Endocarditis infecciosa por Mycobacterium mageritense asociada a dispositivo cardíaco electrónico / Electronic cardiovascular device-associated to infective endocarditis caused by Mycobacterium mageritense

Las micobacterias de crecimiento rápido son una rara causa de endocarditis bacteriana. Durante las últimas décadas han aumentado las infecciones debido a este tipo de micobacterias, en especial las postraumáticas y las posquirúrgicas. Estas infecciones pueden ser localizadas o diseminadas, y también pueden producir brotes nosocomiales debido a la contaminación del equipamiento médico. Por lo general, las tinciones para bacterias ácido-alcohol resistentes no se emplean de rutina en el procesamiento de hemocultivos positivos. Sin embargo, el microbiólogo debe estar atento al ver un bacilo gram positivo, ya que podría tratarse de una micobacteria de crecimiento rápido. Describimos un caso de endocarditis por de Mycobacterium mageritense en una paciente con parche pericárdico autógeno y un catéter para medir la presión en la aurícula izquierda. La bacteria fue identificada por espectrometría de masas (MALDI-TOF MS), score 2,3, y luego confirmada por secuenciación y análisis del gen ARNr 16s con las bases de datos del NCBI y EzTaxon, con una concordancia del 99,8 y el 100%, respectivamente.

Rapidly growing non-tuberculosis mycobacteria are a rare cause of bacterial endocarditis. During the last decades, there has been an increase in infections due to rapidly growing mycobacteria, mainly after trauma and post-surgical procedures, both localized and disseminated, as well as nosocomial outbreaks due to contamination of medical equipment. Routine acid-fast staining for blood culture bottles is not always performed; however, the microbiologist should be aware of potential RGM infections especially when gram positive bacilli are observed. We describe a case of endocarditis caused by Mycobacterium mageritense in a patient with an autologous pericardial patch and a pressure catheter in the left auricle. The bacterial species was identified as Mycobacterium mageritense by mass spectrometry (MALDI-TOF MS), score 2.3, and confirmed by 16S rRNA analysis with 99.8 and 100% agreement, respectively.

[Electronic cardiovascular device-associated to infective endocarditis caused by Mycobacterium mageritense]. / Endocarditis infecciosa por Mycobacterium mageritense asociada a dispositivo cardíaco electrónico.

Rapidly growing non-tuberculosis mycobacteria are a rare cause of bacterial endocarditis. During the last decades, there has been an increase in infections due to rapidly growing mycobacteria, mainly after trauma and post-surgical procedures, both localized and disseminated, as well as nosocomial outbreaks due to contamination of medical equipment. Routine acid-fast staining for blood culture bottles is not always performed; however, the microbiologist should be aware of potential RGM infections especially when gram positive bacilli are observed. We describe a case of endocarditis caused by Mycobacterium mageritense in a patient with an autologous pericardial patch and a pressure catheter in the left auricle. The bacterial species was identified as Mycobacterium mageritense by mass spectrometry (MALDI-TOF MS), score 2.3, and confirmed by 16S rRNA analysis with 99.8 and 100% agreement, respectively.

Bacteriemia por Mycoplasma hominis: un agente etiologico subestimado / Mycoplasma hominis bacteremia: An underestimated etiological agent

Mycoplasma hominis es una bacteria de cultivo exigente y forma parte de la microbiota comensal de la zona urogenital en adultos. Puede ocasionar infecciones del tracto genitourinario, en particular en mujeres, e infecciones sistémicas en neonatos. Además, puede causar infecciones extragenitales graves, en especial en pacientes inmunocomprometidos. Describimos un caso de bacteriemia por M. hominis en una paciente inmunocompetente, luego de un legrado uterino por aborto incompleto. M. hominis está subestimado como agente etiológico de infecciones extragenitales debido a su difícil diagnóstico, ya que al carecer de pared celular no se visualiza por la coloración de Gram, requiere una incubación prolongada en atmósfera de anaerobiosis para su desarrollo y los métodos convencionales de detección pueden fallar. Este es el primer reporte de senal positiva en hemocultivo automatizado (BD BACTEC) con aislamiento de M. hominis.

Mycoplasma hominis is a fastidious bacterium, which usually colonizes the lower urogenital tract and may cause systemic infections in neonates and genital infections in adults. It can also be the cause of serious extra-genital infections, mainly in immunosuppressed or predisposed subjects. Case Presentation: We describe a case of bacteremia caused by M. hominis in a previously healthy woman after uterine curettage due to incomplete abortion. M. hominis could be an underestimated cause of bacteremia in immunocompetent patients. Mycoplasma organisms have fastidious growth requirements, are often difficult to culture on a cell-free medium and have no cell wall. The conventional method for detection may fail. This is the first report of M. hominis isolation from a positive automated blood culture (BD BACTEC, USA).

[Mycoplasma hominis bacteremia. An underestimated etiological agent]. / Bacteriemia por Mycoplasma hominis: un agente etiológico subestimado.

Mycoplasma hominis is a fastidious bacterium, which usually colonizes the lower urogenital tract and may cause systemic infections in neonates and genital infections in adults. It can also be the cause of serious extra-genital infections, mainly in immunosuppressed or predisposed subjects. CASE PRESENTATION: We describe a case of bacteremia caused by M. hominis in a previously healthy woman after uterine curettage due to incomplete abortion. M. hominis could be an underestimated cause of bacteremia in immunocompetent patients. Mycoplasma organisms have fastidious growth requirements, are often difficult to culture on a cell-free medium and have no cell wall. The conventional method for detection may fail. This is the first report of M. hominis isolation from a positive automated blood culture (BD BACTEC, USA).

[Rapid identification of microorganisms by mass spectrometry in a blood culture system. Comparison of two procedures]. / Identificación rápida de microorganismos de frascos de hemocultivos por espectrometría de masas. Comparación de 2 procedimientos diagnósticos.

Rapid identification of microorganisms is critical in hospitalized infected patients. Blood culture is currently the gold standard for detecting and identifying microorganisms causing bacteremia or sepsis. The introduction of mass spectrometry by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF MS) in microbiology laboratories, especially in microorganisms growing in blood culture bottles, provides rapid identification. This study evaluates the performance of the Maldi Sepsityper Biotyper procedure (hereinafter, MS) compared to that of an in-home method (hereinafter, HF). Eight hundred and forty (840) positive blood culture bottles were processed using the HF procedure, 542 of which were also processed using MS. The organisms were identified in 670 (79.76%) and 391 (72.14%) bottles respectively (p = 0,0013). This study demonstrates the effectiveness of both procedures for identifying microorganisms directly from positive blood culture bottles. However, the HF procedure proved to be more effective than MS, especially in the presence of Gram positive organisms.

Identificación rápida de microorganismos de frascos de hemocultivos por espectrometría de masas: Comparación de 2 procedimientos diagnósticos / Rapid identification of microorganisms by mass spectrometry in a blood culture system: Comparison of two procedures

La identificación rápida de microorganismos es crítica, en especial en pacientes sépticos hospitalizados. La espectrometría de masas conocida como matrix-assisted laser desorption/ionization time-of- flight mass spectrometry (MALDI-TOF MS) permite la identificación directa desde botellas de hemocultivos positivos en forma rápida y sencilla. Este estudio evaluó el desempeño del procedimiento basado en el sistema MALDI Biotyper que utiliza el kit comercial MALDI Sepsityper de Bruker Daltonics (en adelante, MS) frente a uno artesanal (en adelante, HF). Se procesaron 840 botellas de hemocultivos positivos con HF y 542 de estas fueron evaluadas también con MS. Se logró la identificación de los microorganismos en 670 (79,76 %) y 391 (72,14 %) botellas, respectivamente (p = 0,0013). Se demostró la efectividad de ambos procedimientos para la identificación de microorganismos desde frascos de hemocultivos positivos. Sin embargo, el procedimiento HF fue superior al MS, en especial frente a bacterias gram positivas.

Rapid identification of microorganisms is critical in hospitalized infected patients. Blood culture is currently the gold standard for detecting and identifying microorganisms causing bacteremia or sepsis. The introduction of mass spectrometry by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF MS) in microbiology laboratories, especially in microorganisms growing in blood culture bottles, provides rapid identification. This study evaluates the performance of the Maldi Sepsityper Biotyper procedure (hereinafter, MS) compared to that of an in-home method (hereinafter, HF). Eight hundred and forty (840) positive blood culture bottles were processed using the HF procedure, 542 of which were also processed using MS. The organisms were identified in 670 (79. 76 %) and 391 (72. 14 %) bottles respectively (p = 0,0013). This study demonstrates the effectiveness of both procedures for identifying microorganisms directly from positive blood culture bottles. However, the HF procedure proved to be more effective than MS, especially in the presence of Gram positive organisms.

[CHROMagar KPC. Comparison with the method proposed by the Centers for Disease Control and Prevention (CDC, USA) for rectal screening and evaluation of false positive results]. / CHROMagar Kpc. Comparación con el método propuesto por los Centros para el Control y Prevención de Enfermedades (CDC, EE.UU.) para el estudio de portación rectal y evaluación de falsos positivos.

Eighty one rectal swabs (RS) were cultured on CHROMagar KPC and the CDC method. Of the 81 samples, 9 were positive for KPC-producing Klebsiella pneumoniae on CHROMagar KPC, and 6 for the CDC method. CHROMagar KPC had two false positive (FP) results: 1 K. pneumoniae and 1 Acinetobacter sp. FP results on the CDC method were: 25 Acinetobacter spp., 2 Escherichia coli and 4 K. pneumoniae: CHROMagar KPC yielded a better recovery of KPC-producing bacteria and less FP results than CDC method. In order to evaluate FP results on CHROMagar KPC, 1247 RS were cultured and yielded 1021 negatives, 171 KPC-producing K. pneumoniae and 55 FP (4.4 %). Because of the FP results growing on CHROMagar KPC, KPC must be phenotypically confirmed in the bacteria isolated.

CHROMagar KPC. Comparación con el método propuesto por los Centros para el Control y Prevención de Enfermedades (CDC, EE.UU.) para el estudio de portación rectal y evaluación de falsos positivos / CHROMagar KPC. Comparison with the method proposed by the Centers for Disease Control and Prevention (CDC, USA) for rectal screening and evaluation of false positive results

Se cultivaron 81 hisopados rectales en el medio CHROMagar KPC y por el método del CDC. Fueron positivos para Klebsiella pneumoniae KPC en CHROMagar KPC, 9/81 y 6/81 con el método del CDC. El medio CHROMagar KPC tuvo dos falsos positivos: 1 K. pneumoniae y 1 Acinetobacter sp. Los falsos positivos del método CDC fueron: 25 Acinetobacter spp., 2 Escherichia coli y4K. pneumoniae. El empleo del medio CHROMagar KPC resultó ser un método con mayor recuperación de aislamientos productores de KPC y menos falsos positivos que el método del CDC. Para evaluar los falsos positivos en el medio CHROMagar KPC se cultivaron 1247 hisopados rectales. Se obtuvieron 1021 negativos, 171 K. pneumoniae KPC y 55 (4,4 %) falsos positivos. Debido al desarrollo de falsos positivos en el medio CHROMagar KPC, se debe confirmar por caracterización fenotípica la presencia de KPC en las bacterias aisladas.

Eighty one rectal swabs (RS) were cultured on CHROMagar KPC and the CDC method. Of the 81 samples, 9 were positive for KPC-producing Klebsiella pneumoniae on CHROMagar KPC, and 6 for the CDC method. CHROMagar KPC had two false positive (FP) results: 1 K. pneumoniae and 1 Acinetobacter sp. FP results on the CDC method were: 25 Acinetobacter spp., 2 Escherichia coli and 4 K. pneumoniae. CHROMagar KPC yielded a better recovery of KPC-producing bacteria and less FP results than CDC method. In order to evaluate FP results on CHROMagar KPC, 1247 RS were cultured and yielded 1021 negatives, 171 KPC-producing K. pneumoniae and 55 FP (4.4 %). Because of the FP results growing on CHROMagar KPC, KPC must be phenotypically confirmed in the bacteria isolated.

CHROMagar KPC. Comparación con el método propuesto por los Centros para el Control y Prevención de Enfermedades (CDC, EE.UU.) para el estudio de portación rectal y evaluación de falsos positivos / CHROMagar KPC. Comparison with the method proposed by the Centers for Disease Control and Prevention (CDC, USA) for rectal screening and evaluation of false positive results

Se cultivaron 81 hisopados rectales en el medio CHROMagar KPC y por el método del CDC. Fueron positivos para Klebsiella pneumoniae KPC en CHROMagar KPC, 9/81 y 6/81 con el método del CDC. El medio CHROMagar KPC tuvo dos falsos positivos: 1 K. pneumoniae y 1 Acinetobacter sp. Los falsos positivos del método CDC fueron: 25 Acinetobacter spp., 2 Escherichia coli y4K. pneumoniae. El empleo del medio CHROMagar KPC resultó ser un método con mayor recuperación de aislamientos productores de KPC y menos falsos positivos que el método del CDC. Para evaluar los falsos positivos en el medio CHROMagar KPC se cultivaron 1247 hisopados rectales. Se obtuvieron 1021 negativos, 171 K. pneumoniae KPC y 55 (4,4 %) falsos positivos. Debido al desarrollo de falsos positivos en el medio CHROMagar KPC, se debe confirmar por caracterización fenotípica la presencia de KPC en las bacterias aisladas.(AU)

Eighty one rectal swabs (RS) were cultured on CHROMagar KPC and the CDC method. Of the 81 samples, 9 were positive for KPC-producing Klebsiella pneumoniae on CHROMagar KPC, and 6 for the CDC method. CHROMagar KPC had two false positive (FP) results: 1 K. pneumoniae and 1 Acinetobacter sp. FP results on the CDC method were: 25 Acinetobacter spp., 2 Escherichia coli and 4 K. pneumoniae. CHROMagar KPC yielded a better recovery of KPC-producing bacteria and less FP results than CDC method. In order to evaluate FP results on CHROMagar KPC, 1247 RS were cultured and yielded 1021 negatives, 171 KPC-producing K. pneumoniae and 55 FP (4.4 %). Because of the FP results growing on CHROMagar KPC, KPC must be phenotypically confirmed in the bacteria isolated.(AU)