Update on Fungal Diagnostics

Abstract

Invasive fungal disease (IFD) is becoming more prevalent in transplant and oncology patients as a result of the potent immunosuppressive therapies used to prevent allograft rejection and/or the use of cytotoxic chemotherapy to treat cancer. Mortality attributable to IFD remains high despite advances in antifungal therapies. There is a continued need for laboratory diagnostics to help improve clinical outcomes. In recent years, culture-based detection strategies and histopathology have been supplemented with molecular and proteomic techniques as well as antigen detection methods. Refinements in these assays are improving the diagnosis of IFD, with the greatest strides made within the molecular and proteomic arenas. This review highlights recent laboratory developments in the diagnosis of invasive candidiasis, cryptococcosis, opportunistic molds, and endemic fungal infections.

Invasive Fungal Infections and Approaches to Their Diagnosis

“…Amplification-based methods are increasingly being applied to the post-culture identification of yeasts and moulds (Brandt et al, 2005;Buchan & Ledeboer, 2014;Buzina et al, 2001;Clark et al, 2013;Hall et al, 2003Hall et al, , 2004Griffin & Hanson, 2014;Hinrickson et al, 2005;Hsiao et al, 2005;Iwen et al, 2002;Kothari, Morgan, & Haake, 2014;Pfaller, Chaturvedi, et al, 2012;Pfaller, Neofytos, et al, 2012;Pfaller, Woosley, et al, 2012;Pounder et al, 2007;Rakeman et al, 2005;Schwarz et al, 2006). These methods are especially useful in identifying nonsporulating moulds that are unable to be identified by conventional methods (Rakeman et al, 2005).…”

“…Successful diagnosis and management of such infections in the compromised patient is highly dependent on a team approach involving clinicians, microbiologists, pharmacists, and pathologists (Ananda-Rajuah, Slavin, & Thursky, 2012;Chandler & Watts, 1987;Koneman & Roberts, 2002; O'Shaughnessy, Shea, & Witebsky, 2003;Schell, 1995). Due to the recognition that delays in administering timely and appropriate antifungal therapy is directly related to patient mortality (Chamilos, Lewis, & Kontoyiannis, 2008;Garey et al, 2006;Morrel, Fraser, & Kollef, 2005), increasingly emphasis has been placed on achieving earlier and less invasive means of diagnosis, in hopes of improving the mortality rates associated with these infections (Alexander & Pfaller, 2006;Arvanitis et al, 2014;Griffin & Hanson, 2014;Zhang, 2013). This chapter provides a review of both the conventional diagnostic approaches (i.e.…”

Género Cryptococcus

“…Recientes avances en los estudios moleculares han permitido clasificar a C. neoformans y C. gattii en ocho tipos moleculares siendo C. neoformans var. grubii clasificado en los tipos moleculares VNI y VNII, la variedad neoformans en VNII y VNIV y C. gattii como VGI, VGII, VGIII y VGIV 1 . Otras especies menos frecuentes son C.albidus, C. laurentii, C. adeliensis y C. curvatus.…”

Differentiation of clinically relevant Mucorales Rhizopus microsporus and R. arrhizus by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)

“…Culturing mucoralean species from patient material may also be difficult because of lack of sporulation in tissue and the coenocytic structure of the mycelium. Histopathological observation remains inconclusive for species or even generic identification, which is essential for optimal antifungal therapy selection (Griffin & Hanson, 2014). DNA-based methods, such as internal transcribed spacer (ITS) sequencing, are time-consuming and require several preparatory steps (e.g.…”

“…Machouart-Dubach et al (2001) introduced RFLP as a rapid method for the separation of the main species of Mucorales, but this technique requires availability of a set of specific primers. No serological indicator for mucormycosis is available at this moment (Griffin & Hanson, 2014). Considering the difficulties in early diagnostics, time needed for identification, the acute invasive infection type, and a steady increase in the number of cases, the availability of reproducible and rapid species recognition are essential to decrease mortality rates due to this infection.…”