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Updated: Feb 22, 2026
In Vitro Selection of Aptamers to Differentiate Infectious from Non-Infectious Viruses
Published on: September 7, 2022
Selection of DNA aptamers specific for live Pseudomonas aeruginosa
1School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand.
Abstract:
Pseudomonas aeruginosa is an opportunistic pathogen that causes significant morbidity and mortality in immunocompromised patients, particular cystic fibrosis sufferers, burns victims, diabetics and neonates. It thrives in moist places where it forms biofilms that are exceedingly difficult to eradicate on hospital surfaces, in water supplies and implanted biomaterials. Using a live cell SELEX approach we selected DNA aptamers to P. aeruginosa grown as biofilms in microfluidic cells. From a pool of aptamer candidates showing tight binding a stem-loop structure was identified as being important for binding. Enhanced binding and increased specificity was achieved by truncating structures and generating chimeric aptamers from the pool of top candidates. The top candidates have low nanomolar binding constants and high discrimination for P. aeruginosa over other Gram-negative bacteria. The aptamers bind both planktonic grown and biofilm grown cells. They do not have intrinsic bacteriostatic or bactericidal activity, but are ideal candidates for modification for use as aptamer-drug conjugates and in biosensors.
Insights
Researchers developed DNA aptamers to target Pseudomonas aeruginosa biofilms. These aptamers show high specificity and low nanomolar binding, offering potential for new diagnostics and therapeutics against this opportunistic pathogen.
Area of Science:
- Microbiology
- Biotechnology
- Molecular Biology
Background:
- Pseudomonas aeruginosa is an opportunistic pathogen causing severe illness in immunocompromised individuals.
- P. aeruginosa forms resilient biofilms on surfaces, posing challenges in healthcare settings.
- Effective detection and eradication of P. aeruginosa biofilms remain critical.
Purpose of the Study:
- To select and optimize DNA aptamers for targeting Pseudomonas aeruginosa biofilms.
- To characterize the binding affinity and specificity of selected aptamers.
- To explore the potential applications of these aptamers in diagnostics and therapeutics.
Main Methods:
- Live cell SELEX (Systematic Evolution of Ligands by Exponential Enrichment) was employed using P. aeruginosa biofilms in microfluidic cells.
- Aptamer candidates were screened for binding affinity and specificity.
- Structural analysis identified a stem-loop motif crucial for binding.
- Truncation and chimera generation were used to enhance aptamer performance.
Main Results:
- Selected DNA aptamers demonstrated low nanomolar binding constants for P. aeruginosa.
- The aptamers exhibited high specificity, distinguishing P. aeruginosa from other Gram-negative bacteria.
- Binding was effective against both planktonic and biofilm-grown P. aeruginosa cells.
- A stem-loop structure was identified as important for aptamer binding efficacy.
Conclusions:
- Optimized DNA aptamers are effective tools for targeting Pseudomonas aeruginosa, including its biofilm form.
- These aptamers possess high specificity and affinity, suitable for diagnostic and therapeutic development.
- The aptamers can be modified for use in aptamer-drug conjugates and advanced biosensors.
