Detección de genes de resistencia a antibióticos en bacteriófagos

La terapia con antibióticos representa uno de los avances médicos más importantes del siglo XX y es un recurso valioso para el combate de enfermedades causadas por bacterias. Sin embargo, este uso terapéutico no ha sido utilizado de forma correcta ya que en años recientes han aparecido bacterias multiresistentes en diversos ambientes. Esta resistencia se genera por mutaciones puntuales generando genes que confieren esta capacidad resistente a los antibióticos como los betalactámicos, quinolonas, etc. La prevalencia de estos genes ha sido descrita tanto en bacterias como en bacteriófagos, al ser elementos genéticos móviles tienen la capacidad de contener y tranferir por medio de la transducción estos genes entre bacterias patógenas y comensales. El objetivo de este estudio es determinar la presencia de los genes qnrA, qnrB y blaTEM, en el ADN fágico. En este trabajo se tomaron un total de 48 muestras de agua en cuatro rastros municipales (Atlacomulco, San Felipe del Progreso, El Oro e Ixtlahuaca), de las cuales se obtuvieron 19 aislamientos de Escherichia coli de agua residual y 18 aislamientos de alcantarilla (37 en total)

Aquatic Cartographies: Oceanic Imaginaries, Histories and Identities,

In her volume The Invisible Empire: White Discourse, Tolerance and Belonging (2009), Georgie Wemyss has discussed lascars as a case study of what she calls the ‘Invisible Empire’ (2009: 3). Unacknowledged and unremembered for decades in colonial historiography, lascars populated English vessels since the early days of imperialism until the Second World War. This singular maritime figure of the Indian Ocean is being belatedly incorporated into historiography as well as into contemporary maritime fiction. This paper will analyse the representation of lascars in a selection of recent sea narratives set in the nineteenth century, namely Amitav Ghosh’s Ibis trilogy (2008-2015) and Shahida Rahman’s Lascar (2012). I argue that lascars, as represented in those sea narratives, reveal the potential of transoceanic mobility to destabilise land-locked parameters of culture and nationality in the nineteenth century and are exemplary of the cosmopolitanism that characterised the Indian Ocean waterworlds. Additionally, I aim at demonstrating that lascars are an apt case study to rethink globalization as glocalization, enabling a reading of the global as “plural versions of the local” (Beyer 2007: 98). In this sense, I contend that lascars’ multifarious identities constituted a negotiation between the global and the local that translated in strategies of resistance against the violence of imperialism. This glocal take on identity challenged, I argue, imperial codes of nationality, religion, and culture as fixed categories, prevalent in an unfolding globalization which, far from being a twentieth-century phenomenon, was already spreading and in full activity in the nineteenth century

Regulated expression of galectin-1 after in vitro productive infection with herpes simplex virus type 1: implications for T cell apoptosis

Apoptosis of cytotoxic T lymphocytes by herpes simplex virus type-1 (HSV-1) has been reported to be a relevant mechanism of viral immune evasion. Galectin-1 (Gal-1), an endogenous lectin involved in T-cell apoptosis, has recently gained considerable attention as a novel mechanism of tumor-immune evasion. Here we investigated whether infection of cells with HSV-1 can modulate the expression of Gal-1. Results show that pro-apoptotic Gal-1, but not Gal-3, is remarkably up-regulated in cell cultures infected with HSV-1. In addition, this protein is secreted to the extracellular milieu, where it contributes to apoptosis of activated T cells in a carbohydrate-dependent manner. Since many viruses have evolved mechanisms to counteract the antiviral response raised by the infected host, our results suggest that HSV-1 may use galectin-1 as a weapon to kill activated T cells and evade specific immune responses.Fil: Gonzalez, Maria Ines. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; ArgentinaFil: Rubinstein, Natalia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ilarregui, Juan Martin. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Toscano, Marta Alicia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Sanjuan, Norberto Aníbal. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; ArgentinaFil: Rabinovich, Gabriel Adrián. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Air-cooled heat exchanger design using successive quadratic programming (SQP)

A nonlinear optimization algorithm is applied to the design of air-cooled heat exchangers. In such equipment, the cold fluid (air) is impelled across banks of finned tubes by means of fans in forced or induced draft. The hot stream flows inside the tubes in one or more passes, and the process that takes place may be cooling of either a gas or a liquid, or condensation of either a pure vapor or a mixture. The objective function is the minimum cost of the unit (investment and operation), subject to certain geometric and thermohydraulic constraints. The optimization algorithm used is that developed by Biegler and Cuthrell [1], and programmed by them in the OPT package. The problem posed in this case is made of 10 optimization variables, subject to five constraints related to geometric and operational parameters of the heat exchanger.Fil: Gonzalez, Maria Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Petracci, Noemi Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Urbicain, Martin Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentin

PREVALENCIA DE GENES DE RESISTENCIA EN BACTERIÓFAGOS Y AISLAMIENTOS DE E. coli EN AVES DE CORRAL EN EL CENTRO-NORTE DEL ESTADO DE MÉXICO

Tesis DoctoralLa epidemiología de patógenos multirresistentes portadores de ARG´s es extremadamente compleja, ya que están vinculados a multiples factores abióticos y bióticos (humanos, animales domesticos y de vida silvestre). En el presente estudio se recolectaron 197 aislamientos de Escherichia coli de pollos, pavos y patos de un total de de 322 muestras procedentes de unidades de producción de traspatio en la zona norte del Estado de México, México. Se registraron 108/197 (54.8%) aislamientos multirresistentes. 80.7% de los aislamientos presentaron resistencia a ampicilina (AM), 64.4% a tetraciclina (TE), 56.3% a carbenicilina (CB) y 26.9% a ácido nalidíxico (NA) y trimetoprim-sulfametoxasol (SXT). Además, 56.3% de los aislamientos presentaron el gen blaTEM, 20.8%,19.2%, 7.6% y 10.1% el tetB, tetA sulI y sulII respectivamente, 9.6% qnrA y 5.5% el qnrB. Para la transducción in vitro se utilizaron bacteriófagos portadores de ARG´s recolectados de aislamientos de E. coli multirresistentes de aves silvestres procedentes de la Ciénega Chimalipan de Lerma. El gen qnrA fue transducido a 5/13 (38.4%) cepas de E. coli, el tetB a 3/13 (23%) y, blaTEM y sulII a 2/13 (15.3%). Se reporta la frecuencia de genes de resistencia vinculados a resistencia fenotípica en aves domésticas y por primera vez se realiza la transducción de ARG’s de cepas de E. coli aislada de aves silvestres a cepas de E. coli aisladas de aves domesticas, con esto, se logra determinar el posible rol de los bacteriófagos en la transmisión de factores de resistencia

A Parallel Application of Matheuristics in Data Envelopment Analysis

Data Envelopment Analysis (DEA) is a non-parametric methodology for estimating technical efficiency and benchmarking. In general, it is desirable that DEA generates the efficient closest targets as benchmarks for each assessed unit. This may be achieved through the application of the Principle of Least Action. However, the mathematical models associated with this principle are based fundamentally on combinatorial NP-hard problems, difficult to be solved. For this reason, this paper uses a parallel matheuristic algorithm, where metaheuristics and exact methods work together to find optimal solutions. Several parallel schemes are used in the algorithm, being possible for them to be configured at different stages of the algorithm. The main intention is to divide the number of problems to be evaluated in equal groups, so that they are resolved in different threads. The DEA problems to be evaluated in this paper are independent of each other, an indispensable requirement for this algorithm. In addition, taking into account that the main algorithm uses exact methods to solve the mathematical problems, different optimization software has been evaluated to compare their performance when executed in parallel. The method is competitive with exact methods, obtaining fitness close to the optimum with low computational time.J. Aparicio and M. González thank the financial support from the Spanish ‘Ministerio de Economía, Industria y Competitividad’ (MINECO), the ‘Agencia Estatal de Investigacion’ and the ‘Fondo Europeo de Desarrollo Regional’ under grant MTM2016-79765-P (AEI/FEDER, UE)

In vitro activity of bedaquiline against rapidly growing nontuberculous mycobacteria

Bedaquiline (BDQ) has been proven to be effective in the treatment of multidrug-resistant tuberculosis. We hypothesized that BDQ could be a potential agent to treat nontuberculous mycobacterial (NTM) infection. The objective of this study was to evaluate the in vitro activity of BDQ against rapidly growing mycobacteria by assessing the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against 18 NTM strains. For MIC determination we performed the resazurin microtitre assay broth dilution, and for the MBC the c.f.u. was determined. BDQ exhibited a strong inhibitory effect against most NTM tested; however, for some NTM strains the MBC was significantly higher than the MIC. A new finding is that Mycobacterium flavescens has a mutation in the gene atpE associated with natural resistance to BDQ. These preliminary promising results demonstrate that BDQ could be potentially useful for the treatment of NTM

Bacteriófagos, los virus come-bacterias: historia de dos mentes científicas

El descubrimiento de los bacteriófagos (virus come bacterias) está lleno de discusiones, ya que algunos autores consideran a Felix d’Herelle como su único descubridor oficial, debido a que pudo comprobar, en 1917, que esos entes totalmente diferentes a todos los que se conocían eran los responsables de la actividad lítica (acción destructiva). En contraste, otros autores proponen a Frederick W. Twort como su verdadero descubridor, ya que, en 1915, reportó una actividad lítica; sin embargo, no pudo determinar su origen. En este artículo se relatan las observaciones, planteamientos e ideas de dos personajes que fueron pilares en el descubrimiento de los bacteriófagos, virus que actualmente son considerados como una propuesta para combatir efectivamente enfermedades mortales de origen bacteriano

The transcriptome of Mycobacterium tuberculosis in a lipid-rich dormancy model through RNAseq analysis

Tuberculosis (TB) is currently the number one killer among infectious diseases worldwide. Lipids are abundant molecules during the infectious cycle of Mycobacterium tuberculosis (Mtb) and studies better mimicking its actual metabolic state during pathogenesis are needed. Though most studies have focused on the mycobacterial lipid metabolism under standard culture conditions, little is known about the transcriptome of Mtb in a lipid environment. Here we determined the transcriptome of Mtb H37Rv in a lipid-rich environment (cholesterol and fatty acid) under aerobic and hypoxic conditions, using RNAseq. Lipids significantly induced the expression of 368 genes. A main core lipid response was observed involving efflux systems, iron caption and sulfur reduction. In co-expression with ncRNAs and other genes discussed below, may act coordinately to prepare the machinery conferring drug tolerance and increasing a persistent population. Our findings could be useful to tag relevant pathways for the development of new drugs, vaccines and new strategies to control TB

A polytrauma patient with an unusual posterior fracture-dislocation of the femoral head: a case report

We report a case of a 27-year-old man who was involved in a high-speed car accident. He sustained multiple organ damage including multiple brain petechiae suggesting diffuse axonal damage, aortic dissection, retroperitoneal haematoma and a fracture-dislocation of the right hip with a femoral head fracture and an ipsilateral intertrochanteric fracture. Due to the general condition of the patient, physiological stabilisation was prioritized, and at 2 weeks the fracture-dislocation of the hip was treated with a proximal femoral nail for the intertrochanteric fracture and Herbert screws for the femoral head fracture. Postoperatively, two episodes of recurrent hip dislocation occurred, and this was stabilized eventually with a Steinman pin inserted across the hip joint and taken out 1 month later. Weight-bearing was allowed according to clinical and radiographical assessments. Heterotopic ossification developed around the hip joint, but without evidence of AVN or osteoarthritis. At 18-months follow-up, the fractures had healed and the patient had a Harris Hip score of 79.1. Anatomical reduction and stable fixation of fracture-dislocations of the hip are important for achieving an acceptable result