36 research outputs found

    Análisis de factores de virulencia en aislamientos de Clostridium difficile de dos hospitales de tercer nivel de México.

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    Clostridium difficile es una bacteria Gram positiva, anaerobia estricta y productora de esporas y es la causa infecciosa más común de diarrea asociada a la atención de la salud. La infección por C. difficile (ICD) se asocia al uso de terapia antimicrobiana ya que alteran la microbiota intestinal y C. difficile puede colonizar el intestino si la microbiota normal intestinal esta disminuida o ausente. El objetivo de este trabajo fue analizar factores de virulencia que contribuyen a la patogénesis, tales como producción de toxinas, formación de biopelícula y expresión de proteínas involucradas en la adhesión en aislamientos clínicos de C. difficile. Se aisló C. difficile a partir de pacientes con ICD y detectaron los genes de las toxinas A, B y toxina binaria por medio de PCR; además, se determinaron los ribotipos por PCR y electroforesis convencional y capilar. Se evaluó la susceptibilidad a antimicrobianos por dilución en agar. Se determinó la producción de biopelícula mediante tinción con cristal violeta y se determinó su composición mediante ensayos de desprendimiento con proteinasa K, NaIO4 y DNAsa I. Finalmente, se evaluó la expresión de cwp84 y slpA mediante PCR en tiempo real. Se recuperaron 132 aislamientos a partir de 332 muestras (39.8 %); todos los aislamientos fueron tcdA+ y tcdB+; además 89 (67.4%) presentaron la deleción de 18 pb en tcdC. La ribotipificación clasificó a 81 (61.4%) aislamientos como ribotipo 027 y a 18 (13.6%) aislamientos como ribotipo 001. Se encontró susceptibilidad reducida (SR) a ciprofloxacino, moxifloxacino, eritromicina, clindamicina y rifampicina en más del 70% de los aislamientos; no hubo SR a fidaxomicina o tetraciclina; sin embargo hubo SR a vancomicina (31%) y metronidazol (17.4%). Más del 70% (98/132) fueron productores fuertes de biopelícula. Los ensayos mostraron el mayor desprendimiento de la biopelicula con el tratamiento de proteinasa K (>90%). En los aislamientos de ribotipo 001 se encontró sobrexpresión de cwp84 en 40% de ellos y slpA fue sobreexpresado en el 100%; en el ribotipo 027 hubo sobrexpresión de cwp84 en un aislamiento solamente; mientras que slpA fue sobreexpresado en 5/13 (38.5%) aislamientos. Los ribotipos más frecuentes en México son el 027 y 001 y son poseen farmacorresistencia, además de producir biopelícula; las proteínas contribuyen principalmente a la formación de la matriz de la biopelícula. SlpA se sobre expresa en las cepas ribotipo 001. ABSTRACT Clostridium difficile is a Gram positive, spore-producing, strict anaerobic bacterium and is the most common infectious cause of health-care associated diarrhea. C. difficile infection (CDI) is associated with substantial morbidity and mortality; in addition, it is associated with antimicrobial therapy since they alter the intestinal microbiota and C. difficile can colonize the intestine if the normal intestinal microbiota is diminished or absent. The objective of this work was to analyze virulence factors that contribute to pathogenesis, such as toxin production, biofilm formation and expression of proteins involved in adhesion in clinical isolates of C. difficile. C. difficile was isolated from patients with CDI and the genes of toxins A, B and binary toxin were detected by PCR; In addition, ribotypes were determined by PCR and conventional and capillary electrophoresis. Antimicrobial susceptibility was evaluated by agar dilution. The production of biofilm was determined by violet crystal staining and its composition was determined by detachment assays with proteinase K, NaIO4 and DNAse I. Finally, the expression of cwp84 and slpA was evaluated by real-time PCR. One hundred thirty two isolates were recovered from 332 samples (39.8%); all isolates were tcdA+ and tcdB+; in addition, 89 isolates (67.4%) presented the 18 bp deletion in tcdC. Ribotyping classified 81 (61.4%) isolates as ribotype 027 and 18 (13.6%) isolates as ribotype 001. Reduced susceptibility (RS) to ciprofloxacin, moxifloxacin, erythromycin, clindamycin and rifampicin was found in more than 70% of the isolates; there was no RS to fidaxomicin or tetracycline; however there was RS to vancomycin (31%) and metronidazole (17.4%). More than 70% of isolates (98/132) were strong biofilm producers. The highest detachment of biofilm was achieved with the proteinase K treatment (> 90%). Overexpression of cwp84 was found in 40% of isolates of ribotype 001, and slpA was overexpressed in 100%; in ribotype 027 there was overexpression of cwp84 in one isolation only; while slpA was overexpressed in 5/13 (38.5%) isolates. The most frequent ribotypes in Mexico are 027 and 001 and they present drug resistance and are biofilm producers; the proteins contribute mainly to the formation of the biofilm matrix. slpA is over expressed in strains ribotype 001

    Molecular epidemiology of coagulase-negative bloodstream isolates: detection of Staphylococcus epidermidis ST2, ST7 and linezolid-resistant ST23

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    The mechanisms contributing to persistence of coagulase-negative staphylococci are diverse; to better understanding of their dynamics, the characterization of nosocomial isolates is needed. Our aim was to characterize phenotypic and molecular characteristics of Staphylococcus epidermidis and Staphylococcus haemolyticus human blood isolates from two tertiary care hospitals in Mexico, the Hospital Universitario in Monterrey and the Hospital Civil in Guadalajara. Antimicrobial susceptibility was determined. Biofilm formation was assessed by crystal violet staining. Detection of the ica operon and Staphylococcal Cassette Chromosome mec typing were performed by PCR. Clonal relatedness was determined by Pulsed-fiel gel electrophoresis and Multi locus sequence typing. Methicillin-resistance was 85.5% and 93.2% for S. epidermidis and S. haemolyticus, respectively. Both species showed resistance >70% to norfloxacin, clindamycin, levofloxacin, trimethoprim/sulfamethoxazole, and erythromycin. Three S. epidermidis and two S. haemolyticus isolates were linezolid-resistant (one isolate of each species was cfr+). Most isolates of both species were strong biofilm producers (92.8% of S. epidermidis and 72.9% of S. haemolyticus). The ica operon was amplified in 36 (43.4%) S. epidermidis isolates. SCCmec type IV was found in 47.2% of the S. epidermidis isolates and SCCmec type V in 14.5% of S. haemolyticus isolates. No clonal relatedness was found in either species. Resistance to clindamycin, levofloxacin, erythromycin, oxacillin, and cefoxitin was associated with biofilm production for both species (p < 0.05). A G2576T mutation in 23S rRNA gene was detected in an S. haemolyticus linezolid-resistant isolate. All linezolid-resistant S. epidermidis isolates belonged to ST23; isolate with SCCmec type IV belonged to ST7, and isolate with SCCmec type III belonged to ST2. This is the first report of ST7 in Mexico. There was a high genetic diversity in both species, though both species shared characteristics that may contibute to virulence

    Staphylococcal Cassette Chromosome mec (SCCmec) in coagulase negative staphylococci

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    Coagulase-negative staphylococci (CoNS) are among the main causative agents of bacteremia. Staphylococcus epidermidis and Staphylococcus haemolyticus are the CoNS species most frequently isolated. These species are often associated with infections in immunocompromised patients who have a medical device implant. Methicillin resistance was first described in Staphylococcus aureus; it has also been reported in CoNS species. Methicillin resistance is conferred by expression of the mecA gene, contained within the staphylococcal cassette chromosome (SCCmec). mecA gene codes for the PBP2a protein which shows poor binding to beta-lactam antibiotics, so methicillin-resistant strains are resistant to beta-lactams. The presence of SCCmec in CoNS species complicates infections caused by these organisms, since it confers resistance to a variety of antibiotics, making treatment difficult. This review analyzes the clinical relevance of SCCmec as well as the diversity and structure of elements present in CoNS species

    Exploraciones, intercambios y relaciones entre el diseño y la tecnología

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    125 páginas.En la obra se exponen avances de los estudios que cada uno de los miembros ha realizado en relación con sus distintos proyectos, los cuales comparten como objetivo común el explorar la relación entre el diseño, la tecnología y otros ámbitos del conocimiento, con el fin de propiciar la reflexión y el análisis teórico-práctico de éstos en la interacción social y productiva. Cada uno de los capítulos, por tanto, representa una mirada específica que abona a la generación del conocimiento sobre la realidad y sus posibilidades, sobre la práctica cotidiana y la innovación. En el primero de ellos, se expone una propuesta que enlaza directamen¬te la investigación y la docencia. Al reflexionar sobre la puesta en práctica de laboratorios de aprendizaje como estrategia en las aulas, Marco Ferruzca recomienda la experiencia como una alternativa para revitalizar y mejorar la educación en diseño. El capítulo dos también divulga maneras de innovar dentro del salón de clase. En este caso, se trata de un proyecto planteado y probado a nivel internacional –con México, Uruguay y Cuba como parti¬cipantes–, dentro del cual se trabajaron diversas aproximaciones creativas orientadas al diseño de productos con distintos materiales. Alda Zizumbo defiende el postulado del diseño como una oportunidad de desarrollo para Latinoamérica. Para el tercer capítulo, Roberto García Madrid acerca a los lectores al campo profesional, inquiriéndolos acerca de los procesos que se siguen para construir soluciones de diseño. Propone la visualización como una herra¬mienta fundamental para profundizar en la comprensión de los problemas y, por tanto, de sus soluciones. En los dos últimos capítulos se cuestionan diseños ya construidos. A lo largo del cuarto, Itzel Sainz presenta un estudio de caso sobre una obra de literatura electrónica, cuyo proceso cultural activo culminó diez años atrás; similitudes respecto a los actores participantes contrastan con los retos para enfrentar un entorno distinto al del libro tradicional. ¿Qué desafíos se reve¬lan a los diseñadores de la comunicación gráfica gracias a esta experiencia? La lectura se retoma en el quinto capítulo, donde Ivonne Murillo, Rámsses Román, Roberto López Martínez y Roberto García Madrid difunden los resul¬tados de un experimento sobre el comportamiento de los usuarios frente a las páginas de dos periódicos en línea. Se cuestiona su usabilidad a la luz de constantes cambios y renovaciones, a los que se suman factores personales, sociales, culturales y tecnológicos

    Randomized clinical trial to evaluate the effect of fecal microbiota transplant for initial Clostridium difficile infection in intestinal microbiome

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    Objective The aim of this study was to evaluate the impact of fecal donor-unrelated donor mix (FMT-FURM) transplantation as first-line therapy for C. difficile infection (CDI) in intestinal microbiome. Methods We designed an open, two-arm pilot study with oral vancomycin (250mg every 6 h for 10–14 days) or FMT-FURM as treatments for the first CDI episode in hospitalized adult patients in Hospital Universitario “Dr. Jose Eleuterio Gonzalez”. Patients were randomized by a closed envelope method in a 1: 1 ratio to either oral vancomycin or FMT-FURM. CDI resolution was considered when there was a reduction on the Bristol scale of at least 2 points, a reduction of at least 50% in the number of bowel movements, absence of fever, and resolution of abdominal pain (at least two criteria). From each patient, a fecal sample was obtained at days 0, 3, and 7 after treatment. Specimens were cultured to isolate C. difficile, and isolates were characterized by PCR. Susceptibility testing of isolates was performed using the agar dilution method. Fecal samples and FMT-FURM were analyzed by 16S rRNA sequencing. Results We included 19 patients; 10 in the vancomycin arm and 9 in the FMT-FURM arm. However, one of the patients in the vancomycin arm and two patients in the FMT-FURM arm were eliminated. Symptoms resolved in 8/9 patients (88.9%) in the vancomycin group, while symptoms resolved in 4/7 patients (57.1%) after the first FMT-FURM dose (P = 0.26) and in 5/7 patients (71.4%) after the second dose (P = 0.55). During the study, no adverse effects attributable to FMT-FURM were observed in patients. Twelve isolates were recovered, most isolates carried tcdB, tcdA, cdtA, and cdtB, with an 18-bp deletion in tcdC. All isolates were resistant to ciprofloxacin and moxifloxacin but susceptible to metronidazole, linezolid, fidaxomicin, and tetracycline. In the FMT-FURM group, the bacterial composition was dominated by Firmicutes, Bacteroidetes, and Proteobacteria at all-time points and the microbiota were remarkably stable over time. The vancomycin group showed a very different pattern of the microbial composition when comparing to the FMT-FURM group over time. Conclusion The results of this preliminary study showed that FMT-FURM for initial CDI is associated with specific bacterial communities that do not resemble the donors’ sample.Peer reviewedFinal Published versio

    Clinical characteristics associated with the severity of Clostridium [Clostridioides] difficile infection in a tertiary teaching hospital from Mexico

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    Background: Clostridium difficile infection (CDI) is a leading cause of healthcare-associated diarrhea worldwide. In this study, risk factors associated with the development of severe-complicated and recurrent outcomes in CDI patients in different age groups, including the non-elderly, were assessed in a third-level hospital. Methods: CDI cases were detected by clinical data and polymerase-chain-reaction (PCR). Clinical, demographic, epidemiological, and microbiological risk factors for CDI were evaluated. Results: During the study period, 248 out of 805 patients with nosocomial diarrhea were diagnosed with CDI and the majority were severe-complicated cases (87.90%). Female gender (OR 3.19, 95% CI 1.19e8.55, p ¼ 0.02) and lymphoma (OR 3.95, 95% CI 1.03e15.13, p ¼ 0.04) were risk factors for severe-complicated CDI. Mature adulthood (51e60 years) (OR 5.80, 95% CI 1.56e21.62, p ¼ 0.01), previous rifampicin use (OR 7.44, 95% CI 2.10e26.44, p ¼ 0.00), and neoplasm (solid malignant neoplasm or hematological malignancies) (OR 4.12, 95% CI 1.01e16.83, p ¼ 0.04) were risk factors for recurrent infection. Autoimmune disorders (OR 6.62, CI 95% 1.26e34.73, p ¼ 0.02), leukemia (OR 4.97, 95% CI 1.05e23.58, p ¼ 0.04), lymphoma (OR 3.79, 95% CI 1.03e12.07, p ¼ 0.04) and previous colistin treatment (OR 4.97, 95% CI 1.05e23.58, p ¼ 0.04) were risk factors for 30-day mortality. Conclusion: Newly identified risk factors for recurrent CDI were rifampicin treatment and age between 51 and 60 years; colistin treatment was identified as a risk factor for 30-day mortality. Previously identified risk factors for severe-complicated CDI were confirmed, but with a major impact on non-elderly patients

    Clostridium difficile outbreak caused by NAP1/BI/027 strain and non-027 strains in a Mexican hospital

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    Background: Clostridium difficile infections caused by the NAP1/B1/027 strain are more severe, difficult to treat, and frequently associated with relapses. Methods: A case–control study was designed to examine a C. difficile infection (CDI) outbreak over a 12-month period in a Mexican hospital. The diagnosis of toxigenic CDI was confirmed by real-time polymerase chain reaction, PCR (Cepheid Xpert C. difficile/Epi). Results: During the study period, 288 adult patients were evaluated and 79 (27.4%) patients had confirmed CDI (PCR positive). C. difficile strain NAP1/B1/027 was identified in 31 (39%) of the patients with confirmed CDI (240 controls were included). Significant risk factors for CDI included any underlying disease (p < 0.001), prior hospitalization (p < 0.001), and antibiotic (p < 0.050) or steroid (p < 0.001) use. Laboratory abnormalities included leukocytosis (p < 0.001) and low serum albumin levels (p < 0.002). Attributable mortality was 5%. Relapses occurred in 10% of patients. Risk factors for C. difficile NAP1/B1/027 strain infections included prior use of quinolones (p < 0.03). Risk factors for CDI caused by non-027 strains included chronic cardiac disease (p < 0.05), chronic renal disease (p < 0.009), and elevated serum creatinine levels (p < 0.003). Deaths and relapses were most frequent in the 027 group (10% and 19%, respectively). Conclusions: C. difficile NAP1/BI/027 strain and non-027 strains are established pathogens in our hospital. Accordingly, surveillance of C. difficile infections is now part of our nosocomial prevention program

    Zientzia eskola egutegia 2022 (euskara)

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    El proyecto “Calendario Científico Escolar 2022” ha consistido en la elaboración de un calendario dirigido al alumnado de educación primaria y secundaria obligatoria. Cada día se ha recogido un aniversario científico o tecnológico como, por ejemplo, nacimientos de personas de estos ámbitos o conmemoraciones de hallazgos destacables. Además, el calendario se acompaña de una guía didáctica con orientaciones para el aprovechamiento educativo transversal del calendario en las clases, incluyendo actividades adaptadas a cada rango de edad y al alumnado con necesidades especiales.Proyecto FCT-20-16375 de la Fundación Española para la Ciencia y la Tecnología (FECYT); Agencia Estatal de Investigación (España); Ministerio de Ciencia e Innovación; Consejo Superior de Investigaciones Científicas; Universidad de León; Instituto de Ganadería de Montaña (IGM, CSIC-ULE); Cátedra de Cultura Científica de la Universidad del País Vasco/ Euskal Herriko Unibertsitatea (UPV/EHU); Delegación del CSIC en Castilla y León; Unidade de Divulgación Científica e Cultural - Universidade da Coruña; Academia de la Llingua Asturiana; Casa Árabe; Alliance Française de Gijón; University of California-Davis; Teagasc; CSIC-Representación Illes Balears; Balearic Islands Coastal Observing and Forecasting System (SOCIB); Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC, CSIC-UIB); Casa de la Ciència de Valencia (CSIC); Federación Española de Esperanto; Asociación Cultural Nogará Religada; Universidad de Zaragoza; Europa Laica; Museo Didáctico e Interactivo de Ciencias de la Vega Baja del Segura (MUDIC VBS-CV); Universidad Miguel Hernández; PuraVida Software.Mujeres con Ciencia; Asociaţia Secular-Umanistă din România; Instituto Geológico y Minero de España (IGME); Centro de Biología Molecular Severo Ochoa (CSIC-UAM); Asociación Española para el Avance de la Ciencia (AEAC); Centro de Investigación del Cáncer (CIC, CSIC-USAL); Discapacitodos; Universitat de les Illes Balears (UIB); Escuela de Estudios Hispano-americanos (CSIC); PRISMA – Asociación para la diversidad afectivo-sexual y de género en ciencia, tecnología e innovación; Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC); Círculo Escéptico; Civiencia; Universidad Autónoma de Madrid; Escuela de Estudios Árabes (CSIC); Evento Ciencia.Peer reviewe

    (árabe - العربية‎) 2022 الرزنامة الدراسية العلمية

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    El proyecto “Calendario Científico Escolar 2022” ha consistido en la elaboración de un calendario dirigido al alumnado de educación primaria y secundaria obligatoria. Cada día se ha recogido un aniversario científico o tecnológico como, por ejemplo, nacimientos de personas de estos ámbitos o conmemoraciones de hallazgos destacables. Además, el calendario se acompaña de una guía didáctica con orientaciones para el aprovechamiento educativo transversal del calendario en las clases, incluyendo actividades adaptadas a cada rango de edad y al alumnado con necesidades especiales.Proyecto FCT-20-16375 de la Fundación Española para la Ciencia y la Tecnología (FECYT); Agencia Estatal de Investigación (España); Ministerio de Ciencia e Innovación; Consejo Superior de Investigaciones Científicas; Universidad de León; Instituto de Ganadería de Montaña (IGM, CSIC-ULE); Cátedra de Cultura Científica de la Universidad del País Vasco/ Euskal Herriko Unibertsitatea (UPV/EHU); Delegación del CSIC en Castilla y León; Unidade de Divulgación Científica e Cultural - Universidade da Coruña; Academia de la Llingua Asturiana; Casa Árabe; Alliance Française de Gijón; University of California-Davis; Teagasc; CSIC-Representación Illes Balears; Balearic Islands Coastal Observing and Forecasting System (SOCIB); Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC, CSIC-UIB); Casa de la Ciència de Valencia (CSIC); Federación Española de Esperanto; Asociación Cultural Nogará Religada; Universidad de Zaragoza; Europa Laica; Museo Didáctico e Interactivo de Ciencias de la Vega Baja del Segura (MUDIC VBS-CV); Universidad Miguel Hernández; PuraVida Software.Mujeres con Ciencia; Asociaţia Secular-Umanistă din România; Instituto Geológico y Minero de España (IGME); Centro de Biología Molecular Severo Ochoa (CSIC-UAM); Asociación Española para el Avance de la Ciencia (AEAC); Centro de Investigación del Cáncer (CIC, CSIC-USAL); Discapacitodos; Universitat de les Illes Balears (UIB); Escuela de Estudios Hispano-americanos (CSIC); PRISMA – Asociación para la diversidad afectivo-sexual y de género en ciencia, tecnología e innovación; Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC); Círculo Escéptico; Civiencia; Universidad Autónoma de Madrid; Escuela de Estudios Árabes (CSIC); Evento Ciencia.Peer reviewe
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