Three-dimensional label-free observation of individual bacteria upon antibiotic treatment using optical diffraction tomography

Jeonghun Oh; Jea Sung Ryu; Moosung Lee; Jaehwang Jung; SeungYun Han; Hyun Jung Chung; Yongkeun Park

doi:10.1364/BOE.377740

Three-dimensional label-free observation of individual bacteria upon antibiotic treatment using optical diffraction tomography

Biomed Opt Express. 2020 Feb 3;11(3):1257-1267. doi: 10.1364/BOE.377740. eCollection 2020 Mar 1.

Authors

Jeonghun Oh^{1

2}, Jea Sung Ryu³, Moosung Lee^{1

2}, Jaehwang Jung^{1

2

4}, SeungYun Han^{1

2}, Hyun Jung Chung^{3

5}, Yongkeun Park^{1

2

6}

Affiliations

¹ Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.
² KAIST Institute for Health Science and Technology, KAIST, Daejeon 34141, South Korea.
³ Graduate School of Nanoscience and Technology, KAIST, Daejeon 34141, South Korea.
⁴ Current Affiliation: Mechatronics R&D Center, Samsung Electronics, Hwasung 18448, South Korea.
⁵ Department of Biological Sciences, KAIST, Daejeon 34141, South Korea.
⁶ Tomocube Inc., Daejeon 34051, South Korea.

Abstract

Measuring alterations in bacteria upon antibiotic application is important for basic studies in microbiology, drug discovery, clinical diagnosis, and disease treatment. However, imaging and 3D time-lapse response analysis of individual bacteria upon antibiotic application remain largely unexplored mainly due to limitations in imaging techniques. Here, we present a method to systematically investigate the alterations in individual bacteria in 3D and quantitatively analyze the effects of antibiotics. Using optical diffraction tomography, in-situ responses of Escherichia coli and Bacillus subtilis to various concentrations of ampicillin were investigated in a label-free and quantitative manner. The presented method reconstructs the dynamic changes in the 3D refractive-index distributions of living bacteria in response to antibiotics at sub-micrometer spatial resolution.