Development of new phytochemical-based disinfectant formulations for the control of healthcare-associated bacterial infections

Authors

  • Mariana Sousa LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical and Biological Engineering, University of Porto, s/n, 4200-465 Porto, Portugal; ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, s/n, 4200-465 Porto, Portugal
  • Anabela Borges LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical and Biological Engineering, University of Porto, s/n, 4200-465 Porto, Portugal; ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, s/n, 4200-465 Porto, Portugal; DEQB—Department of Chemical and Biological Engineering, Faculty of Engineering, University of Porto, s/n, 4200-465 Porto, Portugal
  • Manuel Simões LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical and Biological Engineering, University of Porto, s/n, 4200-465 Porto, Portugal; ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, s/n, 4200-465 Porto, Portugal; DEQB—Department of Chemical and Biological Engineering, Faculty of Engineering, University of Porto, s/n, 4200-465 Porto, Portugal

DOI:

https://doi.org/10.48797/sl.2025.323

Keywords:

Selected Oral Communication

Abstract

Background: Healthcare-associated infections (HAIs) remain a critical public health challenge due to the persistence of multidrug-resistant (MDR) bacteria and the inefficacy of conventional disinfectants [1]. Biofilms further enhance bacterial resistance and limit the effectiveness of biocides [2]. Phytochemicals have emerged as natural alternatives due to their antimicrobial and antibiofilm properties [3]. This study explored the potential of phytochemical-based formulations to enhance disinfection in healthcare settings. Objective: This research aimed to assess the antimicrobial efficacy of selected phytochemicals—eugenol (EUG), salicylic acid (SAL), shikimic acid (SHI), trans-m-coumaric acid (COU), and choline chloride (COL)—alone and in combination with widely used biocides, particularly benzalkonium chloride (BAC) and peracetic acid (PAA). Methods: The antimicrobial activity of phytochemicals and biocides was tested against Staphylococcus aureus and Escherichia colifollowing the European Standard EN 1276 (2019). For this, the dose-response and time-response effects, as well as the minimum bactericidal concentrations (MBCs), were determined. The Checkerboard assay, analyzed with Combenefit software, assessed synergism potential in dual and triple combinations through the Fractional Bactericidal Concentration Index (FBCI). Disinfection kinetics were characterized using the Chick-Watson and Weibull models. Results: Among the phytochemicals tested, SAL (with an MBC of 500 mg/L for both bacteria) and EUG (with an MBC of 1000 mg/L for E. coli and 1700 mg/L for S. aureus) showed the highest antimicrobial efficacy. For both bacteria, MBCs of 3 mg/L and 1 mg/L and high disinfection rates were obtained with BAC and PAA, respectively. BAC combined with EUG (750 mg/L) showed synergistic effects against S. aureus (FBCI = 0.309) and E. coli (FBCI = 0.350). A synergistic interaction was observed between BAC and EUG, while the other dual combinations exhibited additive effects. Triple combinations demonstrated promising bactericidal activity, effectively reducing bacterial culturability. Maximum reductions of (5.78 ± 0.07) log (CFU/mL) for E. coli and (5.82 ± 0.04) log (CFU/mL) for S. aureus within 30 minutes were obtained. Conclusions: This study demonstrated that phytochemicals could enhance the efficacy of conventional biocides, reducing the required concentrations and contributing to the development of effective and sustainable healthcare disinfection strategies.

References

1. Maki, G; Zervos, M. Health care-acquired infections in low- and middle-income countries and the role of infection prevention and control. Infect Dis Clin North Am 2021, 35(3), 827-839, doi: https://doi.org/10.1016/j.idc.2021.04.014.

2. Allemailem, K.S. Antimicrobial potential of naturally occurring bioactive secondary metabolites. J Pharm Bioallied Sci 2021, 13(2), 155-162, doi: 10.4103/jpbs.JPBS_753_20.

3. Malheiro, J.F.; Maillard, J-Y; Borges, F; Simões, M. Biocide potentiation using cinnamic phytochemicals and derivatives. Molecules 2019, 24(21), 3918, doi: https://doi.org/10.3390/molecules24213918.

Downloads

Published

2025-05-27

How to Cite

Sousa, M., Borges, A., & Simões, M. (2025). Development of new phytochemical-based disinfectant formulations for the control of healthcare-associated bacterial infections . Scientific Letters, 1(Sup 1). https://doi.org/10.48797/sl.2025.323

Issue

Vol. 1 No. Sup 1 (2025)

Section

Oral Communications

License

Copyright (c) 2025 Mariana Sousa, Anabela Borges, Manuel Simões

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

In Scientific Letters, articles are published under a CC-BY license (Creative Commons Attribution 4.0 International License), the most open license available. The users can share (copy and redistribute the material in any medium or format) and adapt (remix, transform, and build upon the material for any purpose, even commercially), as long as they give appropriate credit, provide a link to the license, and indicate if changes were made (read the full text of the license terms and conditions of use).

The author is the owner of the copyright.

Most read articles by the same author(s)

Similar Articles

1 2 3 4 5 6 > >> 

You may also start an advanced similarity search for this article.