Bioprospecting of endophytic fungi from semidesert candelilla (Euphorbia antisyphilitica Zucc): Potential for extracellular enzyme production.

Endophytic microbial communities colonize plants growing under various abiotic stress conditions. Candelilla (Euphorbia antisyphilitica Zucc.) is a shrub that develops functionally in arid and semi-arid zones of Mexico; these conditions generate an association between the plant and the microorganisms, contributing to the production of enzymes as a defense mechanism for resistance to abiotic stress. The objective of this research was to isolate and identify endophyte fungi of candelilla and bioprospection of these endophytic fungi for enzyme production using candelilla by-products. Fungi were isolated and identified using ITS1/ITS4 sequencing. Their potency index (PI) was evaluated in producing endoglucanase, xylanase, amylase, and laccase. Fermentation was carried out at 30°C for 8 days at 200 rpm, with measurements every 2 days, using candelilla by-products as substrate. All fungi exhibited higher cellulase, amylase, and laccase activities on the 2nd, 6th, and 8th day of fermentation, respectively, of fermentation. The fungus Aspergillus niger ITD-IN4.1 showed the highest amylase activity (246.84 U/mg), the genus Neurospora showed the highest cellulase activity, reaching up to 13.45 FPU/mg, and the strain Neurospora sp. ITD-IN5.2 showed the highest laccase activity (3.46 U/mg). This work provides the first report on the endophytic diversity of E. antisyphilitica and its potential role in enzyme production.

Utilization of Agave durangensis leaves by Bacillus cereus 4N for polyhydroxybutyrate (PHB) biosynthesis.

Lignocellulosic wastes may provide a means to economize polyhydroxybutyrate (PHB) production. This study has proposed the use of Agave durangensis leaves obtained from the artisanal mezcal industry as a novel substrate for this aim. Results revealed an increase in PHB biosynthesis (0.32 g/L) and improvement in %PHB (16.79-19.51%) by Bacillus cereus 4N when A. durangensis leaves used as carbon source were physically pre-treated by ultrasound for 30 min (ADL + US30') and thermally pre-treated (ADL + Q). Chemical analyses and SEM studies revealed compositional and morphological changes when A. durangensis leaves were physically pre-treated. Also, elemental analysis of growth media showed that carbon/nitrogen ratios of 14-21, and low nitrogen, hydrogen, and protein content were well-suited for PHB biosynthesis. Confocal microscopy revealed morphological changes in the bacterial cell and carbonosome structure under the influence of different substrates. Finally, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analyses showed that homopolymeric PHB with a high thermal-resistance (271.94-272.89 °C) was produced. Therefore, the present study demonstrates the potential use of physically pre-treated A. durangensis leaves to produce PHB. These results promote the development of a circular economy in Mexico, where lignocellulosic wastes can be employed to produce value-added biotechnological products.

Efficient recovery of thermostable polyhydroxybutyrate (PHB) by a rapid and solvent-free extraction protocol assisted by ultrasound.

Nowadays, there are great research interest in polyhydroxybutyrate (PHB) recovery protocols that reduce the use of organic solvents and efficiently recover this bacterial biopolymer. The present study reports an extraction protocol assisted by ultrasound, which is a rapid protocol that increases the amount of polymeric matter extracted, reduces the cellular digestion step with sodium hypochlorite and eliminates the use of organic solvents. Likewise, characterization studies by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) demonstrated that the biopolymer recovered by this protocol is PHB homopolymer with a major thermal-resistance and crystalline properties. Besides, in this study are reported the thermic and crystalline differences between the PHB obtained from the fermentation of complex carbohydrates (agavins) and simple sugars. The biopolymer obtained by this rapid extraction protocol would be suitable for ecological and biomedical applications, due to the low melting temperature, less than 50% crystallinity, and the lack of lipopolysaccharides. Therefore, this extraction protocol might represent an alternative to the traditional protocol based on NaOCl-chloroform and is part of the green trend to improve the PHB production.

Supporting Risk Assessment: Accounting for Indirect Risk to Ecosystem Components.

The multi-scalar complexity of social-ecological systems makes it challenging to quantify impacts from human activities on ecosystems, inspiring risk-based approaches to assessments of potential effects of human activities on valued ecosystem components. Risk assessments do not commonly include the risk from indirect effects as mediated via habitat and prey. In this case study from British Columbia, Canada, we illustrate how such "indirect risks" can be incorporated into risk assessments for seventeen ecosystem components. We ask whether (i) the addition of indirect risk changes the at-risk ranking of the seventeen ecosystem components and if (ii) risk scores correlate with trophic prey and habitat linkages in the food web. Even with conservative assumptions about the transfer of impacts or risks from prey species and habitats, the addition of indirect risks in the cumulative risk score changes the ranking of priorities for management. In particular, resident orca, Steller sea lion, and Pacific herring all increase in relative risk, more closely aligning these species with their "at-risk status" designations. Risk assessments are not a replacement for impact assessments, but-by considering the potential for indirect risks as we demonstrate here-they offer a crucial complementary perspective for the management of ecosystems and the organisms within.

¿Existe un aumento de los nacimientos en Chile en el período 2000-2009?: análisis de los principales indicadores materno-infantiles de la década / Trend in annual live birth in Chile between 2000 and 2009

Objetivo. Describir la tendencia en los nacimientos y los principales indicadores materno-infantiles en Chile desde el año 2000 al 2009. Método. Se realiza un análisis descriptivo de la información obtenida desde el Ministerio de Salud de Chile para el período estudiado. Resultados. Durante el período estudiado nacen aproximadamente 2.400.000 personas, se observa un significativo aumento en su número a partir del año 2004 al 2009 (+9,7 por ciento). Las tasas de mortalidad neonatal precoz, tardía, post neonatal e infantil fueron de 3,86; 1,18; 2,54 y 7,58 por 1000 nacidos vivos durante el año 2009, presentado un porcentaje de disminución de un 13,5; 8,4; 16,2; 13,7 por ciento respectivamente en comparación al año 2000. La mortalidad materna disminuyó en un 13,2 por ciento desde 19,7 a 17,1 por cien mil nacimientos en el mismo período. La prematurez (<37s) incrementa significativamente en un 20,82 por ciento (de 5,96 a 7,2 por ciento). El mayor cambio se observa entre las 32-33 y 34-36 semanas (aumento de un 18 por ciento y 32 por ciento, respectivamente). El porcentaje de nacimientos múltiples (dos) aumento significativamente en un 11 por ciento, desde 1,66 a 1,84 por cien nacimientos. Conclusión. Durante el período estudiado se observa un aumento significativo de los nacimientos totales, del porcentaje de primigestas y de madres sobre 40 años. Se presenta un aumento de la prematurez, del bajo peso al nacer y del porcentaje de embarazos múltiples. Los cambios observados se asocian aun a una mejoría de los indicadores neonatales.

Objective. To describe the trend in annual live birth in Chile between 2000 and 2009, as well as the main descriptive statistics and health indicators associated. Methods. We performed a descriptive analysis form the database provided by the Department of Statistics and Information of the Chilean Ministry of Health. Data of 2.400.000 deliveries were analyzed from 2000 and 2009. We analyzed live births, maternal, fetal, infant mortality, as well as main descriptive characteristics by year. Results. The total of live births in Chile has progressively increased after the year 2005 until 2009 (+ 9.7 percent). The early neonatal, late neonatal, post neonatal mortality and mortality infant were 3.86, 1.18, 2.54 and 7.58 per 1000 live births in 2009, showing a decrease of 13.5; 8.4; 16.2; 13.7 percent respectively compared to 2000. Maternal mortality declined a 13.2 percent from 19.7 to 17.1 x 100.000 births in the same period. Prematurity (<37weeks) increased significantly in a 20.82 percent (5.96 percent to 7.2 percent). The biggest change is observed at late preterm birth 32-33 and 34-36 weeks (increase of 18 percent and 32 percent respectively). The rate of multiple births (two) significantly increased also in a 11 percent, from 1.66 to 1.84 x 100.000 birth. Conclusion. During the study period, a significant increase of total births, the percentage of primipare and mothers over 40 years was observed. It's also shown an increase in prematurity, low birth weight and the percentage of multiple pregnancies. The observed changes are associated with improved neonatal indicators.

Gentamicina en dosis fraccionada y única diaria: comparación de eficacia, toxicidad y costo / Gentamicine in fractioned and single dose a day: comparisson of efficacy, toxicity and cost

En un estudio prospectivo se comparó eficacia, toxicidad renal, coclear y vestibular de gentamicina administrada en dosis fraccionada de 1,7 mg/kg peso cada 8 horas (DF) y dosis única de 3 mg/kg peso/día (DU). El sitio de la infección fue apendicular en 13 casos, urinario en 11, perianal en 9 y otros en 6 casos. En el 59 por ciento de los pacientes se aisló Escherichia coli y en el 23 por ciento otros gérmenes Gram negativos. Fueron tratados 21 pacientes con DF y 18 con DU. La evolución fue similar en relación al número de días con fiebre y compromiso del estado general de los pacientes. El recuento de glóbulos blancos, VHS y proteína C reactiva aumentaron al inicio del tratamiento, pero se normalizaron en ambos grupos al término del mismo. Se registraron 3 fracasos de tratamiento con DF y 1 con DU. La creatinina plasmática no se modificó al término del tratamiento (p = 0,79) y en un control a los 30 días post tratamiento (p = 0,79). El clearence de creatinina se redujo en ambos grupos, siendo esta reducción al término del tratamiento más severa en el grupo DU, pero sin alcanzar significación estadística (p = 0,62), con normalización a los 30 días. La evaluación del 8º par a través de pérdida de audición de frecuencia específica,pérdida media para frecuencias altas y pruebas calóricas no identificó daño post tratamiento en ambos grupos hasta 30 días de seguimiento. El costo diario de la DF fue de $ 1.552 y de la DU de $ 141. El consumo de tiempo de la administración de la DF fue nueve veces mayor. En conclusión, la modalidad de tratamiento con gentamicina en dosis única diaria resultó efectiva,segura, con menos fracasos de tratamiento, considerablemente más barata y de más rápida administración que la alternativa de dosis fraccionada, por lo que recomendamos el uso de gentamicina en dosis única diaria de 3 mg/kg/día

Detección de antígenos virales en lactantes con infección respiratoria aguda baja / Viral antigens in nasopharingeal exudates from infants with acute lower respiratory tract infections

Con el propósito de medir la frecuencia con que se aíslan determinados antígenos virales, en niños con infecciones respiratorias agudas bajas graves (IRAB), se realizaron ensayos de inmunofluorescencia (IF) para antígenos de virus sincicial respiratorio (VSR), adenovirus (ADV), virus parainfluenza 1, 2 y 3 (VPI), virus influenza a y b (VIa y VIb) en las secreciones nasofaríngeas de 660 niños menores de 24 meses que cumplían con criterios clínicos y radiológicos de IRAB grave comúnmente aceptados. En 322 casos (48,8%) se obtubvieron resultados positivos. Los antígenos más frecuentemente identificados fueron los de VSR (56,2%) y ADV (26,7%). La letalidad en niños con IRAB e IF positiva fue 9,9% y 6,2% en aquellos con IF negativa (p NS). En 24 de 32 (75%) pacientes fallecidos con IF positivas, el antígeno identificado correspondía a ADV, siendo el riesgo de morir en estos casos significativamente mayor que en el de pacientes portadores de otros antígenos o ninguno (Z crítico -1,65. Z calculado -1,178). La apnea fue la principal manifestación clínica en 46 pacientes, todos menores de 3 meses y 19 con reacciones de inmunofluorescencia positivas que, con una sola excepción, correspondían a antígenos de VSR