Efficacy Assessment of Clinical Disinfectants for Enterococcus Faecalis via Single-cell Raman Microspectroscopy

doi:10.13701/j.cnki.kqyxyj.2021.11.007

Abstract

Abstract: Objective: To evaluate the susceptibility of enterococcus faecalis (Ef) to clinical disinfectants for the development of effective yet patient-friendly disinfectant formulations. Methods: The growth and metabolism-inhibiting effects of intracanal disinfectants via minimum inhibitory concentration (MIC) and minimum inhibitory concentration were quantitatively assessed based on metabolic activity (MIC-MA), using broth dilution test and D2O-probed Single-Cell Raman Spectra (SCRS) respectively. Results: For hydrogen peroxide (H₂O₂) and sodium hypochlorite (NaClO), at their MIC of 110 mg/L and 0.45 g/L respectively, despite complete halt of growth, metabolic activity of bacterial cells was reduced averagely for 71% and 70% at 8 hours, revealing a "nongrowing but metabolically active" (NGMA) state that may underlie potential refractory infections. In contrast, at their MIC-MA of 220 mg/L and 0.9 g/L respectively, metabolic activity of all cells was completely halted throughout 8 hours' exposure. Moreover, the combination usage of NaClO+H₂O₂ outperformed the solo usage of NaClO or H₂O₂. Conclusion: MIC-MA is advantageous in critically assessing antibacterial efficacy, and NaClO+H₂O₂ can potentially serve as a more efficient disinfectant formula for bacterial pathogens.

Key words: raman micro-spectroscopy, heavy water, Enterococcus faecalis, single-cell technology, clinical disinfectants

LIU Yuhan, MA Yuying, ZHANG Lijuan, LI Xiuzhen, YANG Jiazhen, NIU Yufen, SUN Yanfei, ZENG Fei; YANG Fang. Efficacy Assessment of Clinical Disinfectants for Enterococcus Faecalis via Single-cell Raman Microspectroscopy[J]. Journal of Oral Science Research, 2021, 37(11): 989-993.

References

[1] Kajwadkar R, Shin JM, Lin GH, et al. High-purity nisin alone or in combination with sodium hypochlorite is effective against planktonic and biofilm populations of enterococcus faecalis [J]. J Endod, 2017, 43(6):989-994.
[2] Borzini L, Condò R, De DP, et al. Root canal irrigation: chemical agents and plant extracts against enterococcus faecalis [J]. Open Dent J, 2016, 10(1):692-703.
[3] Severino M, Libonati A, Di Taranto V, et al. Comparative analysis of cleaning ability of two rotary instrument systems: Mtwo and ProTaper^ universal. An in vitro scanning electron microscopic study [J]. J Biol Regul Homeost Agents, 2019, 33(3 Suppl. 1):51-61.
[4] Tomson PL, Simon SR. Contemporary cleaning and shaping of the root canal system [J]. Prim Dent J, 2016, 5(2):46-53.
[5] 尹艳娇,葛翘诚,丁欣欣,等.Qmix、MTAD与EDTA去除根管玷污层的实验观察[J].口腔医学研究,2017,33(11):1197-1200.
[6] Galler KM. Clinical procedures for revitalization: current knowledge and considerations [J]. Int Endod J, 2016, 49(10):926-936.
[7] Tao Y, Wang Y, Huang S, et al. Metabolic-activity based assessment of antimicrobial effects by D₂O-labeled single-cell Raman microspectroscopy [J]. Analytical Chemistry, 2017, 89(7):4108-4115.
[8] Sampaio ADG, Gontijo AVL, Lima GMG, et al. Ellagic acid-cyclodextrin complexes for the treatment of oral candidiasis [J]. Molecules, 2021, 26(2):505.
[9] Ballal NV, Jain I, Tay FR. Evaluation of the smear layer removal and decalcification effect of QMix, maleic acid and EDTA on root canal dentine [J]. J Dent, 2016,51:62-68.
[10] Ulin C, Magunacelaya-Barria M, Dahlén G, et al. Immediate clinical and microbiological evaluation of the effectiveness of 0.5% versus 3% sodium hypochlorite in root canal treatment: A quasi-randomized controlled trial [J]. Int Endod J, 2020, 53(5):591-603.
[11] Akuji MA, Chambers DJ. Hydrogen peroxide: more harm than good?[J]. Br J Anaesth, 2017, 118(6):958-959.
[12] Fisher RA, Gollan B, Helaine S. Persistent bacterial infections and persister cells [J]. Nat Rev Microbiol, 2017, 15(8):453-464.
[13] Sasaki N, Clevers H. Studying cellular heterogeneity and drug sensitivity in colorectal cancer using organoid technology [J]. Curr Opin Genet Dev, 2018, 52:117-122.
[14] Wickramage I, Spigaglia P, Sun X. Mechanisms of antibiotic resistance of Clostridioides difficile [J]. J Antimicrob Chemother, 2021:dkab231.
[15] Patel A. Tackling antimicrobial resistance in the shadow of COVID-19 [J]. mBio, 2021, 12(4):e0047321.
[16] Priyank H, Pandey V, Bagul A, et al. Evaluation of 4% sodium hypochlorite in eliminating enterococcus faecalis from the root canal when used with three irrigation methods: an in vitro study [J]. J Contemp Dent Pract, 2017, 18(3):214-217.
[17] Zahran S, Witherden E, Mannocci F, et al. Characterization of root canal microbiota in teeth diagnosed with irreversible pulpitis [J]. J Endod, 2021, 47(3):415-423.
[18] Swimberghe RCD, Coenye T, De Moor RJG, et al. Biofilm model systems for root canal disinfection: a literature review [J]. Int Endod J, 2019, 52(5):604-628.
[19] Rodrigues ME, Henriques M, Silva S. Disinfectants to fight oral candida biofilms [J]. Adv Exp Med Biol, 2016, 931:83-93.
[20] Lohse MB, Gulati M, Johnson AD, et al. Development and regulation of single- and multi-species Candida albicans biofilms [J]. Nat Rev Microbiol, 2018, 16(1):19-31.