Terpinen-4-ol, the Main Bioactive Component of Tea Tree Oil, as an Innovative Antimicrobial Agent against Legionella pneumophila

Legionella pneumophila (Lp), responsible for a severe pneumonia called Legionnaires' disease, represents an important health burden in Europe. Prevention and control of Lp contamination in warm water systems is still a great challenge often due to the failure in disinfection procedures. The aim of this study was to evaluate the in vitro activity of Terpinen-4-ol (T-4-ol) as potential agent for Lp control, in comparison with the essential oil of Melaleuca alternifolia (tea tree) (TTO. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of T-4-ol were determined by broth micro-dilution and a micro-atmosphere diffusion method to investigate the anti-Lp effects of T-4-ol and TTO vapors. Scanning Electron Microscopy (SEM) was adopted to highlight the morphological changes and Lp damage following T-4-ol and TTO treatments. The greatest antimicrobial activity against Lp was shown by T-4-ol with a MIC range of 0.06-0.125% v/v and MBC range of 0.25-0.5% v/v. The TTO and T-4-ol MIC and MBC decreased with increasing temperature (36 °C to 45 ± 1 °C), and temperature also significantly influenced the efficacy of TTO and T-4-ol vapors. The time-killing assay showed an exponential trend of T-4-ol bactericidal activity at 0.5% v/v against Lp. SEM observations revealed a concentration- and temperature- dependent effect of T-4-ol and TTO on cell surface morphology with alterations. These findings suggest that T-4-ol is active against Lp and further studies may address the potential effectiveness of T-4-ol for control of water systems.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:11

Enthalten in:

Pathogens (Basel, Switzerland) - 11(2022), 6 vom: 14. Juni

Sprache:

Englisch

Beteiligte Personen:

Mondello, Francesca [VerfasserIn]
Fontana, Stefano [VerfasserIn]
Scaturro, Maria [VerfasserIn]
Girolamo, Antonietta [VerfasserIn]
Colone, Marisa [VerfasserIn]
Stringaro, Annarita [VerfasserIn]
Vito, Maura Di [VerfasserIn]
Ricci, Maria Luisa [VerfasserIn]

Links:

Volltext

Themen:

Antibacterial activity
Broth micro-dilution method
Essential oil
Journal Article
Legionella pneumophila
Micro-atmosphere diffusion method
Scanning electron microscopy (SEM)
Tea tree oil
Terpinen-4-ol
Time killing
Vapors

Anmerkungen:

Date Revised 16.07.2022

published: Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.3390/pathogens11060682

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM342666207