Marine degradation and ecotoxicity of conventional, recycled and compostable plastic bags.

Plastic bags are currently a major component of marine litter, causing aesthetical nuisance, and undesirable effects on marine fauna that ingest them or are entangled. Plastic litter also rises concern on the ecotoxicological effects due to the potential toxicity of the chemical additives leached in aquatic environments. Conventional plastic bags are made of polyethylene, either from first use or recycled, but regulations restricting single-use plastics and limiting lightweight carrier bags (<50 µm thickness) have fostered the replacement of thin PE bags by compostable materials advertised as safer for the environment. In this study, we assess the degradation of commercially available plastic bags in marine conditions at two scales: aquariums (60 days) and outdoors flow-through mesocosm (120 days). Strength at break point and other tensile strength parameters were used as ecologically relevant endpoints to track mechanical degradation. Ecotoxicity has been assessed along the incubation period using the sensitive Paracentrotus lividus embryo test. Whereas PE bags did not substantially lose their mechanical properties within the 60 d aquarium exposures, compostable bags showed remarkable weight loss and tensile strength decay, some of them fragmenting in the aquarium after 3-4 weeks. Sediment pore water inoculum promoted a more rapid degradation of compostable bags, while nutrient addition pattern did not affect the degradation rate. Longer-term mesocosms exposures supported these findings, as well as pointed out the influence of the microbial processes on the degradation efficiency of compostable/bioplastic bags. Compostable materials, in contrast toPE, showed moderate toxicity on sea-urchin larvae, partially associated to degradation of these materials, but the environmental implications of these findings remain to be assessed. These methods proved to be useful to classify plastic materials, according to their degradability in marine conditions, in a remarkably shorter time than current standard tests and promote new materials safer for the marine fauna.

Improving the 3D Printability and Mechanical Performance of Biorenewable Soybean Oil-Based Photocurable Resins.

The general requirement of replacing petroleum-derived plastics with renewable resources is particularly challenging for new technologies such as the additive manufacturing of photocurable resins. In this work, the influence of mono- and bifunctional reactive diluents on the printability and performance of resins based on acrylated epoxidized soybean oil (AESO) was explored. Polyethylene glycol di(meth)acrylates of different molecular weights were selected as diluents based on the viscosity and mechanical properties of their binary mixtures with AESO. Ternary mixtures containing 60% AESO, polyethylene glycol diacrylate (PEGDA) and polyethyleneglycol dimethacrylate (PEG200DMA) further improved the mechanical properties, water resistance and printability of the resin. Specifically, the terpolymer AESO/PEG575/PEG200DMA 60/20/20 (wt.%) improved the modulus (16% increase), tensile strength (63% increase) and %deformation at the break (21% increase), with respect to pure AESO. The enhancement of the printability provided by the reactive diluents was proven by Jacobs working curves and the improved accuracy of printed patterns. The proposed formulation, with a biorenewable carbon content of 67%, can be used as the matrix of innovative resins with unrestricted applicability in the electronics and biomedical fields. However, much effort must be done to increase the array of bio-based raw materials.

Enhancement of 3D Printability by FDM and Electrical Conductivity of PLA/MWCNT Filaments Using Lignin as Bio-Dispersant.

To increase the applications of FDM (fusion deposition modeling) 3D printing in electronics, it is necessary to develop new filaments with good electrical properties and suitable processability. In this work, polymer composites filament-shaped with superior electrical performance based on polylactic acid (PLA) carbon nanotubes and lignin blends have been studied by combining solution mixing and melt blending. The results showed that composites achieve electrical percolation from 5 wt.% of nanotubes, with high electrical conductivity. Moreover, the introduction of a plasticizing additive, lignin, improved the printability of the material while increasing its electrical conductivity (from (1.5 ± 0.9)·10-7 S·cm-1 to (1.4 ± 0.9)·10-1 S cm-1 with 5 wt.% carbon nanotubes and 1 wt.% lignin) maintaining the mechanical properties of composite without additive. To validate lignin performance, its effect on PLA/MWCNT was compare with polyethylene glycol. PEG is a well-known commercial additive, and its use as dispersant and plasticizer in PLA/MWCNT composites has been proven in bibliography. PLA/MWCNT composites display easier processability by 3D printing and more adhesion between the printed layers with lignin than with PEG. In addition, the polyethylene glycol produces a plasticizing effect in the PLA matrix reducing the composite stiffness. Finally, an interactive electronic prototype was 3D printed to assess the printability of the new conducting filaments with 5 wt.% of MWCNT.

Lignin as a High-Value Bioaditive in 3D-DLP Printable Acrylic Resins and Polyaniline Conductive Composite.

With increasing environmental awareness, lignin will play a key role in the transition from the traditional materials industry towards sustainability and Industry 4.0, boosting the development of functional eco-friendly composites for future electronic devices. In this work, a detailed study of the effect of unmodified lignin on 3D printed light-curable acrylic composites was performed up to 4 wt.%. Lignin ratios below 3 wt.% could be easily and reproducibly printed on a digital light processing (DLP) printer, maintaining the flexibility and thermal stability of the pristine resin. These low lignin contents lead to 3D printed composites with smoother surfaces, improved hardness (Shore A increase ~5%), and higher wettability (contact angles decrease ~19.5%). Finally, 1 wt.% lignin was added into 3D printed acrylic resins containing 5 wt.% p-toluensulfonic doped polyaniline (pTSA-PANI). The lignin/pTSA-PANI/acrylic composite showed a clear improvement in the dispersion of the conductive filler, reducing the average surface roughness (Ra) by 61% and increasing the electrical conductivity by an order of magnitude (up to 10-6 S cm-1) compared to lignin free PANI composites. Thus, incorporating organosolv lignin from wood industry wastes as raw material into 3D printed photocurable resins represents a simple, low-cost potential application for the design of novel high-valued, bio-based products.

Sensibilidad a azitromicina en Salmonella no tifoidea: opción terapéutica / Susceptibility to azithromycin in non-typhoid Salmonella: A therapeutic option

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Printability Study of a Conductive Polyaniline/Acrylic Formulation for 3D Printing.

There is need for developing novel conductive polymers for Digital Light Processing (DLP) 3D printing. In this work, photorheology, in combination with Jacobs working curves, efficaciously predict the printability of polyaniline (PANI)/acrylate formulations with different contents of PANI and photoinitiator. The adjustment of the layer thickness according to cure depth values (Cd) allows printing of most formulations, except those with the highest gel point times determined by photorheology. In the working conditions, the maximum amount of PANI embedded within the resin was ≃3 wt% with a conductivity of 10-5 S cm-1, three orders of magnitude higher than the pure resin. Higher PANI loadings hinder printing quality without improving electrical conductivity. The optimal photoinitiator concentration was found between 6 and 7 wt%. The mechanical properties of the acrylic matrix are maintained in the composites, confirming the viability of these simple, low-cost, conductive composites for applications in flexible electronic devices.

Vigilancia activa de cepas de Salmonella entericano tifoidea con fenotipo no clásico de resistencia a quinolonas (2014-2019) / Active surveillance of nontyphoidal Salmonella enterica strains with nonclassical quinolone resistance phenotype (2014-2019)

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Infecciones invasoras por Streptococcus pyogenes (2011-2018): serotipos y presentación clínica / Invasive Streptococcus pyogenes infections (2011-2018): EMM-type and clinical presentation

INTRODUCCIÓN: Streptococcus pyogenes (S. pyogenes) es un importante patógeno humano responsable de una gran diversidad de infecciones, algunas de las cuales presentan un carácter severo con elevada morbimortalidad asociada. La proteína M es un determinante de virulencia crítico de este microorganismo. Diferentes estudios comunican un incremento de enfermedad invasora por S. pyogenes (EISP) relacionado con un aumento de serotipos M1 y M3, de reconocida virulencia. El objetivo del trabajo es confirmar el incremento observado de las enfermedades invasoras por S. pyogenes durante 2011-2018, y conocer qué serotipos pudieran estar implicados. MATERIAL Y MÉTODOS: La identificación de los aislados se realizó mediante pruebas fenotípicas convencionales: morfología de las colonias, β-hemólisis, pruebas bioquímicas y detección de antígeno A de Lancefield (DiaMondiaL Strep Kit, DiaMondiaL, Langenhagen, Alemania). La sensibilidad antibiótica se determinó mediante microdilución (Vitek®2 Compact, bioMeriéux, Inc., Durham, NC). La caracterización genotípica incluyó el gen emm y el perfil de superantígenos. RESULTADOS: Entre 2011-2018 se recuperaron 29 S. pyogenes invasores de sangre (16), líquido pleural (9), líquido sinovial (3) y líquido cefalorraquídeo (1). Entre 2011 y 2013, se cuantificó una cepa por año. Entre 2014 y 2018 se aislaron 2, 5, 4, 6 y 9 cepas, respectivamente. Las entidades clínicas más frecuentes fueron bacteriemia y neumonía (10 y 9 casos). Los serotipos mayoritarios fueron M1 (11) y M3 (3), asociados predominantemente a neumonía (6/7 casos) e infección profunda de partes blandas (3/3 casos). CONCLUSIONES: Se constata un incremento de las enfermedad invasora por S. pyogenes en el periodo estudiado resultando mayoritarios, conforme a la bibliografía, los serotipos M1 y M3, los cuales se asocian con neumonía e infección profunda de partes blandas

INTRODUCTION: Streptococcus pyogenes (S. pyogenes) is an important human pathogen that is responsible for a broad range of infections, from uncomplicated to more severe and invasive diseases with high morbidity/mortality. The M protein (emm type) is a critical virulence factor. Several studies have shown an increased incidence of invasive S. pyogenes disease. This was associated with an increase in the prevalence of M1 and M3 types, well-recognised virulent M types. The aim of the present study was to confirm the resurgence of invasive S. pyogenes disease during 2011-2018 and to identify the relationship between specific M types with disease presentation. MATERIAL AND METHODS: Isolates were confirmed using standard techniques: colony morphology, β-haemolysis, biochemical tests, and agglutination with specific antisera (DiaMondiaL Strep Kit, DiaMondiaL, Langenhagen, Germany). The antibiotic sensitivity was performed using microdilution (Vitek®2 Compact, bioMeriéux, Inc., Durham, NC). Molecular analysis included the determination of the emm gene and superantigen profile. RESULTS: A total of 29 invasive isolates were collected (2011-2018) from blood (16), pleural fluid (9), synovial fluid (3), and cerebrospinal fluid (1). One strain per year was isolated between 2011 and 2013, with 2, 5, 4, 6, and 9 strains being isolated between 2014 and 2018, respectively. The most frequent clinical presentations were bacteraemia and pneumonia (10 and 9 cases). The predominant types were M1 (11 isolates) and M3 (3 isolates). A correlation was found between M1 and M3 types, and pneumonia (6/7 cases) and deep soft tissue infections (3/3 cases). CONCLUSIONS: An increased incidence of invasive S. pyogenes disease was observed during the study period, with M1 and M3 types being those most commonly isolated and associated with pneumonia and deep soft tissue infections

[Invasive Streptococcus pyogenes infections (2011-2018): EMM-type and clinical presentation]. / Infecciones invasoras por Streptococcus pyogenes (2011-2018): serotipos y presentación clínica.

INTRODUCTION: Streptococcus pyogenes (S. pyogenes) is an important human pathogen that is responsible for a broad range of infections, from uncomplicated to more severe and invasive diseases with high morbidity/mortality. The M protein (emm type) is a critical virulence factor. Several studies have shown an increased incidence of invasive S. pyogenes disease. This was associated with an increase in the prevalence of M1 and M3 types, well-recognised virulent M types. The aim of the present study was to confirm the resurgence of invasive S. pyogenes disease during 2011-2018 and to identify the relationship between specific M types with disease presentation. MATERIAL AND METHODS: Isolates were confirmed using standard techniques: colony morphology, ß-haemolysis, biochemical tests, and agglutination with specific antisera (DiaMondiaL Strep Kit, DiaMondiaL, Langenhagen, Germany). The antibiotic sensitivity was performed using microdilution (Vitek®2 Compact, bioMeriéux, Inc., Durham, NC). Molecular analysis included the determination of the emm gene and superantigen profile. RESULTS: A total of 29 invasive isolates were collected (2011-2018) from blood (16), pleural fluid (9), synovial fluid (3), and cerebrospinal fluid (1). One strain per year was isolated between 2011 and 2013, with 2, 5, 4, 6, and 9 strains being isolated between 2014 and 2018, respectively. The most frequent clinical presentations were bacteraemia and pneumonia (10 and 9 cases). The predominant types were M1 (11 isolates) and M3 (3 isolates). A correlation was found between M1 and M3 types, and pneumonia (6/7 cases) and deep soft tissue infections (3/3 cases). CONCLUSIONS: An increased incidence of invasive S. pyogenes disease was observed during the study period, with M1 and M3 types being those most commonly isolated and associated with pneumonia and deep soft tissue infections.

Vigilancia de multirresistentes: Enterococcus spp. resistente a vancomicina / Surveillance of multiresistance: vancomycin-resistant Enterococcus spp

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Molecular epidemiology of an enterovirus A71 outbreak associated with severe neurological disease, Spain, 2016.

IntroductionEnterovirus A71 (EV-A71) is an emerging pathogen that causes a wide range of disorders including severe neurological manifestations. In the past 20 years, this virus has been associated with large outbreaks of hand, foot and mouth disease with neurological complications in the Asia-Pacific region, while in Europe mainly sporadic cases have been reported. In spring 2016, however, an EV-A71 outbreak associated with severe neurological cases was reported in Catalonia and spread further to other Spanish regions.AimOur objective was to investigate the epidemiology and clinical characteristics of the outbreak.MethodsWe carried out a retrospective study which included 233 EV-A71-positive samples collected during 2016 from hospitalised patients. We analysed the clinical manifestations associated with EV-A71 infections and performed phylogenetic analyses of the 3'-VP1 and 3Dpol regions from all Spanish strains and a set of EV-A71 from other countries.ResultsMost EV-A71 infections were reported in children (mean age: 2.6 years) and the highest incidence was between May and July 2016 (83%). Most isolates (218/233) were classified as subgenogroup C1 and 217 of them were grouped in one cluster phylogenetically related to a new recombinant variant strain associated with severe neurological diseases in Germany and France in 2015 and 2016. Moreover, we found a clear association of EV-A71-C1 infection with severe neurological disorders, brainstem encephalitis being the most commonly reported.ConclusionAn emerging recombinant variant of EV-A71-C1 was responsible for the large outbreak in 2016 in Spain that was associated with many severe neurological cases.

Condensación pulmonar versus absceso esplénico por Salmonella / Pulmonary consolidation versus splenic abscess due toSalmonella enterica

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Chitosan and Kappa-Carrageenan Vaginal Acyclovir Formulations for Prevention of Genital Herpes. In Vitro and Ex Vivo Evaluation.

Vaginal formulations for the prevention of sexually transmitted infections are currently gaining importance in drug development. Polysaccharides, such as chitosan and carrageenan, which have good binding capacity with mucosal tissues, are now included in vaginal delivery systems. Marine polymer-based vaginal mucoadhesive solid formulations have been developed for the controlled release of acyclovir, which may prevent the sexual transmission of the herpes simplex virus. Drug release studies were carried out in two media: simulated vaginal fluid and simulated vaginal fluid/simulated seminal fluid mixture. The bioadhesive capacity and permanence time of the bioadhesion, the prepared compacts, and compacted granules were determined ex vivo using bovine vaginal mucosa as substrate. Swelling processes were quantified to confirm the release data. Biocompatibility was evaluated through in vitro cellular toxicity assays, and the results showed that acyclovir and the rest of the materials had no cytotoxicity at the maximum concentration tested. The mixture of hydroxyl-propyl-methyl-cellulose with chitosan- or kappa-carrageenan-originated mucoadhesive systems that presented a complete and sustained release of acyclovir for a period of 8-9 days in both media. Swelling data revealed the formation of optimal mixed chitosan/hydroxyl-propyl-methyl-cellulose gels which could be appropriated for the prevention of sexual transmission of HSV.

[New methodological advances: algorithm proposal for management of Clostridium difficile infection]. / Nuevos avances metodológicos: propuesta de algoritmo para el manejo de la infección por Clostridium difficile.

INTRODUCTION: Clostridium difficile infection (CDI) is considered the most common cause of health care-associated diarrhea and also is an etiologic agent of community diarrhea. The aim of this study was to assess the potential benefit of a test that detects glutamate dehydrogenase (GDH) antigen and C. difficile toxin A/B, simultaneously, followed by detection of C. difficile toxin B (tcdB) gene by PCR as confirmatory assay on discrepant samples, and to propose an algorithm more efficient. MATERIAL AND METHODS: From June 2012 to January 2013 at Hospital Infantil Universitario Niño Jesús, Madrid, the stool samples were studied for the simultaneous detection of GDH and toxin A/B, and also for detection of toxin A/B alone. When results between GDH and toxin A/B were discordant, a single sample for patient was selected for detection of C. difficile toxin B (tcdB) gene. RESULTS: A total of 116 samples (52 patients) were tested. Four were positive and 75 negative for toxigenic C. difficile (Toxin A/B, alone or combined with GDH). C. difficile was detected in the remaining 37 samples but not toxin A/B, regardless of the method used, except one. Twenty of the 37 specimens were further tested for C. difficile toxin B (tcdB) gene and 7 were positive. DISCUSSION: The simultaneous detection of GDH and toxin A/B combined with PCR recovered undiagnosed cases of CDI. In accordance with our data, we propose a two-step algorithm: detection of GDH and PCR (in samples GDH positive). This algorithm could provide a superior cost-benefit ratio in our population.

Nuevos avances metodológicos: propuesta de algoritmo para el manejo de la infección por Clostridium difficile / New methodological advances: algorithm proposal for management of Clostridium difficile infection

Introducción. La infección por Clostridium difficile (ICD) es la causa más frecuente de diarrea asociada a los cuidados sanitarios y también se reconoce un papel etiológico en la diarrea de adquisición comunitaria. El objetivo de este trabajo fue evaluar si la detección simultánea de GDH y toxinas A/B de C. difficile, seguida de PCR como test confirmatorio supuso una mejora frente a la detección única de toxinas A/B, y plantear un algoritmo más eficiente. Material y métodos. Entre Junio 2012 y Enero 2013, en el Hospital Infantil Universitario Niño Jesús, Madrid, se estudiaron muestras de heces para la detección simultánea de GDH y toxinas A/B, y también para la detección única de toxinas A/B. Cuando los resultados entre GDH y toxinas A/B fueron discordantes, se seleccionó una única muestra por paciente para la detección de toxina B (tcdB) de C. difficile por PCR. Resultados. Se estudiaron 116 muestras de 52 pacientes. Por ambos tests, 4 muestras fueron positivas y 75 negativas para la detección de C. difficile toxigénico. En las 37 muestras restantes se detectó C. difficile pero no producción de toxinas independientemente del método utilizado, salvo en un caso. De estas muestras se seleccionaron 20 para detección de toxina B (tcdB) por PCR, siendo 7 positivas. Discusión. La detección simultánea de GDH y toxinas A/B seguida de PCR supuso la recuperación de casos de ICD. La detección de GDH y PCR (en muestras GDH positivas) es la combinación que ofrecería una superior relación coste/efectividad en la población atendida (AU)

Introduction. Clostridium difficile infection (CDI) is considered the most common cause of health care-associated diarrhea and also is an etiologic agent of community diarrhea. The aim of this study was to assess the potential benefit of a test that detects glutamate dehydrogenase (GDH) antigen and C. difficile toxin A/B, simultaneously, followed by detection of C. difficile toxin B (tcdB) gene by PCR as confirmatory assay on discrepant samples, and to propose an algorithm more efficient. Material and Methods. From June 2012 to January 2013 at Hospital Infantil Universitario Niño Jesús, Madrid, the stool samples were studied for the simultaneous detection of GDH and toxin A/B, and also for detection of toxin A/B alone. When results between GDH and toxin A/B were discordant, a single sample for patient was selected for detection of C. difficile toxin B (tcdB) gene. Results. A total of 116 samples (52 patients) were tested. Four were positive and 75 negative for toxigenic C. difficile (Toxin A/B, alone or combined with GDH). C. difficile was detected in the remaining 37 samples but not toxin A/B, regardless of the method used, except one. Twenty of the 37 specimens were further tested for C. difficile toxin B (tcdB) gene and 7 were positive. Discussion. The simultaneous detection of GDH and toxin A/B combined with PCR recovered undiagnosed cases of CDI. In accordance with our data, we propose a two-step algorithm: detection of GDH and PCR (in samples GDH positive). This algorithm could provide a superior cost-benefit ratio in our population (AU)

Bacteriemia por anaerobios en pacientes pediátricos / Anaerobic bacteraemia in paediatric patients

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