Assessment of the antibacterial activity of tea tree oil using the European EN 1276 and EN 12054 standard suspension tests
Introduction
Morbidity and mortality due to life-threatening hospital-acquired infections remains a significant problem in health care today. The major mode of infection transmission is still thought to be hand carriage of pathogens from staff to patient, and from patient to patient.1, 2, 3 Despite clear evidence that appropriate handwashing and skin antisepsis play a major role in reducing the spread of infections in hospital settings,2, 4, 5 compliance with hand-hygiene practices is still unacceptably low.3, 6, 7 Most soaps and detergents can be damaging to the skin when applied routinely during handwashing, leading to a change in microbial flora, an increase in bacterial shedding and thus an increased risk of transmission of micro-organisms.1, 8
The essential oil of Melaleuca alternifolia [tea tree oil (TTO)] has been used medicinally for about 80 years.9 TTO has broad-spectrum antimicrobial9 and anti-inflammatory10, 11 activity in vitro. Hammer et al.12 showed that transient skin organisms were more susceptible to TTO than commensal organisms. This finding supports the use of TTO-containing handwash products since the normal skin flora represents one of the natural defences against colonization by pathogenic organisms.13 Other reports have suggested that the repeated use of TTO-containing hand wash does not lead to the dermatological problems associated with some formulations,14 and this finding might be used to encourage healthcare staff's compliance with handwashing. Although the antibacterial activity of TTO has been well established in vitro,11, 15, 16, 17, 18, 19 TTO has not yet been assessed using European standard methods that are now widely accepted for the evaluation of disinfectant and antiseptic efficacy. In this study, we assessed the activity of TTO and TTO-containing formulations according to two European standard suspension methods, EN 127620 and prEN 12054.21
Section snippets
Micro-organisms
Staphylococcus aureus (ATCC 25923), Acinetobacter baumannii (NCTC 7844), Escherichia coli K12 (NCTC 10538) and Pseudomonas aeruginosa (NCTC 6749) stock cultures were made on tryptone soya agar (TSA; Oxoid, Basingstoke, Hampshire, UK) plates, stored at 4 °C and renewed once a week.
Working cultures of bacteria
Subcultures on to further TSA plates were prepared from the stock cultures and incubated for 18–24 h at 37 °C. From this second subculture, a third subculture was produced in the same way. As recommended by European
Antibacterial activity and efficacy of the neutralizer
As shown in Table I, the neutralizer did not reduce the concentration of bacterial cells significantly (P>0.05). The neutralizing solutions quenched the antiseptics effectively (P>0.05) at the concentrations tested (Table II).
Antibacterial activity of the TTO-containing antiseptics
According to the European standard method used, the products under test had to achieve log10 reduction in bacterial cell numbers of at least after a 1- or 5-min contact time. Products that complied with the European standard are listed in Table III. After a 1-min contact
Discussion
Handwashing is one of the most important measures to reduce the transmission of infection in hospital settings.24 However, compliance with hand-hygiene guidelines is low6, 7 and this can be partly attributed to the fact that most recommended handwash agents available in healthcare settings are irritant to the skin when used repetitively.25 The efficacy of TTO has been demonstrated in vitro and its incorporation into skin products does not appear to cause the dermatological problems commonly
Acknowledgements
This work was supported by a grant from the Rural Industries Research and Development Corporation, Canberra, Australia (UWA-72A).
References (47)
- et al.
The effectiveness of interventions aimed at increasing handwashing in healthcare workers—a systematic review
J Hosp Infect
(2001) Handwashing and hand disinfection
J Hosp Infect
(1986)Compliance with hand disinfection and its impact on hospital-acquired infections
J Hosp Infect
(2001)- et al.
Handwashing frequencies in an intensive care unit
J Hosp Infect
(2002) - et al.
Susceptibility of transient and commensal skin flora to the essential oil of Melaleuca alternifolia (tea tree oil)
Am J Infect Control
(1996) - et al.
Antimicrobial efficacy of biocides tested on skin using an ‘ex-vivo’ test
J Hosp Infect
(1998) - et al.
Hand hygiene and patient care: pursuing the Semmelweis legacy
Lancet Infect Dis
(2001) - et al.
The in-vitro activity of povidone-iodine cream against Staphylococcus aureus and its bioavailability in nasal secretions
J Hosp Infect
(2000) - et al.
Effectiveness of hand-cleansing agents for removing Acinetobacter baumannii strain from contaminated hands
Am J Infect Control
(1999) - et al.
Development and evaluation of a new alcohol-based surgical hand scrub formulation with persistent antimicrobial characteristics and brushless application
Am J Infect Control
(1998)
Povidone iodine gel alcohol: a 30-second, onetime application preoperative skin preparation
Am J Infect Control
Efficacy of hand disinfectants against vancomycin-resistant enterococci in vitro
J Hosp Infect
Evaluation of the bactericidal effect of five products for surgical hand disinfection according to prEN 12054 and prEN 12791
J Hosp Infect
Dermal tolerance of Sterillium, a propanol-based hand rub
J Hosp Infect
Skin hygiene and infection prevention: more of the same or different approaches?
Clin Infect Dis
Guideline for hand hygiene in health-care settings: recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force
Infect Control Hosp Epidemiol
An organizational climate intervention associated with increased handwashing and decreased nosocomial infections
Behav Med
Hygiene of the skin: when is clean too clean?
Emerg Infect Dis
Antimicrobial activity of the essential oil of Melaleuca alternifolia
Lett Appl Microbiol
The water-soluble components of the essential oil of Melaleuca alternifolia (tea tree oil) suppress the production of superoxide by human monocytes, but not neutrophils, activated in vitro
Inflamm Res
Tea tree oil reduces histamine-induced skin inflammation
Br J Dermatol
Skin bacteriology and the role of Staphylococcus aureus in infection
Br J Dermatol
Toxicity of the essential oil of Melaleuca alternifolia or tea tree oil
J Toxicol Clin Toxicol
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