Antimicrobial efficacy of silver ions in combination with tea tree oil against Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans

Abstract

Tea tree oil (TTO) and silver ions (Ag(+)), either alone or in combination with other antimicrobial compounds, have been used in the treatment of topical infections. However, there appears to be little data on the efficacy of TTO combined with silver in the absence of any other agents. TTO and Ag(+) were added, alone and in combination, to suspension cultures of Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Treatment of these cultures with TTO and Ag(+) at sub-minimal lethal concentrations resulted in an enhanced loss of viability compared with treatment with individual agents. The order of sensitivity to the combined agents was P. aeruginosa>S. aureus>C. albicans. The fractional lethal concentration index (FLCI) showed that these combinations of TTO and Ag(+) exerted a synergistic effect against P. aeruginosa (FLCI=0.263) and an indifferent effect against S. aureus and C. albicans (FLCI=0.663 and 1.197, respectively). The results indicate that combining these antimicrobial agents may be useful in decreasing the concentration of antimicrobial agents required to achieve an effective reduction in opportunistic pathogenic microorganisms that typically infect wounds.

Distribution ofMelaleuca alternifoliaessential oil in liposomes with Tween 80 addition and enhancement ofin vitroantimicrobial effect

“…[22] Minimal lethal concentrations of LTTOs (KLV 3 3.00) against S. aureus, E. coli and C. albicans were 0.15%À0.3%, 0.075%À0.15% and 0.005%À0.01% of TTO terminal concentration. Compared with TTO: polyvinyl alcohol (PVA 30-70 kDa )-loaded liposomes, [23] the value of prepared LTTOs against the Gram-positive bacteria was similar, but smaller than that against the Gram-negative bacteria and fungi. The inhibitory and lethal effects of PBS containing TTO and LTTOs suspension against fungi surpassed those against bacteria.…”

“…TTO-loaded liposomal suspensions were prepared by reverse-phase evaporation vesicles method and their antimicrobial activities were evaluated. [22,23] Recently, the feasibility and antimicrobial efficacy of encapsulated TTO and Ag C in combination has been investigated. [23,24] Encapsulating silver ions and TTO in a controlled release liposomal carrier system can improve their antimicrobial efficacy as well as reduce the effective concentration required.…”

“…[22,23] Recently, the feasibility and antimicrobial efficacy of encapsulated TTO and Ag C in combination has been investigated. [23,24] Encapsulating silver ions and TTO in a controlled release liposomal carrier system can improve their antimicrobial efficacy as well as reduce the effective concentration required. [23] Meanwhile, silver nanoparticles encapsulated in nanoliposomes have been developed as effective antimicrobial agents.…”

“…[23,24] Encapsulating silver ions and TTO in a controlled release liposomal carrier system can improve their antimicrobial efficacy as well as reduce the effective concentration required. [23] Meanwhile, silver nanoparticles encapsulated in nanoliposomes have been developed as effective antimicrobial agents. [25] However, potential health risks of nano and ionic forms of silver might exist and need to be weighed in the future due to their cytotoxicity.…”

Broad-Spectrum Antibacterial Characteristics of Four Novel Borate-Based Bioactive Glasses

“…[15], and S. aureus [13] [16] [18]. Silver ions in solution have also shown antimicrobial efficacy against P. aeruginosa, S. aureus, and C. albicans when in combination with natural products [19]. Additionally, silver nanoparticles have been incorporated into polymers and have also shown antimicrobial effects [17] [20] [21].…”