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Development of a whole-cell SELEX process to select species-specific aptamers against Aspergillus niger
Valeria Ellena1,2, Alexandra Ioannou1,2, Claudia Kolm3,4
1Research Group Biochemistry, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria.
Background:
Spores produced by the filamentous fungus Aspergillus niger are abundant in a variety of environments. The proliferation of this fungus in indoor environments has been associated to health risks and its conidia can cause allergic reaction and severe invasive disease in animals and humans. Therefore, the detection and monitoring of Aspergillus conidia is of utmost importance to prevent serious fungal infections and contaminations. Among others, aptamers could serve as biosensors for the specific detection of fungal spores.
Results:
In this study, DNA aptamers specific to conidia of A. niger were developed by optimizing a whole-cell SELEX approach. Three whole-cells SELEX experiments were performed in parallel with similar conditions. Quantification of recovered ssDNA and melting curve analyses were applied to monitor the ongoing SELEX process. Next-generation sequencing was performed on selected recovered ssDNA pools, allowing the identification of DNA aptamers which bind with high affinity to the target cells. The developed aptamers were shown to be species-specific, being able to bind to A. niger but not to A. tubingensis or to A. nidulans. The binding affinity of two aptamers (AN01-R9-006 and AN02-R9-185) was measured to be 58.97 nM and 138.71 nM, respectively, which is in the range of previously developed aptamers.
Conclusions:
This study demonstrates that species-specific aptamers can be successfully developed via whole-cell SELEX to distinguish different Aspergillus species and opens up new opportunities in the field of diagnostics of fungal infections.
Insights
Researchers developed species-specific DNA aptamers for detecting Aspergillus niger spores using whole-cell SELEX. These aptamers offer a promising tool for monitoring fungal contamination and diagnosing infections.
Area of Science:
- Molecular Biology
- Biotechnology
- Mycology
Background:
- Aspergillus niger spores are common environmental contaminants.
- Detection of Aspergillus conidia is crucial for preventing health risks like allergic reactions and invasive diseases.
- Aptamers show potential as biosensors for specific fungal spore detection.
Purpose of the Study:
- To develop DNA aptamers that specifically recognize and bind to Aspergillus niger conidia.
- To establish a method for distinguishing Aspergillus species using aptamer-based detection.
Main Methods:
- Optimization of a whole-cell SELEX (Systematic Evolution of Ligands by Exponential Enrichment) approach.
- Parallel SELEX experiments with monitoring via ssDNA quantification and melting curve analysis.
- Next-generation sequencing for identifying high-affinity DNA aptamers.
Main Results:
- Successfully developed DNA aptamers specific to Aspergillus niger conidia.
- Demonstrated species-specificity, with aptamers binding to A. niger but not A. tubingensis or A. nidulans.
- Measured binding affinities for two aptamers (AN01-R9-006 and AN02-R9-185) at 58.97 nM and 138.71 nM, respectively.
Conclusions:
- Whole-cell SELEX is an effective method for developing species-specific aptamers against Aspergillus species.
- These aptamers open new avenues for the diagnostics of fungal infections.
- The developed aptamers can differentiate between various Aspergillus species.
