Abstract Although infections with NonTuberculous Mycobacteria have become less common in AIDS patients, they are important opportunistic infections after surgical procedures, likely because they are ubiquitous and not efficiently killed by many commonly used disinfectants. In Venezuela there have recently been many non-tuberculous mycobacteria soft tissue infections after minor surgical procedures, some apparently related to the use of a commercial disinfectant based on a Quaternary Ammonium Compound. We studied the activity of this and other quaternary ammonium compounds on different non-tuberculous mycobacteria by transforming the mycobacteria with a dnaA-gfp fusion and then monitoring fluorescence to gauge the capacity of different quaternary ammonium compounds to inhibit bacterial growth. The minimum inhibitory concentration varied for the different quaternary ammonium compounds, but M. chelonae and M. abscessus were consistently more resistant than M. smegmatis, and M. terrae more resistant than M. bovis BCG.

Abstract Fibers were obtained in order to make use of the agave leaves (A. salmiana) once the heart of the plant was removed. The leaves were treated with acid hydrolysis (HCl) and alkaline hydrolysis (NaOH), using a pressure of 1.1 kg/ cm2 (acid-alkali TAF with pressure). The percentage of cellulose and lignin was determined, as well as the physicochemical changes through Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), Infrared Spectroscopy (IR) and Environmental Scanning Electron Microscopy (ESEM). The highest cellulose content (79.95%) was obtained from the acid-alkali TAF treatment without pressure, presenting a higher crystallinity as well (50.07). The microstructure showed that the acid-alkali TAF treatment with pressure presented more empty spaces, this due to the degradation of the fibers which is associated with cellulose loss. Both treatments affected the structure and composition of the agave fibers.

Resumen Para aprovechar las pencas de agaves (A. salmiana) una vez que se retiran de la piña de la planta, se obtuvieron fibras. Las hojas fueron tratadas con hidrólisis ácida (HCl) e hidrólisis alcalina (NaOH), usando presión de 1.1 kg/cm2 (FACT ácido- álcali con presión), a 121 °C por 4 h y otro tratamiento a presión atmosférica con reflujo (FACT ácido-álcali sin presión). Se determinó el porcentaje de celulosa y lignina, así como los cambios fisicoquímicos por medio de calorimetría diferencial de barrido (DSC), termogravimetría (TG), Difracción de rayos X (DRX), Espectroscopia infrarroja (IR) y Microscopia electrónica de barrido ambiental (MEB). El mayor contenido de celulosa (79.95%) se obtuvo para el tratamiento FACT ácido-álcali sin presión, presentando también una mayor cristalinidad (50.07). La microestructura mostró que el tratamiento FACT ácido-álcali con presión mostró más espacios vacíos, esto debido a la degradación de las fibras, lo cual se asocia a una pérdida de celulosa. Ambos tratamientos afectaron la estructura y composición de las fibras de agave.