Quinolone Resistance: Much More than Predicted

Since quinolones are synthetic antibiotics, it was predicted that mutations in target genes would be the only mechanism through which resistance could be acquired, because there will not be quinolone-resistance genes in nature. Contrary to this prediction, a variety of elements ranging from efflux pumps, target-protecting proteins, and even quinolone-modifying enzymes have been shown to contribute to quinolone resistance. The finding of some of these elements in plasmids indicates that quinolone resistance can be transferable. As a result, there has been a developing interest on the reservoirs for quinolone-resistance genes and on the potential risks associated with the use of these antibiotics in non-clinical environments. As a matter of fact, plasmid-encoded, quinolone-resistance qnr genes originated in the chromosome of aquatic bacteria. Thus the use of quinolones in fish-farming might constitute a risk for the emergence of resistance. Failure to predict the development of quinolone resistance reinforces the need of taking into consideration the wide plasticity of biological systems for future predictions. This plasticity allows pathogens to deal with toxic compounds, including those with a synthetic origin as quinolones

Predictive analysis of transmissible quinolone resistance indicates Stenotrophomonas maltophilia as a potential source of a novel family of Qnr determinants

Additional files: Microsoft excel document containing the descriptions of the genes shown in Figure 2.Background Predicting antibiotic resistance before it emerges at clinical settings constitutes a novel approach for preventing and fighting resistance of bacterial pathogens. To analyse the possibility that novel plasmid-encoded quinolone resistance determinants (Qnr) can emerge and disseminate among bacterial pathogens, we searched the presence of those elements in nearly 1000 bacterial genomes and metagenomes. Results We have found a number of novel potential qnr genes in the chromosomes of aquatic bacteria and in metagenomes from marine organisms. Functional studies of the Stenotrophomonas maltophilia Smqnr gene show that plasmid-encoded SmQnr confers quinolone resistance upon its expression in a heterologous host. Conclusion Altogether, the data presented in our work support the notion that predictive studies on antibiotic resistance are feasible, using currently available information on bacterial genomes and with the aid of bioinformatic and functional tools. Our results confirm that aquatic bacteria can be the origin of plasmid-encoded Qnr, and highlight the potential role of S. maltophilia as a source of novel Qnr determinants.This work has been supported by grants BIO2005-04278, LSHM-CT-2005-518152 and LSHM-CT-2005-018705. L. M-M and J.M. R.-M. are supported by REIPI, RD06/0008 from ISCIII, Ministerio de Sanidad y Consumo, Spain.Peer reviewe

Efecto del estimulo sexual del reproductor sobre el porcentaje de natalidad de vacas blanco orejinegro en lactación

Ganado de leche-Ganadería lech

Disputas del territorio rural: la Cholula prehispánica frente a la expansión de la Puebla colonial

This essay exposes the territorial recomposition that suburbanmunicipalities in the Cholula region, in the state of Puebla,México, have suffered as a result of their connection withthe state’s capital. We start from the conceptualization ofthe Cholula territory, conceiving it as a space that has beenconstituted historically. Social relations and domination patternsprevalent in successive historical stages of its development areexamined, which finally derived in the current conformation ofthe territory.En este ensayo se expone la recomposición territorial que hansufrido los municipios conurbados de la región de Cholula, enel estado de Puebla, México, como resultado de su vinculacióncon la capital del estado. Se parte de la conceptualización delterritorio cholulteca, concibiéndolo como un espacio históricamenteconstituido. Se examinan relaciones sociales y patrones dedominación imperantes en las sucesivas etapas históricas de sudesarrollo, que finalmente derivaron en la conformación actualdel territorio

ESTRATEGIAS ECONÓMICO-PRODUCTIVAS EN COMUNIDADES RURALES TRANSNACIONALES: EL CASO DE SAN MATEO OZOLCO, PUEBLA

Se caracterizan las estrategias de reproducción de los grupos domésticos de San Mateo Ozolco, comunidad rural con antecedentes indígenas, la cual registra una alta incidencia migratoria desde hace ya varias décadas. Para ello se llevaron a cabo visitas de campo, entrevistas a profundidad, entrevistas grupales y talleres; así como la aplicación de un cuestionario aplicado a una muestra de 49 familias. El trabajo enfatiza los aspectos de orden productivo, social y cultural, vinculados a las prácticas migratorias de los pobladores de esta comunidad. Se constata que el fenómeno migratorio no sólo se ha intensificado y extendido con rapidez en San Mateo Ozolco, sino que además ha propiciado cambios en las formas de organización y en las estrategias de reproducción que emprenden las familias de esta localidad, trastocando la identidad de sus habitantes. Entre las principales conclusiones destaca el hecho de que si bien la migración representa, junto con la agricultura, la principal fuente de ingresos de los grupos domésticos, ésta actividad no parece configurarse como una práctica central que articule al resto de las actividades que emprenden los grupos domésticos. En el caso de la comunidad de San Mateo Ozolco, esta centralidad corresponde todavía a las prácticas agrícolas, pecuarias y forestales, depositarias no sólo de la identidad de los habitantes de Ozolco, sino de los recursos económicos provenientes de las remesas y otras actividades no agropecuarias que se llevan a cabo, de manera complementaria, al interior de los grupos domésticos pluriactivos que habitan en esta localidad

Neuromielitis óptica tratada inicialmente como esclerosis múltiple: A propósito de un caso

El síndrome de Devic o neuromielitis óptica (NMO) es una entidad clínica infrecuente autoinmune, desmielinizante e inflamatoria que se caracteriza por la presencia de hallazgos clínicos, imagenológicos y de laboratorio que evidencian neuritis óptica, mielitis aguda con lesión longitudinal de más de tres segmentos medulares y seropositividad para anticuerpos IgG específicos para el canal de acuaporina 4. Caso: Presentamos el caso de una mujer de 28 años con diagnóstico inicial de Esclerosis múltiple de hace 14 meses, quien consulta al servicio de urgencias del Hospital Universitario San Jorge de Pereira por disminución progresiva de la fuerza en miembros inferiores y retención urinaria con cinco días de evolución. Como antecedentes refiere neuritis óptica bilateral en tratamiento con Interferón Beta, con pobre mejoría clínica y corticoide parenteral para los cuadros agudos. Se realiza resonancia magnética de columna vertebral que reporta columna lumbar sin alteraciones y columna dorsal con mielopatía en los segmentos T5-T8, posible desmielinización. Cuadro hemático, química sanguínea, Proteina C Reactiva, complemento C3 y C4 dentro de los rangos normales. Conclusión: La presentación aislada de neuritis óptica como debut en un cuadro clínico nos lleva a sospechar inicialmente en una enfermedad desmielinizante tipo esclerosis múltiple, lo que puede alterar el manejo inicial de los pacientes con neuromielitis óptica de base.Devic’s syndrome or neuromyelitis optica (NMO) is an autoimmune, inflammatory and demyelinating uncommon clinical entity characterized by the presence of clinical, imagining and laboratory evidence of optic neuritis, acutemyelitis with longitudinal injury in more than thre espinal segments and finally, NMO IgG seropositive for antibodies specific for the aquaporin channel 4. Case: We report a 28 years old woman diagnosed with multiple sclerosis 14 months ago, who consulted to emergency of Hospital Universitario San Jorge from Pereira by progressive reduction of strength in lower extremities and unrinary retention with duration of five days. She had a history of bilateral optic neuritis in treatment with interferon Beta 1-B, with poor clinical improvement, and parenteral corticosteroid for acute symptoms. Is performed a spinal Magnetic Resonance Imaging (MRI) reported a lumbar spine without changes and a dorsal spine with myelopathy in segments T5-T8, possible demyelinitation. Blood count, blood chemistry, C Reactive Protein, complement C3 and C4 within normal ranges. Discussion: The presentation of isolated optic neuritis as a clinical debut leads us to suspect initially in a demyelinating disease, multiple sclerosis type which can alterthe initial management of patients with NMO.http://revistas.utp.edu.co/index.php/revistamedic

Exploiting visual saliency for assessing the impact of car commercials upon viewers

Content based video indexing and retrieval (CBVIR) is a lively area of research which focuses on automating the indexing, retrieval and management of videos. This area has a wide spectrum of promising applications where assessing the impact of audiovisual productions emerges as a particularly interesting and motivating one. In this paper we present a computational model capable to predict the impact (i.e. positive or negative) upon viewers of car advertisements videos by using a set of visual saliency descriptors. Visual saliency provides information about parts of the image perceived as most important, which are instinctively targeted by humans when looking at a picture or watching a video. For this reason we propose to exploit visual information, introducing it as a new feature which reflects high-level semantics objectively, to improve the video impact categorization results. The suggested salience descriptors are inspired by the mechanisms that underlie the attentional abilities of the human visual system and organized into seven distinct families according to different measurements over the identified salient areas in the video frames, namely population, size, location, geometry, orientation, movement and photographic composition. Proposed approach starts by computing saliency maps for all the video frames, where two different visual saliency detection frameworks have been considered and evaluated: the popular graph based visual saliency (GBVS) algorithm, and a state-of-the-art DNN-based approach.This work has been partially supported by the National Grants RTC-2016-5305-7 and TEC2014-53390-P of the Spanish Ministry of Economy and Competitiveness.Publicad