad; el propósito de este artículo es revisar las patologías cutáneas más frecuentemente asociadas a la misma. Algunas de las patologías dermatológicas en la obesidad se producen por cambios en la fisiología cutánea generadas por la misma, otras se relacionan con la resistencia a la insulina, o bien, constituye un factor exacerbante de las dermatosis. En este artículo se incluyen las características clínicas, así como su relación con la obesidad y manejo.

A quantitative study of fungiform papillae and taste pore density in adults and children.

Male children (8-9 years) are reported to have a higher sensitivity than male adults to the sweet tastant sucrose when small regions of the anterior tongue are stimulated. The present study investigated the hypothesis that the higher sensitivity was due to a greater density of fungiform papillae and taste pores (buds), since it has been reported in adults that increased densities of these two structures correlates with increased taste suprathreshold sensitivity [Physiol. Behav. 47 (1990) 1213]. Quantitative measures of the number and size of papillae and pores in two areas of the tongue that had been shown to have a higher sensitivity for sucrose were achieved in 20 male children 8-9 years of age and 20 adults 18-30 years of age, using videomicroscopy and NIH Image software. Customized templates and a red food dye were used to define the equivalent tongue locations across the 40 subjects and taste pores were stained with methylene blue. Children were found to have substantially smaller papillae than adults but significantly higher papilla densities in both areas. Similar numbers of taste pores per papilla were found for both groups, resulting in children having much higher taste pore densities in each area than adults. Other differences included smaller taste pore diameters in children compared to adults, and the papillae tended to be rounder in children. Overall, the results support the hypothesis that the higher densities of fungiform papillae and taste pores in children underlie their greater sensitivity for sucrose in the two areas. In addition, the anatomical differences between adults and children indicate the sense of taste is in a state of development during mid-childhood.