PCR Technology for Detection of Invasive Aspergillosis.

P. White,Rosemary Barnes

doi:10.3390/jof2030023

Abstract

The application of molecular technologies to aid diagnosis and management of infectious diseases has had a major impact and many assays are in routine use. Diagnosis of aspergillosis has lagged behind. Lack of standardization and limited commercial interest have meant that PCR was not included in consensus diagnostic criteria for invasive fungal disease. In the last ten years careful evaluation and validation by the Aspergillus European PCR initiative with the development of standardized extraction, amplification and detection protocols for various specimen types, has provided the opportunity for clinical utility to be investigated. PCR has the potential to not only exclude a diagnosis of invasive aspergillosis but in combination with antigen testing may offer an approach for the early diagnosis and treatment of invasive aspergillosis in high-risk populations, with the added benefit of detection of genetic markers associated with antifungal resistance.

Highlights

The availability of sensitive molecular methods for the diagnosis of infectious diseases is widespread, but polymerase chain reaction (PCR) for the diagnosis of fungal infection, aspergillosis, is still not widely used
The categories of probable and possible invasive aspergillosis are used to indicate established disease, a diagnosis reached on a basis of suggestive radiological signs with or without the detection of biomarkers (Galactomannan or β-D-glucan) or culture of Aspergillus
The Invasive Aspergillosis Animal Model (IAAM) group and Aspergillus technology (AsTec) consortium have developed, through collaboration with the European PCR initiative (EAPCRI), a quantified a DNA calibrator that can be used to compare PCR amplification methods negating the need for a single PCR test [28]

Summary

Introduction

The availability of sensitive molecular methods for the diagnosis of infectious diseases is widespread, but polymerase chain reaction (PCR) for the diagnosis of fungal infection, aspergillosis, is still not widely used. NA sequences unique from other eukaryotic organisms plus difficulties in the interpretation of results has hindered the development of commercial assays This has resulted in a plethora of in–house assays using different samples, targets, platforms and overall methodologies [1]. These ubiquitous environmental organisms are common laboratory contaminants but relatively rare causes of invasive disease occurring predominantly as opportunist infection in severely immunocompromised hosts. The categories of probable and possible invasive aspergillosis are used to indicate established disease, a diagnosis reached on a basis of suggestive radiological signs with or without the detection of biomarkers (Galactomannan or β-D-glucan) or culture of Aspergillus. The advantages of a rapid and highly sensitive molecular diagnostic test outweigh these problems

Recent Advances

Clinical Evaluation

Screening

Diagnostic

Commercial Assays

Future Developments

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