Abstract Background: Pseudomonas aeruginosa is a relevant infectious agent affecting patients within health care setting; this situation is worsening with the appearance of strains resistance to carbapenems. Aims: To study carbapenemase production in P. aeruginosa with decreased susceptibility to carbapenems processed in the microbiology laboratory of the Health Network UC-CHRISTUS in 2014-2015 and compare them with the strains studied in 2004-2005. Methods: Between January 2014 and June 2015, 459 strains of P. aeruginosa from clinical samples were isolated. Susceptibility was determined by dilution in agar and strains with reduced susceptibility to carbapenems were tested for carbaNP. Positive strains were studied by PCR for blaVIM, blaVIM-1, blaVIM-2, blaIMP, blaNDM, blaKPC, blaOXA and blaIMI genes. Pulsed field electrophoresis was performed on selected strains. Results: From 459 strains studied, 300 had reduced susceptibility to carbapenems (65.3%). Of these, 183 were viable for study, corresponding to 164 patients. The carbaNP test was positive in 44 strains of the 183 strains (24%). The resistance genes found were: blaVIM-2 in 35 strains, blaKPC-2+VIM-2 in 7 strains and blaKPC-2 in 2 strains. In the blaKPC-2 strains clonal relation between them was found. Conclusions: A 65.3% of P. aeruginosa presented decreased susceptibility to carbapenems being the presence of carbapenemases not the main resistance mechanism. In addition, the emergence in Chile of P. aeruginosa strains with bla of the KPC-2 type alone or in combination with VIM-2 is described.

Resumen Introducción: Pseudomonas aeruginosa es relevante en infecciones asociadas a la atención de salud, principalmente cuando presenta resistencia a carbapenémicos. Objetivos: Estudiar la producción de carbapenemasas en P. aeruginosa, con susceptibilidad disminuida a carbapenémicos procesadas en el Laboratorio de Microbiología de la Red de Salud UC-CHRISTUS entre 2014-2015, y compararlas con las cepas estudiadas en 2004-2005. Métodos: Entre enero de 2014 y junio de 2015, se aislaron 459 cepas de P. aeruginosa provenientes de muestras clínicas. La susceptibilidad fue determinada por dilución en agar y a las cepas con susceptibilidad disminuida a carbapenémicos se les realizó test de carbaNP. Las cepas positivas fueron estudiadas por RPC para genes blaVIM, blaVIM-1, blaVIM-2, blaIMP, blaNDM, blaKPC, blaOXA y blaIMI. Se realizó en cepas seleccionadas electroforesis de campo pulsado. Resultados: De las 459 cepas estudiadas, 300 presentaban susceptibilidad disminuida a carbapenémicos (65,3%). De éstas, 183 fueron viables para estudio, correspondientes a 164 pacientes. El test de carbaNP fue positivo en 44 cepas de las 183 cepas (24%). Los genes de resistencia encontrados fueron: blaVIM-2 en 35 cepas, blaKPC-2+VIM-2 en 7 cepas y blaKPC-2 en 2 cepas. En las cepas blaKPC-2 se encontró relación clonal entre ellas. Conclusiones: Un 65,3% de P. aeruginosa presentó susceptibilidad disminuida a carbapenémicos, observándose que la presencia de carbapenemasas no es el principal mecanismo de resistencia. Además, se describe la emergencia en Chile de cepas de P. aeruginosa con carbapenemasas del tipo KPC-2 sola o en combinación con VIM-2.

Background: A portfolio is a compilation of academic work that demonstrates student's knowledge, reflection and critical thinking. Aim: To describe the development and implementation of an undergraduate portfolio in the School of Medicine at the Pontificia Universidad Católica de Chile, its temporal evolution and its educational impact after 10 years of experience. Material and Methods: The development and implementation of a portfolio for 4th-year undergraduate medical student was analyzed. Its design, teaching and learning methodologies, results and perceptions of students and teachers were assessed. The educational impact was measured using Kirkpatrick's levels. Results: A total of 1,320 students participated between 2007 and 2017, supported by six teachers and 190 assistant-students. The portfolio included clinical cases, narrative medicine, palliative care and evidence-based medicine (EBM). The overall student's perception was positive, highlighting the development of critical analysis, clinical reasoning and professionalism. The delivery of feedback and learning assessment, allowed students to obtain excellent grades. There were only two cases of plagiarism reported. Fifteen EBM articles and two books with 52 narrative medicine essays were published. The greatest organizational impact of this teaching innovation, was that it evolved to become an established and continuous assessment instrument in 10 consecutive years. Conclusions: This portfolio is a project with a high educational impact, with a favorable perception by students and tutors, excellent results related to grades, stimulating both scientific writing and reflective practice.

Background: Carbapenems are the preferred β-lactamics for treatment for infections caused by enterobacteria producing extended-spectrum β-lactamases (ESBL); however, clinical studies show effectiveness of piperacillin/tazobactam in certain infections by Escherichia coli ESBL producers. Aim: To determine the clinical and micro-biological cure with piperacillin/tazobactam in patients with infections caused by E. coli ESBL producers, CTXM type. Methods: Retrospective descriptive study with adults hospitalized in a university hospital. We included urinary tract infections (UTI), intra-abdominal infections (IAI), soft tissue infections (STI) and/or bacteremia. Results: We studied 40 patients, where 65% corresponded to UTI, 25% to IAI and 10% were STI. The overall clinical cure was achieved in 89.4%, with the best results in the ITU (100%), followed by STI (80%) and 70% in IAI. The 85% of the strains had minimum inhibitory concentrations (MIC) ≤8 μg/ml and 70% with MIC ≤4 μg/mL, however the rate of failure were high in intra-abdominal infections with high inocula or not controlled; CTX-M-15 was found in the 62.5%. Conclusions: Piperacillin/tazobactam was efficient to obtain clinical and microbiological cure in patients with infections caused by ESBL producers but susceptible E. coli, especially in UTI and STI and to a lesser extent in IAI.

Resumen Introducción: En las infecciones por enterobacterias productoras de β-lactamasas de espectro extendido (BLEE), los β-lactámicos preferidos para tratamiento son los carbapenémicos. Sin embargo, estudios clínicos muestran eficacia de piperacilina/tazobactam en ciertas infecciones por Escherichia coli productoras de BLEE. Objetivo: Determinar la cura clínica y microbiológica con piperacilina/tazobactam en pacientes con infecciones por E. coli productoras de BLEE, tipo CTX-M. Materiales/Métodos: Estudio descriptivo, retrospectivo, con adultos internados en un hospital universitario. Incluimos infecciones del tracto urinario (ITU), intra-abdominales (IIA) e infecciones de tejidos blandos (ITB). Resultados: Estudiamos 40 pacientes, donde 65% correspondían a ITU, 25% IIA y 10 % ITB. La cura clínica global se logró en 89,4%, con mejores resultados en las ITU (100%), seguidas de ITB (80%) e IIA (70%). El 85% de las cepas tenía concentraciones inhibitorias mínimas (CIM) ≤ 8 μg/mL y 70% con CIM ≤ 4 μg/mL. La tasa de fracaso fue mayor en las infecciones con inóculos altos intraabdominales. La BLEE del tipo CTX-M-15 se encontró en 62,5%. Conclusiones: Piperacilina/tazobactam logró cura clínica y microbiológica, en pacientes con infecciones por E. coli productoras de BLEE susceptibles, especialmente en ITU e IPB y en menor medida en IIA.

Leishmaniasis is an infection caused by protozoa of the genus Leishmania sp. and transmitted by sandfly vectors. Cutaneous leishmaniasis (CL) is the most frequent form of presentation. Clinically, chronic and painless ulcers are observed, which usually occur at the site of the sandfly bite. The diagnosis and treatment of this disease is specially challenging in non-endemic countries such as Chile, requiring the use of diverse laboratory techniques as well as the support of expert physicians. Herein we report an imported case of a healthy 42-year-old male with CL caused by L. braziliensis with successful response to liposomal amphotericin B.

Resumen La leishmaniasis es una infección producida por protozoos del género Leishmania, transmitida por insectos hematófagos. La forma de presentación más frecuente es la leishmaniasis cutánea (LC), en la cual se observan úlceras crónicas e indoloras, usualmente localizadas en el sitio de la picadura del insecto. El diagnóstico y tratamiento de esta enfermedad son especialmente desafiantes en zonas no endémicas como nuestro país, requiriendo el uso de diversas técnicas de laboratorio y el apoyo de expertos. Se reporta el caso clínico importado de un varón de 42 años con LC causada por L. braziliensis con respuesta exitosa al tratamiento con anfotericina B liposomal.

Introduction: Incidence of multi-resistant bacteria is an indicator that permits better estimation of the magnitude of bacterial resistance in hospitals. Aim: To evaluate the incidence of relevant multi-drug resistant bacteria in intensive care units (ICUs) of Chile. Methods: Participating hospitals submitted information about the number of isolates from infected or colonized patients with 7 epidemiologically relevant multi-resistant bacteria in adult and pediatric ICUs between January 1, 2014 and October 31, 2015 and the number of bed days occupied in these units in the same period was requested. With these data incidence was calculated per 1,000 patient days for each unit. Results: Information from 20 adults and 9 pediatric ICUs was reviewed. In adult ICUs the bacteria with the highest incidence were K. pneumoniae ESBL [4.72 × 1,000 patient day (1.21-13.89)] and oxacillin -resistant S. aureus [3.85 (0.71-12.66)]. In the pediatric units the incidence was lower, highlighting K. pneumoniae ESBL [2.71 (0-7.11)] and carbapenem -resistant P. aeruginosa [1.61 (0.31-9.25)]. Conclusion: Important differences between hospitals in the incidence of these bacteria were observed. Incidence of multi-resistant bacteria in adult ICU was significantly higher than in pediatric ICU for most of the studied bacterias.

Resumen Introducción: La vigilancia de incidencia de bacterias multi-resistentes es un indicador que permite estimar mejor la magnitud de la resistencia bacteriana en los servicios hospitalarios. Objetivo: Evaluar la incidencia de bacterias multi-resistentes relevantes en unidades de cuidados intensivos del país y establecer las diferencias entre población adulta y pediátrica. Metodología: Se solicitó a los hospitales participantes información del número de aislados de siete bacterias multi-resistentes epidemiológicamente relevantes de unidades de cuidados intensivos (UCI) de adulto y pediátrico entre enero de 2014 y octubre de 2015, y el número de días-cama ocupados en dichas unidades en el mismo período. Con estos datos se calculó incidencia por 1.000 pacientes-día para cada unidad. Resultados: Se recibió información de 20 UCI adultos y 9 UCI pediátricas. En UCI adultos las bacterias de mayor incidencia fueron K. pneumoniae productora de BLEE [4,72 × 1.000 días cama (1,21-13,89)] y S. aureus resistente a oxacilina [3,85 (0,71-12,66)]. En pediatría la incidencia fue menor, destacando K. pneumoniae productora de BLEE [2,71 (0-7,11)] y P. aeruginosa resistente a carbapenémicos [1,61 (0,31-9,25)]. Conclusión: Se observan importantes diferencias entre los distintos hospitales en la incidencia de las bacterias estudiadas. La incidencia de bacterias multi-resistentes en UCI de adultos es significativamente mayor que en UCI pediátrica para la mayoría de las bacterias estudiadas.

Introduction: Red Salud UC is an Academic health network where HIV-infected patients from the public and private health system are followed by a multidisplinary team. Aim: To determine virologic and immunologic response after 144 weeks of starting first antiretroviral therapy in these patients. Methods: A retrospective analysis of adult HIV patients attended between 1992 and 2011 was performed. Demographic and clinical characteristics, antiretroviral therapies data and immunologic and virologic outcomes were collected. CD4 count and HIV viral load changes up to 144 weeks after initiation of antiretroviral therapy were analyzed. Results: 860 patients were included in the analyses. Median age was 42 years, 93% were men. Median CD4+ count at baseline was 202 cells/mm³. The most used ART regimen was zidovudine/lamivudine plus efavirenz. First line anti-retroviral therapy was changed in 42% patients, being the most common cause, drug toxicity. At week 144, median CD4+ lymphocyte cell count was 449 cells/mm³. Ninety percent and 96% had undetectable viral load measured as < 50 copies/mL or < 400 copies/mL respectively. Discussion: First report of a university cohort, with CD4 and viral load follow up for 144 weeks, including Chilean patients from public and private system. After initiation of ART, an excellent immunologic and virologic response was observed in this cohort.

Introducción: La Red de Salud UC es una red académica de atención, donde pacientes portadores del VIH del área pública y privada de salud son atendidos por un equipo profesional multidisciplinario. Objetivo: Determinar las respuestas virológicas e inmunológicas a 144 semanas de iniciada la primera terapia antiretroviral en dichos pacientes. Métodos: Análisis retrospectivo de registros de pacientes adultos portadores de VIH atendidos entre 1992 y 2011. Se recolectaron datos demográficos, clínicos, terapia anti-retroviral, resultados inmunológicos y virológicos. Se analizaron los resultados de linfocitos T CD4+ y carga viral de VIH a las 144 semanas de iniciada la primera terapia anti-retroviral. Resultados: Fueron incluidos en el análisis 860 pacientes. El promedio de edad fue 42 años, 93% hombres. La mediana basal de LT CD4+ fue 202 céls/mm³. La terapia más utilizada fue zidovudina/lamivudina/efavirenz. En 42% de los pacientes se cambió la terapia de primera línea; la causa más común fue toxicidad a los anti-retrovirales. A la semana 144 de iniciada la terapia, la mediana de LT CD4+ fue de 449 céls/mm³. Alcanzaron cargas virales indetectables 90 y 96% con < 50 copias ARN/mL o < 400 copias ARN/mL respectivamente. Discusión: Primer reporte de pacientes tratados en un centro universitario, con seguimiento inmuno-virológico a 144 semanas, que incluye pacientes del área pública y privada de salud chilena. Después del inicio de la terapia, se observó una excelente respuesta inmuno-virológica.

Surveillance of antimicrobial consumption is a central part in programs of antibiotic stewardship. However, in Chile there are no national data on antibiotic consumption representing a significant number of hospitals by clinical services. In 2013 a survey was sent to multiple Chilean hospitals to evaluate antimicrobial consumption in medical services (MS), surgery services (SS) and critical care units (ICU). We used the standardized methodology recommended by the WHO, using the number of DDD/100 days beds. In the MS and SS beta-lactam and no beta-lactam antibiotics commonly used were evaluated. In the ICU consumption vancomycin, linezolid, imipenem, merope-nem, colistin and tigecycline was evaluated. Fifteen hospitals reported the density of antimicrobial consumption. Ceftriaxone and cloxacillin were the most commonly used antibiotics in general services (average cloxacillin 4,9 DDD/100 bed days in MS and 8,0 DDD/100 in SS; ceftriaxone 13,5 DDD/100 in MS and 16,7 DDD/100 in SS). In the SS there was also a significant consumption of metronidazole (average 14,5 DDD/100 bed days). In the ICU there was an important variability of consumption of selected antibiotics. This study reports the average and range of antibiotic consumption in MS, SS, and ICU from a significant number of hospitals in the country, during 2013. This information allows hospitals to compare their consumption of antibiotics with a significant sample of Chilean hospitals. Analysis of this information should consider a careful interpretation according to the sample shown here and the reality of each hospital.

La vigilancia del consumo de antimicrobianos es parte central en los programas de utilización de antimicrobianos. Sin embargo, en Chile no se conocen datos del consumo de antibacterianos por servicios clínicos, que representen un número importante de hospitales. En el año 2013 se envió una encuesta a múltiples hospitales chilenos para evaluar el consumo de antimicrobianos en los servicios clínicos de Medicina (SM), Cirugía (SC) y Unidades de Pacientes Críticos (UPC). Para ello se usó la metodología estandarizada recomendada por la OMS de DDD/100 días camas. En los SM y SC se evaluaron antibacterianos β-lactámicos y no β-lactámicos de uso frecuente. En las UPC se evaluó el consumo de vancomicina, linezolid, imipenem, meropenem, colistín y tigeciclina. Se obtuvo resultados de 15 hospitales, los cuales informaron la densidad de consumo de antimicrobianos de los servicios mencionados. Ceftriaxona y cloxacilina fueron los antimicrobianos más utilizados en servicios generales (promedio cloxacilina 4,9 DDD/100 días cama en SM y 8,0 DDD/100 en SC; ceftriaxona 13,5 DDD/100 en SM y 16,7 DDD/100 en SC). En los SC se agrega además un consumo importante de metronidazol (promedio 14,5 DDD/100 días cama). En las UPC destaca la variabilidad de consumo de antimicrobianos seleccionados. Este estudio reporta el promedio y rangos de consumo de antibacterianos en SM, SC y UPC de un número importante de hospitales del país durante el año 2013. Esta información permite a los hospitales comparar su consumo de antibacterianos con una muestra significativa de hospitales chilenos. El análisis de esta información debe considerar una cuidadosa interpretación de acuerdo a la muestra aquí representada y la realidad de cada uno de los hospitales.

Five issues were reviewed in depth at the 2014 annual meeting of Colaborative Group Against Bacterial Resistance and the antecedents and conclusions are detailed in this document. I.- News in CLSI 2014: the difficulties and implications on its implementation at the local level were reviewed and recommendations were set. II.- Criteria for determining the incidence of multi-resistant microorganism in critical care units where indicators and monitoring methodology for better quantification of microorganisms were defined. III.- Quality requirements were established to be considered by the professionals involved in the selection of antimicrobials in the hospital. IV.- Transfer policies, screening and contact precautions for the control of transmission of multiresistant bacteria. V.- Recommendations for health facilities when a carbapenemase producing enterobacteriacea is detected, in a checklist format for rapid deployment in hospitals without endemia of these agents. These are suggestions that arise from the joint work of specialists from many hospitals that do not represent consensus or recommendation, but may help to control the resistance level of each health facility in the country.

En la reunión anual del Grupo Colaborativo de Resistencia Bacteriana del año 2014 se revisaron en profundidad cinco tópicos cuyos antecedentes y conclusiones se detallan en este documento. Los temas fueron: I.- Novedades del CLSI 2014: se revisaron las dificultades e implicancias de su implementación a nivel local y se establecen recomendaciones. II.- Criterios para la determinación de incidencia de microoganismos multi-resistentes en unidades de pacientes críticos, donde se definieron los indicadores y la metodología de vigilancia para una mejor cuantificación del problema. III.- Se establecieron requisitos de calidad a considerar por los profesionales que participan en la selección de antimicrobianos en el hospital. IV.- Se discutieron las políticas de traslado, tamizaje y precauciones de contacto para el control de la transmisión de bacterias multiresistentes. V.- Se establecieron recomendaciones para los establecimientos de salud frente a la pesquisa de una enterobacteria productora de carbapenemasa en formato de lista de chequeo para la implementación rápida en hospitales sin endemia de estos agentes. Estas sugerencias nacen del trabajo conjunto de especialistas de muchos hospitales, no representan un consenso o normativa pero pueden ser de ayuda para el control de la resistencia en cada establecimiento de salud del país.

Background: Assessment for learning is a paradigm that is taking shape in the field of medical education. This approach aims to embed the assessment process within the educational and learning process. Aim: To evaluate the impact of curricular changes, from a focus of assessment of learning to one of assessment for learning, in the perception of undergraduate students of medicine and their final grades obtained in a theoretical course (TCG). Material and Methods: In the year 2011 lectures were reduced and intermediate assessments followed by a feedback session were introduced. The activities of each program course, surveys about student perceptions of the course and the final grades of students (assessments with multiple choice questions) were compared between the periods prior and after curricular changes (2005-2010 and 2011-2013). Results: As a consequence of curricular changes, time for lectures was reduced by 19.5%, time for summative assessments was increased by 8.5%, and feedback activity, occupying 7.3% of the course time was added. There were significant improvements in student is perceptions in all areas assessed by surveys, emphasizing feedback and assessments. The overall grade assigned to the course dictated after implementing the changes increased from 6.18 to 6.59 (p < 0.001, 1-7 scale). The grades of students also improved from an average of 5.78 to 6.43 (p < 0.001, 1-7 scale). Conclusions: Assessment for learning achieved the desired educational impact without increasing the assigned curricular time. Programmatic assessment is favorably perceived by students.

Visual assessment of surfaces may not be enough to document the level of cleanliness in the hospital setting. It is necessary to introduce quantitative methods to document the results of this practice.Objective:To evaluate the efficacy of hospital terminal cleaning procedures, using an adenosine triphosphate (ATP) bioluminescence method in a teaching hospital.Method:During 2008 we conducted an evaluation using ATP bioluminescence LIGHTNING MVP™ (Arquimed) of external and internal housekeeping service. After conducting an initial evaluation we implemented education of cleaning practices and finally we did a post intervention evaluation. Using chi-square method we compared prior versus after cleaning, quality of cleaning performed by external versus internal personnel, single versus double terminal cleaning procedures and prior versus after intervention. A finding of three RLU or less was considered a clean surface.Results:We performed 198 evaluations in 33 patient units and nine OR. Internal personnel accomplished 25.37% of clean surfaces before and 80% after the education intervention (p = 0.01). In contrast, external personnel obtained 68.8% before and 73.33% after intervention (p = 0.3).Conclusions:This study suggests that visual assessment is not enough to ensure quality of the process and it is necessary to document the level of cleanliness by quantitative methods.

Background: Formative evaluation is a range of formal assessment employed by professors during the teaching process in order to modify curriculum activities, to improve student attainment. For students, it is helpful to evaluate their learning process. Although recommended, it is seldom used. Aim: To evaluate the perception and performance of medical students subjected to formative assessments during an integrative clinical course. Material and Methods: Fourth year medical students that participated in a multiple choice formative assessment, similar to the final exam during 2007 and 2008, responded a survey about the usefulness and quality of such assessment. Student achievement was expressed as the percentage of correct answers of the tests. Results: The formative assessment was answered by 99% of students. In 2007 97% of students considered the experience as excellent or very good and 92% evaluated it as useful or very useful. During 2008 the figures were 89% and 79%. The students outlined that this assessment oriented their study, allowed them to discover their weaknesses and have a perception of the degree of difficulty of the final exam. Over 90% of students that took the formative evaluation, improved their academic achievement. Conclusions: Formative assessments are well evaluated by medical students and improve their academic achievement.

To review the epidemiology of nosocomial extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America, a systematic search of the biomedical literature (PubMed) was performed for articles published since 2005. Rates of nosocomial infections caused by extended spectrum β-lactamase-producing Enterobacteriaceae in Latin America have increased since 2005. Up to 32% of Escherichia coli and up to 58% of Klebsiella pneumoniae isolates are extended spectrum β-lactamase-positive, rates that are higher than in other world regions. From a region-wide perspective, 11-25% of E. coli isolates and 45-53% of K. pneumoniae isolates were nonsusceptible to third-generation cephalosporins. At the country level, there was a wide range in Enterobacteriaceae resistance rates to third-generation cephalosporins, with especially high rates of resistance to E. coli in Guatemala, Honduras, and Mexico, and high resistance rates to Klebsiella spp. in Argentina, Brazil, Chile, Guatemala, Honduras, and Paraguay. Susceptibility of extended spectrum β-lactamase-producing Enterobacteriaceae to cefepime, fluoroquinolones, ampicillin/sulbactam, aminoglycosides, and piperacillin/tazobactam has also been compromised, leaving the carbapenems, tigecycline, and colistin as the only antibiotics with >90% susceptibility rates. There is a steady increase in the prevalence and types of extended spectrum β-lactamases produced by Enterobacteriaceae isolates in Latin American hospitals (particularly CTX-Ms), suggesting endemic conditions overlaid by clonal outbreaks. Appropriate treatment decisions and infection control strategies informed by surveillance of regional and local susceptibilities and mechanisms of resistance are required to mitigate this major public health concern.

Bacteria antimicrobial resistance is an uncontrolled public health problem that progressively increases its magnitude and complexity. The Grupo Colaborativo de Resistencia, formed by a join of experts that represent 39 Chilean health institutions has been concerned with bacteria antimicrobial susceptibility in our country since 2008. In this document we present in vitro bacterial susceptibility accumulated during year 2012 belonging to 28 national health institutions that represent about 36% of hospital discharges in Chile. We consider of major importance to report periodically bacteria susceptibility so to keep the medical community updated to achieve target the empirical antimicrobial therapies and the control measures and prevention of the dissemination of multiresistant strains.

La resistencia bacteriana es un problema de salud pública que lejos de estar controlado, aumenta en cantidad y complejidad. El Grupo Colaborativo de Resistencia, es un conjunto de profesionales que representan a 39 establecimientos de salud del país y que se ha ocupado desde 2008 de recolectar información sobre la susceptibilidad antimicrobiana de bacterias en Chile. En este documento se presenta la susceptibilidad in vitro acumulada del año 2012, de 28 establecimientos de salud del país que representan, al menos, 36% de los egresos hospitalarios de Chile. Consideramos de la mayor relevancia reportar periódicamente la susceptibilidad bacteriana de modo de mantener a la comunidad médica actualizada para orientar las terapias empíricas y las medidas de control y prevención de la diseminación de cepas multi-resistentes.