ABSTRACT Background: Clostridioides difficile infection (CDI) is the most common cause of healthcare-associated infections in Western countries. Risk factors, mortality, and healthcare utilization for CDI in Latin America are poorly understood. This study assessed risk factors and burden associated with nosocomial CDI in four Latin American countries. Methods: This retrospective, case-control study used databases and medical records from 8 hospitals in Argentina, Brazil, Chile, and Mexico to identify nosocomial CDI cases from 2014 − 2017. Cases were patients aged ≥18 years with diarrhea and a positive CDI test ≥72 h after hospital admission. Two controls (without diarrhea; length of hospital stay [LOS] ≥3 days; admitted ±14 days from case patient; shared same ward) were matched to each case. CDI-associated risk factors were assessed by univariate and multivariable analyses. CDI burden (LOS, in-hospital mortality) was compared between cases and controls. Results: The study included 481 cases and 962 controls. Mean age and sex were similar between cases and controls, but mean Charlson comorbidity index (4.3 vs 3.6; p< 0.001) and recent hospital admission (35.3% vs 18.8%; p< 0.001) were higher among cases. By multivariable analyses, CDI risk was associated with prior hospital admission within 3 months (odds ratio [OR], 2.08; 95% CI: 1.45, 2.97), recent antibiotic use (ie, carbapenem; OR, 2.85; 95% CI: 1.75, 4.64), acid suppressive therapy use (OR, 1.71; 95% CI: 1.14, 2.58), and medical conditions (ie, renal disease; OR, 1.48; 95% CI: 1.19, 1.85). In-hospital mortality rate (18.7% vs 6.9%; p< 0.001) and mean overall LOS (33.5 vs 18.8 days; p< 0.001) were higher and longer, respectively, in cases versus controls. Conclusion: Antibiotic exposure, preexisting medical conditions, and recent hospital admission were major risk factors for CDI in Argentina, Brazil, Chile, and Mexico. CDI was associated with increased in-hospital risk of death and longer LOS. These findings are consistent with published literature in Western countries.

Abstract Chrysodeixis includens has become the major Lepidopteran pest of soybean crops, especially in the Brazilian Cerrado (savanna) region. A native isolate of Chrysodeixis includens nucleopolyhedrovirus (ChinNPV) from this region, Buritis, MG, was assessed for its biological and molecular features. In addition, in vitro co-infection with Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV), another virus of an important soybean pest, was tested. The ChinNPV-Buritis isolate presented an average LC50 of 7,750 occlusion bodies (OBs)/ml of diet in C. includens larvae. Analysis of restriction endonuclease profiles of viral DNA revealed similarities with previously described ChinNPV isolates IE, IF, and IG from Brazil, although the presence of submolar bands indicates genetic heterogeneity. Optical microscopy analysis in conjunction with quantitative PCR (qPCR) demonstrated in vitro infection of this isolate in IPLB-SF-21AE, Sf9, and BTI-Tn-5B1-4 cell lines, but the amount of ChinNPV tends to decrease through serial passages. The qPCR method developed in this study successfully detected both AgMNPV and ChinNPV from cell culture and from infected larvae. The cell line Tn-5B1-4 is indicated for future development of in vitro production and co-infection studies.

ABSTRACT Background Nephron sparing surgery (NSS) is well established as the standard of care for most surgical small renal tumors when technically feasible. While the majority of sporadic renal tumors are solitary, multifocal tumors have been reported in 5.4% to 25% of patients with tumors smaller than 5cm. We present a video where we approach, through laparoscopy, four tumors on the same kidney. Case study Male, 58y, went through a routine abdominal ultrasound which showed a 5cm left kidney nodule. His MRI pointed a total of 4 nodules on his left kidney. The aspect suggested a papillary cancer due to high cellularity and low vascularization. The patient was submitted to partial nephrectomy under ischemia to remove the two largest tumors (inferior pole) and a resection without clamping of the other two ipsilateral tumors. Result We performed the surgery in 2 stages. In the first one, we approached the 2 tumors located on the inferior pole inducing warm ischemia, whereas in the second stage we resected the 2 remaining tumors using the technique without clamping. The surgery lasted 220 minutes, with 800mL of blood loss, not requiring blood transfusion. Ischemia time was 35 minutes. The histopathological analysis confirmed that the 4 tumors were papillary cancer, with free margins. Conclusion NSS can be performed and should be tried in patients with multiple kidney tumors, preferably through laparoscopy or assisted by robot. It can be made either using or not clamping of the pedicle, depending on the RENAL score.

En la última década, con el objetivo de detectar tempranamente y/o evaluar el grado de extensión de alteraciones arteriales, se han desarrollado nuevos estudios seguros, no invasivos, rápidos, de bajo costo y de elevada sensibilidad y especificidad. Recientemente se ha incluido su empleo en recomendaciones internacionales para la prevención cardiovascular en niños y adolescentes. Con el objetivo de que niños uruguayos accedan a estos estudios se ha implementado recientemente un servicio de evaluación arterial no invasivo destinado a la población pediátrica (CUiiDARTE-Pediátrico) en el Centro Hospitalario Pereira Rossell. Allí se aplica un abordaje de evaluación arterial con fines diagnósticos, preventivos, y de valoración de daño y/o de evaluación de acciones terapéuticas en niños y adolescentes. Se realiza determinación no invasiva e innocua de parámetros complementarios de estructura y función arterial: (1) evaluación de presencia/composición histológica (“histología virtual”) de placas de ateroma; (2) espesores parietales; (3) rigidez arterial global, regional y local; (4) reactividad vascular (función endotelial); (5) presión aórtica central; (6) parámetros derivados de la onda del pulso asociados a reflexiones de onda; (7) índice tobillo-brazo; (8) parámetros ecográficos vasculares estándar, y (9) monitorización no invasiva (consultorio y ambulatoria) de presión arterial, rigidez arterial, resistencias periféricas y/o gasto cardíaco. Habiendo evaluado más de 450 niños, el presente artículo tiene como objetivo presentar los estudios (marcadores) arteriales allí realizados.

Non-invasive, secure, fast and inexpensive systems and studies have been developed in the past decade allowing for early detection of vascular disorders with high sensitivity and specificity. International guidelines aimed at cardiovascular prevention, risk stratification and/or target organ damage assessment in adults recommend non-invasive vascular studies. Recently, vascular evaluation has also been considered in guidelines for cardiovascular prevention in children. Within this context, an arterial evaluation Center (CUiiDARTE-Pediátrico) has been developed and implemented in Pereira-Rossell Hospital to allow children access to non-invasive vascular studies in our country. In the Center, a multi-parameter approach is applied to assess the vascular health condition of children and adolescents by joint analysis of complimentary structural and functional arterial indexes and parameters: (1) detection and evaluation of atherosclerotic plaque composition ("Virtual histology"), (2) arterial wall thickness, (3) global, regional and local arterial stiffness, (4) vascular reactivity (endothelial function), (5) central aortic pressure, (6) pulse wave and waved reflection analysis, (7) ankle-brachial index, (8) arterial blood flow velocities and patterns (arterial Doppler), (9) ambulatory (or hospital) arterial pressure, stiffness and cardiac output monitoring. This study aimed to introduce our vascular approach and non-invasive studies.

Las estrategias preventivas, de detección precoz y el tratamiento de las alteraciones cardiovasculares continúan centrados en los adultos. Esto ocurre a pesar de evidencias que indican que la aterosclerosis comienza en la niñez, que la presencia de factores de riesgo cardiovascular y el tiempo de exposición a ellos en niños se asocian con cambios arteriales precoces y con el riesgo y morbimortalidad cardiovascular en la vida adulta, y que intervenciones que reduzcan la exposición a factores de riesgo en niños asocian reducción en morbimortalidad cardiovascular. Buscando revisar la bibliografía existente que sustenta realizar acciones preventivas, de valoración del riesgo cardiovascular y de daño arterial en subpoblaciones de niños, el objetivo del presente artículo es analizar evidencias acerca de: (a) la génesis y progresión de la aterosclerosis en niños y su relación con la del adulto; (b) la asociación entre factores de riesgo en la niñez y alteraciones arteriales y riesgo del adulto, y (c) los efectos que la intervención sobre los factores de riesgo tiene en el sistema arterial del niño.

Strategies for prevention, early detection and treatment of cardiovascular diseases are focused in adults. This is so despite it is known that: a) atherosclerosis starts in childhood; b) exposure to cardiovascular risk factors associates early vascular changes in children and increased cardiovascular risk when they become adults; c) cardiovascular risk factors’ control in childhood associates an improvement in cardiovascular morbi-mortality. In this context, in this work we review available evidence aiming at analyzing: a) cardiovascular risk factors exposure and development of vascular alterations in childhood and their relationship with adults’ atherosclerosis and cardiovascular risk; b) the vascular effects/impact of interventions designed to control cardiovascular risk factors in childhood.

Introducción: si bien se acepta que en adultos la obesidad asocia riesgo aumentado de enfermedades o eventos cardiovasculares, poco se conoce aún acerca de si la obesidad infantil asocia, y de ser así en qué magnitud, alteraciones arteriales precoces. El objetivo del trabajo fue caracterizar el estado funcional y estructural del sistema arterial de niños y adolescentes, y analizar los potenciales cambios arteriales asociados a la presencia de obesidad. Métodos: se seleccionaron 224 niños y adolescentes (93 de sexo femenino) asintomáticos (edad: 4-15 años), que presentasen normopeso (n = 142; percentil de índice de masa corporal (pIMC), 15 £ pIMC < 85) u obesidad (n = 82; pIMC ³ 97). Fueron criterios de exclusión: presentar comorbilidades crónicas (por ejemplo, cardiovasculares, renales), ser diabético, consumir fármacos cardioactivos y/o estar bajo tratamientos que afecten el sistema cardiovascular. Se realizó entrevista clínica, valoración antropométrica y evaluación arterial no invasiva que incluyó medición de: espesor íntima-media carotídeo (CIMT; ultrasonografía/software específico), presión arterial periférica y aórtica central (tonometría de aplanamiento), rigidez aórtica (velocidad de onda de pulso carótido-femoral, (VOP); tonometría de aplanamiento) y reactividad vascular (vasodilatación mediada por flujo). Se compararon los resultados de niños con normopeso y los de los obesos, para la población total y subgrupos sin dislipemia. Resultados: respecto de los niños con normopeso, con independencia de la presencia de dislipemia, los obesos presentaron mayor presión arterial sistólica y de pulso periférica y central, mayores diámetros carotídeos y CIMT, mayor rigidez aórtica y menor vasodilatación mediada por flujo. Conclusión: la obesidad en niños y adolescentes asocia aumento de espesor carotídeo, de rigidez y presión aórticas, y reducción de la reactividad vascular.

Introduction: while it is accepted that in adults the obesity is associated to an increased risk of disease or cardiovascular events, little is known yet if childhood obesity leads also, and if so in what magnitude, to early arterial changes. The objective of this work was to characterize the functional and structural state of the arterial system in children and adolescents, and analyze the potential arterial changes associated with the presence of obesity. Methods: 224 asymptomatic children and adolescents were selected (age: 4-15 years; 93 females), with normal weight (n= 142; body mass index percentile (p BMI), 15£ p IMC< 85) or obesity (n= 82, p BMI ³ 97). Inclusion criteria were: not to present chronic co-morbidities (such as cardiovascular and/or renal), not being diabetic, not being cardio-active drugs consumers or being under treatment that could affect cardiovascular system. Clinical interview, anthropometrical evaluation was assessed and non-invasive arterial evaluation was performed, in which carotid Intima-media thickness (CIMT; ultrasonography/specific software), arterial peripheral and central aortic pressures (applanation tonometry), aortic stiffness (Carotid-femoral Pulse Wave Velocity, PWV; applanation tonometry) and vascular reactivity (flow-mediated dilation) measurement were analyzed. The results of children with normal weight and obesity were compared for both total population and children without dyslipemia. Results: compared with children with normal weight, and with independence of the presence of dyslipidemia, obese children had higher systolic and pulse peripheral and aortic blood pressure, larger diameters and carotid CIMT, increased aortic stiffness, and reduced flow-mediated vasodilation. Conclusion: obesity in children and adolescents leads to arterial remodeling, increased carotid thickness, aortic stiffness, central aortic pressure and reduced vascular reactivity.

Introducción: Los estudios arteriales no-invasivos se emplean en adultos para valoración de daño de órgano blanco, re-clasificación de riesgo cardiovascular y/o detección temprana de alteraciones en estructura y función arterial. Recientemente, se recomendó su empleo en niños, dado que permitirían detectar aquellos con mayor susceptibilidad a daño aterosclerótico y realizar intervenciones específicas tempranas que permitirían reducir el daño arterial, y por tanto el riesgo cardiovascular en la vida adulta. En Uruguay, en 2014 se inició la implementación de un servicio de evaluación arterial no-invasiva, gratuito. En este se aplican integradamente diversos estudios como evaluación de la rigidez arterial regional y local, espesor parietal, reactividad vascular, presión aórtica central, análisis de parámetros de reflexión de ondas de pulso, viabilidad sub-endocárdica, que permiten valorar el estado estructural y funcional arterial. Objetivo: determinar la prevalencia de alteraciones arteriales en niños y adolescentes asintomáticos evaluados en el nuevo servicio, empleando para ello criterios diagnósticos recientemente propuestos por la Asociación Americana del Corazón (AHA). Métodos: se incluyeron 365 niños/adolescentes (3-17 años, mediana 12 años) sin enfermedad conocida, en los que se valoraron factores de riesgo cardiovascular y se realizó estudio arterial integral. Se analizó: espesor íntima-media carotideo (CIMT; Ultrasonografía/software específico), rigidez aórtica (velocidad de onda de pulso carótido-femoral, VOP; Tonometría de aplanamiento) y reactividad vascular (RV; vasodilatación mediada por flujo). Se consideró alterado: 1) CIMT o VOP ³ percentil 95 (p95; para edad y sexo, propuesto por AHA), 2) RV <5%. Se cuantificó prevalencia de alteraciones, y relación con sexo y edad (mayores vs. menores de 12 años). Resultados: la prevalencia de alteración estructural (CIMT»35%) y funcional (RV»25%) fue elevada, así como la de factores de riesgo cardiovascular. La prevalencia se elevó con la edad. No existió diferencia en prevalencia asociadas al sexo. Conclusión: en los niños/adolescentes evaluados existió elevada prevalencia de niveles de CIMT, VOP y RV, por fuera de niveles de normalidad propuestos por la AHA. Dicha prevalencia, podría estar influenciada por la alta exposición a factores de riesgo. El aumento edad-relacionado en prevalencia de VOP elevada, podría asociarse a mayor tiempo de exposición a factores de riesgo al aumentar la edad (daño acumulado). La prevalencia encontrada podría estar influenciada por inadecuación de los valores de corte propuestos por la AHA para aplicarse en nuestra población. Esto refuerza la necesidad de contar con niveles de referencia/corte nacionales.

Introduction: non-invasive vascular studies are used in adults for assessment of target organ damage (TOD), cardiovascular risk re-classification and early detection of impairment in both arterial structure and function. Recently, it has been recommended to apply these studies in pediatric population, in order to detect those children with greater risk of developing atherosclerotic arterial disease and design early specific interventions that would allow to reduce arterial damage, and thus cardiovascular risk during adulthood. In 2014, an open access/free center (service) for children arterial evaluation was created in Uruguay. In this center, several studies are applied as an integrated approach to assess arterial structure and function parameters such as: local and regional arterial stiffness, arterial wall thickness, vascular reactivity, central aortic pressure, pulse-wave reflection analysis and sub-endocardial viability ratio. The aim of this study was to determine the prevalence of arterial alterations in children and adolescents evaluated in the new center, using reference values recently proposed by the American Heart Association (AHA). Methods: 365 children/adolescents without known disease were included (3-17 years old, median 12 years). Cardiovascular risk-factor exposure was assessed and integrated arterial evaluation was applied. Carotid Intima-Media Thickness (CIMT; Ultrasonography/specific border detection software), aortic stiffness (Carotid-femoral Pulse Wave Velocity, PWV; applanation tonometry) and vascular reactivity (VR; flow-mediated dilation) were analyzed. Arterial impairment was considered when: 1) CIMT or PWV = 95th percentile (for age and sex, reference values from AHA), 2) VR<5%. Vascular impairment prevalence was quantified, and its relationship with age (<12 y.o vs. >12 y.o) and sex. Results: the prevalence of structural (CIMT» 35%) and functional (VR» 25%) vascular impairment was high, and so was cardiovascular risk-factor exposure. Prevalence increased with age. No sex-related differences were found. Conclusion: the children/adolescents evaluated showed high prevalence of CIMT, PWV and VR levels outside the reference ranges from the AHA. This prevalence could be partly explained by the high cardiovascular risk-factor exposure. The age-related increase in PWV high levels could be associated with a longer time of risk-factor exposure (accumulated damage). The prevalence found could also be explained by mismatch of the AHA reference values with Uruguayan population, thus enhancing the needs for national reference/normative values

Introduction Local recurrence of Renal Cell Carcinoma (RCC) after radical nephrectomy is a rare event. Some known risk factors are: clinical/pathological stage, locorregional disease and lyimph node positivity. Since up to 30-40% of patients can achieve a disease-free status, we show a case (video) in which we performed a laparoscopic excision of a local RCC, taking advantage of all the well-known benefits of laparoscopy.Case report A 56 years old female with a history of open radical nephrectomy two years before was diagnosed with a mass at the time of surveillance CT imaging during follow-up. The suspected local recurrence was 12cm, and vascularized predominantly by tributaries originating from the iliac vessels. There was no other site of disease (i.e. brain, lung, liver, bones) and laboratory tests were normal. Laparoscopic approach was approached, by inserting 4 trocars (2 of 10 and 2 of 5mm) with the patient in the lateral position.Result The procedure lasted 130 minutes, with 220mL of estimated bleeding; the larger vessels were ligated with polymer clips (Hem-o-lok) and the smaller handled by ultrasonic clamp. The specimen was removed by a small incision below the umbilicus in an appropriate bag. The patient was feed in the first postoperative day and discharged on the third day. Histopathology revealed sarcoma, with a high degree of mitosis, and negative surgical margins. She was referred to medical oncology for adjuvant therapy consideration.Conclusion The laparoscopic resection of recurrent tumor should be encouraged in highly selected cases. The minimally invasive method, with its known advantages, especially for more debilitated patients, can be advantageous when applied to suitable cases.

Objective About 10% of renal pelvis are bifids and not so there is a larger index of kidney disease over the normal pelves. The laparoscopy and minimally invasive techniques treat the ureteropelvic junction disease in a low agressive manner. We showed a video of an atypical pyeloplasty of ureteropelvic junction obstruction of a lower unit. The patient is a 33 year-old woman with an intermitent lumbar pain for 3 years. Your image exams showed a bifid left pelvis with a stenosis of the lower unit. We chose to do the fix of this pathology laparoscopically. Materials and Methods We positioned the patient in a right lateral decubitus and 3 trocars was placed, we identify the obstructed junction and a terminolateral anastomosis was performed. Results: The procedure lasted 95 minutes, with little blood loss and the patient was discharged in 2 days. We withdraw the double J catheter after 1 month, a pyelography and a ureteroscopy was performed which showed a pervious anastomosis. After 2 months of follow-up the patient is doing well. Conclusions As far as we know, this is the first case of literature with correction by laparoscopy. The stenosis of ureteropelvic junction in the lower unit of a bifid pelvis can be corrected effectively by laparoscopic surgery.

The intensive care units (ICUs) are often considered as the epicenters of antibiotic resistance. Therefore, the total antibiotic consumption is approximately ten fold greater in ICU wards than in general hospital wards. The aim of this study was to evaluate the current use of antibiotics in Latin American ICUs. Three cross-sectional (one-day point) prevalence studies were undertaken in 43 Latin American ICUs. Of 1644 patients admitted, 688 received antibiotic treatment on the days of the study (41.8 %) and, 392 cases (57 %) were due to nosocomial-acquired infections. Of all infections, 22 % (151/688) corresponded to septic shock; and 22 % (151/688) to nosocomial pneumonia (50/151 [33 %], ventilator-associated pneumonia). In 485 patients (70.5 %), cultures were performed before starting antibiotic treatment. The most common microorganisms isolated were extended-spectrum ß-lactamase Enterobacteriaceae, (30.5 %), and Pseudomonas aeruginosa (17 %). Carbapenems (imipenem or meropenem) were the antibiotics most frequently prescribed (151/688, 22 %), followed by vancomycin (103/688, 15 %), piperacillin-tazobactam (86/688, 12.5 %) and broad-spectrum cephalosporins (mainly cefepime) (83/688, 12 %). In summary, carbapenems were the most frequent antibiotics prescribed in Latin American ICUs. This practice seems justified for the high rates of ESBL-producing Gram-negatives found in our patients. Beyond this reason, the problem of bacterial resistance in LA requires that physicians improve the use of carbapenems. The high prevalence of carbapenem-resistant A. baumannii and P. aeruginosa in the region, along with the prevalence of carbapenem-resistant Enterobacteriaceae, have increased markedly. A comprehensive evidence-based stewardship program based on local antimicrobial use and resistance problems should be implemented in our clinical settings.

Prescripción de antibióticos en unidades de cuidados intensivos de Latinoamérica. Las unidades de cuidados intensivos (UCI) son a menudo consideradas el epicentro de la resistencia a los antibióticos. En este sentido, el consumo total de antibióticos es aproximadamente diez veces mayor en las UCI que en las salas de internación general. El objetivo de este estudio fue evaluar el hábito prescriptivo de antibióticos en las UCI de varios países de Latinoamérica. A tal fin, se realizó un estudio transversal con tres evaluaciones puntuales de un día de duración cada una, para determinar la prevalencia del uso de antibióticos en las 43 UCI ubicadas en distintos países del continente americano. De los 1644 pacientes admitidos, 688 estaban recibiendo tratamiento antibiótico en los días en que se realizó el relevamiento (41,8 %), en 392 casos (57 %), debido a infecciones nosocomiales. De todas las infecciones, 22 % (151/688) correspondieron a shock séptico y 22 % (151/688) a neumonía nosocomial (de estas últimas, el 33 % [50/151] fueron neumonías asociadas a ventilación mecánica). En 485 pacientes (70,5 %) se obtuvieron cultivos antes del inicio del tratamiento antibiótico. Entre los aislamientos, los microorganismos más comúnmente aislados fueron las enterobacterias productoras de ß-lactamasas de espectro extendido (BLEE) (30,5 %) y Pseudomonas aeruginosa (17 %). Los carbapenems (imipenem o meropenem) fueron los antibióticos prescriptos con mayor frecuencia (151/688, 22 %), seguidos por la vancomicina (103/688, 15 %), la piperacilina-tazobactama (86/688, 12,5 %) y las cefalosporinas de amplio espectro (principalmente cefepima) (83/688, 12 %). En conclusión, los carbapenems fueron los antibióticos más frecuentemente prescriptos en las UCI de los países latinoamericanos evaluados. Esta práctica podría estar justificada por las altas tasas de enterobacterias productoras de BLEE halladas en los pacientes de esas regiones. Más allá de esta razón, el problema de la resistencia bacteriana en muchos países del continente requiere que los médicos optimicen el uso de los carbapenems, ya que la prevalencia de aislamientos resistentes a este grupo de antimicrobianos se ha incrementado marcadamente, tanto en A. baumannii y P. aeruginosa como en enterobacterias. Frente a este panorama, en todos estos países se torna necesario implementar programas de optimización del uso de antibióticos, basados en la epidemiología y en las tasas de resistencia locales.

Community-acquired pneumonia (CAP) in adults is probably one of the infections affecting ambulatory patients for which the highest diversity of guidelines has been written worldwide. Most of them agree in that antimicrobial therapy should be initially tailored according to either the severity of the infection or the presence of comorbidities and the etiologic pathogen. Nevertheless, a great variability may be noted among the different countries in the selection of the primary choice in the antimicrobial agents, even for the cases considered as at a low-risk class. This fact may be due to the many microbial causes of CAP and specialties involved, as well as the different health-care systems effecting on the availability or cost of antibiotics. However, many countries or regions adopt some of the guidelines or design their own recommendations regardless of the local data, probably because of the scarcity of such data. This is the reason why we have developed a guideline for the initial treatment of CAP by 2002 upon the basis of several local evidences in South América (ConsenSur I). However, several issues deserve to be currently rediscussed as follows: certain clinical scores other than the Physiological Severity índex (PSI) have become more popular in clinical practice (i.e. CURB-65, CRB-65); some pathogens have emerged in the región, such as community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) and Legionella spp; new evidences on the performance of the rapid test for the etiologic diagnosis in CAP have been reported (eg. urinary Legionella andpneumococcus antigens); new therapeutic considerations needs to be approached (i.e. dosage reformulation, duration of treatment, emergence of novel antibiotics and clinical impact of combined therapy). Like in the first versión of the ConsenSur (ConsenSur I), the various current guidelines have helped to organize and stratify the present proposal, ConsenSur II.

La neumonía adquirida por adultos en la comunidad (NAC) es, probablemente, una de las infecciones que afecta a los pacientes ambulatorios para la cual se ha escrito la mayor diversidad de lineamientos en todo el mundo. La mayoría de ellos concuerdan en que el tratamiento antimicrobiano debe ser ajustado inicialmente de acuerdo con la gravedad de la infección o con la presencia de co-morbilidades y el patógeno etiológico. Aun así, se puede notar una gran variabilidad entre los diferentes países en la selección de la elección primaria de los agentes antimicrobianos, incluso en los casos considerados como de bajo riesgo. Este hecho puede deberse a las múltiples causas microbianas de la NAC y las especialidades médicas involucradas, como así también los diferentes sistemas de asistencia de salud que afectan la disponibilidad o el costo de los antimicrobianos. No obstante, muchos países o regiones adoptan alguno de los lineamientos o diseñan sus propias recomendaciones independientemente de los datos locales, probablemente debido a la escasez de dichos datos. Por esta razón desarrollamos lineamientos para el tratamiento inicial de la NAC hacia el año 2002, sobre la base de varias evidencias locales en Sudamérica (ConsenSur I). Sin embargo, varios temas merecen discutirse nuevamente como sigue: ciertos puntajes clínicos además del índice Fisiológico de Severidad (IFS) se hicieron más populares en la práctica clínica (por ej. CURB-65, CRB-65); emergieron algunos patógenos en la región, tal como Staphylococcus aureus resistente adquirido en la comunidad (SAMR-AC) y Legionella spp; se reportaron nuevas evidencias sobre el desempeño de la prueba rápida para el diagnóstico etiológico de NAC (por ejemplo, Legionella urinaria y antígenos de Streptococcus pneumoniae); deben abordarse nuevas consideraciones terapéuticas (por ej.: reformulación de la dosis, duración del tratamiento, emergencia de antimicrobianos nuevos e impacto clínico del tratamiento combinado). Como en la primera versión del ConsenSur (ConsenSur I), los diversos lineamientos actuales ayudaron a organizar y estratificar la presente propuesta, ConsenSur II.

The objective of this multicenter study was to determine tigeeyeline susceptibility rates, measured by agar diffusion, in nine hospitals in Santiago and to compare these rates with other antimicrobials. Each center studied 20 strains per month. All intermedíate and fully resistant strains as well as 10% of susceptibile strains were also studied by the broth microdilution method. Overall, 2301 strains were studied displaying the foliowing susceptibility rates for tigeeyeline: 100% for Streptococcus sp, Enterococcus sp, and E. coli respectively, 99.8% for Staphylococcus sp, 93% for Klebsiella and 80% for Acinetobacter baumarmii. For Proteus, Providencia and Morganella the susceptibility rates were 4%. For cefotaxime-resistant Klebsiella and imipenem-resistant A. baumarmii susceptibility rates were 95% and 80% respectively. The agar diffusion and broth dilution method were 100% concordant for tigeeyeline susceptible strains but only 27% for resistant or intermedíate strains represented mostly by Acinetobacter baumannii. The majority of these strains (57/59) proved to be susceptible after retesting. The great majority (96,6%) of strains tested from nine Chilean hospitals proved to be susceptible to tigeeyeline with exception for Proteus, Providencia and Morganella (66% resistance). Using the agar diffusion method for measuring tigeeyeline susceptibility to A. baumannii may be misleading.

Para conocer la susceptibilidad a tigeciclina por difusión en agar en nueve hospitales de Santiago y comparar la susceptibilidad con otros antimicrobianos, se diseñó este estudio multicéntrico. Cada centro estudió 20 cepas mensualmente. Las intermedias, resistentes y 10%o de las susceptibles se re-testearon y estudiaron por microdilución en caldo. Se incluyeron 2.304 cepas. Fueron susceptibles a tigeciclina Strep-tococcus sp (100%o), Enterococcus sp (100%), E. coli (100%o), Staphylococcus sp (99,8%), Klebsiella pneumoniae (93%) y Acinetobacter baumannii (80%). En Proteus, Providencia y Morganella la susceptibilidad fue 4%o. Klebsiella resistente a cefotaxima y Acinetobacter resistente a imipenem, 95%o y 80%o fueron susceptibles a tigeciclina, respectivamente. La concordancia en cepas susceptibles y en las enviadas como resistentes o intermedias (A. baumannii) fue 100%o y 27%o respectivamente. El re-testeo confirmó que la mayoría eran susceptibles. Los patrones de susceptibilidad bacteriana muestran muy buena actividad in vitro a tigeciclina. La resistencia in vitro de A. baumannii por difusión en agar debe interpretarse con precaución.

Tigecycline is a glicylcicline with broad antimicrobial spectrum. Susceptibility testing to this drug for Acinetobacter is difficult in hospitals due to the utilization of the disk diffusion method. FDA break points have shown an unacceptable rate of errors (23%) for disk diffusion versus broth microdilution in American studies and overcall of resistance depending on the brand of Mueller Hinton agar used. Modifications to these FDA break points have been proposed, but there is not enough evidence yet. Data from a multicenter study from Chile allowed the evaluation of the characteristics of the agar used for susceptibility testing and the utility of E-test as an alternative MIC method for Acinetobacter. The Mueller Hinton agar brand is an important factor that affects disk diffusion method results. There is very good correlation between broth microdilution and E-test for the susceptibility category as well as for MIC determination. The intermedíate and resistant results obtained with disk diffusion method should be checked by using E-test.

Tigeciclina es una glicilciclina de amplio espectro antimicrobiano. La determinación de la susceptibilidad a este fármaco presenta dificultades en el laboratorio asistencial al utilizar la técnica de difusión por disco para Acinetobacter spp. Los puntos de corte -según la (FDA- han mostrado una tasa inaceptable de errores (23%) en comparación con el método de micro-dilución en caldo en estudios americanos, diversas evaluaciones demuestran que existe una sobreestimación de resistencia in vitro dependiendo de las características del agar Mueller Hinton utilizado. Se han propuesto modificaciones a los puntos de corte pero no se han oficializado por insuficientes evidencias. Los datos de un estudio multicéntrico realizado en Chile permitieron evaluar la influencia de las distintas marcas de medios de cultivo en el tamaño de los halos y la utilidad de la epsilometría (E-test®) como método CIM para Acinetobacter sp. La marca de agar Mueller Hinton y otros factores propios del medio dificultan la determinación de la susceptibilidad a tigeciclina utilizando difusión por disco. Existe muy buena correlación entre la micro-dilución en caldo y el E- test®, tanto para la categoría de susceptibilidad como para la CIM. Por esto, se sugiere que los resultados intermedios o resistentes obtenidos por difusión en agar para A. baumannii sean comprobados mediante el uso de E-test®.