EAGER: Addressing the Cyclospora Cayetanensis Detection Gap: A DNA Aptamer and Microfluidic Device Approach

Purdue University, West Lafayette IN

Investigators

Abstract

Bacteria and parasites that infect water often end up on produce, which threatens human health. Among these, some parasites, such as Cyclospora cayetanensis, are very difficult or impossible to culture, which creates often insurmountable barriers standing in the way of efforts of their effective detection. The lack of specific and easily accessible diagnostic tools that could prevent infected produce ending up on people’s tables often leads to outbreaks of disease. The project addresses this critical gap by developing new molecules, named DNA aptamers, that bind specifically to the Cyclospora cayetanensis parasite and then using them to fabricate a user-friendly paper-based test. This work aims to enable rapid, affordable, and accurate detection of this parasite, especially in areas where specialized laboratory facilities are not easily available. The project addresses both scientific understanding by discovering the first DNA aptamer for the Cyclsopora cayetanensis parasite and holds the potential to significantly improve public health by preventing disease outbreaks. This project's goal is to discover the first DNA aptamers that specifically recognize Cyclospora cayetanensis and integrate them into a paper-based microfluidic device for field-ready diagnostics. Most previous efforts towards meeting this goal have been limited by our lack of through understanding of this unique pathogen. Unlike other coccidian parasites, such as Toxoplasma gondii, which has been extensively studied and has a broader range of hosts, Cyclospora cayetanensis is a monoxenous coccidian, infecting the enterocytes of humans exclusively. This host specificity, paired with the lack of comprehensive data on its membrane structure and infection mechanisms, makes it an exceptionally difficult target. Thus, this project’s approach, aligned with the EAGER funding mechanism, addresses the unmet need for a biological recognition element that is specifically binding to Cyclospora cayetanensis, which is a necessary step for the development of point-of-need diagnostics effective for the detection of this unculturable monoexenous coccidian in water sources. The project involves two main objectives: (1) design and select highly selective and stable Cyclsopora cayetanensis aptamers through the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) process and (2) develop and test a paper-based microfluidic device (μPAD) coupled with a color analysis system for detecting specific Cyclospora cayetanensis antigens. These efforts will contribute to an in-depth understanding of unculturable pathogen detection and provide a the first rapid, low-cost, and highly accessible diagnostic tool for this parasite in water sources. The societal impact of this project lies in its potential to serve as a model for developing similar diagnostic tools for other challenging pathogens. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.