PCR diagnostic platforms for non-Aspergillus mold infections: ready for routine implementation in the clinic?

Abstract

Introduction: While Aspergillus spp. remain the predominant cause of invasive mold infections, non-Aspergillus molds, such as the Mucorales or Fusarium spp., account for an increasing proportion of cases. The diagnosis of non-Aspergillus invasive mold infections (NAIMI) is challenging because of the low sensitivity and delay of conventional microbiological tests. Therefore, there is a particular interest to develop molecular tools for their early detection in blood or other clinical samples.

Areas covered: This extensive review of the literature discusses the performance of Mucorales-specific PCR and other genus-specific or broad-range fungal PCR that can be used for the diagnosis of NAIMI in diverse clinical samples, with a focus on novel technologies.

Expert opinion: PCR currently represents the most promising approach, combining good sensitivity/specificity and ability to detect NAIMI in clinical samples before diagnosis by conventional cultures and histopathology. Several PCR assays have been designed for the detection of Mucorales in particular, but also Fusarium spp. or Scedosporium/Lomentospora spp. Some commercial Mucorales PCRs are now available. While efforts are still needed for standardized protocols and the development of more rapid and simpler techniques, PCR is on the way to becoming an essential test for the early diagnosis of mucormycosis and possibly other NAIMIs.