Rapid Detection of Carbapenemase and Extended-Spectrum ß-Lactamase Producing Gram-Negative Bacteria Directly from Positive Blood Cultures Using a Novel Protocol.

BACKGROUND: Early and adequate antibiotic treatment is the cornerstone of improving clinical outcomes in patients with bloodstream infections (BSI). Delays in appropriate antimicrobial therapy have catastrophic consequences for patients with BSI. Microbiological characterization of multi-drug resistant pathogens (MDRP) allows clinicians to provide appropriate treatments. Current microbiologic techniques may take up to 96 h to identify causative pathogens and their resistant patterns. Therefore, there is an important need to develop rapid diagnostic strategies for MDRP. We tested a modified protocol to detect carbapenemase and extended-spectrum ß-lactamase (ESBL) producing Gram-negative bacteria (GNB) from positive blood cultures. METHODS: This is a prospective cohort study of consecutive patients with bacteremia. We developed a modified protocol using the HB&L® system to detect MDRP. The operational characteristics were analyzed for each test (HB&L-ESBL/AmpC® and HB&L-Carbapenemase® kits). The kappa coefficient, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratios (LR) with 95% confidence intervals (CI), and reduction in identification time of this novel method were calculated. RESULTS: Ninety-six patients with BSI were included in the study. A total of 161 positive blood cultures were analyzed. Escherichia coli (50%, 81/161) was the most frequently identified pathogen, followed by Klebsiella pneumoniae (15%, 24/161) and Pseudomonas aeruginosa (8%, 13/161). Thirty-three percent of isolations had usual resistance patterns. However, 34/161 (21%) of identified pathogens were producers of carbapenemases and 21/161 (13%) of extended-spectrum ß-lactamases. Concordance between our HB&L® modified protocol and the traditional method was 99% (159/161). Finally, identification times were significantly shorter using our HB&L®-modified protocol than traditional methods: median (IQR) 19 h (18, 22) vs. 61 h (60, 64), p < 0.001. CONCLUSIONS: Here, we provide novel evidence that using our HB&L®-modified protocol is an effective strategy to reduce the time to detect MDRP producers of carbapenemases or extended-spectrum ß-lactamases, with an excellent concordance rate when compared to the gold standard. Further studies are needed to confirm these findings and to determine whether this method may improve clinical outcomes.

Fulminant myocarditis due to the influenza B virus in adults: Report of two cases and literature review / Miocarditis fulminante en adultos por el virus de la influenza B: reporte de dos casos y revisión de la literatura

La miocarditis es una enfermedad inflamatoria del miocardio. Las infecciones virales son la causa más común, aunque también puede deberse a reacciones de hipersensibilidad y de etiología autoinmunitaria, entre otras. El espectro clínico de la enfermedad es variado y comprende desde un curso asintomático, seguido de dolor torácico, arritmias y falla cardiaca aguda, hasta un cuadro fulminante. El término 'fulminante' se refiere al desarrollo de un shock cardiogénico con necesidad de soporte vasopresor e inotrópico o dispositivos de asistencia circulatoria, ya sea oxigenación por membrana extracorpórea o balón de contrapulsación intraaórtico. Cerca del 10 % de los casos de falla cardiaca por miocarditis corresponde a miocarditis fulminante. La miocarditis por influenza se considera una condición infrecuente; no obstante, su incidencia ha aumentado desde el 2009 a raíz de la pandemia de influenza por el virus AH1N1. Por su parte, la miocarditis por influenza de tipo B sigue siendo una condición infrecuente. Se describen aquí dos casos confirmados de miocarditis fulminante por el virus de la influenza B atendidos en un centro cardiovascular, que requirieron dispositivos de asistencia circulatoria mecánica.

Myocarditis is an inflammatory disease of the myocardium. Viral infections are the most common cause, although it can also be due to hypersensitivity reactions and autoimmune etiology, among other causes. The clinical spectrum of the disease is varied, from an asymptomatic course, followed by chest pain, arrhythmias, and acute heart failure, to a fulminant episode. The term fulminant refers to the development of cardiogenic shock with a need for vasopressor support and inotropic or assisted circulation devices either extracorporeal membrane oxygenation (ECMO) or intra-aortic counterpulsation balloon. About 10% of cases of heart failure due to myocarditis correspond to fulminant myocarditis. Influenza myocarditis has been considered an infrequent condition. However, its incidence has increased since 2009 as a result of the AH1N1 pandemic; otherwise, myocarditis due to the Influenza type B virus remains an infrequent entity. We describe the experience in a cardiovascular center of two confirmed cases of fulminant myocarditis due to influenza B that required circulatory assistance devices.

[Behavior of carbapenemase-producing Klebsiella pneumoniae cases in cancer patients at a third level hospital in Bogotá, D.C]. / Comportamiento de casos de Klebsiella pneumoniae productora de carbapenemasas en pacientes con cáncer de un hospital de tercer nivel de Bogotá, D.C.

INTRODUCTION: The presence of carbapenemase-producing Enterobacteriaceae in hospitals is increasingly common. Patients with advanced cancer who require invasive means for diagnosis, treatment or palliative care, and the use of broad-spectrum antimicrobials to treat secondary infections show increased susceptibility to infections caused by these bacteria. OBJECTIVE: To report the behavior of carbapenemase-producing Klebsiella pneumoniae (CPKP) isolates at the Instituto Nacional de Cancerología in Bogotá between January 2010 and December 2012. MATERIALS AND METHODS: By analyzing the database kept by the infection committee of the institution, as well as the records of patients with CPKC isolates, we identified and described the epidemiology of detected cases. Outbreaks were determined by using quality control statistical tools. RESULTS: Between January 2010 and December 2012, we found 45 patients with CPKC isolates recovered from any sample. There were more isolates from patients with malignant solid tumors. CPKC isolates from urine samples were more often recovered; 17.7% of CPKC isolates corresponded to colonization, and 82.3% to infection; 35.5% of patients (16/45) survived. We identified two outbreaks during this period, which were controlled using a multimodal approach. CONCLUSIONS: This study found that CPKC presence is more frequent as infection than as colonization. During the two years of the study we detected two outbreaks, which were controlled by limiting multi-resistant bacteria cross transmission using conventional control strategies.

Comportamiento de casos de Klebsiella pneumoniae productora de carbapenemasas en pacientes con cáncer de un hospital de tercer nivel de Bogotá, D.C. / Behavior of carbapenemase-producing Klebsiella pneumoniae cases in cancer patients at a third level hospital in Bogotá, D.C.

Introducción. La presencia en los hospitales de enterobacterias productoras de carbapenemasas es cada vez más frecuente. Los pacientes con cáncer en estado avanzado requieren medios invasivos para el diagnóstico, el tratamiento o los cuidados paliativos, así como el uso de antimicrobianos de amplio espectro para tratar infecciones secundarias, lo cual aumenta su propensión a las infecciones causadas por estas bacterias. Objetivo. Informar el comportamiento de Klebsiella pneumoniae productora de carbapenemasas de tipo KPC en el Instituto Nacional de Cancerología de Bogotá, entre enero de 2010 y diciembre de 2012. Materiales y métodos. Mediante el análisis de la base de datos y de los registros de los pacientes con aislamientos de K. pneumoniae productores de carbapenemasas de tipo KPC, a cargo del comité de infecciones de la institución, se identificaron y describieron las características epidemiológicas de los casos detectados. La determinación de brotes se efectuó con herramientas de control estadístico de calidad. Resultados. Entre enero de 2010 y diciembre de 2012 se identificaron 45 pacientes con aislamiento de K. pneumoniae productor de carbapenemasas de tipo KPC en alguna muestra. Hubo más aislamientos en pacientes de cáncer con tumores sólidos. La identificación se logró más frecuentemente en muestras de orina; el 17,7 % de los casos correspondió a colonización y el 82,3 %, a infección; 35,5 % (16/45) de los pacientes sobrevivió. Durante este periodo se identificaron dos brotes que se controlaron aplicando una estrategia multimodal. Conclusiones. Se encontró que la presencia de KPC fue más frecuente en infecciones que en colonizaciones. Durante estos dos años ocurrieron dos brotes que fueron controlados limitando la transmisión cruzada de bacterias multirresistentes por medio de estrategias de control convencionales.

Introduction: The presence of carbapenemase-producing Enterobacteriaceae in hospitals is increasingly common. Patients with advanced cancer who require invasive means for diagnosis, treatment or palliative care, and the use of broad-spectrum antimicrobials to treat secondary infections show increased susceptibility to infections caused by these bacteria. Objective: To report the behavior of carbapenemase-producing Klebsiella pneumoniae (CPKP) isolates at the Instituto Nacional de Cancerología in Bogotá between January 2010 and December 2012. Materials and methods: By analyzing the database kept by the infection committee of the institution, as well as the records of patients with CPKC isolates, we identified and described the epidemiology of detected cases. Outbreaks were determined by using quality control statistical tools. Results: Between January 2010 and December 2012, we found 45 patients with CPKC isolates recovered from any sample. There were more isolates from patients with malignant solid tumors. CPKC isolates from urine samples were more often recovered; 17.7% of CPKC isolates corresponded to colonization, and 82.3% to infection; 35.5% of patients (16/45) survived. We identified two outbreaks during this period, which were controlled using a multimodal approach. Conclusions: This study found that CPKC presence is more frequent as infection than as colonization. During the two years of the study we detected two outbreaks, which were controlled by limiting multi-resistant bacteria cross transmission using conventional control strategies.