Resistencia a nitrofuranos mediada por mutaciones en los genes cnr y snrA en Salmonella enterica procedentes de muestras cárnicas para consumo humano

En el presente estudio, se analizaron los mecanismos de resistencia a nitrofuranos en 18 muestras cárnicas con Salmonella enterica (15 de pollo, 2 de ternera y 1 de cerdo) de mercados de Lima (Perú). Determinaron los serotipos de los aislamientos y la sensibilidad a furazolidona y nitrofurantoina (con y sin el inhibidor de bombas de expulsión Phenyl-Arginine-β-Naphthylamide [PAβN]), las mutaciones en los genes snrA y cnr por PCR y la transferabilidad de la resistencia por conjugación. Se identificaron 15 muestras con S. infantis (13 muestras de pollo), 2 con S. enteritidis y 1 con S. anatum. Todos los aislamientos, excepto S. anatum, fueron resistentes a ambos nitrofuranos (concentración mínima inhibidora [CMI] a furazolidona: 32-64 μg/mL, CMI a nitrofurantoina: 128-256 μg/mL), sin diferencias al adicionarse PAβN. Todos los aislamientos resistentes a nitrofuranos presentaron sustituciones en snrA y cnr (S. infantis: snrA STOP-151; cnr STOP-137; S. enteritidis: snrA STOP-180; cnr STOP-179). No se detectaron mecanismos transferibles de resistencia a nitrofuranos

Evaluation of pathogen disinfection efficiency of electrochemical advanced oxidation to become a sustainable technology for water reuse

Water treatment and reuse is gaining acceptance as a strategy to fight against water contamination and scarcity, but it usually requires complex treatments to ensure safety. Consequently, the electrochemical advanced processes have emerged as an effective alternative for water remediation. The main objective here is to perform a systematic study that quantifies the efficiency of a laboratory-scale electrochemical system to inactivate bacteria, bacterial spores, protozoa, bacteriophages and viruses in synthetic water, as well as in urban wastewater once treated in a wetland for reuse in irrigation. A Ti|RuO2-based plate and Si|BDD thin-film were comparatively employed as the anode, which was combined with a stainless-steel cathode in an undivided cell operating at 12 V. Despite the low resulting current density (<15 mA/cm2), both anodes demonstrated the production of oxidants in wetland effluent water. The disinfection efficiency was high for the bacteriophage MS2 (T99 in less than 7.1 min) and bacteria (T99 in about 30 min as maximum), but limited for CBV5 and TuV, spores and amoebas (T99 in more than 300 min). MS2 presented a rapid exponential inactivation regardless of the anode and bacteria showed similar sigmoidal curves, whereas human viruses, spores and amoebas resulted in linear profiles. Due the different sensitivity of microorganisms, different models must be considered to predict their inactivation kinetics. On this basis, it can be concluded that evaluating the viral inactivation from inactivation profiles determined for bacteria or some bacteriophages may be misleading. Therefore, neither bacteria nor bacteriophages are suitable models for the disinfection of water containing enteric viruses. The electrochemical treatment added as a final disinfection step enhances the inactivation of microorganisms, which could contribute to safe water reuse for irrigation. Considering the calculated low energy consumption, decentralized water treatment units powered by photovoltaic modules might be a near reality

Contextualizando la cerámica impressa : horizontes culturales en la Península Ibérica

Organizado por: GRAMPO: Grup de Recerques Arqueològiques al Mediterrani i Pròxim Orient. Universitat Autònoma de Barcelona PREMEDOC: Grup de Recerca de Prehistòria del Mediterràni Occidental. Universitat de València Servei d'Arqueologia. Ajuntament de Barcelona. Con la colaboración de: Museu d'Història de Barcelona. Ajuntament de BarcelonaDesde hace poco tiempo en el estudio sobre los orígenes de las primeras sociedades agrícolas en el Mediterráneo Occidental se ha generado un amplio debate en torno a la filiación y características culturales de los primeros grupos que practican una economía de subsistencia. En este contexto encuentra sentido la discusión sobre la presencia en la península Ibérica un momento relacionable con la denominada Impressa-Ligur presente en diferentes regiones del arco Ligur Provenzal. Este volumen, fruto de una reunión científica, reúne información actualizada sobre la posible presencia de estos contextos cerámicos en torno a la mitad del VI milenio cal en la península Ibérica dentro del marco más amplio del Mediterráneo occidental. Las primeras producciones cerámicas del Occidente son analizadas poniendo énfasis tanto en sus características como sobre todo en el contexto y la lectura histórica que aportan. Estructuradas por áreas geográficas, las 14 contribuciones realizadas por 38 investigadores nacionales e internacionales, ofrecen una visión inédita y original sobre una de las novedades más importantes de la investigación en Prehistoria reciente en el último decenio

Macrolide resistance mechanisms in Enterobacteriaceae

From its introduction in 1952 onwards, the clinical use of macrolides has been steadily increasing, both in human and veterinary medicine. Although initially designed to the treatment of Grampositive microorganisms, this antimicrobial family has also been used to treat specific Gram-negative bacteria. Some of them, as azithromycin, are considered in the armamentarium against Enterobacteriaceae infections. However, the facility that this bacterial genus has to gain or develop mechanisms of antibiotic resistance may compromise the future usefulness of these antibiotics to fight against Enterobacteriaceae infections. The present review is focused on the mechanisms of macrolide resistance, currently described in Enterobacteriaceae.CG has a PhD fellowship of the ISCIII [grant number: FI12/ 00561]. GH has a PhD fellowship from the Schlumberger Foundation – Faculty for The Future Program. LR-R has a PhD fellowship from Sistema Riojano de Innovaci on del Gobierno de La Rioja. MJP has a postdoctoral fellowship from CONCYTEC [grant number: CG05-2013-FONDECYT]. JR has a fellowship from the program I3, of the ISCIII [grant number: CES11/012]. The study was supported by the Generalitat de Catalunya, Departament d’Universitats, Recerca i Societat de la Informaci o [2014 SGR 26] and by the Spanish Network for the Research in Infectious Diseases [REIPI RD12/0015].Revisión por pare

Sheep herd management during the Early Neolithic in the inland of the Iberian Peninsula. Isotopic analyses of El Mirador cave (Sierra de Atapuerca, Spain)

The beginning of husbandry in the Iberian Peninsula has been documented from the second half of the 6th millennium BCE and was based on the breeding of domestic caprines, mainly sheep. The first evidence of these practices comes from the Mediterranean region, but they quickly expanded inland. Previous studies have reported on the importance of the El Mirador sheepfold cave (Sierra de Atapuerca, Burgos, Spain) for understanding the process of the adoption of a farming economy in this inland region. In this study, we focus on husbandry and sheep management occurring in the 6th and 5th millennium cal BCE occupations of El Mirador cave by means of sequential oxygen (δ18O) and carbon (δ13C) isotope analyses in sheep molar tooth enamel. The results show a rapid adaptation and adoption of domestic sheep in the inland of the Iberian Peninsula. In El Mirador cave, well-organised sheep breeding was developed based on the concentration of births at the end of winter and early spring, for a period of ~2.64 months, which made husbandry more compatible with other economic activities. In 5th millennium levels, autumn births were also documented and may be indicative of the intervention of the shepherd in the reproductive cycle of the sheep and of a progressive adaptation of these animals to the interior of the Peninsula. All these strategies may have been supported by the recurrent occupations of the sheepfold, flocks grazing in the areas surrounding the cave and the possible use of leaf fodder in winter