Point-of-care diagnosis of opportunistic fungal infections using innovative molecular biosensors.

Human fungal infections have emerged as one of the most pressing global health problems in recent years. Endemic infections affect healthy immunocompetent individuals causing a range of diseases which generally resolve with chemotherapy but hospital-acquired nosocomial infections pose a serious threat to immunocompromised patients in hospital wards and intensive care units worldwide. Despite the availability of chemotherapy nosocomial infections cause high mortality rates, often exceeding 50%.

Current diagnosis of fungal infections relies on the isolation and identification of fungi from clinical samples, but such microbiological methods are time consuming and lack sensitivity. Alternative fast, efficient and economic diagnostic methods and tools are urgently required. Nucleic Acids Enzymes are catalytic DNA or RNA sequences that can act as biomarker sensors and molecular switches. Innovative multi-component PlexZyme systems that can identify DNA biomarkers with high sensitivity and specificity have been recently developed. PlexZyme biosensors efficiently differentiate and quantify target biomarkers that differ in a single base pair thus allowing species-level identification of microorganisms and/or detection of single nucleotide polymorphisms associated with drug resistance. PlexZyme biosensors offer superior multiplexing capacity compared to alternative technologies and can be used under isothermal conditions or in cycling temperatures. They are relatively inexpensive, chemically stable and require simple instrumentation, making them ideal diagnostic products for use in resource constrained medical facilities and diagnostics laboratories worldwide.

This project will develop and implement PlexZymes as simple nucleic acids biosensors for the accurate, fast and reliable diagnosis of human candidiasis, Combining the use of molecular sensors for Candida DNA biomarkers with isothermal DNA amplification, we will create innovative diagnostic tools amenable to future automation that can be applied at the point of care.

Molecular diagnostics; fungal infections; human candidiasis; Candida; PlexZyme technology; molecular biosensors; Medical Mycology.