Cultureless enumeration of live bacteria in urinary tract infection by single-cell Raman spectroscopy

Jingkai Wang; Kang Kong; Chen Guo; Guangyao Yin; Siyu Meng; Lu Lan; Liqiang Luo; Yizhi Song

doi:10.3389/fmicb.2023.1144607

Cultureless enumeration of live bacteria in urinary tract infection by single-cell Raman spectroscopy

Front Microbiol. 2023 Mar 23:14:1144607. doi: 10.3389/fmicb.2023.1144607. eCollection 2023.

Authors

Jingkai Wang¹, Kang Kong^{1

2}, Chen Guo^{1

3}, Guangyao Yin¹, Siyu Meng¹, Lu Lan⁴, Liqiang Luo², Yizhi Song^{1

3

5}

Affiliations

¹ Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China.
² Department of Chemistry, College of Sciences, Shanghai University, Shanghai, China.
³ Division of Life Sciences and Medicine, School of Biomedical Engineering (Suzhou), University of Science and Technology of China, Suzhou, China.
⁴ VibroniX, Inc., Suzhou, China.
⁵ Chongqing Guoke Medical Technology Development Co., Ltd., Chongqing, China.

Abstract

Urinary tract infections (UTIs) are the most common outpatient infections. Obtaining the concentration of live pathogens in the sample is crucial for the treatment. Still, the enumeration depends on urine culture and plate counting, which requires days of turn-around time (TAT). Single-cell Raman spectra combined with deuterium isotope probing (Raman-DIP) has been proven to identify the metabolic-active bacteria with high accuracy but is not able to reveal the number of live pathogens due to bacteria replication during the Raman-DIP process. In this study, we established a new approach of using sodium acetate to inhibit the replication of the pathogen and applying Raman-DIP to identify the active single cells. By combining microscopic image stitching and recognition, we could further improve the efficiency of the new method. Validation of the new method on nine artificial urine samples indicated that the exact number of live pathogens obtained with Raman-DIP is consistent with plate-counting while shortening the TAT from 18 h to within 3 h, and the potential of applying Raman-DIP for pathogen enumeration in clinics is promising.

Keywords: Raman spectroscopy; live cell enumeration; single-cell; sodium acetate; urinary tract infection.

Grants and funding

This work was supported by grants from National Key R&D Program of China (MOST, 2022YFC2403300), the National Natural Science Foundation of China (32170173), Gusu Innovation and Entrepreneurship Leading Talents of Suzhou City (ZXL2021422), the Primary Research & Development Plan of Jilin Province (grant 20210204117YY), and SIBET Funding (Chongqing) (grant number: E1050Q80).