# Development of Rapid Disk Diffusion Device Using Laser Speckle Formation Technology for Rapid Antimicrobial Susceptibility Testing

## TL;DR

This paper introduces a new rapid antimicrobial susceptibility testing method using laser speckle formation technology that shows promising results compared to traditional methods.

## Contribution

The study presents a novel rapid disk diffusion method using laser speckle formation technology for faster antimicrobial susceptibility testing.

## Key findings

- Preclinical experiments showed over 70% categorical agreement with conventional methods.
- Clinical experiments revealed 40–79% categorical agreement with 30% major and 11% minor discrepancies.
- The laser-based RDD method demonstrated higher potential than previous comparable technologies.

## Abstract

The escalation of antimicrobial resistance (AMR) due to the excessive and inappropriate use of antimicrobials has prompted the urgent need for more rapid and effective antimicrobial susceptibility testing (AST) methods. Conventional AST techniques often take 16–24 h, leading to empirical prescription practices and the potential emergence of AMR. The study aimed to develop a rapid disk diffusion (RDD) method utilizing laser speckle formation (LSF) technology to expedite AST results. The study aimed to evaluate the performance of LSF technology in determining antimicrobial susceptibility. In this study, preclinical and clinical settings were established to compare the LSF technology with conventional disk diffusion (DD) methods to measure the inhibition zones. Preclinical experiments with different bacterial strains demonstrated more than 70% categorical agreement (CA) against most antimicrobials. Further, clinical experiments with multiple strains and antibiotics revealed CA ranging from 40 to 79%, while major and minor discrepancies were observed around 30% and 11%, respectively. These observations revealed high concordance between RDD and DD for multiple antimicrobials in multiple species. The results underscore the potential of RDD-based LSF technology for hastening AST procedures. The current study is marked by a unique equipment setup and analysis approach. Collectively, the suggested laser-based RDD showed greater potential than previously developed comparable methods. The proposed method and design have a higher application potential than formerly developed similar technologies. Together, the study contributes to the ongoing development of rapid AST methods.

The online version contains supplementary material available at 10.1007/s00284-024-03798-3.