Comparison of methods for the identification and sub-typing of O157 and non-O157 Escherichia coli serotypes and their integration into a polyphasic taxonomy approach

peer-reviewedPhenotypic, chemotaxonomic and genotypic data from 12 strains of Escherichia coli were collected, including carbon source utilisation profiles, ribotypes, sequencing data of the 16S–23S rRNA internal transcribed region (ITS) and Fourier transform-infrared (FT-IR) spectroscopic profiles. The objectives were to compare several identification systems for E. coli and to develop and test a polyphasic taxonomic approach using the four methodologies combined for the sub-typing of O157 and non-O157 E. coli. The nucleotide sequences of the 16S–23S rRNA ITS regions were amplified by polymerase chain reaction (PCR), sequenced and compared with reference data available at the GenBank database using the Basic Local Alignment Search Tool (BLAST) . Additional information comprising the utilisation of carbon sources, riboprint profiles and FT-IR spectra was also collected. The capacity of the methods for the identification and typing of E. coli to species and subspecies levels was evaluated. Data were transformed and integrated to present polyphasic hierarchical clusters and relationships. The study reports the use of an integrated scheme comprising phenotypic, chemotaxonomic and genotypic information (carbon source profile, sequencing of the 16S–23S rRNA ITS, ribotyping and FT-IR spectroscopy) for a more precise characterisation and identification of E. coli. The results showed that identification of E. coli strains by each individual method was limited mainly by the extension and quality of reference databases. On the contrary, the polyphasic approach, whereby heterogeneous taxonomic data were combined and weighted, improved the identification results, gave more consistency to the final clustering and provided additional information on the taxonomic structure and phenotypic behaviour of strains, as shown by the close clustering of strains with similar stress resistance patterns.The authors acknowledge the financial contribution of the Spanish INIA, the Research Council of Norway (project 178230/I10), Foundation for Levy on Foods, the Norwegian Research Fees Fund for Agricultural Goods, the Norwegian Independent Meat and Poultry Association, Nortura SA and NHO Matog Landbruk

Evaluation of the Efficacy and Safety of a Marine-Derived Bacillus Strain for Use as an In-Feed Probiotic for Newly Weaned Pigs

peer-reviewedForty eight individual pigs (8.7±0.26 kg) weaned at 28±1 d of age were used in a 22-d study to evaluate the effect of oral administration of a Bacillus pumilus spore suspension on growth performance and health indicators. Treatments (n = 16) were: (1) non-medicated diet; (2) medicated diet with apramycin (200 mg/kg) and pharmacological levels of zinc oxide (2,500 mg zinc/kg) and (3) B. pumilus diet (non-medicated diet + 1010 spores/day B. pumilus). Final body weight and average daily gain tended to be lower (P = 0.07) and feed conversion ratio was worsened (P<0.05) for the medicated treatment compared to the B. pumilus treatment. Ileal E. coli counts were lower for the B. pumilus and medicated treatments compared to the non-medicated treatment (P<0.05), perhaps as a result of increased ileal propionic acid concentrations (P<0.001). However, the medicated treatment reduced fecal (P<0.001) and cecal (P<0.05) Lactobacillus counts and tended to reduce the total cecal short chain fatty acid (SCFA) concentration (P = 0.10). Liver weights were lighter and concentrations of liver enzymes higher (P<0.05) in pigs on the medicated treatment compared to those on the non-medicated or B. pumilus treatments. Pigs on the B. pumilus treatment had lower overall lymphocyte and higher granulocyte percentages (P<0.001) and higher numbers of jejunal goblet cells (P<0.01) than pigs on either of the other two treatments or the non-medicated treatment, respectively. However, histopathological examination of the small intestine, kidneys and liver revealed no abnormalities. Overall, the B. pumilus treatment decreased ileal E. coli counts in a manner similar to the medicated treatment but without the adverse effects on growth performance, Lactobacillus counts, cecal SCFA concentration and possible liver toxicity experienced with the medicated treatment.The study was funded by the Higher Education Authority/Institutes of Technology Ireland Technological Sector Research Strand III Programme

Apolipoproteína AI e lipoproteínas de alta densidade: estrutura e papel na homeostase do colesterol celular

La apolipoproteína A-I (apoAI) es el componente proteico mayoritario de las lipoproteínas de alta densidad (HDL), cuyo nivel sérico se correlaciona inversamente con el riesgo aterogénico. Las propiedades antiaterogénicas son atribuidas en gran parte al rol protagónico que tiene en el transporte reverso de colesterol (RCT), proceso que remueve el exceso de colesterol de los tejidos periféricos. La apoAI es una proteína anfitrópica formada casi en exclusividad por a-hélices anfipáticas, y presenta una gran flexibilidad conformacional que es crucial para su ciclo funcional, en el que se interconvierte entre diferentes estados: libre, unida a membranas, o a una gran variedad de complejos lipoproteicos de diferente tamaño, morfología y composición. En este reporte se revisa el conocimiento actual sobre la estructura y propiedades de interacción con lípidos de apoAI, en relación a la biogénesis de HDL y su función en el RCT. Se trata en particular la configuración de apoAI en HDL discoidales, así como la interacción con lípidos y la importancia para la remoción celular de colesterol de un par de a-hélices anfipáticas que presentan una distribución particular de los residuos cargados y se localizan en el centro de la molécula de apoAI.Apolipoprotein A-I (apoAI) is the major protein component of high density lipoprotein (HDL), whose serum level is inversely correlated with atherogenic risk. Antiatherogenic properties are largely attributed to its key role in reverse cholesterol transport (RCT), a process that removes cholesterol excess from peripheral tissues. ApoAI is an amphitropic protein that almost exclusively contains amphipathic a-helices, and presents a large conformational flexibility that is crucial for its functional cycle, in which it inter-converts into different states: free or bound to membranes, or into a lipoprotein complex variety of different sizes, compositions and morphologies. This report reviews the current knowledge of the structure and lipid interaction properties of apoAI, in relation with HDL biogenesis and function in RCT. In particular, focus is made on the apoAI configuration in discoidal HDL; as well as on the interaction with lipids, and the importance for cellular cholesterol efflux, of an amphipathic a-helix pair having a particular distribution of the charged residues and that locate at the center of the apoAI molecule.Apolipoproteína A-I (apoAI) é o principal componente proteico das lipoproteínas de alta densidade (HDL), cujo nível sérico se correlaciona inversamente com o risco aterogênico. As propriedades antiaterogênicas são atribuídas, em grande parte, a seu papel principal no transporte reverso de colesterol (RCT), um processo que remove o excesso de colesterol dos tecidos periféricos. A ApoAI é uma proteína anfitrópica constituída quase exclusivamente por α-hélices anfipáticas, e apresenta uma grande flexibilidade conformacional que é essencial para seu ciclo funcional, no qual se interconverte entre diferentes estados: livre, ligada a membranas ou a uma grande variedade de complexos lipoproteicos de diferente tamanho, morfologia e composição. Este relatório analisa o conhecimento atual sobre a estrutura e propriedades de interação com lipídios de apoAI, com relação à biogênese de HDL e sua função no RCT. Em particular, trata-se a configuração de apoAI em HDL discoidais; bem como a interação com lipídios e a importância para a remoção celular de colesterol de um par de α-hélices anfipáticas que apresentam uma distribuição específica dos resíduos carregados e se localizam no centro da milécula de apoAI.Fil: Garda, Horacio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Investigaciones Bioquímicas de La Plata; Argentina; ArgentinaFil: Toledo, Juan Domingo.Fil: Gonzalez, Maria Cecilia.Fil: Prieto, Eduardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Cuellar, Luz Ángela.Fil: Cabaleiro, Laura Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Investigaciones Bioquímicas de La Plata; Argentina; ArgentinaFil: Chirillano, Lucio Alfonso.Fil: Almeyra, Carla Mariel

Target-independent high-throughput sequencing methods provide evidence that already known human viral pathogens play a main role in respiratory infections with unexplained etiology

Despite the advanced PCR-based assays available, a fraction of the pediatric respiratory infections remain unexplained every epidemic season, and there is a perception that novel viruses might be present in these specimens. We systematically collected samples from a prospective cohort of pediatric patients with respiratory infections, that returned negative results by validated molecular RT-PCR assays, and studied them with a target-independent, high-throughput sequencing-based approach. We also included a matched cohort of children with no symptoms of respiratory infection, as a contrast study population. More than fifty percent of the specimens from the group of patients with unexplained respiratory infections were resolved. However, the higher rate of detection was not due to the presence of novel viruses, but to the identification of well-known viral respiratory pathogens. Our results show that already known viral pathogens are responsible for the majority of cases that remain unexplained after the epidemic season. High-throughput sequencing approaches that use pathogen-specific probes are easier to standardize because they ensure reproducible library enrichment and sequencing. In consequence, these techniques might be desirable from a regulatory standpoint for diagnostic laboratories seeking to benefit from the many advantages of these sequencing technologies.This work was supported by The Joint Science and Technology Office for Chemical and Biological Defense (JSTO-CBD) of the Defense Threat Reduction Agency (DTRA) under plan #CB10246. This study has been partially supported by Fondo de Investigaciones Sanitarias (FIS) – Spanish Health Research Fund Grant PI12/01291, and Instituto de Salud Carlos III (ISCIII), Grant PI15CIII/00028.S

Choosing Short: An Explanation of the Similarities and Dissimilarities in the Distribution Patterns of Binding and Covaluation

Covaluation is the generalization of coreference introduced by Tanya Reinhart. Covaluation distributes in patterns that are very similar yet not entirely identical to those of binding. On a widespread view, covaluation and binding distribute similarly because binding is defined in terms of covaluation. Yet on Reinhart's view, binding and covaluation are not related that way: binding pertains to syntax, covaluation does not. Naturally, the widespread view can easily explain the similarities between binding and covaluation, whereas Reinhart can easily explain the dissimilarities. Reciprocally, the widespread view finds it harder to explain the dissimilarities, whereas Reinhart finds it harder to explain the similarities. Reinhart and others have proposed more than one explanation of the similarities, but as I argue, these explanations do not work. Hence although I adopt Reinhart's view, I propose a new explanation of the similarities and dissimilarities between binding and covaluation: While Reinhart has invoked semantic structure only to explain dissimilarities, I do so to explain both similarities and dissimilarities at once. Finally, I examine in light of this approach the topics of language acquisition, only-constructions, the identity predicate, the Partee/Bach/Higginbotham problem, the Dahl puzzle and its recent versions by Roelofsen

Different Modes of Regulation of the Expression of Dextransucrase in Leuconostoc lactis AV1n and Lactobacillus sakei MN1

Leuconostoc lactis AV1 strain isolated from a Tunisian avocado was characterized as a dextran producer. The promoter PdsrLL and the dsrLL gene encoding the DsrLL dextransucrase responsible for the dextran synthesis were transcriptionally fused to the mCherry coding gene generating the pRCR20 plasmid. Upon plasmid transfer, both AV1n and the dextran non-producing Leuconostoc mesenteroides CM70 became red due to expression of the mCherry from the PdsrLL-dsr-mrfp transcriptional fusion. Characterization of the polymers present in cultures supernatants revealed that the DsrLL encoded from pRCR20 in the recombinant bacteria was able to synthesize dextran. The production of dextran by the DsrLL in AV1n increased in response to low temperature, reaching 10-fold higher levels at 20°C than at 37°C (4.15 g/L versus 0.41 g/L). To analyze if this stress response includes activation at the transcriptional level and if it was only restricted to Leuconostoc, AV1n was transformed with plasmids carrying either the PdsrLL-mrfp fusion or the PdsrLS of Lactobacillus sakei MN1 fused to the mrfp gene, and the influence of temperature and carbon source on expression from the Dsr promoters was monitored by measurement of the mCherry levels. The overall expression analysis confirmed an induction of expression from PdsrLL upon growth at low temperature (20°C versus 30°C and 37°C) in the presence of sugars tested (sucrose, glucose, maltose, and fructose). In addition, the presence of sucrose, the substrate of Dsr, also resulted in activation of expression from PdsrLL. A different behavior was detected, when expression from PdsrLS was evaluated. Similar levels of fluorescence were observed irrespectively of the carbon source or temperature, besides a sequential decrease at 30°C and 20°C, when sucrose was present in the growth medium. In conclusion, the two types of regulation of expression of Dsr presented here revealed two different mechanisms for environmental adaptation of Leuconostoc and Lactobacillus that could be exploited for industrial applications

Perceção e estratégias do sector do turismo no município de San Gil: Perception and strategies of the Tourism Sector in the municipality of San Gil

El siguiente documento tiene por objeto mostrar el resultado del estudio realizado por un selecto grupo de docentes y estudiantes del programa de Ingeniería Industrial pertenecientes a la UNIVERSIDAD DE INVESTIGACIÓN Y DESARROLLO UDI. Las metodologías utilizadas brindan un valor significativo para la realización de capacitación y talleres en materia de turismo. El estudio consiste en exponer el desarrollo local y regional enfocado en el turismo, ya que este integra factores influyentes, destacando la economía y cultura presentes en el municipio de San Gil, Santander, con el objetivo de poder identificar la viabilidad y diferentes estrategias metodológicas utilizadas que implica la realización de dicha actividad. La investigación sobre el turismo surge debido al cambio constante de intereses en la sociedad ya que esto representa amenazas para el sector turístico al no contar con la debida participación de los visitantes y un buen plan estratégico que permita minimizar el impacto económico al que se enfrentaría el sector

Management of acute diverticulitis with pericolic free gas (ADIFAS). an international multicenter observational study

Background: There are no specific recommendations regarding the optimal management of this group of patients. The World Society of Emergency Surgery suggested a nonoperative strategy with antibiotic therapy, but this was a weak recommendation. This study aims to identify the optimal management of patients with acute diverticulitis (AD) presenting with pericolic free air with or without pericolic fluid. Methods: A multicenter, prospective, international study of patients diagnosed with AD and pericolic-free air with or without pericolic free fluid at a computed tomography (CT) scan between May 2020 and June 2021 was included. Patients were excluded if they had intra-abdominal distant free air, an abscess, generalized peritonitis, or less than a 1-year follow-up. The primary outcome was the rate of failure of nonoperative management within the index admission. Secondary outcomes included the rate of failure of nonoperative management within the first year and risk factors for failure. Results: A total of 810 patients were recruited across 69 European and South American centers; 744 patients (92%) were treated nonoperatively, and 66 (8%) underwent immediate surgery. Baseline characteristics were similar between groups. Hinchey II-IV on diagnostic imaging was the only independent risk factor for surgical intervention during index admission (odds ratios: 12.5, 95% CI: 2.4-64, P =0.003). Among patients treated nonoperatively, at index admission, 697 (94%) patients were discharged without any complications, 35 (4.7%) required emergency surgery, and 12 (1.6%) percutaneous drainage. Free pericolic fluid on CT scan was associated with a higher risk of failure of nonoperative management (odds ratios: 4.9, 95% CI: 1.2-19.9, P =0.023), with 88% of success compared to 96% without free fluid ( P &lt;0.001). The rate of treatment failure with nonoperative management during the first year of follow-up was 16.5%. Conclusion: Patients with AD presenting with pericolic free gas can be successfully managed nonoperatively in the vast majority of cases. Patients with both free pericolic gas and free pericolic fluid on a CT scan are at a higher risk of failing nonoperative management and require closer observation

experiencias de profesores para las comunidades universitarias

Libro Completo.En esta compilación de diferentes visiones del conocimiento de las múltiples disciplinas que cobijan la formación de los profesionales de la actualidad, encontrarán la visión y la exposición de las diferentes dinámicas pedagógicas y profesionales de los profesores de la Rectoría Cundinamarca de la Corporación Universitaria Minuto de Dios. Desde las diferentes perspectivas de la docencia, en los distintos programas académicos, se comprenderá y situará la visión estratégica y conceptual que redunda en la interdisciplinariedad, la integralidad y, por supuesto, la trasversalidad de las disciplinas profesionales. Será un recorrido a través de más de quince miradas de diversos profesionales dedicados a la academia, a diferentes conceptos que van desde la discusión de las ciencias sociales, pasando por la comprensión de las dinámicas de los sujetos y la visión de su diario vivir y, por supuesto aterrizándolas en conceptos de las ciencias exactas que, resaltarán la importancia del ejercicio disciplinar de diferentes profesiones. Asimismo, las temáticas conceptuales aquí expuestas son un material de consulta constante para otros profesores, estudiantes y público general, que tienen el deseo de ir más allá en la ampliación de sus saberes. Por lo anterior, se describen aquí dinámicas de reconocimiento conceptual y práctico de diferentes temáticas discutidas que le apuntan a cuatro líneas de saberes, pertenecientes al Plan de Desarrollo Profesoral 2020 – 2025 de la Rectoría de Cundinamarca