180 research outputs found
Lactococcus garvieae, an unusual pathogen in infective endocarditis: case report and review of the literature
Lactococcus garvieae is an unusual cause of infective endocarditis (IE). No current diagnostic and therapeutic guidelines are available to treat IE caused by these organisms. Based on a case report, we provide a review of the literature of IE caused by L. garvieae and highlight diagnostic and treatment challenges of these infections and implications for management.
A 50-year-old Asian male with mitral prosthetic valve presented to the hospital with intracranial haemorrhage, which was successfully treated. Three weeks later, he complained of generalized malaise. Further work up revealed blood cultures positive for Gram-positive cocci identified as L. garvieae by MALDI-TOF. An echocardiogram confirmed the diagnosis of IE. Susceptibility testing showed resistance only to clindamycin. Vancomycin plus gentamicin were started as empirical therapy and, subsequently, the combination of ceftriaxone plus gentamicin was used after susceptibility studies were available. After two weeks of combination therapy, ceftriaxone was continued as monotherapy for six additional weeks with good outcome.
Twenty-five cases of IE by Lactococcus garvieae have been reported in the literature. Compared to other Gram-positive cocci, L. garvieae affects more frequently patients with prosthetic valves. IE presents in a subacute manner and the case fatality rate can be as high as 16%, comparable to that of streptococcal IE (15.7%). Reliable methods for identification of L. garvieae include MALDI-TOF, 16S RNA PCR, API 32 strep kit and BD Automated Phoenix System. Recommended antimicrobials for L. garvieae IE are ampicillin, amoxicillin, ceftriaxone or vancomycin in monotherapy or in combination with gentamicin
Comparative high-density linkage mapping reveals conserved genome structure but variation in levels of heterochiasmy and location of recombination cold spots in the common frog
DR_SEQAN: a PC/Windows-based software to evaluate drug resistance using human immunodeficiency virus type 1 genotypes
BACKGROUND: Genotypic assays based on DNA sequencing of part or the whole reverse transcriptase (RT)- and protease (PR)-coding regions of the human immunodeficiency virus type 1 (HIV-1) genome have become part of the routine clinical management of HIV-infected individuals. However, the results are difficult to interpret due to complex interactions between mutations found in viral genes. RESULTS: DR_SEQAN is a tool to analyze RT and PR sequences. The program output includes a list containing all of the amino acid changes found in the query sequence in comparison with the sequence of a wild-type HIV-1 strain. Translation of codons containing nucleotide mixtures can result in potential ambiguities or heterogeneities in the amino acid sequence. The program identifies all possible combinations of 2 or 3 amino acids that derive from translation of triplets containing nucleotide mixtures. In addition, when ambiguities affect codons relevant for drug resistance, DR_SEQAN allows the user to select the appropriate mutation to be considered by the program's drug resistance interpretation algorithm. Resistance is predicted using a rule-based algorithm, whose efficiency and accuracy has been tested with a large set of drug susceptibility data. Drug resistance predictions given by DR_SEQAN were consistent with phenotypic data and coherent with predictions provided by other publicly available algorithms. In addition, the program output provides two tables showing published drug susceptibility data and references for mutations and combinations of mutations found in the analyzed sequence. These data are retrieved from an integrated relational database, implemented in Microsoft Access, which includes two sets of non-redundant core tables (one for combinations of mutations in the PR and the other for combinations in the RT). CONCLUSION: DR_SEQAN is an easy to use off-line application that provides expert advice on HIV genotypic resistance interpretation. It is coded in Visual Basic for use in PC/Windows-based platforms. The program is freely available under the General Public License. The program (including the integrated database), documentation and a sample sequence can be downloaded fro
Scientific evidence for the control of antimicrobial resistance
[Extract]. Antimicrobial resistance (AMR) is one of the greatest global threats to human health. It is estimated that by 2050, AMR will lead to approximately 10 million annual deaths worldwide. Considering the impact of AMR on reproductive capacity and food production, in addition to its direct effect on infected people, the world's population could drop by between 11 and 444 million inhabitants by 2050 if AMR control is not achieved. As migrations and shared economies lead to the transmission of resistant bacteria across borders, the impacts of AMR become regionally significant. In the United States, methicillin-resistant Staphylococcus aureus caused 10 600 deaths in 2017. In Latin American and Caribbean countries, information is available from studies conducted in hospitals and other health facilities on the prevalence of antimicrobial-resistant pathogens. In many hospitals in Mexico, Peru, and Colombia, for example, resistance to third-generation cephalosporins and fluoroquinolones in Escherichia coli isolates is reaching almost 60%. Moreover, the dynamics of colonization and infection of multidrug-resistant organisms (such as carbapenemaseproducing Klebsiella pneumoniae) are unique in endemic areas of Latin America, favoring spread and dissemination. [...
Valoración del trabajo colaborativo y rendimiento académico en el proceso de enseñanza de un curso de investigación en estudiantes de medicina
Introduction. Collaborative work promotes learning through active participation of students, allowing the development of social abilities and the construction of their own knowledge. Objective. To analyze collaborative work and its relationship with academic performance in medical students in a research course. Methods. Cross-sectional study, in which 148 human medicine students enrolled in the research course participated, selected using a non-probabilistic sample. The questionnaire called analysis of cooperative work in higher education that assesses the importance of collaborative work, of 49 questions distributed in seven dimensions, was used. A Likert scale was used in a range of 1 to 5, where 1 is valued as a total disagreement and 5 totally agree. Three groups were established: low group to 33 percentile; middle group, from 34th percentile to 66th percentile; and high group, from 67th percentile to more. Results. The average age was 22,4 years and 52,7% corresponded to the female gender. In the “conception of work” dimension, 40,5% of students belonged to the middle group; in the dimension “planning the work of the groups by the teacher”, 41,9% to the low group; in “criteria for organizing groups”, 37,8% for the low group; in “internal operation”, 43,2% to the low group; and in “work efficiency”, 32,4% to the high group and 39,9% to the low group. The global average of grades corresponded to 12,7. The academic performance in students of the low and medium group was similar, and in the female students of the high group it was significantly higher (p=0,049). Conclusions. The low group predominated in the dimensions “teacher’s work planning”, “criteria for organizing groups”, “operating standards”, “internal functioning” and “efficiency”. 54,7% of students corresponded to the high group and the overall grade point average was 12,7. There was no relationship between the variables studied.Introducción. El trabajo colaborativo incentiva el aprendizaje mediante la participación activa de los estudiantes, permitiendo desarrollar habilidades sociales y construir sus propios conocimientos. Objetivo. Analizar el trabajo colaborativo y su relación con el rendimiento académico en estudiantes de medicina de un curso de investigación. Métodos. Estudio transversal, en el que participaron 148 estudiantes de medicina humana matriculados en el curso de investigación, seleccionados mediante una muestra no probabilística. Se utilizó el cuestionario denominado análisis del trabajo cooperativo en educación superior que valora la importancia del trabajo colaborativo, de 49 preguntas distribuidas en siete dimensiones. Se utilizó una escala de Likert en un rango de 1 a 5, donde 1 se valora como total desacuerdo y 5 totalmente de acuerdo. Se establecieron tres grupos: grupo bajo hasta percentil 33; grupo medio, de percentil 34 a percentil 66; y grupo alto, de percentil 67 a más. Resultados. La edad promedio fue 22,4 años y 52,7% correspondieron al género femenino. En la dimensión “concepción del trabajo”, 40,5% de estudiantes pertenecieron al grupo medio; en la dimensión “planificación del trabajo de los grupos por el profesor”, 41,9% al grupo bajo; en “criterios para organizar grupos”, 37,8% al grupo bajo; en “funcionamiento interno”, 43,2% al grupo bajo; y en “eficacia del trabajo”, 32,4% al grupo alto y 39,9% al grupo bajo. El promedio global de notas correspondió a 12,7. El rendimiento académico en estudiantes del grupo bajo y medio fue similar, y en las estudiantes de género femenino del grupo alto fue significativamente mayor (p=0,049). Conclusiones. El grupo bajo predominó en las dimensiones “planificación del trabajo del profesor”, “criterios para organizar grupos”, “normas de funcionamiento”, “funcionamiento interno” y “eficacia”. 54,7% de estudiantes correspondió al grupo alto y el promedio global de calificaciones fue 12,7. No existió relación entre las variables estudiadas
Active methodology and learning styles in the teaching process of the research methodology course of a faculty health sciences
Introducción. El modelo educativo centrado en el aprendizaje intenta desarrollar en el estudiante un rol más importante en su proceso de adquirir conocimiento; para ello, se requiere identificar las preferencias o estilos de aprendizaje de los estudiantes. Objetivo. Analizar la influencia del uso de la metodología activa y los estilos de aprendizaje participativo en estudiantes del curso de metodología de la investigación del nivel de pregrado. Métodos. Estudio cuantitativo de diseño cuasi experimental, prospectivo, de corte longitudinal. La población de estudio estuvo conformada por estudiantes de pregrado del curso de metodología de la investigación, se utilizó una muestra no probabilística por conveniencia, conformada por 79 estudiantes. El instrumento utilizado fue el test de estilo de aprendizaje elaborado por David Kolb. La implementación de la metodología activa se realizó durante el desarrollo del curso. Resultados. La participación de los estudiantes durante el desarrollo de clases y el uso de textos presentó un incremento significativo. El estilo de aprendizaje asimilador correspondió a 78,5% y 12,6% para el divergente antes de la implementación de la metodología y, al finalizar el estudio, los estudiantes modificaron su estilo de aprendizaje en forma significativa con un predomino del estilo de aprendizaje asimilador 62% y 22,8% para el estilo convergente. Conclusiones. La metodología activa permite la participación activa del estudiante mediante preguntas, aportes y fomenta el uso de textos. Asimismo, modifica significativamente el estilo de aprendizaje hacia un estilo asimilador y convergente.Introduction. The educational model focused on learning attempts to provide the student a more important role in the process of acquiring knowledge, for this it is necessary to identify preferences or learning style of the students. Objectives. Analysis the influence of the use of active methodology and learning styles in students of the methodology course of undergraduate research. Methods. Quantitative study of quasi-experimental, prospective longitudinal design, the study population consisted of undergraduate students of the research methodology course. A non-probabilistic sample was used for convenience, consisting of 79 students. The instrument used was the learning style test developed by David Kolb. The implementation of the active methodology was carried out during the development of the course. Results The participation of the students during the development of classes and the use of texts presented a significant increase. The assimilator learning style corresponded 78,5% and 12,6% for the divergent before the implementation of the methodology and at the end of the study, the students modified their learning style in a significant way with a predominance of assimilator learning style 62 % and 22,8% for the convergent style. Conclusions. The active methodology allows the active participation of the student through questions, contributions and encourages the use of texts. It also significantly modifies the learning style towards an assimilator and convergent style
Trajectory of post-COVID brain fog, memory loss, and concentration loss in previously hospitalized COVID-19 survivors:the LONG-COVID-EXP multicenter study
OBJECTIVE: This study aimed to apply Sankey plots and exponential bar plots for visualizing the trajectory of post-COVID brain fog, memory loss, and concentration loss in a cohort of previously hospitalized COVID-19 survivors.METHODS: A sample of 1,266 previously hospitalized patients due to COVID-19 during the first wave of the pandemic were assessed at 8.4 (T1), 13.2 (T2), and 18.3 (T3) months after hospital discharge. They were asked about the presence of the following self-reported cognitive symptoms: brain fog (defined as self-perception of sluggish or fuzzy thinking), memory loss (defined as self-perception of unusual forgetfulness), and concentration loss (defined as self-perception of not being able to maintain attention). We asked about symptoms that individuals had not experienced previously, and they attributed them to the acute infection. Clinical and hospitalization data were collected from hospital medical records.RESULTS: The Sankey plots revealed that the prevalence of post-COVID brain fog was 8.37% (n = 106) at T1, 4.7% (n = 60) at T2, and 5.1% (n = 65) at T3, whereas the prevalence of post-COVID memory loss was 14.9% (n = 189) at T1, 11.4% (n = 145) at T2, and 12.12% (n = 154) at T3. Finally, the prevalence of post-COVID concentration loss decreased from 6.86% (n = 87) at T1, to 4.78% (n = 60) at T2, and to 2.63% (n = 33) at T3. The recovery exponential curves show a decreasing trend, indicating that these post-COVID cognitive symptoms recovered in the following years after discharge. The regression models did not reveal any medical record data associated with post-COVID brain fog, memory loss, or concentration loss in the long term.CONCLUSION: The use of Sankey plots shows a fluctuating evolution of post-COVID brain fog, memory loss, or concentration loss during the first years after the infection. In addition, exponential bar plots revealed a decrease in the prevalence of these symptoms during the first years after hospital discharge. No risk factors were identified in this cohort.</p
Resistencia inicial a drogas antituberculosas en Buenaventura, Colombia.
In 2001, Buenaventura, Colombia, the rate of smear-positive pulmonary tuberculosis was of 66 per 100,000 inhabitants. The poor control of the tuberculosis in this city during the last 10 years and the inadequate use of first-line anti-tuberculosis drugs was an opportune situation for the development of high resistance to these drugs. Two surveys of initial resistance to first-line antituberculosis drugs were conducted in new cases of pulmonary TB, in the city of Buenaventura--the first from August 1, of 1997 to January 31 of 1998 and the second from November 15, of 2000 to November 15, 2001. The method of multiple proportions was used to determine drug susceptibility. Mycobacterium tuberculosis was isolated in 93% and 55% of the new cases of lung TB during each respective period. The initial resistance to at least one drug was 25% (9/36) and 32% (23/72), respectively. The initial multi-drug resistance (defined as resistance to at least isoniazid and rifampicin) was 6% for both surveys. This demonstrates the dissemination of multidrug-resistant bacilli and shows the need for surveillance of resistance to antituberculosis drugs in control of the disease, particularly in those areas where the TB control program has been erratically applied. In areas where multi-drug resistant TB occurs, the control strategy should be enhanced with the careful introduction of second-line drugs.La tasa de notificación de tuberculosis pulmonar bacilífera en 2001 en Buenaventura, Colombia, fue de 66 por 100.000 habitantes. El pobre control de la tuberculosis en este municipio durante los últimos 10 años y el uso inadecuado de medicamentos de primera línea hace sospechar una elevada resistencia a estas drogas antituberculosas. En este artículo se presentan y discuten los resultados de dos encuestas de resistencia inicial a drogas antituberculosas de primera línea en personas con tuberculosis pulmonar realizadas en Buenaventura entre el 1° de agosto de 1997 y el 31 de enero de 1998, y entre el 15 de noviembre de 2000 y el 15 de noviembre de 2001, con un intervalo de dos años y nueve meses. En las dos encuestas se utilizó el método de proporciones múltiples. Se logró aislar Mycobacterium tuberculosis en 93% y 55% de los casos nuevos de tuberculosis pulmonar diagnosticados en cada uno de los periodos estudiados. La resistencia inicial a cualquier medicamento antituberculoso fue de 25% (9/36) y 32% (23/72) en la primera y segunda encuesta, respectivamente. La multirresistencia inicial (definida como resistencia, al menos, a isoniacida y rifampicina) fue de 6% en ambas encuestas. Este porcentaje de resistencia encontrado demuestra la diseminación de cepas multirresistentes y destaca a la vigilancia epidemiológica de la resistencia a drogas antituberculosas como un componente esencial en el control de la enfermedad, por lo menos, en las zonas en las que el programa ha sido errático en el pasado. De esta manera, se podrán identificar las áreas en las que la estrategia DOTS deba ser reforzada con el uso de drogas de segunda línea (DOTS-plus)
Clinical, virological and biochemical evidence supporting the association of HIV-1 reverse transcriptase polymorphism R284K and thymidine analogue resistance mutations M41L, L210W and T215Y in patients failing tenofovir/emtricitabine therapy
Background: Thymidine analogue resistance mutations (TAMs) selected under treatment with nucleoside analogues generate two distinct genotypic profiles in the HIV-1 reverse transcriptase (RT): (i) TAM1: M41L, L210W and T215Y, and (ii) TAM2: D67N, K70R and K219E/Q, and sometimes T215F. Secondary mutations, including thumb subdomain polymorphisms (e.g. R284K) have been identified in association with TAMs. We have identified mutational clusters associated with virological failure during salvage therapy with tenofovir/emtricitabine-based regimens. In this context, we have studied the role of R284K as a secondary mutation associated with mutations of the TAM1 complex. Results: The cross-sectional study carried out with >200 HIV-1 genotypes showed that virological failure to tenofovir/emtricitabine was strongly associated with the presence of M184V (P < 10-10) and TAMs (P < 10-3), while K65R was relatively uncommon in previously-treated patients failing antiretroviral therapy. Clusters of mutations were identified, and among them, the TAM1 complex showed the highest correlation coefficients. Covariation of TAM1 mutations and V118I, V179I, M184V and R284K was observed. Virological studies showed that the combination of R284K with TAM1 mutations confers a fitness advantage in the presence of zidovudine or tenofovir. Studies with recombinant HIV-1 RTs showed that when associated with TAM1 mutations, R284K had a minimal impact on zidovudine or tenofovir inhibition, and in their ability to excise the inhibitors from blocked DNA primers. However, the mutant RT M41L/L210W/T215Y/R284K showed an increased catalytic rate for nucleotide incorporation and a higher RNase H activity in comparison with WT and mutant M41L/L210W/T215Y RTs. These effects were consistent with its enhanced chain-terminated primer rescue on DNA/DNA template-primers, but not on RNA/DNA complexes, and can explain the higher fitness of HIV-1 having TAM1/R284K mutations. Conclusions: Our study shows the association of R284K and TAM1 mutations in individuals failing therapy with tenofovir/emtricitabine, and unveils a novel mechanism by which secondary mutations are selected in the context of drug-resistance mutations
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