Aptamers are single-stranded DNA or RNA molecules, which can bind their
targets with high affinity and specificity. SELEX (Systematic Evolution of Ligands by
Exponential Enrichment) is the technology that allows to select aptamers from a
random oligonucleotide library. Binding properties of aptamers are comparable to those
of antibodies. But, unlike antibodies, aptamer production is a more rapid and less
expensive process. One remarkable application is aptamer-based biosensors for specific
and sensitive detection of bacterial toxins. In addition, a few aptamers have been shown
to inhibit pathogens by blocking the activity of virulence factors. The chapter mainly
covers aptamers that target virulence factors, rather than pathogen cells. First, general
methodology for selection of aptamers is described. Then, aptamers developed against
toxins, protein virulence factors and quorum sensing molecules are reviewed. In
addition, chemical modification strategies to improve drug potential of aptamers are
addressed. Although aptamers are excellent antimicrobial drug candidates, there are
only a few studies that describe functional cell-based assays and potential therapeutic
use. In this chapter, analytical applications of aptamers, as well as limited studies on
their antimicrobial effect are reviewed.
Keywords: Antimicrobial resistance, Antibacterial aptamers, Aptamers, In vitro
selection, Modified aptamers, Multi-drug resistant pathogens, SELEX,
Therapeutic aptamers, Virulence factors.