FINDING A SURFACE BIORECEPTOR FOR IDENTIFICATION OF STREPTOCOCCUS PNEUMONIAE.
Streptococcus pneumoniae is the principal etiological agent of otitis and meningitis in children around the world. In the last years a strain of this pathogen resistant to optochin has been detected. Therefore, there is a possibility to find false negatives in the current methods used to identify this pathogen. Then it is necessary to develop new identification methods.
Here, a strategy is presented to select a molecule that binds to S. pneumoniae surface, which would allow the specific identification of this pathogen. This strategy consists on using short single-stranded DNA (aptamer).
The selected aptamer was able to bind the S. pneumoniae surface, but not to other bacteria such as: Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus pyogenes and Pseudomonas aeruginosa, with which can be confused during the identification processes. The aptamer selected was cloned in a plasmid vector and sequenced to know the sequence and to model the 3D structure. The aptamer was coupled to gold nanoparticles to obtain a bio-conjugated molecule and this structure also bound the S. pneumoniae surface indicating that the structure was not altered by the nanoparticles.
This aptamer is proposed as a bioreceptor to design a biosensor for the easy, fast and specific identification of S. pneumoniae.