Immuno-polymerase chain reaction for detection ofAspergillus fumigatus

Challenges in prevention, diagnosis and therapy of emerging fungal diseases. Aspergillosis: A case study

Diseases caused by pathogenic filamentous fungi, are an emerging threat to public health in the wake of increasing incidence of HIV and tuberculosis. At this point, discovery and development of fungal therapeutics and diagnostics are serious challenges for biomedical researchers. Recent technological advances in genomics and proteomics offer great scope for development of preventive and therapeutic measures for fungal diseases.Aspergillus, one of the medically important filamentous pathogenic fungi causes a wide spectrum of clinical disorders ranging from allergic aspergillosis to systemic invasive aspergillosis. Increase in incidence of drug resistance and the cytotoxic effects are two serious limitations of the antifungal drugs presently in use. This is primarily due to lack of understanding of biological mechanisms operative in these fungi. Today, it is possible to understand the biological mechanisms of the fungus for its colonisation, survival and invasion of the host. Future developments based on such leads can result in development of precise and specific diagnostic, therapeutic and preventive measures for a wide clinical spectrum of fungal diseases.

Detection ofAspergillus Fumigatus based on Asp fl gene in clinical specimens

Oligonucleotide primers were synthesised based on the gene sequence of an 18 kDa allergen/antigen ofA. fumigatus isolated from a pathogenic strain. Polymerase chain reaction (PCR) was carried out using the forward and reverse primers and genomic DNA ofA. fumigatus, A. flavus andA. niger as template. This resulted in a PCR product of 480 bp with onlyA. fumigatus. The absence of PCR product inA. flavus andA. niger with the primers of Asp fl facilitated use of these primers for detection ofA. fumigatus in clinical specimens of patients. The results were compared with microscopy, culture and serology. Application of PCR test to clinical samples of aspergillosis patients is discussed.