%A Li,Fan
%A Ren,Lihui
%A Chen,Rongze
%A Sun,Xi
%A Xu,Jian
%A Zhu,Pengfei
%A Yang,Fang
%D 2022
%J Frontiers in Cellular and Infection Microbiology
%C
%F
%G English
%K Heavy water,Single-cell technology,Candida albicans,Chlorhexidine Gluconate,Sodium Hypochlorite,Hydrogen Peroxide
%Q
%R 10.3389/fcimb.2022.772378
%W
%L
%M
%P
%7
%8 2022-February-23
%9 Original Research
%+ Pengfei Zhu,Single-Cell Center, Chinese Academy of Science Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Shandong Energy Institute, Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences,China,yangf82@qdu.edu.cn
%+ Pengfei Zhu,University of Chinese Academy of Sciences,China,yangf82@qdu.edu.cn
%+ Fang Yang,Stomatology Center, Qingdao Municipal Hospital,China,yangf82@qdu.edu.cn
%+ Fang Yang,School of Stomatology, Qingdao University,China,yangf82@qdu.edu.cn
%#
%! Screening disinfectants for fungal pathogens
%*
%<
%T Assessing Efficacy of Clinical Disinfectants for Pathogenic Fungi by Single-Cell Raman Microspectroscopy
%U https://www.frontiersin.org/articles/10.3389/fcimb.2022.772378
%V 12
%0 JOURNAL ARTICLE
%@ 2235-2988
%X Disinfectants are crucial for root canal therapy (RCT), as metabolism of canal-inhabiting microbes can cause refractory infections. To develop effective yet patient- and environment-friendly disinfectant formulations, we quantitatively assessed the metabolism-inhibiting effects of intracanal disinfectants via D2O-probed Single-Cell Raman Spectra (SCRS), using Candida albicans (C. albicans) as a pathogen model. For chlorhexidine gluconate (CHX), sodium hypochlorite (NaClO), and hydrogen peroxide (H2O2), at their MIC of 4, 168, and 60 μg/ml, respectively, despite the complete growth halt, metabolic activity of individual fungal cells was reduced on average by 0.4%, 93.9%, and 94.1% at 8 h, revealing a “nongrowing but metabolically active” (NGMA) state that may underlie potential refractory infections, particularly for CHX. In contrast, at their Metabolic Activity-based Minimum Inhibitory Concentrations (MIC-MA) of 8, 336, and 120 μg/ml, respectively, metabolic activity of all cells was completely halted throughout 8 h exposure. Moreover, combined use of NaClO+H2O2 (combination at 0.5× MIC-MA each) outperforms solo uses of CHX, NaClO, H2O2, or other binary combinations. Furthermore, dynamics of SCRS revealed distinct fungicidal mechanisms of CHX, NaClO, H2O2, and their pairwise combinations. MIC-MA is advantageous in critically assessing antifungal efficacy, and NaClO+H2O2 can potentially serve as a more efficient disinfectant formula for fungal pathogens.