Transcriptomic Insights Into the Effect of LuxP-Targeting DNA Aptamer Developed by Ni-NTA SELEX in Pathogenic Vibrio...

Vibrio species are the main causative agents of vibriosis, the most prevalent bacterial disease affecting the aquaculture industry. Since 2009, Vibrio parahaemolyticus has been identified as the key pathogen responsible for Acute Hepatopancreatic Necrosis Disease (AHPND), leading to widespread outbreaks across several Southeast Asian countries. Although V. parahaemolyticus is the primary causative agent of AHPND, recent studies have shown that other Vibrio species, such as V. campbellii and V. harveyi, can also cause AHPND when they acquire the PirAB toxin-encoding plasmid. This study aimed to develop DNA aptamers that specifically target the LuxP receptor protein, a key component of the quorum sensing system. QS regulates the expression of multiple virulence factors, including novel toxins involved in Vibrio infection. Using Ni-NTA Systematic Evolution of Ligand by Exponential Enrichment, the DNA aptamer, VPQ1, was developed, which binds to the LuxP receptor. From the SELEX cycles, a total of 1114 aptamer candidates were isolated and sequenced. Thermodynamic analyses demonstrated that the interactions between recombinant LuxP and the selected aptamers VPQ1 and VPQ2 were exothermic, with a dissociation constant of 23.3 nanomolar and 24.2 nanomolar, respectively. Functional assays showed that the treatment with VPQ1 led to downregulation of genes associated with bacterial metabolism, quorum sensing, flagellar assembly and biofilm formation. These findings suggest that aptamer VPQ1 may serve as a promising anti-virulence agent to disrupt QS and mitigate Vibrio infection in aquaculture systems.