The Usage of an AMCA-Modified Aptamer Facilitates the Rapid Detection of Vibrio vulnificus

Abstract

Background: Vibrio vulnificus can cause serious infections in human beings associated with the consumption of raw oysters or cuts exposed to seawater. The traditional method for culturing V. vulnificus is time-consuming and has a high failure rate. Objectives: This study aims to detect V. vulnificus using an AMCA-modified specific DNA aptamer. Methods: Common pathogenic microorganisms present in the seawater of the Fujian Sea area were collected, cultured, and identified. The samples were found to contain mainly V. vulnificus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, V. alginolyticus, V. parahaemolyticus, and V. cholerae. AMCA was conjugated with 5’ ends of the aptamer using N-hydroxysuccinimide ester (NHS ester) to target V. vulnificus and produce a fluorescent signal upon binding. The aptamer was screened and optimized for rapid detection of V. vulnificus. We collected the 50 bacterial strains isolated from clinical secretion samples and used a fluorescence microscope to determine whether the sample contained V. vulnificus or not. We compared these results with those obtained from VITEK MS (considered the gold standard) to test the sensitivity and specificity of the AMCA-modified aptamer using IBM SPSS Statistics 22. Results: In this experiment, the sensitivity and specificity of the modified aptamer for detecting V. vulnificus were determined to be 100% [95% CI (0.39, 1)] and 93.4% [95% CI (0.81, 0.98)], respectively. The positive predictive value was 57% [95% CI (0.20, 0.88)], and the negative predictive value was 100% [95% CI (0.89, 1)]. These findings indicate that V. vulnificus specimens can be rapidly detected via fluorescence reaction within 30 minutes. Conclusions: Our results suggest that this modified DNA aptamer has the potential to be used for diagnosing V. vulnificus. Further research is needed to explore the application of aptamers in pathogen infections.