Epidemiology of antimicrobial resistance in bacteria isolated from inpatient and outpatient samples, Ecuador, 2018.

Objective: To compare the epidemiology of antimicrobial resistance in bacteria isolated from inpatient and outpatient samples in Ecuador. Methods: A secondary analysis was done of data on bacteria isolated from inpatient and outpatient samples. Data were taken from the 2018 national antimicrobial resistance surveillance database of the National Reference Center for Antimicrobial Resistance. The variables included were: age, sex, inpatient versus outpatient setting, type of specimen, bacterial species identified, pattern of resistance to antibiotics, and geographic area. Results: Data from 57 305 bacterial isolates were included in the study: 48.8% were from hospitalized patients, 55.7% were from women, and 60.1% were from patients older than 45 years. Urine (42.9%) and blood (12.4%) were the most common clinical samples. Overall, 77.1% of bacterial isolates were gram-negative (83% and 71% in outpatients and inpatients, respectively). The most common gram-positive and gram-negative species were Staphylococcus aureus and Escherichia coli, respectively. Antimicrobial resistance levels were high (up to 80% for some antimicrobial drugs), and were higher in hospitalized patients compared with outpatients. A variety of carbapenemases were found to confer resistance to carbapenems (antibiotics of last resort) in gram-negative bacteria. Conclusions: The study findings provide an important baseline on antimicrobial resistance in Ecuador. This will allow the strengthening of guidelines of the surveillance system, the creation of public policies for standardization of laboratory methodologies, the proper handling of information, and the development of empirical therapy guidelines based on local epidemiology.

Operational research to strengthen evidence-based interventions to tackle antimicrobial resistance in the Region of the Americas

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Epidemiology of antimicrobial resistance in bacteria isolated from inpatient and outpatient samples, Ecuador, 2018 / Características epidemiológicas de la resistencia antimicrobiana en cepas bacterianas aisladas en pacientes de servicios hospitalarios y ambulatorios de Ecuador, 2018 / Epidemiologia da resistência aos antimicrobianos em bactérias isoladas de amostras hospitalares e ambulatoriais no Equador, 2018

ABSTRACT Objective. To compare the epidemiology of antimicrobial resistance in bacteria isolated from inpatient and outpatient samples in Ecuador. Methods. A secondary analysis was done of data on bacteria isolated from inpatient and outpatient samples. Data were taken from the 2018 national antimicrobial resistance surveillance database of the National Reference Center for Antimicrobial Resistance. The variables included were: age, sex, inpatient versus outpatient setting, type of specimen, bacterial species identified, pattern of resistance to antibiotics, and geographic area. Results. Data from 57 305 bacterial isolates were included in the study: 48.8% were from hospitalized patients, 55.7% were from women, and 60.1% were from patients older than 45 years. Urine (42.9%) and blood (12.4%) were the most common clinical samples. Overall, 77.1% of bacterial isolates were gram-negative (83% and 71% in outpatients and inpatients, respectively). The most common gram-positive and gram-negative species were Staphylococcus aureus and Escherichia coli, respectively. Antimicrobial resistance levels were high (up to 80% for some antimicrobial drugs), and were higher in hospitalized patients compared with outpatients. A variety of carbapenemases were found to confer resistance to carbapenems (antibiotics of last resort) in gram-negative bacteria. Conclusions. The study findings provide an important baseline on antimicrobial resistance in Ecuador. This will allow the strengthening of guidelines of the surveillance system, the creation of public policies for standardization of laboratory methodologies, the proper handling of information, and the development of empirical therapy guidelines based on local epidemiology.

RESUMEN Objetivo. Comparar las características epidemiológicas de la resistencia a los antimicrobianos en cepas bacterianas aisladas de muestras de pacientes de servicios hospitalarios y ambulatorios en Ecuador. Métodos. Se realizó un análisis secundario de los datos sobre cepas bacterianas aisladas en muestras de pacientes de servicios hospitalarios y ambulatorios. Se recogieron los datos de la base de datos nacional del 2018 para la vigilancia de la resistencia a los antimicrobianos del Centro de Referencia Nacional para la Resistencia a los Antimicrobianos. Las variables incluidas fueron: edad, sexo, entorno hospitalario frente a entorno ambulatorio, tipo de muestra, especies bacterianas detectadas, patrón de resistencia a los antibióticos y zona geográfica. Resultados. En el estudio se incluyeron datos de 57 305 cepas aislamientos bacterianos: 48,8% fueron de pacientes hospitalizados, 55,7% fueron de mujeres y 60,1% fueron de pacientes mayores de 45 años. La orina (42,9%) y la sangre (12,4%) fueron las muestras clínicas más comunes. En general, 77,1% de las cepas bacterianas aisladas fueron gramnegativas (83% y 71% en pacientes de servicios ambulatorios y hospitalarios, respectivamente). Las especies grampositivas y gramnegativas más comunes fueron Staphylococcus aureus y Escherichia coli, respectivamente. Los niveles de resistencia a los antimicrobianos fueron elevados (hasta 80% en el caso de algunos fármacos antimicrobianos) y fueron más elevados en los pacientes de servicios hospitalarios en comparación con los pacientes de servicios ambulatorios. Se encontró que una variedad de carbapenemasas confiere resistencia a los carbapenémicos (antibióticos de último recurso) en bacterias gramnegativas. Conclusiones. Los resultados del estudio proporcionan una línea de base importante sobre la resistencia a los antimicrobianos en Ecuador, que permitirá el fortalecimiento de las directrices del sistema de vigilancia, la creación de políticas públicas para la estandarización de los métodos de laboratorio, una adecuada gestión de la información y la elaboración de orientaciones de tratamiento empírico basadas en las características epidemiológicas locales.

RESUMO Objetivo. Comparar a epidemiologia da resistência aos antimicrobianos em bactérias isoladas de amostras hospitalares e ambulatoriais no Equador. Métodos. Foi feita uma análise secundária de dados sobre bactérias isoladas de amostras hospitalares e ambulatoriais. Os dados foram obtidos do banco de dados nacional de vigilância da resistência aos antimicrobianos de 2018 do Centro Nacional de Referência para a Resistência aos Antimicrobianos. As variáveis incluídas foram: idade, sexo, ambiente hospitalar versus ambiente ambulatorial, tipo de espécime, espécies bacterianas identificadas, padrão de resistência a antibióticos e área geográfica. Resultados. Foram incluídos no estudo os dados de 57 305 isolados bacterianos: 48,8% eram de pacientes hospitalizados, 55,7% eram de mulheres e 60,1% eram de pacientes com mais de 45 anos. As amostras clínicas mais comuns foram urina (42,9%) e sangue (12,4%). No total, 77,1% dos isolados bacterianos eram gram-negativos (83% e 71% em pacientes ambulatoriais e pacientes internados, respectivamente). As espécies gram-positivas e gram-negativas mais comuns foram Staphylococcus aureus e Escherichia coli, respectivamente. Os níveis de resistência aos antimicrobianos foram elevados (até 80% para alguns antimicrobianos) e foram mais elevados em pacientes hospitalizados em comparação com pacientes ambulatoriais. Foram encontradas várias carbapenemases que conferem resistência aos carbapenêmicos (antibióticos de último recurso) em bactérias gram-negativas. Conclusões. Os resultados do estudo fornecem uma importante linha de base sobre a resistência aos antimicrobianos no Equador. Isto permitirá o fortalecimento das diretrizes do sistema de vigilância, a criação de políticas públicas para padronização de metodologias laboratoriais, o manejo adequado de informações e o desenvolvimento de diretrizes para a antibioticoterapia empírica com base na epidemiologia local.

Comparative Evaluation of Phenotypic Synergy Tests versus RESIST-4 O.K.N.V. and NG Test Carba 5 Lateral Flow Immunoassays for the Detection and Differentiation of Carbapenemases in Enterobacterales and Pseudomonas aeruginosa.

The spread of carbapenem-resistant Pseudomonas aeruginosa and carbapenemase-producing Enterobacterales (CPE) has dramatically impacted morbidity and mortality. COVID-19 pandemic has favored the selection of these microorganisms because of the excessive and prolonged use of broad-spectrum antibiotics and the outbreaks related to patient transfer between hospitals and inadequate personal protective equipment. Therefore, early CPE detection is considered essential for their control. We aimed to compare conventional phenotypic synergy tests and two lateral flow immunoassays for detecting carbapenemases in Enterobacterales and P. aeruginosa. We analyzed 100 carbapenem-resistant Gram-negative bacilli isolates, 80 Enterobacterales, and 20 P. aeruginosa (86 isolates producing KPC, NDM, OXA-48, IMP, and VIM carbapenemases and 14 non-carbapenemase-producing isolates). We performed a modified Hodge test, boronic acid and ethylenediaminetetraacetic acid (EDTA) synergy tests, and two lateral flow immunoassays: RESIST-4 O.K.N.V. (Coris Bioconcept) and NG Test Carba 5 (NG Biotech). In total, 76 KPC, seven VIM, one NDM, one OXA-48, and one isolate coproducing KPC + NDM enzymes were included. The concordance of different methods estimated by the Kappa index was 0.432 (standard error: 0.117), thus showing a high variability with the synergy tests with boronic acid and EDTA and reporting 16 false negatives that were detected by the two immunochromatographic methods. Co-production was only detected using immunoassays. Conventional phenotypic synergy tests with boronic acid and EDTA for detecting carbapenemases are suboptimal, and their routine use should be reconsidered. These tests depend on the degree of enzyme expression and the distance between disks. Lateral flow immunoassay tests are a rapid and cost-effective tool to detect and differentiate carbapenemases, improving clinical outcomes through targeted therapy and promoting infection prevention measures. IMPORTANCE Infections due to multidrug-resistant pathogens are a growing problem worldwide. The production of carbapenemases in Pseudomonas aeruginosa and Enterobacterales cause a high impact on the mortality of infected patients. Therefore, it is of great importance to have methods that allow the early detection of these multi-resistant microorganisms, achieving the confirmation of the type of carbapenemase present, with high sensitivity and specificity, with the aim of improving epidemiological control, dissemination, the clinical course to through targeted antibiotic therapy and promoting infection control in hospitals.

Consensus Recommendations Based on Evidence for Abdominal Sepsis in the Pediatric and Adult Population of Colombia / Consenso colombiano de la sepsis abdominal en la poblacion pediatrica y de adultos: Recomendaciones basadas en la evidencia

Abstract Intra-abdominal infections are frequent at all levels of health care, therefore, it is necessary to maintain a high level of clinical suspicion, performing the fastest and most cost-effective measures to confirm the diagnosis and offer a precise and targeted multidisciplinary therapy, this being the only way to have an impact on the morbidity of this infection, reducing mortality and minimizing the complications and costs of health care. Intra-abdominal infections are linked to the appearance and selection of resistant mutants in both bacteria and fungi, becoming currently a major public health problem. Increasing bacterial resistance when associated with a greater possibility of difficulties in antimicrobial treatment increases mortality. This evidence-based consensus brings together the recommendations for the diagnosis and treatment of intra-abdominal infections in the pediatric and adult population. With strict monitoring of bacterial resistance and stimulating the control of the risk factors that have the greatest impact on the appearance of this phenomenon, this consensus is intended to be a practical guide that is easy to implement, and with periodic updates it will favor and facilitate multidisciplinary and the adequacy of the therapeutic management of intra-abdominal infections.

Resumen Las infecciones intrabdominales son frecuentes en todos los niveles de atención en salud, por ende, es necesario mantener un alto nivel de sospecha clínica, realizando las medidas más rápidas y costoefectivas para confirmar el diagnóstico y así ofrecer de una forma precisa y dirigida la terapéutica multidisciplinaria, siendo esta la única manera de tener impacto en la morbilidad de esta infección, disminuyendo la mortalidad y minimizando las complicaciones y los costos de la atención en salud. Las infecciones intrabdominales se encuentran ligadas a la aparición y selección de las mutantes resistentes tanto en las bacterias como en los hongos, convirtiéndose en la actualidad en una gran problemática en la salud pública. La creciente resistencia bacteriana al asociarse a mayor posibilidad de dificultades en el tratamiento antimicrobiano incrementa la mortalidad. Este consenso basado en la evidencia, reúne las recomendaciones en el diagnóstico y en el tratamiento de las infecciones intrabdominales en la población pediátrica y de adultos. Con un estricto seguimiento de la resistencia bacteriana y estimulando el control de los factores de riesgo que tienen mas impacto en la aparición de este fenómeno, este consenso pretende ser una practica guía de fácil implementación, y con periódicas actualizaciones favorecerá y facilitará el manejo multidisciplinario y la adecuación del manejo terapéutico de las infecciones intrabdominales.

Colonización rectal por Enterobacterales productores de múltiples carbapenemasas: Reporte de un caso de coproducción / Rectal colonization by Enterobacterales producing multiple carbapenemases: a co-production case report

Resumen El constante aumento de Enterobacterales productores de carbapenemasas (CPE) se constituye en un problema de salud pública a nivel mundial, por el impacto generado en la mortalidad de los pacientes. El tracto gastrointestinal es el principal reservorio de este tipo de microorganismos, por lo cual, la colonización rectal se convierte en un importante factor de riesgo para el desarrollo de posteriores infecciones. Una de las estrategias de vigilancia epidemiológica activa, es la búsqueda de pacientes colonizados, a través de cultivos de tamización para detectar estos microrganismos multirresistentes. Reportamos el caso de un paciente, con historia de sepsis de origen pulmonar, colonizado por Klebsiella pneumoniae con coproducción de carbapenemasas NDM + KPC y Escherichia coli con carbapenemasa NDM. Este hallazgo es cada vez más frecuente, lo cual implica un reto en su detección y diagnóstico. Se describen características del paciente, procedimientos realizados y hallazgos microbiológicos.

Abstract The constant increase in carbapenemase-producing Enterobacterales (CPE) constitutes a public health problem worldwide, due to the impact generated on the mortality of patients. The gastrointestinal tract is the main reservoir for this microorganism, which is why, rectal colonization becomes an important risk factor for the development of subsequent infections. One of the active epidemiological surveillance strategies is the search for colonized patients through screening cultures, to detect these multi-resistant microorganisms. We report the case of a patient, with a history of sepsis of pulmonary origin, colonized by Klebsiella pneumoniae with co-production of NDM + KPC carbapenemases and NDM carbapenemase-producing Escherichia coli. This finding is more and more frequent, which implies a challenge in its detection and diagnosis. Patient characteristics, procedures performed and microbiological findings are described.

Should ceftriaxone-resistant Enterobacterales be tested for ESBLs? A PRO/CON debate.

ESBLs are a group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that pose a therapeutic challenge today in hospital- and community-acquired infections. Thirty-six years after the first report, diagnostic and therapeutic approaches for ESBLs are still the subject of controversy. Detection of these enzymes is recommended for epidemiological purposes and facilitates targeted therapy, necessary for antimicrobial stewardship. On the other hand, ESBLs are not confined to specific species, phenotypic detection methods have pitfalls, and concerns exist about the accuracy of antimicrobial susceptibility testing systems to rely on MIC values for cephalosporins and ß-lactam combination agents. In this issue, we present a PRO/CON debate on ESBL testing for ceftriaxone-non-susceptible Enterobacterales.

Clinical practice guideline for screening of patients at risk of colonization by carbapenemase-producing Enterobacterales and the treatment of infections caused by these bacteria / Guía de práctica clínica para la tamización de pacientes con riesgo de colonización por Enterobacterales productores de carbapenemasasy el manejo de infecciones causadas por estas bacterias

Abstract Carbapenemase-producing Enterobacterales (CPE) infections have increased in recent years. Colombia has become an endemic country for this group of microorganisms, and the infections they cause have a serious impact in terms of morbidity and mortality. The early identification of CPE carriers who are admitted to health care centers as patients is necessary to implement adequate isolation and infection control measures to limit the spread of this type of microorganisms in hospitals. Furthermore, treating these infections is a challenging task due to the limited therapeutic alternatives available and the fact that there are only a few studies proving their effectiveness in this setting. Therefore, the objective of the present work is to develop a clinical practice guideline (CPG) for the screening of patients at risk of CPE colonization and the treatment of inpatients with suspected or confirmed infections caused by this type of bacteria through a CPG adaptation process based on the ADAPTE methodology. With this purpose in mind, evidence-informed recommendations for the screening and timely identification of CPE carriers admitted to hospitals are made, as well as for the adequate pharmacological treatment of CPE infections in this context.

Resumen Las infecciones por Enterobacterales productores de carbapenemasas (EPC) han aumentado en los últimos años. Colombia se ha convertido en un país endémico para este grupo de microorganismos y las infecciones que causan tienen un impacto importante en términos de morbimortalidad. La identificación temprana de los portadores de EPC que ingresan como pacientes a las instituciones de salud es necesaria para implementar medidas de aislamiento y control de infecciones adecuadas que limiten la diseminación de este tipo de microorganismos en los hospitales. Además, el tratamiento de estas infecciones es difícil debido a las limitadas alternativas terapéuticas disponibles y la escasez de estudios que demuestren su efectividad en este escenario. Por lo anterior, el objetivo del presente trabajo es desarrollar una guía de práctica clínica (GPC) para la tamización de pacientes con riesgo de colonización por EPC y para el manejo de pacientes con infecciones, ya sea sospechadas o confirmadas, causadas por este tipo de bacterias, mediante un proceso de adaptación de GPC basado en la metodología ADAPTE. Con este propósito en mente, se hacen recomendaciones informadas en evidencia para realizar la tamización y oportuna identificación de portadores de EPC admitidos en instituciones hospitalarias, así como para el adecuado manejo farmacológico de las infecciones por CPE en este escenario.

Update on the epidemiology of carbapenemases in Latin America and the Caribbean.

INTRODUCTION: Carbapenemases are ß-lactamases able to hydrolyze a wide range of ß-lactam antibiotics, including carbapenems. Carbapenemase production in Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter spp., with and without the co-expression of other ß-lactamases is a serious public health threat. Carbapenemases belong to three main classes according to the Ambler classification: class A, class B, and class D. AREAS COVERED: Carbapenemase-bearing pathogens are endemic in Latin America. In this review, we update the status of carbapenemases in Latin America and the Caribbean. EXPERT OPINION: Understanding the current epidemiology of carbapenemases in Latin America and the Caribbean is of critical importance to improve infection control policies limiting the dissemination of multi-drug-resistant pathogens and in implementing appropriate antimicrobial therapy.

Consenso de grupo Ad-hoc sobre recomendaciones para la evaluación y controles de calidad para el diagnóstico molecular y serológico de la infección humana por SARS CoV-2 / Ad-hoc group consensus recommendations on the evaluation and quality control of molecular and serological diagnostics tests for SARS CoV-2 human infection

Se formulan recomendaciones de un grupo de consenso de expertos sobre los criterios para evaluar el desempeño diagnóstico (tamaño y selección de muestras para sensibilidad y especificidad analíticas, criterios para establecer límites de detección, criterios para establecer el estándar de oro para las serologías) que deberían ser tenidos en cuenta al evaluar y validar las pruebas diagnósticas para SARS CoV-2. Con el propósito de asegurar la calidad de las pruebas serológicas a utilizar en el país, se recomienda la participación en un programa de control de calidad externo, que garantice la idoneidad y desempeño en la realización de las pruebas diagnósticas serológicas y moleculares durante esta pandemia, ya que su uso tiene profundas implicaciones para las medidas de intervención clínicas individuales y de seguimiento y control en salud pública.

We formulate recommendations from a consensus working group on the criteria to evaluate the diagnostic performance (size and criteria of selection of samples to determine sensitivity, analytical specificity, criteria for limit of detection, criteria for gold standard to evaluate serological assays) that should be taken into account during the evaluation and validation/verification of diagnostic tests for SARS CoV-2 infection. A national external quality control program should be established to guarantee the suitability and performance of these diagnostic serological and molecular tests during this pandemic, that will have deep implications for decisions on clinical and public health.

Bacterias Gram negativas resistentes a carbapenemicos en Colombia: un desafío continuo al sistema de salud: [Editorial] / Carbapenem resistant Gram negative bacteria in Colombia: a continuous challenge for the health system: [Editorial]

En Colombia, los Enterobacterales (Escherichia coli, Klebsiella spp y Enterobacter spp) ocupan los primeros lugares en la epidemiología de las infecciones asociadas a la atención en salud (IAAS) y de las adquiridas en comunidad. Estas bacterias pueden desarrollar resistencia a carbapenemicos (Ertapenem, Imipenem, Meropenem y Doripenem) por una combinación de mecanismos que incluye la producción de enzimas hidrolíticas (como las betalactamasas de espectro extendido o BLEEs, las cefalosporinasas AmpC y las carbapenemasas) y las mutaciones en proteínas de la membrana externa. Desde su aparición en 1996, las carbapenemasas han sido las enzimas más temidas. Klebsiella pneumoniae carbapenemase (KPC) Verona integron-mediated metallo- ß-lactamase (VIM), New Delhi metallo-ß-lactamase (NDM), Imipenemase (IMP) y oxacillinase-48-like carbapenemase (OXA-48) han sido las más estudiadas por su diseminación y alta mortalidad. En 2006 se reportó por primera vez la presencia de carbapenemasas en Colombia correspondiente a una KPC-24 . Desde entonces, varios reportes de diversas enzimas han sido publicados por grupos de investigación y por el Instituto Nacional de Salud (INS) en cuyo último informe 66% de los Enterobacterales resistentes a carbapenémicos expresan KPC, 23% expresan NDM y 6% expresan VIM. Llama la atención un 12% de aislamientos sin carbapenemasas detectables.

In Colombia, Enterobacteriaceae (Escherichia coli, Klebsiella spp and Enterobacter spp) occupy the first places in the epidemiology of healthcare-associated infections (HAI) and community-acquired infections. These bacteria can develop resistance to carbapenemics (Ertapenem, Imipenem, Meropenem and Doripenem) by a combination of mechanisms including the production of hydrolytic enzymes (such as extended-spectrum beta-lactamases or BLEEs, AmpC cephalosporinases and carbapenemases) and mutations in outer membrane proteins. Since their emergence in 1996, carbapenemases have been the most feared enzymes. Klebsiella pneumoniae carbapenemase (KPC) Verona integron-mediated metallo- ß-lactamase (VIM), New Delhi metallo-ß-lactamase (NDM), Imipenemase (IMP) and oxacillinase-48-like carbapenemase (OXA-48) have been the most studied because of their dissemination and high mortality. In 2006, the presence of carbapenemases in Colombia corresponding to a KPC-24 was reported for the first time. Since then, several reports of various enzymes have been published by research groups and by the National Institute of Health (INS) in whose last report 66% of carbapenem-resistant Enterobacteriaceae express KPC, 23% express NDM and 6% express VIM. It is noteworthy that 12% of isolates had no detectable carbapenemases.

Carbapenemase-producing Enterobacteriaceae: A diagnostic, epidemiological and therapeutic challenge / Enterobacteriaceae productoras de carbapenemasas: Un reto diagnóstico, epidemiológico y terapéutico

The global spread of carbapenemase-producing Enterobacteriaceae (CPE) has become a public health problem. Not all CPE are resistant to carbapenems creating a diagnostic and therapeutic challenge. Furthermore, as resistance to carbapenems can also be mediated by other β-lactamases combined with defects in membrane permeability, their detection can be difficult by microbiology laboratories that lack molecular tools, which may limit and often delay the correct antibiotic selection. There is only limited evidence regarding infection control measures to contain the spread of CPE. However, recomendations have been published from the World Health Organization (WHO) and the European Prevention Center and Disease Control (ECDC). Because of the lack of randomized control trials, treatment regimens are mostly based on observational clinical studies. Several of those studies have reported that combination therapy with two or more in vitro-active agents including a carbapenem is superior to monotherapy. On the other hand, a new β-lactamase inhibitor in combination with ceftazidime has shown clinical efficacy Against KPC and some OXA-type producing Enterobacteriaceae

La diseminación global de las Enterobacteriaceae productoras de carbapenemasas (EPC) se ha convertido en un problema de salud pública. No todas las EPC son resistentes a los carbapenémicos, por lo que representan un reto diagnóstico y terapéutico. Adicionalmente, como la resistencia a los carbapenémicos puede ser mediada por otras β-lactamasas en combinación con cambios de la permeabilidad de la membrana plasmática, su detección puede ser difícil en laboratorios de microbiología que no cuentan con técnicas de diagnóstico molecular, lo que puede restringir y frecuentemente retrasar el inicio de la terapia antimicrobiana adecuada. La evidencia respecto a las medidas para la contención de las EPC es escasa. Sin embargo, existen recomendaciones por parte de la Organización Mundial de la Salud y del European Prevention Center and Disease Control (ECDC). Debido a la ausencia de estudios controlados y aleatorizados, los esquemas terapéuticos se basan en estudios clínicos observacionales. Varios de estos estudios han reportado mejores resultados con la terapia combinada de dos o más agentes activos in vitro, incluyendo a los carbapenémicos, en comparación con la monoterapia. Por otra parte, un nuevo inhibidor de β-lactamasas en combinación con ceftazidime, ha mostrado eficacia clínica contra infecciones por Enterobacteriaceae productoras de KPC y algunas carbapenemasas de tipo OXA.

Aspectos microbiológicos en el diagnóstico de infecciones del tracto urinario / Microbiological aspects in the diagnosis of urinary tract infections

Introducción: Las infecciones del tracto urinario (ITU) se encuentran entre las causas de consulta ambulatoria y de urgencias más frecuentes. La ausencia de pautas y consenso para el diagnóstico dadas por el laboratorio de microbiología puede dificultar la obtención de datos relevantes y confiables sobre los hallazgos microbiológicos y retrasar la toma de conductas clínicas apropiadas. Objetivo: Elaborar un algoritmo de decisión en ITU basado en la evidencia actual para el procesamiento de la muestra de orina, que incluye desde la recolección, el transporte y almacenamiento hasta su cultivo, con el fin de generar una directriz desde el laboratorio para la correcta toma de decisiones del médico. Metodología: Se lleva a cabo una búsqueda en la literatura y el concepto de expertos en Microbiología e Infectología basada en la revisión de las referencias bibliográficas disponibles en los términos de búsqueda relacionados, haciendo énfasis en estudios locales. Resultados: Se generaron recomendaciones para el diagnóstico por el laboratorio de las ITU en Colombia, que incluyen recolección, almacenamiento y transporte, siembra y pruebas de susceptibilidad antimicrobiana.

Background: Urinary tract infections (UTI) are one of the most frequent reasons for consultation in outpatient and emergency settings. The absence of guidelines and consensus from the microbiology laboratory for the diagnosis of UTI may affect the relevance and reliability of the results and delay the physician's treatment determination. Objective: To creat e an algorithm for the laboratory diagnosis of UTI in Colombia based on current evidence, in order to provide recommendations regarding sample collection, storage, transport and processing and to provide guidance for physicians' decision making. Methods: We reviewed the current standards and guidelines for the diagnosis of UTI and considered comments from microbiology and infectious disease experts based on a literature search using relevant search terms and emphasizing local studies. Results: We generated recommendations for collecting samples, storage, transport, culture and susceptibility testing for the reliable diagnosis of UTI in patients in Colombia.

Estrategias para la implementación y reporte de los puntos de corte CLSI vigentes y pruebas fenotípicas confirmatorias para BLEE y carbapenemasas en bacilos Gram negativos en laboratorios clínicos de Colombia / Strategies for implementation and reporting of current CLSI Breakpoints and phenotypic confirmatory tests for ESBLs and carbapenemases in Gram-negative bacilli in Colombian clinical laboratories

En 2010, el Instituto Americano de Estándares Clínicos y de Laboratorio (CLSI) inició un proceso de revisión y actualización de los puntos de corte para microdilución y disco difusión para cefalosporinas (cefazolina, cefotaxima, ceftriaxona, ceftizoxima, ceftazidima), monobactámicos (aztreonam) y carbapenémicos (imipenem, meropenem, ertapenem, doripenem). Los cambios se basaron en modelos PK/PD que buscan predecir la respuesta clínica con el uso exclusivo de la concentración inhibitoria mínima (CIM) y esquemas específicos de dosificación de forma independiente al mecanismo de resistencia expresado. Este nuevo paradigma eliminaría la necesidad de realizar pruebas fenotípicas para beta-lactamasas de espectro extendido (BLEE) y carbapenemasas para tomar decisiones terapéuticas y permitiría utilizarlas únicamente para fines epidemiológicos. Sin embargo, ante las limitaciones de las metodologías actuales para pruebas de susceptibilidad en Colombia, el desconocimiento de estos cambios y la alarma epidemiológica por la aparición de nuevas ß-lactamasas en el país, se hace necesario generar recomendaciones para los laboratorios clínicos, con el fi n de unifi car los criterios para la realización e informe de los antibiogramas en bacilos Gram negativos, incluyendo la implementación de los puntos de corte actuales y la aplicación de las pruebas fenotípicas para la detección de BLEE y carbapenemasas.

In 2010, the Clinical and Laboratory Standards Institute (CLSI) began a process to revise and update the breakpoints for broth microdilution and disk diffusion for cephalosporins (Cefazolin, Cefotaxime, Ceftriaxone, Ceftazidime), monobactams (Aztreonam) and carbapenems (Imipenem, Meropenem, Ertapenem and Doripenem). The changes made were based on PK/PD models that attempt to predict clinical outcomes using minimum inhibitory concentration (MIC) and specific dosage regimens, regardless of the resistance mechanism expressed by the organism. The new breakpoints would eliminate the need to perform screening and confirmatory testing for ESBLs and carbapenemases for treatment decisions, and thus they would be used only for infection control purposes. Nevertheless, there are limitations to current methods in Colombia, a lack of knowledge regarding the recent changes and epidemiologic alarm over new B-lactamases spreading in our country. Therefore it was necessary to formulate and issue recommendations for clinical laboratories, with the aim of standardizing the criteria for reports on antibiograms in Gram-negative bacilli, including the current CLSI breakpoints and applying phenotypic confirmatory testing to detect ESBLs and Carbapenemases.

The use of clinical guidelines for referral of patients with lesions suspicious for oral cancer may ease early diagnosis and improve education of healthcare professionals.

UNLABELLED: Early diagnosis and referral of oral cancer is essential. Successful implementation of clinical guidelines must include current practitioners and students. OBJECTIVE: To evaluate the diagnostic accuracy of students at oral cancer screening and to assess the effectiveness of clinical referral guidelines. STUDY DESIGN: Fifth year dental students were randomly allocated to either control (n=19) or experimental groups (n = 18). Both received the customary training in oral diagnosis. The experimental group underwent a 2 hour workshop where the guidelines for the referral of suspicious lesions were discussed. Three months later, a set of 51 clinical cases including benign, malignant, and precancerous conditions/lesions were used to assess the screening ability of each subject. RESULTS: All 37 students entered the study. Sensitivity (control group) ranged from 16.7% to 66.7%; the experimental group scored from 16.7% to 83.3%. Fifty percent of the experimental students reached sensitivity values ≥ 62.5% (p = 0.01). Diagnostic specificity (control group) spanned from 80% to 93.3% (median = 50%); amongst experimental group it ranged from 82.2% to 97.8% (median = 92.8%); (p = 0.003). Concordance -control group- was X = 82.5 (SD = 3.2), and X = 88.2 (SD = 4.3) for the experimental, (p > 0.001). Cohen's kappa test was poor (K < 0.40) for the controls and moderate for the experimental group. The experimental group referred more oral cancers urgently (p = 0.002) and left less unreferred cancers (0.04). This group also referred more precancerous lesions/conditions urgently (p = 0.02). CONCLUSIONS: The implementation of a clinical referral guideline at undergraduate level has proved valuable, under experimental conditions, to significantly increase diagnostic abilities of the examiners and thus to improve screening for oral cancer.