RESUMEN
This review will focus on the infectious etiologies and more common noninfectious causes of lower respiratory tract syndromes among major immunosuppressed populations. The changing epidemiology of infections in the era of highly active antiretroviral therapy (HAART) in the case of HIV-positive patients and the impacts of both newer immune-suppressant therapies and anti-infective prophylaxis for other immunocompromised hosts will be discussed, with emphasis on diagnostic approaches and practice algorithms.
Asunto(s)
Huésped Inmunocomprometido , Neumonía/epidemiología , Neumonía/etiología , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/etiología , Humanos , Control de Infecciones/métodos , Neumonía/diagnóstico , Neumonía/terapia , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/terapiaRESUMEN
Mycobacterial identification using MALDI-ToF MS (MALDI) has been hindered by inadequate extraction methods. Adaptive Focused Acoustics™ uses concentrated ultrasonic energy to achieve cellular disruption. Using this technology, we developed a rapid mycobacterial inactivation/protein extraction method for MALDI-based identification. Agreement for identification to the species level versus conventional identification was stratified by log confidence cut-offs of ≥2.0, ≥ 1.8, or ≥1.7. A total of 182 mycobacterial isolates were tested. Complete inactivation of all species/strains was achieved after 2min. Using a log confidence cut-off of ≥2.0, overall agreement for the commercial method (CM) was 41.7% versus 66.7% for the novel method (NM). For the CM, agreement increased to 66.7% and 83.3% using log confidence cut-offs of ≥1.8 and ≥1.7, respectively; for the NM, agreement was 100% for both cut-offs with all isolates. With no alteration to the existing database, overall agreement for the NM was 83.4%, largely due to low scores for clinical isolates of M. chelonae and M. mucogenicum. Addition of spectra from a single clinical strain of each species to the existing database increased overall agreement to 93.1%.
Asunto(s)
Proteínas Bacterianas/análisis , Proteínas Bacterianas/aislamiento & purificación , Mycobacterium/química , Mycobacterium/clasificación , Manejo de Especímenes/normas , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Ondas Ultrasónicas , Desinfección/métodos , Desinfección/normas , Humanos , Viabilidad Microbiana/efectos de la radiación , Mycobacterium/aislamiento & purificación , Mycobacterium/efectos de la radiación , Infecciones por Mycobacterium/diagnóstico , Infecciones por Mycobacterium/microbiología , Manejo de Especímenes/métodosRESUMEN
Commercial extraction methods for identification of mycobacteria using MALDI-ToF MS are laborious and time consuming. We have developed a novel extraction method which utilizes a bead beater and zirconia/silica beads to significantly shorten the existing protocol. This novel method provides a more rapid extraction of mycobacteria versus the commercial standard.
Asunto(s)
Infecciones por Mycobacterium/microbiología , Mycobacterium/química , Extracción en Fase Sólida/métodos , Humanos , Mycobacterium/genética , Mycobacterium/crecimiento & desarrollo , Mycobacterium/aislamiento & purificación , Extracción en Fase Sólida/instrumentación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
Herbaspirillum spp. are rare causes of human infections associated primarily with bacteremia in cancer patients. We report the first fatal case of bacteremia secondary to pneumonia caused by Herbaspirillum seropedicae in a 65-year-old man with end-stage renal disease and multiple myeloma.