Disseminated sporotrichosis following iatrogenic immunosuppression for suspected pyoderma gangrenosum.

Sporotrichosis is an infection caused by the dimorphic fungus Sporothrix schenckii and related species that often arises from traumatic inoculation of inhabited soil and organic debris into skin. The infection is usually limited to the skin in immunocompetent patients, usually as lymphocutaneous sporotrichosis. Accurate diagnosis rests on clinical data and culture, and might be facilitated by biopsy identification of suppurative and granulomatous inflammation with fungal elements. In this Grand Round, we present a dramatic case of cutaneous sporotrichosis initially presented with an atypical large ulcer without associated lymphocutaneous spread, clinically mimicking pyoderma gangrenosum, and subsequently progressed to disseminated sporotrichosis in the setting of iatrogenic immunosuppression. We further review the clinical features, risk factors, and treatment of these disseminated sporotrichosis cases, and discuss the need for improved awareness of this fungus' potential link to cause disseminated and invasive fungal infections.

Lower Respiratory Tract Infections.

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.

A rapid, standardized protein extraction method using adaptive focused acoustics for identification of mycobacteria by MALDI-ToF MS.

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%.

Fatal case of Herbaspirillum seropedicae bacteremia secondary to pneumonia in an end-stage renal disease patient with multiple myeloma.

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.

A novel protein extraction method for identification of mycobacteria using MALDI-ToF MS.

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.