ECX: An R Package for Studying Sensitivity of Antimicrobial Substances Using Spiral Plating Technology

Abstract

Spiral plating technique is reliable, repeatable, and more efficient than dilution plating methods in studying the efficacy of antimicrobial products. In this method, the concentration of chemicals can be varied at different positions on agar plates, but its calculation requires using a commercial software. To establish a user-friendly and costfree platform, the R package ECX was developed to calculate chemical concentrations in spiral plating technique. Mathematical models were established for calculating dispensed volume on agar plates using variables (molecular weight and agar height) that affect diffusion. In addition to the R packages, the web-based Shiny exten-interface for calculating individual concentrations, multiple concentrations, and stock concentrations, respectively. No significant differences were observed (P > 0.05) when ECX was compared with the commercial software. The ability to import and process large datasets makes the ECX package a better option for spiral plating technique studies. Furthermore, the multiplatform nature of the ECX package overcomes limitations presented in other software. Therefore, these ECX characteristics can increase the use of the spiral plating technique for sensitivity studies.