RESUMO
Abstract The aim of this study was to compare the performance of two MALDI-TOF MS systems in the identification of clinically relevant strict anaerobic bacteria. The 16S rRNA gene sequencing was the gold standard method when discrepancies or inconsistencies were observed between platforms. A total of 333 isolates were recovered from clinical samples of different centers in Buenos Aires City between 2016 and 2021. The isolates were identified in duplicate using two MALDI-TOF MS systems, BD Bruker Biotyper (Bruker Daltonics, Bremen, Germany) and Vitek MS (bioMèrieux, Marcy-l'Etoile, France). Using the Vitek MS system, the identification of anaerobic isolates yielded the following percentages: 65.5% (n: 218) at the species or species-complex level, 71.2% (n: 237) at the genus level, 29.4% (n: 98) with no identification and 5.1% (n: 17) with misidentification. Using the Bruker Biotyper system, the identification rates were as follows: 85.3% (n: 284) at the species or species-complex level, 89.7% (n: 299) at the genus level, 14.1% (n: 47) with no identification and 0.6% (n: 2) with misidentification. Differences in the performance of both methods were statistically significant (p-values <0.0001). In conclusion, MALDI-TOF MS systems speed up microbial identification and are particularly effective for slow-growing microorganisms, such as anaerobic bacteria, which are difficult to identify by traditional methods. In this study, the Bruker system showed greater accuracy than the Vitek system. In order to be truly effective, it is essential to update the databases of both systems by increasing the number of each main spectrum profile within the platforms.
Resumen El objetivo de este estudio fue comparar el desempeño de dos sistemas MALDI-TOF MS en la identificación de bacterias anaerobias estrictas de interés clínico. La secuenciación del gen 16S ARNr fue el método de referencia utilizado cuando se observaron discrepancias o inconsistencias entre plataformas. Se recuperaron 333 aislados de muestras clínicas de diferentes centros de la Ciudad Autónoma de Buenos Aires entre 2016 y 2021. Los aislados se identificaron por duplicado mediante dos sistemas MALDI-TOF MS: el BD Bruker Biotyper (Bruker Daltonics, Bremen, Alemania) y el Vitek MS (bioMèrieux, Marcy-l'Etoile, Francia). A través del sistema Vitek MS, los mismos fueron identificados a nivel de especie o complejo de especies en un 65,5% (n: 218) y de género en un 71,2% (n: 237), mientras que no se identificaron en un 29,4% (n: 98) y fue incorrecta en el 5,1% (n: 17). Mediante el sistema Bruker Biotyper, dichos valores fueron del 85,3% (n: 284), del 89,7% (n: 299), del 14,1% (n: 47) y del 0,6% (n: 2), respectivamente. La diferencia entre ambos métodos fue estadísticamente significativa (p<0,0001). En conclusión, los sistemas MALDI-TOF MS aceleran la identificación microbiana. Son especialmente útiles para los microorganismos de crecimiento lento, como las bacterias anaerobias, que son difíciles de identificar con los métodos tradicionales. El sistema Bruker demostró ser más preciso que el Vitek MS. Para que estos métodos sean realmente efectivos es fundamental actualizar las bases de datos de ambos sistemas e incrementar el número de espectros de referencia dentro de las plataformas.
RESUMO
The aim of this study was to compare the performance of two MALDI-TOF MS systems in the identification of clinically relevant strict anaerobic bacteria. The 16S rRNA gene sequencing was the gold standard method when discrepancies or inconsistencies were observed between platforms. A total of 333 isolates were recovered from clinical samples of different centers in Buenos Aires City between 2016 and 2021. The isolates were identified in duplicate using two MALDI-TOF MS systems, BD Bruker Biotyper (Bruker Daltonics, Bremen, Germany) and Vitek MS (bioMèrieux, Marcy-l'Etoile, France). Using the Vitek MS system, the identification of anaerobic isolates yielded the following percentages: 65.5% (n: 218) at the species or species-complex level, 71.2% (n: 237) at the genus level, 29.4% (n: 98) with no identification and 5.1% (n: 17) with misidentification. Using the Bruker Biotyper system, the identification rates were as follows: 85.3% (n: 284) at the species or species-complex level, 89.7% (n: 299) at the genus level, 14.1% (n: 47) with no identification and 0.6% (n: 2) with misidentification. Differences in the performance of both methods were statistically significant (p-values <0.0001). In conclusion, MALDI-TOF MS systems speed up microbial identification and are particularly effective for slow-growing microorganisms, such as anaerobic bacteria, which are difficult to identify by traditional methods. In this study, the Bruker system showed greater accuracy than the Vitek system. In order to be truly effective, it is essential to update the databases of both systems by increasing the number of each main spectrum profile within the platforms.
Assuntos
Bactérias Anaeróbias , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Bactérias Anaeróbias/genética , RNA Ribossômico 16S/genética , ArgentinaRESUMO
Resumen Los objetivos de este estudio fueron determinar el desempeño del panel BCID de FilmArray® y establecer el impacto de estos resultados en el tratamiento antimicrobiano de pacientes con bacteriemia en 11 hospitales de Latinoamérica. Se incluyeron 397 episodios de bacteriemia y se documentaron 551 microorganismos aislados de hemocultivos. La identificación microbiana fue correcta en el 91,4% (504/551) de los aislados y en el 98,6% (504/511) si se consideran solo los microorganismos incluidos en el panel BCID. La sensibilidad en la detección de los genes mecA, vanA/B y blaKPC fue del 100% y la especificidad fue del 97%, 100% y 99,6% respectivamente. La notificación temprana del resultado permitió cambios terapéuticos en 242 episodios (60,9%). El panel BCID es un método confiable y rápido para la detección de mecanismos críticos de resistencia y de los microorganismos más frecuentemente aislados de bacteriemias y permite la optimización temprana del tratamiento antimicrobiano.
Abstract The objectives of this study were to determine the performance of the BCID panel and to establish the impact of these results on the antimicrobial treatment of patients with bacteremia in 11 hospitals in Latin America. Three hundred and ninety-seven episodes of bacteremia were included and 551 microorganisms isolated from blood cultures were documented. Microbial identification was correct in 91.4% (504/551) of the isolates and in 98.6% (504/511) if only the microorganisms included in the BCID panel are considered. The sensitivity in the detection of the genes mecA, vanA/B and blaKPC was 100% and the specificity was 97%, 100% and 99.6% respectively. Early notification of the outcome allowed therapeutic changes in 242 episodes (60.9%). The BCID panel is a reliable and rapid method for the detection of critical resistance mechanisms and of the microorganisms most frequently isolated from bacteremia and it enables early optimisation of antimicrobial treatment.
Resumo Os objetivos deste estudo foram determinar o desempenho do painel BCID do FilmArray® e estabelecer o impacto desses resultados no tratamento antimicrobiano de pacientes com bacteremia em 11 hospitais da América Latina. Trezentos e noventa e sete episódios de bacteremia foram incluídos e 551 microrganismos isolados de hemoculturas foram documentados. A identificação microbiana foi correta em 91,4% (504/551) dos isolados e em 98,6% (504/511) considerando apenas os microrganismos incluídos no painel BCID. A sensibilidade na detecção dos genes mecA, vanA/B e blaKPC foi de 100% e a especificidade foi de 97%, 100% e 99,6% respectivamente. A notificação precoce do desfecho permitiu mudanças terapêuticas em 242 episódios (60,9%). O painel BCID é um método confiável e rápido para a detecção de mecanismos críticos de resistência e dos microrganismos mais frequentemente isolados da bacteremia e permite a otimização precoce do tratamento antimicrobiano.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Análise Custo-Eficiência , Bacteriemia/diagnóstico , Hemocultura/métodos , Anti-Infecciosos/farmacologiaRESUMO
Two commercial MALDI-TOF MS systems were used to identify 18 isolates, belonging to the Peptoniphilus genus; also the 16S rRNA sequencing identity was compared against the MALDI-TOF MS system results. Bruker Biotyper system provided higher accuracy than Vitek MS system, however, adding spectra could allow a more reliable species level identification.
Assuntos
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Técnicas de Tipagem Bacteriana/métodos , RNA Ribossômico 16S/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodosRESUMO
Resumen La bacteriemia es una de las principales causas de muerte en todo el mundo y se asocia con alto costo. Los resultados rápidos obtenidos desde los hemocultivos positivos son una herramienta importante para la optimización temprana del tratamiento antimicrobiano. Los objetivos de este trabajo fueron evaluar el rendimiento del panel BCID del sistema FilmArrayTM y determinar su impacto en la adecuación del tratamiento antimicrobiano. Se analizaron 127 episodios de bacteriemia. Un porcentaje significativo de los tratamientos (45,8%) fueron cambiados en base a este resultado. La identificación global correcta fue del 89,2% y del 97,2% para los microorganismos incluidos en la base de datos, en tanto que la sensibilidad para la detección de los genes mecA y KPC fue del 100%. El panel BCID de FilmArrayTM es un método rápido y confiable para la detección de los microorganismos relacionados a bacteriemia y de alto impacto en la decisión terapéutica.
Abstract Bacteremia is one of the leading causes of death worldwide and is associated with high cost. The rapid results obtained from positive blood cultures are an important tool for early optimization of antimicrobial therapy. The objectives of this work were to evaluate the performance of the BCID panel of the FilmArrayTM system and determine its impact on the adequacy of the antimicrobial treatment. One hundred and twenty seven episodes of bacteremia were analyzed. A significant percentage of the treatments (45.8%) were changed based on this result. The correct global identification was 89.2% and 97.2% for the microorganisms included in the database, while the sensitivity for the detection of the mecA and KPC genes was 100%. The FilmArrayTM BCID panel is a fast and reliable method for the detection of microorganisms related to bacteremia and has a high impact on the therapeutic decision.
Resumo A bacteremia é uma das principais causas de morte no mundo e está associada a alto custo. Resultados rápidos obtidos de hemoculturas positivas são uma ferramenta importante para a otimização precoce da terapia antimicrobiana. Os objetivos deste trabalho foram avaliar o desempenho do painel BCID do sistema FilmArrayTM e determinar seu impacto na adequação do tratamento antimicrobiano. Foram analisados 127 episódios de bacteremia. Percentual significativo dos tratamentos (45,8%) foi alterado com base nesse resultado. A correta identificação global foi de 89,2% e 97,2% para os microrganismos incluídos na base de dados, enquanto a sensibilidade para detecção dos genes mecA e KPC foi de 100%. O painel FilmArrayTM BCID é um método rápido e confiável para a detecção de microrganismos relacionados à bacteremia e tem alto impacto na decisão terapêutica.
RESUMO
En diciembre de 2019 se identificó en Wuhan, China, un nuevo coronavirus denominado SARS-CoV-2, agente causal de la epidemia de neumonía atípica COVID-2019, que el 11 de marzo de 2020 fue declarada pandemia por la OMS.Hasta el 30 de septiembre de 2020, en Argentina fueron confirmados 751.001 casos y más de 16.937 muertes.La frecuencia y el impacto de las coinfecciones que afectan a los pacientes infectados por SARS-Cov-2 se ha estudiado junto con el avance de la pandemia. Entre las debidas a hongos se encuentran las fungemias por Candida sp, la aspergilosis invasora, las micosis sistémicas endémicas y la neumocistosis. Presentamos las distintas coinfecciones micosis-COVID-19 que fueron asistidas en nuestra institución entre abril y septiembre de 2020, y se realiza un análisis de las características de estas infecciones en pacientes con y sin sida. En este período se internaron 2837 pacientes, 2287 tuvieron diagnóstico confirmado de COVID-19. La coinfección de COVID-19 con micosis pulmonares o sistémicas fue menor al 1%.Dieciocho pacientes presentaron infecciones fúngicas pulmonares o sistémicas. Ocho padecieron candidemias, cinco criptococosis meningeas, dos histoplasmosis, dos aspergilosis invasoras agudas probables y una aspergilosis pulmonar crónica. La estadía prolongada en terapia intensiva facilitó las fungemias por Candida sp, los casos de histoplasmosis y criptococosis parecen relacionarse con la enfermedad avanzada por VIH y no con COVID-19. Los enfermos con un componente inflamatorio basal alto con neumonía grave por coronavirus se relacionan más con micosis invasoras que los enfermos VIH positivos con niveles bajos de LTCD4+
On December 2019 a new coronavirus (SARS-CoV2) result in atypical pneumonía epidemic, it was identified in Wuhan China and it was called COVID-19. Then on March 11 was declared pandemic by the WHO.Until September 30, 2020 in Argentina 751,001 cases and more than 16,937 deaths have been confirmed. The frequency and impact of co-infections affecting SARS-Cov2 infected patients has been studied with the advance of the pandemic. Among those due to fungi are Candida sp fungemias, invasive aspergillosis, endemic systemic mycoses, and pneumocystosis.We present the different mycosis-COVID-19 co-infections that were assisted in F. J. Muñiz Hospital between April and September of this year and review the characteristics of these infections in patients with and without AIDS is carried out.In this period, 2,837 patients were admitted in the Muñiz hospital, 2,287 had a confirmed diagnosis of COVID-19.Co-infection of COVID-19 with pulmonary or systemic mycoses was less than 1%.Eighteen patients had pulmonary or systemic fungal infections. Eight suffered from candidemia, five meningeal cryptococcosis, two histoplasmosis, two probable acute invasive aspergillosis, and one chronic pulmonary aspergillosis.Prolonged stay in intensive care facilitated fungemia due to Candida sp. Histoplasmosis and cryptococcosis cases seem to be related to advanced HIV disease and not to COVID-19.Patients with a high baseline inflammatory component with severe coronavirus pneumonia are more associated with invasive mycoses than HIV-positive patients with low levels of LTCD4 +
Assuntos
Humanos , Epidemiologia Descritiva , Estudos Retrospectivos , Aspergilose Pulmonar Invasiva/microbiologia , Candidemia/microbiologia , Coinfecção , Pneumopatias Fúngicas/microbiologiaRESUMO
Clostridioides difficile es el principal agente causal de diarreas asociadas al cuidado de la salud. Esta bacteria produce toxinas y una enzima que se encuentra muy conservada en la especie: la glutamato deshidrogenasa (GDH). El diagnóstico rápido y el tratamiento efectivo permiten la pronta mejoría del paciente, con el consecuente control de la diseminación del microorganismo. Sin embargo, aún no se cuenta con un método diagnóstico óptimo y se propone la realización de diversas pruebas, cuyos resultados se interpretan en el contexto de ciertos algoritmos. En este trabajo se evaluó el desempeño de la GDH como prueba de tamizaje en el diagnóstico de la diarrea por c. difficile. Se estudiaron 615 muestras de materia fecal. Se determinó la presencia de GDH y de toxinas mediante el equipo diagnóstico de enzimoinmunoensayo de membrana C. DIFF QUIK-CHEK COMPLETE® (TECHLAB) y se realizaron cultivos para la búsqueda de C. difficile. Se calcularon los valores de sensibilidad, especificidad, VPP y VPN con un nivel de significación p < 0,05. Se detectó GDH en 266 muestras (43,25%), con una sensibilidad del 100% y una especificidad del 87,10%, IC95: 84,58-91,42. Se hallaron toxinas en 218 muestras (35,45%) y C. difficile desarrolló en 235 cultivos (38,21%). De 48 muestras GDH positivas y sin producción de toxina/s, 17 fueron positivas al cultivo de C. difficile, con 15 aislamientos toxigénicos y 2 no toxigénicos. No hubo desarrollo de C. difficile en las 31 muestras restantes. Ninguna muestra GDH negativa dio resultado positivo de toxina/s ni desarrollo en el cultivo, por lo cual el VPN de la GDH fue del 100%, mientras que el VPP fue del 81,9%. Concluimos que la determinación de GDH representa un screening adecuado para descartar casos de diarrea por C. difficile, por lo tanto de valor en los algoritmos diagnósticos de las diarreas infecciosas.
Clostridioides difficile is the main etiological agent of diarrhea associated with health care, it produces toxins and glutamate dehydrogenase (GDH), an enzyme that is highly conserved in this species. Rapid diagnosis and effective treatment produce prompt improvement of the patient and subsequent control of the microorganism spread. There are several techniques whose results are interpreted in the context of algorithms. However, the optimal diagnostic method is yet unknown. The performance of GDH as a screening test for the diagnosis of C. difficile diarrhea was assessed. Six hundred and fifteen stool samples were studied. The presence of GDH and toxins presence was determined by TECHLAB® C. DIFF QUIK-CHEK COMPLETE and the samples were cultured for the search of C. difficile. The values of sensitivity, specificity, PPV and NPV were calculated with a p value of 0.05 or less. GDH was detected in 266 samples (43.25%), with a sensitivity of 100% and specificity of 87.10%, IC95: 84.58-91.42; toxin/s were detected in 218 (35.45%) and C. difficile developed in 235 cultures (38.21%). From 48 samples with positive GDH and negative toxin/s, 15 toxigenic and 2 non-toxigenic isolates were obtained, the remaining 31 samples were negative for C. difficile. All GDH-negative samples were negative for toxins or culture, therefore, GDH NPV was 100%, while PPV was 81.9%. We conclude that GDH is a suitable screening test for the diagnostic algorithm of C. difficile diarrhea.
Assuntos
Humanos , Clostridioides difficile , Infecções por Clostridium , Glutamato Desidrogenase , Proteínas de Bactérias , Toxinas Bacterianas , Clostridioides difficile/enzimologia , Sensibilidade e Especificidade , Infecções por Clostridium/diagnóstico , Diarreia , Enterotoxinas , Fezes , Glutamato Desidrogenase/análiseRESUMO
Clostridioides difficile is the main etiological agent of diarrhea associated with health care, it produces toxins and glutamate dehydrogenase (GDH), an enzyme that is highly conserved in this species. Rapid diagnosis and effective treatment produce prompt improvement of the patient and subsequent control of the microorganism spread. There are several techniques whose results are interpreted in the context of algorithms. However, the optimal diagnostic method is yet unknown. The performance of GDH as a screening test for the diagnosis of C. difficile diarrhea was assessed. Six hundred and fifteen stool samples were studied. The presence of GDH and toxins presence was determined by TECHLAB® C. DIFF QUIK-CHEK COMPLETE and the samples were cultured for the search of C. difficile. The values of sensitivity, specificity, PPV and NPV were calculated with a p value of 0.05 or less. GDH was detected in 266 samples (43.25%), with a sensitivity of 100% and specificity of 87.10%, IC95: 84.58-91.42; toxin/s were detected in 218 (35.45%) and C. difficile developed in 235 cultures (38.21%). From 48 samples with positive GDH and negative toxin/s, 15 toxigenic and 2 non-toxigenic isolates were obtained, the remaining 31 samples were negative for C. difficile. All GDH-negative samples were negative for toxins or culture, therefore, GDH NPV was 100%, while PPV was 81.9%. We conclude that GDH is a suitable screening test for the diagnostic algorithm of C. difficile diarrhea.