Seleção de aptâmeros contra cepas e isolados bacterianos resistentes a antibióticos

Abstract

The growing threat of antimicrobial resistance (AMR) represents one of the main challenges to global public health and is considered one of the greatest current concerns by the World Health Organization (WHO). This scenario is exacerbated by the spread of resistant bacteria such as Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. In light of the scarcity of new antibiotics and the urgency for rapid and effective diagnostics, aptamers have emerged as promising tools. These single-stranded oligonucleotides, selected through the SELEX technique (Systematic Evolution of Ligands by Exponential Enrichment), demonstrate high specificity and affinity for a variety of molecular targets. This study aimed to select aptamers with biotechnological potential against resistant Gram-negative bacterial strains using both exogenous and endogenous SELEX methodologies. The experimental process involved subtraction, selection, purification, cell lysis, agarose gel electrophoresis, and PCR amplification, allowing qualitative and quantitative analysis of the samples. In addition, the application of ultrasound was incorporated after the SELEX process as a refinement step to eliminate low-affinity aptamers. The results obtained from Qubit fluorometric quantification of the selected products indicate the presence of genetic material ranging from 80 to 60 base pairs in length, which was expected due to the library used. These findings highlight the need for sequencing and further research to explore the future applications of the selected aptamers. It is concluded that the SELEX methodology, integrated with molecular biology tools and ultrasound application, proved effective in selecting aptamers with high specificity. The obtained oligonucleotides show great biotechnological potential, with possibilities for targeted therapeutic application, as well as use in biosensors and the development of tools for rapid diagnostics — contributing to faster, more effective, and targeted treatment against resistant bacterial strains.