Identification of antibiotic-resistance markers of Edwardsiella tarda using aptamers

Abstract

Edwardsiella tarda poses significant challenges in the aquaculture sector due to its antibiotic resistance, leading to substantial economic loss in the aquaculture industry. Therefore, it is imperative to identify antibiotic-resistance markers to prevent and control E. tarda. In the present study, we used tetracycline-sensitive (S) and resistant (R) E. tarda strains and six non-target bacterial strains, to develop aptamers through the Systematic Evolution of Ligands by Exponential Enrichment technique. We then conducted comparative analysis of these aptamers based on their relative importance index values and selected six candidate sequences (M1, M13, M15, N57, N69, and N71) for affinity verification. The results showed that M1 had significantly higher affinity towards both the S and R strains compared to the non-target strains. M13 and M15 had significantly higher affinities for the S strain compared to the R strain and non-target strains, and N57, N69, and N71 had significantly higher affinities for R strains relative to the sensitive and non-target strains. Subsequent analysis indicated that N57 and N69 specifically recognized unique sites in the R strain. Therefore, our study presents a novel approach for detecting and controlling antibiotic-resistant strains of E. tarda and identification of drug-resistant markers in bacteria.