Rapid AST: Possibility of inferring resistance mechanisms with complex phenotypes / Pruebas rápidas de sensibilidad a los antimicrobianos: ¿es posible inferir mecanismos de resistencia con fenotipos complicados?

The new automated systems designed for rapid performance of AST have significantly reduced the response time for susceptibility testing of microorganisms causing bacteremia and sepsis. The Accelerate Pheno® system (AAC) is one such system. Our objective for this study was to determine whether the AAC system is capable of providing an accurate susceptibility profile to infer resistance mechanisms in different carbapenemase-producing isolates when compared to the MicroScan WalkAway System (MWS). Disk diffusion method was also performed on all isolates as a reference method. Additionally, we compared the results obtained with the routine AST production system. We selected 19 isolates from the cryobank of the Microbiology department, all of which were carbapenemase-producing gram-negative bacilli. AAC was able to identify and infer the resistance of a total of 10 isolates, with an EA and CA of 84.2% for meropenem and 88.2% and 64.7% for ertapenem EA and CA, respectively. If we consider the disk diffusion technique, the CA was 57.9% and 76.5% for meropenem and ertapenem. However, in the presence of carbapenemases, AAC was not able to provide adequate MICs or infer the resistance mechanisms of the isolates accurately. Further studies with a larger number of isolates, including the new antibiotics ceftolozane/tazobactam and ceftazidime/avibactam, are needed for a more comprehensive comparison. (AU)

Los nuevos sistemas automatizados diseñados para la realización rápida de antibiogramas han reducido significativamente el tiempo de respuesta para las pruebas de susceptibilidad de los microorganismos causantes de bacteriemia y sepsis. El sistema Accelerate Pheno® (AAC) es uno de ellos. Nuestro objetivo para este estudio era determinar si el sistema AAC es capaz de proporcionar un perfil de sensibilidad preciso para inferir mecanismos de resistencia en diferentes aislados productores de carbapenemasas en comparación con el sistema MicroScan WalkAway (MWS). El método de disco difusión fue incluido también en todos los aislados como método de referencia. Además, comparamos los resultados obtenidos con el sistema rutinario de producción de antibiogramas rápidos. Seleccionamos 19 aislados del criobanco del departamento de Microbiología, todos ellos bacilos gramnegativos productores de carbapenemasas. AAC fue capaz de identificar e inferir la resistencia de un total de 10 aislados, con una EA y CA del 84,2% para el meropenem y del 88,2% y 64,7% para la EA y CA del ertapenem, respectivamente. Si consideramos la técnica de disco difusión, la CA fue de un 57.9% y de un 76.5% para meropenem y ertapenem. Sin embargo, en presencia de carbapenemasas, AAC no fue capaz de proporcionar CMIs adecuadas ni de inferir con precisión los mecanismos de resistencia de los aislados. Se necesitan más estudios con un mayor número de aislados incluyendo también los nuevos antibióticos ceftolozano/tazobactam y ceftazidima/avibactam para una comparación más exhaustiva. (AU)

El papel del laboratorio de microbiología en el diagnóstico de infecciones por bacilos gramnegativos multirresistentes. Importancia de la determinación de mecanismos de resistencias / The role of the microbiology laboratory in the diagnosis of multidrug-resistant Gram-negative bacilli infections. Importance of the determination of resistance mechanisms

Un diagnóstico y tratamiento precoz tiene un impacto importante en la morbimortalidad de las infecciones producidas por bacterias multirresistentes. Los bacilos gramnegativos multirresistentes constituyen la principal amenaza actual en los hospitales y muy especialmente en las unidades de cuidados intensivos. El papel del laboratorio de microbiología es esencial en dar una respuesta rápida y eficaz. En esta revisión se actualiza los procedimientos del laboratorio de microbiología para la detección rápida de los bacilos gramnegativos multirresistentes y de sus determinantes de resistencia. También se estudia el papel del laboratorio en la vigilancia y control de brotes por estas bacterias, incluyendo las técnicas de tipificación. Se destaca la importancia de proporcionar mapas de resistencia normalizados que permitan conocer la situación epidemiológica de las diferentes unidades. Finalmente se revisa la importancia de sistemas de comunicación eficaces para la transmisión de resultados y la toma de decisiones en el manejo de pacientes infectados por bacilos gramnegativos multirresistentes (AU)

Early diagnosis and treatment has an important impact on the morbidity and mortality of infections caused by multidrug-resistant bacteria. Multidrug-resistant gram-negative bacilli constitute the main current threat in hospitals and especially in intensive care units. The role of the microbiology laboratory is essential in providing a rapid and effective response. This review updates the microbiology laboratory procedures for the rapid detection of multidrug-resistant gram-negative bacilli and its resistance determinants. The role of the laboratory in the surveillance and control of outbreaks caused by these bacteria, including typing techniques, is also studied. The importance of providing standardized resistance maps that allow knowing the epidemiological situation of the different units is emphasized. Finally, the importance of effective communication systems for the transmission of results and decision making in the management of patients infected by multidrug-resistant gram-negative bacilli is reviewed (AU)

The role of the microbiology laboratory in the diagnosis of multidrug-resistant Gram-negative bacilli infections. The importance of the determination of resistance mechanisms.

Early diagnosis and treatment has an important impact on the morbidity and mortality of infections caused by multidrug-resistant bacteria. Multidrug-resistant gram-negative bacilli (MR-GNB) constitute the main current threat in hospitals and especially in intensive care units (ICU). The role of the microbiology laboratory is essential in providing a rapid and effective response. This review updates the microbiology laboratory procedures for the rapid detection of BGN-MR and its resistance determinants. The role of the laboratory in the surveillance and control of outbreaks caused by these bacteria, including typing techniques, is also studied. The importance of providing standardized resistance maps that allow knowing the epidemiological situation of the different units is emphasized. Finally, the importance of effective communication systems for the transmission of results and decision making in the management of patients infected by BGN-MR is reviewed.

El problema de la multi-resistencia en bacilos gram-negativos en las unidades de cuidados intensivos: estrategias de tratamiento y prevención / The problem of multi-resistance in gram-negative bacilli in intensive care units: Treatment and prevention strategies

El aumento global de infecciones causadas por bacilos gram-negativos multi-resistentes (BGN-MR), lo cual incluye a los carbapenemes, supone uno de los grandes retos actuales en materia de sanidad. Esto incluye Enterobacterales productores de β-lactamasas de espectro extendido, productoras de AmpC desreprimida o Enterobacterales productores de carbapenemasas, así como BGN-MR no fermentadores como Pseudomonas aeruginosa o Acinetobacter baumannii. En Pseudomonas aeruginosa predominan otros mecanismos de resistencias diferentes a las β-lactamasas tales como bombas de expulsión o pérdida de porinas. A. baumannii presenta con frecuencia varios de estos mecanismos de resistencia. La mortalidad es elevada especialmente si el tratamiento empírico es inadecuado. En este capítulo se revisan las estrategias de tratamiento haciendo hincapié en las herramientas para identificar los pacientes en los que estaría justificado tratamiento antibiótico empírico para cubrir BGN-MR, la importancia de la optimización de la administración de estos antibióticos, así como las estrategias de prevención para evitar su diseminación desde pacientes colonizados o infectados por un BGN-MR (AU)

The rise of infections caused by multi-resistant gram-negative bacilli (MR-GNB), which includes carbapenems, represents one of the major current challenges worldwide. These MR-GNB include extended spectrum β-lactamase-producing Enterobacterales, derepressed AmpC-producing or carbapenemase-producing Enterobacterales as well as non-fermenting Gram-negative bacilli such as Pseudomonas aeruginosa or Acinetobacter baumannii. P. aeruginosa predominantly exhibits other resistance mechanisms different to β-lactamases such as expulsion pumps or loss of porins. A. baumannii frequently presents several of these resistance mechanisms. Mortality is high especially if empirical treatment is inadequate. In this review, treatment strategies are revised, describing the tools available to identify patients in whom empirical antibiotic treatment would be justified to cover MR-GNB, the importance of optimizing the administration of these antibiotics, as well as prevention strategies to avoid its spread from patients colonized or infected by a MR-GNB (AU)

The problem of multi-resistance in gram-negative bacilli in intensive care units: Treatment and prevention strategies.

The rise of infections caused by multi-resistant gram-negative bacilli (MR-GNB), which includes carbapenems, represents one of the major current challenges worldwide. These MR-GNB include extended spectrum ß-lactamase-producing Enterobacterales, derepressed AmpC-producing or carbapenemase-producing Enterobacterales as well as non-fermenting Gram-negative bacilli such as Pseudomonas aeruginosa or Acinetobacter baumannii. P. aeruginosa predominantly exhibits other resistance mechanisms different to ß-lactamases such as expulsion pumps or loss of porins. A. baumannii frequently presents several of these resistance mechanisms. Mortality is high especially if empirical treatment is inadequate. In this review, treatment strategies are revised, describing the tools available to identify patients in whom empirical antibiotic treatment would be justified to cover MR-GNB, the importance of optimizing the administration of these antibiotics, as well as prevention strategies to avoid its spread from patients colonized or infected by a MR-GNB.

Impact of sink removal from intensive care unit rooms on the consumption of antibiotics and on results of Zero Resistance Project.

INTRODUCTION: Due to the favourable impact of removing the sinks on isolations in bronchoaspirate samples of patients with mechanical ventilation, we now evaluate the impact on the consumption of antibiotics as well as on the results of the Zero Resistance Project (ZRP). PATIENTS AND METHODS: All the patients admitted to the unit in a quasi-experimental before-after study with a pre-intervention period between 2014 and 2016 and a post-intervention period from 2016 to 2017, to evaluate antibiotic consumption in defined daily doses, and until 2018, to evaluate the ZRP indicators. The intervention was the removal of the sinks from the rooms of the ICU. We evaluated antibiotic consumption densities and their ratios, grouped as Enterobacteriaceae and non-fermenting gram-negative bacilli (NFGNB) according to their antibiograms; the absolute number of 'antibiotic days', 'hospitalised days', 'isolation days', and 'multi-resistant bacteria (MRB) days'; as well as their incidence densities per 1000 hospitalised days and the ratio between the two years prior to and the two years after the intervention. RESULTS: Post-intervention antibiotic use was 1.61-fold (1.60-1.62) and 2.24-fold (2.10-2.37) lower for antibiotics used against Enterobacteriaceae and NFGNB, respectively. There were also reductions in the number of days of antibiotic use by 1.29-fold (1.22-1.36), number of MRB days by 1.84-fold (1.63-2.08), and number of patient isolation days by 1.51-fold (1.38-1.66). DISCUSSION: The results suggest that the intervention had a favourable impact on the consumption of antibiotics, as well as on the number of days on antibiotics, MRB, and isolation.

Patrones de susceptibilidad de gramnegativos en un hospital pediátrico de tercer nivel: 2013 vs. 2018 / Gram-negative susceptibility patterns in a tertiary pediatric hospital: 2013 vs. 2018

Resumen Introducción: Los gramnegativos continúan siendo los causantes de infecciones asociadas a la atención a la salud (IAAS). Material y métodos:: Analizamos la resistencia antimicrobiana de patógenos durante el 2013 vs. 2018 y lo comparamos con lo publicado en 2006 vs. 2012. Resultados: Identificamos nueve patógenos gramnegativos, de un total de 404 aislamientos, con una prevalencia en 2013 (N = 227 [0.22]) vs. 2018 (N = 177 [0.17]) y una incidencia por egresos (6,607 en el 2013 y 7,778 en el 2018) del 3.4 y 2.2% respectivamente. Destacaron tres patógenos: Klebsiella pneumoniae (129 [31.93%]), Pseudomonas aeruginosa (85 [21.03%]) y Escherichia coli (80 [19.80%]). Estos, llamados patógenos ESKAPE-E, prevalecieron como causantes de IAAS. Identificamos un aumento en los patrones de resistencia para muchos patógenos en 2018. Conclusión: La multirresistencia a patógenos ESKAPE-E es un serio problema de salud pública, por carecer de alternativas terapéuticas para enfrentar este reto. Los mapas de resistencia bacteriana ayudan en la prescripción antibiótica.

Abstract Background: Gram-negatives continue to be the cause of infections associated with health care (HCAI). Material and methods: We analyzed the antimicrobial resistance of pathogens during 2013 vs. 2018 and we compare it with what was published in 2006 vs. 2012. Results: We identified 9 gram-negative pathogens, out of a total of 404 isolates, with a prevalence in 2013 (N = 227 [0.22]) vs. 2018 (N = 177 [0.17]) and an incidence due to discharges (6,607 in 2013 and 7,778 in 2018) of 3.4 and 2.2%, respectively.Three pathogens stood out Klebsiella pneumoniae (129 [31.93%]), Pseudomonas aeruginosa (85 [21.03%]) and Escherichia coli (80 [19.80%]). These, called ESKAPE-E pathogens, prevailed as the cause of HCAI. We identified an increase in resistance patterns for many pathogens in 2018. Conclusion: Multi-resistance to ESKAPE-E pathogens is a serious public health problem, due to the lack of therapeutic alternatives to face this challenge. Bacterial resistance maps help in antibiotic prescription.

Evaluation of Vitek-MS™ and Microflex LT™ commercial systems for identification of Acinetobacter calcoaceticus-baumannii complex.

INTRODUCTION: Acinetobacter is a genus that comprises a group of opportunistic pathogens responsible for a variety of nosocomial infections. The Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex includes some species of clinical importance, mainly A. baumannii, A. pittii and A. nosocomialis, which share phenotypic similarities that make it very difficult to distinguish between them using a phenotypic approach. The aim of this study was to evaluate two commercial matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems for the identification of different Acinetobacter species, with a special focus among those belonging to the Acb complex. METHODS: One hundred and fifty-six Acinetobacter spp. clinical strains, identified by amplified ribosomal DNA restriction analysis (ARDRA) and rpoB gene sequencing, were analysed by two different MALDI-TOF systems. RESULTS: Considering only the 144 strains of the Acb complex evaluated in this study, the Vitek-MS™ and Microflex LT™ systems correctly identified 129 (89.6%) and 143 (99.3%) strains, respectively. CONCLUSION: After analysing 156 strains belonging to Acinetobacter spp., both Vitek-MS™ and Microflex LT™ proved to be rapid and accurate systems for the identification of Acb complex species showing a good correlation. However, both manufacturers should improve their databases to include new species in them.

Presencia de Bacilos Gram-negativos y Candida albicans en provisionales de polimetilmetacrilato (PMM)en pacientes de Clínica Integrada de la Universidad Autónoma de Asunción / Presence of Gram-negative bacilli and Candida albicans in provisional polymethylmethacrylate in patients of the Integrated Clinic of the Autonomous University of Asunción

Las resinas a base de polimetilmetacrilato (PMM) son una solución para la reposición de estructuras dentarias. Este material ha sido muy utilizado debido a su buena estética, pero las rugosidades, grietas y defectos de este material son propicios para la proliferación de microrganismos que podrían constituir un riesgo para la salud de los pacientes. Estudio observacional descriptivo de corte transversal, donde se tomaron muestras de provisorios de PMM de 20 pacientes de la cátedra de Clínica Integrada de Odontología de la Universidad Autónoma de Asunción. Los datos sobre el crecimiento de los microorganismos fueron anotados en planillas Excel para análisis estadísticos. De los 20 pacientes que participaron en esta investigación, 50% fueron de sexo femenino y 50% masculino, el promedio de edad fue de 32,35 años (DE±11,94). Se analizaron un total de 7 pónticos (6 pónticos de 3 piezas y 1 de 6 piezas) y 19 coronas unitarias, el tiempo de permanencia en boca fue de entre 4 a 20 semanas con una media de 8,6 semanas. El 65% de las muestras dio positivo al cultivo microbiológico. En algunas muestras se aislaron más de un género de microorganismos. Se aislaron 5 especies de bacterias Gram-negativas, la más frecuente fue K. pneumoniae con un 40%. Se aisló C. albicans en un 10% de las muestras. En el proceso de elección de los materiales para rehabilitación es fundamental considerar la situación global de cada paciente, pues exponerlos a un material con grandes capacidades retentivas de microrganismos conlleva un peligro

Polymethylmethacrylate (PMM) based resins are a solution for the replacement of dental structures. This material has been widely used due to its good aesthetics, but the roughness, cracks and defects of this material are propitious for the proliferation of microorganisms that could constitute a risk to the health of patients. This was a descriptive cross-sectional observational study, where samples of PMM provisionals were taken from 20 patients of the Department of Integrated Dental Clinic of the Autonomous University of Asunción. Data on the growth of microorganisms were recorded in Excel spreadsheets for statistical analysis. Of the 20 patients who participated in this research, 50% was female and 50% male, and the average age was 32.35 years (SD±11.94). Seven pontics (6 pontics of 3 pieces and 1 of 6 pieces) and 19 unit crowns were analyzed, the time spent in the mouth was between 4 to 20 weeks with an average of 8.6 weeks. Sixty-five percent of the samples tested positive in the microbiological culture. In some samples, more than one genus of microorganisms was isolated. Five species of Gram-negative bacteria were isolated, the most frequent was Klebsiella pneumoniae with 40%. Candida albicans was isolated in 10% of the samples. In the process of choosing materials for rehabilitation, it is essential to consider the overall situation of each patient, since exposing them to a material with high retention capacities of microorganisms carries a danger

Primer reporte de bacterias y dinoflagelados marinos luminiscentes del Parque Nacional Isla del Coco, Costa Rica

Introducción: La bioluminiscencia es la capacidad de ciertos organismos para transformar la energía química en energía lumínica mediante varios procesos bioquímicos. Objetivo: El aislamiento e identificación por primera vez de bacterias luminiscentes en agua marina superficial y la identificación de dinoflagelados luminiscentes marinos del Parque Nacional Isla del Coco, Costa Rica. Metodología: Se colectaron muestras de agua marina obtenida por buceo a 20 m y a nivel superficial de 13 sitios en la Isla del Coco, Costa Rica. Por otra parte, se analizaron muestras de fitoplancton colectadas desde la superficie hasta los 30 m de profundudad en los alrededores de 8 sitios de la Isla del Coco, y se determinaron varias especies luminiscentes pertenecientes a los géneros Ornithocercus y Ceratocorys. Resultados: Se logró obtener 7 aislados bacterianos luminiscentes, se identificaron y caracterizaron bioquímicamente mediante una plataforma automatizada (Vitek) con altos niveles de confianza, se ubicaron taxonómicamente dentro del género Vibrio,2 especies: V. alginolyticus y V. parahaemolyticus, además, algunos aislados presentaron resistencia al antibiótico ampicilina y 100% capacidad hemolítica. Esta investigación muestra evidencia de la presencia de especies microscópicas marinas en Isla del Coco, Costa Rica, capaces de presentar el fenómeno de la luminiscencia, por lo que profundizar en su estudio sería relevante en cuanto a la importancia de estos microorganismos en la producción de metabolitos secundarios y como indicadores de floraciones algales nocivas, por lo que se hace necesario realizar más investigación científica para determinar su potencial biotecnológico. Conclusiones: De la misma forma, los resultados obtenidos en esta investigación sugieren expandir las localidades de colecta y aislamientos de microorganismos luminiscentes, acompañado de una caracterización bioquímica y molecular, con el fin de explorar la diversidad microbiana asociada a eventos de luminiscencia y determinar los ambientes en el que estas especies se desarrollan.

Introduction: Bioluminescence is the ability of certain organisms to transform chemical energy into light energy through various biochemical processes. Objective: Isolation and identification for the first time of luminescent bacteria of superficial marine water, and the identification of marine luminescent dinoflagellates of Isla del Coco National Park, Costa Rica. Methods: Samples of seawater obtained by diving at 20 m and at a surface level of 13 sites were collected. On the other hand, phytoplankton samples collected from the surface up to 30 m deep were analyzed in the surroundings of 8 sites of Cocos Island, and several luminescent species belonging to the genera Ornithocercus and Ceratocorys were determined. Results: Seven luminescent bacterial isolates were obtained, they were identified and characterized biochemically by means of an automated platform (Vitek) with high levels of confidence, they were taxonomically located within the genus Vibrio, 2 species: V. alginolyticus and V. parahaemolyticus, in addition, some isolates presented resistance to the antibiotic ampicillin and 100% hemolytic capacity. This research shows evidence of the presence of marine microscopic species in Cocos Island, Costa Rica, capable of presenting the phenomenon of luminescence, so that further study would be relevant in terms of the importance of these microorganisms in the production of metabolites secondary and as indicators of harmful algal blooms, so it is necessary to conduct more scientific research to determine their biotechnological potential. Conclusions: In the same way, the results obtained in this investigation suggest expanding the collection and isolation of luminescent microorganisms, accompanied by a biochemical and molecular characterization, in order to explore the microbial diversity associated with luminescence events and determine the environments in which that these species develop.

New antibiotics for the treatment of infections by multidrug-resistant microorganisms. / Nuevos antibióticos para el tratamiento de las infecciones por microorganismos multirresistentes.

One of the current priorities of the World Health Organization is multidrug-resistant bacteria, because they are a global problem due to their rapid spread and the difficulty of their treatment. In addition, they are associated with high morbidity, mortality and high economic costs. There are multidrug-resistant bacteria, both Gram-positive and Gram-negative, including Pseudomonas aeruginosa and Acinetobacter baumannii resistant to carbapenems, enterobacteria producing carbapenemases, Staphylococcus aureus resistant to methicillin and/or with intermediate sensitivity to vancomycin, and Enterococcus faecium (and less frequently Enterococcus faecalis) resistant to vancomycin. This review will comment on the new antibiotics that have been incorporated into the therapeutic arsenal in recent years, as well as other promising antibiotics that are in their final stages of development.

Prevalência, susceptibilidade antimicrobiana e virulência de bacilos Gram-negativos e enterococos isolados do biofilme subgengival associado à doenca periodontal' / Prevalence, antimicrobial susceptibility and virulence of Gram-negative bacilli and enterococci isolated from subgingival biofilm associated with periodontal disease

Objetivos: A cavidade oral pode atuar como reservatório de vários patógenos de importância clínica, incluindo bacilos Gram-negativos (BGN) e Enterococcus spp. Essas espécies podem ainda aumentar em uma condição disbiótica, como ocorre nas doenças periodontais. Assim, este estudo teve como objetivo determinar a prevalência, susceptibilidade antimicrobiana e presença de fatores de virulência de BGN e enterococos isolados do biofilme subgengival de indivíduos com diferentes condições periodontais, correlacionando esses achados com parâmetros clínicos e composição da microbiota subgengival. Métodos: Na análise dos BGN, amostras de biofilme subgengival foram obtidas de indivíduos com Saúde Periodontal (SP, n=81), Gengivite (G, n=74) e Periodontite (P, n=207); para Enterococcus spp., amostras foram coletadas de 139 indivíduos com SP, 103 com G e 305 com P. As amostras foram cultivadas em meio seletivo e as colônias isoladas e identificadas por MALDI-ToF. A susceptibilidade antimicrobiana foi determinada por disco-difusão (CLSI); já os genes de virulência de enterococos e genes codificadores de ESBL e carbapenemases em BGN foram pesquisados por PCR. A produção de ESBL e carbapenemases por BGN foi avaliada pelo teste de sinergia de disco duplo e hidrólise de imipenem por espectrofotometria, respectivamente. A microbiota subgengival desses indivíduos foi determinada pelo Checkerboard. Diferenças entre os grupos foram avaliadas pelos testes de KruskalWallis, Mann-Whitney e Qui-quadrado. Resultados: BGN foram isolados em 36.2% das amostras, com maior prevalência (p<0,001) em pacientes com P (46.4%) em comparação com SP (22.2%) e G (22.9%). Pseudomonas aeruginosa (27.5%), Enterobacter cloacae (16.8%) e Enterobacter asburiae (10.7%) foram as espécies mais predominantes. Resistência/sensibilidade reduzida a ≥ 1 antimicrobiano foi encontrada em 60% dos BGN, mas apenas 4.6% eram multirresistentes. Altas taxas de resistência (>40%) foram observadas na família Enterobacteriacea para cefoxitina, cefalotina, amoxicilina- clavulanato e cefazolina. Uma única cepa de K. pneumoniae apresentou resistência/sensibilidade reduzida ao imipenem, embora o fenótipo ESBL e a detecção dos genes codificadores de beta-lactamases foram negativos. Enterococcus spp. foram isolados em 7.4% de todas as amostras, 53.7% eram E. faecalis. Essas espécies foram mais predominantes na P (9.8%) e G (7.8%) do que na SP (2.2%, p< 0,05); entretanto não houve correlação com os níveis de gravidade da P. Altas taxas de resistência/susceptibilidade reduzida foram observadas para ciprofloxacina, eritromicina e rifampicina. Os fatores de virulência mais predominantes incluíram ace, asa e esp, todos relacionados à formação de biofilme e colonização. F. nucleatum foi mais prevalente na microbiota de indivíduos enterococos +. Por outro lado, Dialister pneumosintes foi pouco detectado em indivíduos portadores de enterococos bopD+. Estreptococos orais foram prevalentes (>70%) na microbiota de pacientes que apresentavam enterococos suceptíveis à doxiciclina (p<0,05), frequentemente bopD- e esp- (p<0,01). Conclusão: Uma prevalência elevada de BGN da família Enterobacteriacea com resistência a cefalosporinas e penicilina é observada na microbiota subgengival de indivíduos com P. Enterococcus spp., principalmente E. faecalis são pouco frequentes na microbiota subgengival associada à SP, porém aumentam significativamente nas doenças periodontais. Os mesmos apresentam diversos genes de virulência compatíveis com destruição tecidual, bem como resistência a antimicrobianos de uso na clínica periodontal, o que pode limitar uma resposta terapêutica favorável. (AU)

Background/Aim: The oral cavity can act as a reservoir for several pathogens of clinic importance, including Gram-negative bacilli (GNB) and Enterococcus spp. These species may increase even more in a dysbiotic condition as seen in periodontal diseases. Thus, this study aimed to determine the prevalence, antimicrobial susceptibility and virulence factors of GNB and enterococci isolated from subgingival biofilm of individuals with different periodontal conditions, correlating these findings with clinical parameters and the composition of the subgingival microbiot. Methods: For GNB analysis, subgingival biofilm was obtained from individuals with periodontal health (PH, n=81), gingivitis (G, n=74) and periodontitis (P, n=207), whereas for enterococci isolation samples were taken from 139 patients with PH, 103 with G, and 305 with P. Samples were cultivated in selective media and isolated colonies were identified by MALDI-ToF. Antimicrobial susceptibility was determined by CLSI disk diffusion, whereas virulence genes by PCR. Production of ESBL and carbapenemases were evaluated by double disk synergy test and spectrophotometric detection of imipenem hydrolysis, respectively, and ESBL and carbapenemase encoding genes were surveyed by PCR. The subgingival microbiota was determined by checkerboard. Differences among groups were examined by Chi-square, Kruskal-Wallis or Mann-Whitney tests. Results: GNB were isolated from 36.2% of all samples, with a significantly greater prevalence (p<0.001) in P patients (46.4%) compared to PH (22.2%) and G (22.9%). Pseudomonas aeruginosa (27.5%), Enterobacter cloacae (16.8%) and Enterobacter asburiae (10.7%) were the most predominant species. Resistance/reduced sensitivity to ≥ 1 antimicrobial was found in 60% of GNB, but only 4.6% were multidrug resistant. High resistance rates (>40%) were seen in the Enterobacteriaceae family for cefoxitin, cephalotin, amoxicillin-clavulanate, and cefazolin. One strain of K. pneumoniae showed resistance/reduced sensitivity to imipenem, although the ESBL-phenotype and PCR targeting beta-lactamase encoding genes were negative. Enterococcus spp. were isolated from 7.4% of all samples; 53.7% were E. faecalis. Enterococci were more predominant in P (9.8%) and G (7.8%) samples than PH (2.2%; p<0.05), however there were no associations with distinct levels of disease severity. High rates of low susceptibility/resistance were seen for ciprofloxacin, erythromycin and rifampicin. Predominant virulence factors included ace, asa and esp, all related to colonization and biofilm formation. F. nucleatum was prevalent in the microbiota of enterococci+ individuals. In contrast, lower frequency of Dialister pneumosintes was found in patients carrying bopD+ enterococci. Oral streptococci were prevalent (>70%) in the microbiota of patients carrying enterococci susceptible to doxycycline (p<0.05), which were also frequently bopD- and esp- (p<0.01). Conclusion: A high prevalence of GNB of the Enterobacteriacea family, resistant to cephalosporins and penicillins is observed in the subgingival microbiota of patients with P, Enterococcus spp., mainly E.faecalis are not commonly detected in the healthy-related subgingival microbiota, however their frequency increases significantly in patients with periodontal diseases. These species carry several genes related to tissue destruction, as well as resistance to antimicrobials routinely used in the periodontal clinic, which may hinder a successful therapeutic response. (AU)

Costos médicos directos de las infecciones del tracto urinario por bacilos Gram negativos resistentes a betalactámicos en un hospital de alta complejidad de Medellín, Colombia / Direct medical costs of urinary tract infections by Gram-negative bacilli resistant to beta-lactams in a tertiary care hospital in Medellín, Colombia

Resumen Introducción. Las infecciones del tracto urinario son muy frecuentes en el ámbito hospitalario. Debido a la aparición de la resistencia antimicrobiana, la complejidad de los procesos de atención ha aumentado y, con ello, la demanda de recursos. Objetivo. Describir y comparar el exceso de los costos médicos directos de las infecciones del tracto urinario por Klebsiella pneumoniae, Enterobacter cloacae y Pseudomonas aeruginosa resistentes a betalactámicos. Materiales y métodos. Se llevó a cabo un estudio de cohorte en una institución de tercer nivel de Medellín, Colombia, entre octubre del 2014 y septiembre del 2015. Se incluyeron los pacientes con infección urinaria, unos por bacterias sensibles a los antibióticos betalactámicos, y otros por bacterias resistentes a las cefalosporinas de tercera y cuarta generación y a los antibióticos carbapenémicos. Los costos se analizaron desde la perspectiva del sistema de salud. La información clínico-epidemiológica se obtuvo de las historias clínicas y los costos se calcularon utilizando los manuales tarifarios estándar. El exceso de costos se estimó mediante análisis multivariados. Resultados. Se incluyeron 141 pacientes con infección urinaria: 55 (39 %) por bacterias sensibles a los betalactámicos, 54 (38,3 %) por bacterias resistentes a las cefalosporinas y 32 (22,7 %) por bacterias resistentes a los carbapenémicos. El exceso de costos totales ajustado de los 86 pacientes con infecciones del tracto urinario por bacterias resistentes a las cefalosporinas y a los carbapenémicos, fue de USD$ 193 (IC95% -347 a 734) y USD$ 633 (IC95% -50 a 1.316), respectivamente comparados con el grupo de 55 pacientes por bacterias sensibles a los betalactámicos. Las diferencias se presentaron principalmente en el uso de antibióticos de amplio espectro, como el meropenem, la colistina y la fosfomicina. Conclusión. Los resultados evidenciaron un incremento sustancial de los costos médicos directos de los pacientes con infecciones del tracto urinario por bacterias resistentes a las cefalosporinas o a los carbapenémicos. Esta situación genera especial preocupación en los países endémicos como Colombia, donde la alta frecuencia de infecciones del tracto urinario y de resistencia a los betalactámicos puede causar un mayor impacto económico en el sector de la salud.

Abstract Introduction: Urinary tract infections are very frequent in the hospital environment and given the emergence of antimicrobial resistance, they have made care processes more complex and have placed additional pressure on available healthcare resources. Objective: To describe and compare excess direct medical costs of urinary tract infections due to Klebsiella pneumoniae, Enterobacter cloacae and Pseudomonas aeruginosa resistant to beta-lactams. Materials and methods: A cohort study was conducted in a third level hospital in Medellín, Colombia, from October, 2014, to September, 2015. It included patients with urinary tract infections caused by beta-lactam-susceptible bacteria, third and fourth generation cephalosporin-resistant, as well as carbapenem-resistant. Costs were analyzed from the perspective of the health system. Clinical-epidemiological information was obtained from medical records and the costs were calculated using standard tariff manuals. Excess costs were estimated with multivariate analyses. Results: We included 141 patients: 55 (39%) were sensitive to beta-lactams, 54 (38.3%) were resistant to cephalosporins and 32 (22.7%) to carbapenems. The excess total adjusted costs of patients with urinary tract infections due to cephalosporin- and carbapenem-resistant bacteria were US$ 193 (95% confidence interval (CI): US$ -347-734) and US$ 633 (95% CI: US$ -50-1316), respectively, compared to the group of patients with beta-lactam sensitive urinary tract infections. The differences were mainly found in the use of broad-spectrum antibiotics such as meropenem, colistin, and fosfomycin. Conclusion: Our results show a substantial increase in the direct medical costs of patients with urinary tract infections caused by beta-lactam-resistant Gram-negative bacilli (cephalosporins and carbapenems). This situation is of particular concern in endemic countries such as Colombia, where the high frequencies of urinary tract infections and the resistance to beta-lactam antibiotics can generate a greater economic impact on the health sector.

Avaliação da multirresistência a antibióticos e produção de ESBL e carbapenemases em bacilos gram-negativos de efluente hospitalar e urbano / Evaluation of antibiotic multi-resistance and production of ESBL and carbapenemases in gram-negative bacilli of hospital and urban effluent

A multirresistência aos antibióticos observada em bacilos gram-negativos é um grave problema de saúde pública devido a alta morbidade e mortalidade apresentada, especialmente em instituições assistenciais de saúde. Como consequência do intenso uso de antibióticos, a multirresistência a esses fármacos é principalmente mediada por enzimas hidrolisantes, onde destaca-se as enzimas ?-lactamases, principal mecanismo de resistência aos ?-lactâmicos verificado em bacilos gram-negativos. Os esgotos de origem hospitalar e de estações de tratamento de esgoto (ETE) são considerados como reservatórios de bactérias multirresistentes pela presença de antibióticos que as selecionam e por favorecem a transmissão de determinantes de resistência. Nesse sentido, o presente estudo objetivou avaliar a multirresistência a antibióticos e a produção de enzimas ?-lactamases em bacilos gram-negativos isolados de efluente hospitalar e da estação de tratamento de esgoto, na cidade de Ribeirão Preto, SP. No hospital terciário, amostras de esgotos foram coletadas dos ambulatórios, das enfermarias e da junção do esgoto hospitalar. Na ETE, amostras foram coletadas na caixa de entrada do esgoto bruto e após ao tratamento. Dez microlitros foram semeados em ágar MacConkey, SalmonellaShigella, Cetrimide e TCBS e a identificação dos bacilos gram-negativos foi realizada pelo kit Bactray®. O teste de susceptibilidade aos antibióticos foi realizado pelo método de discodifusão em ágar. A detecção fenotípica de bacilos produtores de ESBL foi realizada pelos testes de sinergia de disco-duplo e disco combinado com ácido clavulânico, e para detecção de isolados produtores de carbapenemases foi utilizado os testes de disco combinado com ácido fenilborônico e EDTA e o teste Blue Carba. A PCR foi utilizada para amplificação dos genes codificadores de ESBL e carbapenemases. No total, 45 bacilos gram-negativos foram isolados, sendo as espécies Klebsiella pneumoniae e Pseudomonas aeruginosa as de maiores prevalências. Ampla resistência foi verificada aos antibióticos ?-lactâmicos, sendo a resistência ao aztreonam, a cefepime e a cefotaxima mais expressiva nos isolados do esgoto hospitalar, com diferenças estatisticamente significante (p<0,05). O fenótipo multidroga resistente foi atribuído a 33,3%, nos isolados exclusivamente do esgoto hospitalar, com diferença estatisticamente significante (p = 0,0025) em relação aos isolados do esgoto da ETE. Genes de ?-lactamases foram encontrados em 35,6% das bactérias, sendo o blaKPC e blaTEM os de maiores ocorrências, ambos em 17,8% dos isolados, e os genes blaSHV e blaCTX-M em 13,3% e 8,9%. Somente em um isolado de Enterobacter cloacae no esgoto tratado da ETE foi identificado o gene blaSHV, os demais isolados portadores dos genes de ?-lactamases foram encontrados no esgoto hospitalar. Os dados obtidos neste estudo são importantes levando em consideração que no Brasil o esgoto hospitalar pode ser lançado in natura na rede coletora municipal, no entanto, acredita-se que tal permissão favorece a disseminação da multirresistência bacteriana, posto que, os resultados demonstram alta frequência de bactérias portadoras de genes de resistência a antibióticos no esgoto hospitalar estudado. Assim, a implementação do tratamento de efluentes hospitalares, especialmente os de hospitais terciários, e adicionalmente ao tratamento da ETE evitaria a propagação dessas bactérias no ambiente e de impactar negativamente os recursos hídricos

Antibiotic multi-resistance observed in Gram-negative bacilli is a serious public health problem due to high morbidity and mortality, especially in health care institutions. As a consequence of the intense use of antibiotics, multi-resistance to these drugs is mainly mediated by hydrolyzing enzymes, in which ?-lactamases, the main ?-lactam resistance mechanism observed in Gramnegative bacilli, are prominent. Hospital sewage and wastewater treatment plants (WWTP) are considered reservoirs of multiresistant bacteria by the presence of antibiotics that select these bacteria and favor the transmission of resistance determinants. In this sense, the present study aimed to evaluate the antibiotics multi-resistance and the production of ?-lactamase enzymes in Gram-negative bacilli isolated from hospital effluent and the wastewater treatment plants in Ribeirão Preto city, SP. In the tertiary hospital, sewage samples from the outpatient clinics, rooms patients and the hospital sewage junction were collected. In the WWTP, raw and treated sewage were collected. Ten microliters were seeded on MacConkey, Salmonella-Shigella, Cetrimide and TCBS agar and the identification of Gram-negative bacilli was performed by the Bactray® kit. Antibiotic susceptibility test was performed by agar-diffusion method. Phenotypic detection of ESBL-producing bacilli was performed by double-disc and discsynergy tests combined with clavulanic acid, and for the detection of carbapenemase-producing isolates the combined disk tests with phenylboronic acid and EDTA and Blue Carba test were used. PCR amplification of ESBL and carbapenemases-encoding genes was used. In total, 45 Gram-negative bacilli were isolated, and Klebsiella pneumoniae and Pseudomonas aeruginosa being the most prevalent. Extensive resistance was verified to ?-lactam antibiotics and resistance to aztreonam, cefepime and cefotaxime was more pronounced in hospital sewage isolates, with statistically significant differences (p<0.05). Multidrug-resistant phenotype was attributed to 33.3% in isolates exclusively from hospital sewage, with a statistically significant difference (p = 0.0025) in relation to the sewage isolates from the WWTP. ?-lactamase genes were found in 35.6% of the bacteria, with blaKPC and blaTEM having the highest occurrences, both in 17.8% of the isolates, and the blaSHV and blaCTX-M genes in 13.3% and 8, 9%. Only in an isolate of Enterobacter cloacae in the treated sewage from WWTP was the blaSHV gene identified, the other isolates carrying the ?-lactamases genes were found in hospital sewage. The data obtained in this study are important considering that in Brazil the hospital sewage can be released in nature in municipal collection network, however, it is believed that such permission favors the dissemination of bacterial multi-resistance, since, the results show high frequency of bacteria carrying antibiotic resistance genes in the hospital sewer studied. Thus, the implementation of treatment of hospital effluents, especially those in tertiary hospitals, and in addition to the treatment of WWTP would prevent the spread of these bacteria in the environment and negatively impact water resources

Leclercia adecarboxylata, a rare cause of soft tissue infections in immunocompromised patients, case report and review of the literature / Leclercia adecarboxylata, una causa rara de infección de tejidos blandos en pacientes inmunocomprometidos, reporte de caso y revisión de la literatura

Leclercia adecarboxylata is a member of the Enterobacteriaceae family that has been isolated from several environmental and animal specimens, however it rarely causes diseases in human beings. It has natural resistance to several antibiotics, and has shown the ability to harbor and produce enzymes capable of hydrolyzing most of the antibiotics used in daily clinical practice, making its treatment a challenge when a strain with such characteristics causes disease. Here we report the first known case of infection by Leclercia adecarboxylata after a trauma with plant material, in a 69-year-old male patient, with poorly controlled Diabetes Mellitus type 2.

Leclercia adecarboxylata es un miembro de la familia Enterobacteriaceae que ha sido aislada tanto de muestras de animales como medioambientales, sin embargo raramente produce enfermedad en seres humanos. Tiene resistencia natural a varios antibióticos y se ha encontrado que tiene enzimas capaces de hidrolizar la mayoría de los antibióticos utilizados en la práctica clínica, lo cual hace un verdadero tratar una infección por este microorganismo en humanos. Aquí reportamos el primer caso de infección por Leclercia adecarboxylata luego de un trauma con material vegetal, en un paciente de 69 años y con una diabetes tipo 2, mal controlada.

Bacterial resistance in bats from the Phyllostomidae family and its relationship with unique health / Resistência bacteriana em morcegos da família Phyllostomidae e sua relação com a saúde única

The Phyllostomidae family is important among the bats found in Brazil, with several species and diverse eating habits, and is the only one to have frugivorous representatives. These bats can be found in urban and in wild life environments in search for the best reproductive and feeding conditions. The versatility of environments can be associated with the incidence and/or distribution of some diseases through pathogenic agents. The present paper has the purpose to identify the oral and perianal microbiota and to detect the bacterial resistance of frugivorous bats captured near communities inhabited by humans in the northwestern region of the state of Paraná. A total of 68 bats were captured, belonging to four species of the Phyllostomidae family, namely Artibeus lituratus, Artibeus planirostris, Carollia perspicillata and Sturnira lillium, originated from forest fragments in the micro region of Umuarama, state of Paraná. A total of 64 isolates from oral bacteria and 39 from perianal region were submitted to identification. They were later submitted to a susceptibility test to 22 human and veterinary antimicrobials. The most prevalent bacteria were Escherichia coli 33.3% in the oral region, and 35.90% in the perianal region, Enterobacter aerogenes 12.7% and 5.13%, Enterobacter agglomerans 7.9% and 10.25%, and Serratia liquefaciens 9.5% and 5.13% in the oral and perianal region respectively. All bat species studied had resistant strains, with a few of them presenting multi-resistance to antimicrobials. The species with the highest multi-resistance index to antimicrobials was Carollia perspicillata, with three strains of the oral region resistant to 15 antimicrobials; it also presented two strains in the perianal region, which were resistant to 13 and 10 antimicrobials respectively. Based on the results found, it is possible to conclude that the oral and perianal microbiota of bats is composed of several enterobacterial species resistant to one or several antimicrobials used in human and veterinarian medicine. This is an issue and a future warning for unique health, since high percentages of resistance were found against antimicrobials broadly used, such as ampicillin, amoxicillin and amoxicillin+clavulonate.(AU)

A família Phyllostomidae se destaca entre as famílias de morcegos encontrados no Brasil, com diversificadas espécies e hábitos alimentares, sendo a única a apresentar representantes frugívoros, podendo ser encontrada tanto em meio urbano, como de vida livre, em busca de melhores condições reprodutivas e alimentares. Essa versatilidade de ambientes pode estar associada à incidência e/ou distribuição de determinadas doenças por agentes patogênicos. O presente trabalho objetivou identificar a microbiota oral e perianal e detectar a resistência bacteriana em morcegos frugívoros capturados próximos às comunidades habitadas pelo homem na região noroeste do estado do Paraná. Foram capturados 68 morcegos, de quatro espécies da família Phyllostomidae, são eles Artibeus lituratus, Artibeus planirostris, Carollia perspicillata e Sturnira lillium, oriundos de fragmentos de Mata da microrregião de Umuarama, estado do Paraná. Um total de 64 isolados de bactérias da região oral e 39 da região perianal foram submetidos, identificação e posteriormente teste de susceptibilidade a 22 antimicrobianos de uso humano e veterinário. As bactérias mais prevalentes foram Escherichia coli 33,3% na região da boca e 35,90% na região perianal, Enterobacter aerogenes 12,7% e 5,13%, Enterobacter agglomerans 7,9% e 10,25% e Serratia liquefaciens 9,5% e 5,13% na região da boca e perianal, respectivamente. Todas as espécies de morcegos estudadas apresentaram cepas que foram resistentes, e algumas multirresistência aos antimicrobianos. A espécie que apresentou maior índice de multirresistência aos antimicrobianos foi Carollia perspicillata, com três cepas na região oral resistente a 15 antimicrobianos, e duas na perianal, com resistência a 13 e 10 antimicrobianos respectivamente. Baseados nos resultados encontrados, é possível concluir que a microbiota oral e perianal de morcegos, é composta por diversas espécies de enterobactérias, resistentes a um, ou vários antimicrobianos utilizados na medicina humana e veterinária, tornando-se um problema, e um alerta futuro para a saúde única, uma vez que foram encontrados elevados percentuais de resistência contra antimicrobianos utilizados em larga escala tais como ampicilina, amoxicilina e amoxicilina+clavulonato.(AU)

El desafio en la dosificación de colistin: actualización de las recomendaciones disponibles / The challenge in colistin dosing: updating available recommendations

Resumen Las polimixinas están disponibles desde la década de los 60; sin embargo, debido a sus efectos adversos su uso ha sido reservado para el tratamiento de infecciones provocadas por bacterias multi-resistentes. El aumento en la experiencia clínica adquirida en los últimos años y la literatura médica publicada han planteado dudas respecto de la información entregada del producto, poniendo en manifiesto la necesidad de actualizar las recomendaciones posológicas, su farmacocinética y la información farmacocinética/farmacodinámica. Además, las diferencias en cuanto a concentración y dosis entre los distintos productos del colistín pueden dar lugar a errores de indicación/administración y suponer un riesgo para los pacientes. El año 2013, la Agencia Europea de Medicamento (EMA) encargó al Comité de Productos Medicinales para uso Humano (CHPM) la revisión de los datos disponibles y que formulara recomendaciones actualizadas del uso de colistín. Dicho procedimiento arrojó un primer informe en 2014. Esta revisión destaca los aspectos críticos de seguridad y eficacia, revisa los recientes avances farmacocinéticos y de estabilidad, las formas farmacéuticas disponibles en Chile, proporcionando los esquemas actualmente recomendados por agencias sanitarias y expertos en el tema para distintos escenarios clínicos.

Polymyxins have been available since the 1960s, however, because of their adverse effects, their use has been reserved for the treatment of infections caused by multiresistant bacteria. The increase in the clinical experience acquired in recent years and the published medical literature have raised doubts about the information provided by the product, indicating the need to update dosage recommendations, pharmacokinetics and pharmacokinetic/pharmacodynamic information (PK/PD). In addition, differences in concentration and dose between the different products of colistin may lead to errors of indication/administration and pose a risk to patients. In 2013, the European Medicines Agency (EMA) commissioned the Committee for Medicinal Products for Human Use (CHPM) to review available data and to make updated recommendations on the use of colistin. This procedure yielded a first report in 2014. This review highlights critical safety and efficacy aspects, reviews the recent pharmacokinetic and stability advances, the available pharmaceutical forms in Chile, providing the schemes currently recommended by health care agencies and experts in the field.

Características clínicas y microbiológicas de pacientes con periodontitis agresiva generalizada / Clinical and microbiological characteristics of a patients with generalized aggressive periodontitis

RESUMEN: Objetivo: el objetivo de este estudio es describir las características clínicas y microbiológicas de una muestra de pacientes diagnosticados con periodontitis agresiva generalizada (PAgG). Materiales y métodos: En este estudio de corte transversal, 20 sujetos menores de 30 años con PAgG atendidos en las clínicas odontológicas de la Universidad de Antioquia en Medellín Colombia, fueron invitados a participar entre diciembre del 2015 y marzo del 2017, las muestras microbiológicas fueron analizadas usando técnicas de cultivo y tomadas en los seis sitios más profundos de cada paciente (≥ 5mm). Resultados: Prevotella ssp y F. nucleatum fueron detectados en altos porcentajes, Porphyromonas gingivalis (P.g) fue positivo para la mitad de los sujetos estudiados; además de los microorganismos comúnmente estudiados, el 10% de los pacientes fueron positivos para bacilos entéricos gram-negativos. Conclusiones: se observaron grandes proporciones de microorganismos que incluyeron Prevotella spss y F. nucleatum; el 10% de los pacientes fueron positivos para bacilos entéricos gram-negativos.

ABSTRACT: Aim: The aim of this study is to describe the clinical and microbiological characteristics of a sample of patients diagnosed with generalized aggressive periodontitis (PAgG). Materials and methods: In this cross-sectional study, 20 subjects under 30 years of age with PAgG treated at the dental clinics of the University of Antioquia in Medellín, Colombia were invited to participate between December 2015 and March 2017, the microbiological samples analyzed using culture techniques were taken at the six deepest sites of each patient (≥ 5mm). Results: Prevotella ssp and F. nucleatum were detected in high percentages, Porphyromonas gingivalis (P.g) was positive for half of the studied subjects; In addition to the microorganisms commonly studied, 10% of the patients were positive for gram-negative enteric bacilli. Conclusions: large proportions of microorganisms were observed, including Prevotella spss and F. nucleatum; 10% of the patients were positive for gram-negative enteric bacilli.

Evaluación de la susceptibilidad directa desde hemocultivos positivos utilizando el sistema Vitek 2: comparación de dos protocolos rápidos / Evaluation of antimicrobial susceptibility testing directly from positive blood cultures using the Vitek 2 system: comparison of two rapid protocols

Antimicrobial susceptibility testing using Vitek® 2 (bioMérieux) cards inoculated directly from positive blood cultures was compared with the standard method for gramnegative rods. Two different protocols for the inoculum preparation were evaluated. Protocol 2 was faster and easier to perform. Rapid susceptibility testing was accurate and reduced time to results in 24 h.

Se comparó el ensayo de susceptibilidad a los antimicrobianos utilizando las tarjetas Vitek® 2 (bioMérieux) inoculadas directamente de hemocultivos positivos con el método estándar para bacilos gramnegativos. Se evaluaron dos protocolos diferentes para la preparación del inóculo. El segundo protocolo fue más rápido y fácil de realizar. Las pruebas de susceptibilidad rápida fueron precisas y redujeron el tiempo de los resultados en 24 h.

Factores asociados a nefrotoxicidad por polimixina B en un hospital universitario de Neiva, Colombia. 2011-2015 / Risk factors for acute kidney injury in patients treated with polymyxin B experience from 139 cases at a tertiary university hospital in Colombia

Background: The rise of infections caused by multidrug-resistant Gram negative bacilli (MDR-GNB), added to paucity of newer therapy, have led to increase polymyxin B use, despite adverse renal toxicity profile. Aim: To determine the incidence and risk factors associated to acute kidney injury (AKI) and polymyxin B use, in patients with infections caused by MDR-GNB. Methods: A retrospective cohort, with a nested case-control study of adults who received polymyxin B for more than 48 hours at a tertiary university hospital in Colombia (2011-2015) was performed. AKI was defined by AKIN criteria. Results: Of 139 patients included in our study, 102 were male with median age of 49 years (IQR:28-64). Sixty-one patients (44%) developed AKI. Independent risk factors for development of AKI included: total polymyxin B daily dose (OR = 2.19, 95% CI, 1.04-4.64); length of stay at ICU (OR = 1.03, 95% CI, 1.00-1.06); nosocomial infection (OR = 6.43, 95% CI, 2.12, -19.47); and vasopressor use (OR = 5.38, 95% CI, 2.40-12.07). Mortality was higher among AKI-patients (58.6%) compared with non-AKI patients (25.6%) (p = 0.001). Conclusion: In this study, the rate of AKI associated to polymyxin B use was greater than reported in studies from last decade, and associated with increased mortality. AKI associated to polymyxin B use is likely multifactorial and aggravated by the critically ill state of patients suffering nosocomial infections caused by mdr-gnb.

Introducción: El surgimiento de infecciones graves causadas por bacilos gramnegativos multi-resistentes (BGN-MR), sumado a la carencia de nuevas opciones terapéuticas efectivas, ha llevado a retomar el uso de polimixina B, a pesar de su perfil de nefrotoxicidad. Objetivo: Determinar la incidencia y factores relacionados con el desarrollo de nefrotoxicidad asociada al uso de polimixina B, en pacientes adultos con infecciones causadas por BGN-MR. Materiales y Métodos: Estudio observacional, analítico, tipo cohorte histórica, con un análisis de casos y controles anidado, realizado en un hospital universitario de tercer nivel de Colombia entre 2011 y 2015, en pacientes que recibieron polimixina B intravenosa por más de 48 h. Resultados: De 139 pacientes incluidos en el estudio, 61 (44%) desarrollaron falla renal aguda por criterios AKIN. Los factores de riesgo independientes para nefrotoxicidad fueron: dosis diaria de polimixina B (OR 2,19; IC 95% 1,04-4,64), días de estancia en UCI (OR 1,03; IC 95% 1,00-1,06), presencia de infección nosocomial (OR 6,43; IC 95% 2,12-19,47) y requerimiento de fármacos vasopresores (OR 5,38; IC 95%: 2,40-12,07). Conclusión: La tasa de nefrotoxicidad observada en pacientes que recibieron polimixina B es considerable; su origen probablemente multifactorial y agravada por estado crítico de pacientes con infecciones nosocomiales por BGN-MR.