The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms.

Cristiane Aparecida Pereira,Antonio Olavo Cardoso Jorge,Fernanda Bispo Reis Di Iorio,Jéssica Rabelo Mina Zambrana,Sarah Almeida Coelho Oliveira

doi:10.1590/s1806-83242013005000024

Cristiane Aparecida Pereira, Antonio Olavo Cardoso Jorge + Show 3 more

Open Access

https://doi.org/10.1590/s1806-83242013005000024

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Abstract

The aim of this study was to evaluate the effects of Citrus limonum and Citrus aurantium essential oils (EOs) compared to 0.2% chlorhexidine (CHX) and 1% sodium hypochlorite (NaOCl) on multispecies biofilms formed by Candida albicans, Enterococcus faecalis and Escherichia coli. The biofilms were grown in acrylic disks immersed in broth, inoculated with microbial suspension (106 cells/mL) and incubated at 37°C / 48 h. After the biofilms were formed, they were exposed for 5 minutes to the solutions (n = 10): C. aurantium EO, C. limonum EO, 0.2% CHX, 1% NaOCl or sterile saline solution [0.9% sodium chloride NaCl)]. Next, the discs were placed in sterile 0.9% NaCl and sonicated to disperse the biofilms. Tenfold serial dilutions were performed and the aliquots were seeded onto selective agar and incubated at 37°C / 48 h. , the number of colony-forming units per milliliter was counted and analyzed statistically (Tukey test, p ≤ 0.05). C. aurantium EO and NaOCl inhibited the growth of all microorganisms in multi-species biofilms. C. limonum EO promoted a 100% reduction of C. albicans and E. coli, 49.3% of E. faecalis. CHX was less effective against C. albicans and E. coli, yielding a reduction of 68.8% and 86.7%, respectively. However, the reduction of E. faecalis using CHX (81.7%) was greater than that obtained using C. limonum EO. Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were not only similar to those of NaOCl, but even higher than those achieved by CHX, in some cases.

Highlights

The oral cavity is heavily colonized by a complex, relatively specific and highly interrelated group of microorganisms that are organized in biofilms
The reduction of E. faecalis using CHX (81.7%) was greater than that obtained using C. limonum essential oils (EOs). Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were similar to those of NaOCl, but even higher than those achieved by CHX, in some cases
This study aimed at evaluating the effects of C. limonum EO and C. aurantium EO, compared to other solutions of known antimicrobial activity, such as 0.2% CHX and 1% NaOCl, on multi-species biofilms formed on acrylic resin by C. albicans, E. faecalis and E. coli reference strains

Summary

Introduction

The oral cavity is heavily colonized by a complex, relatively specific and highly interrelated group of microorganisms that are organized in biofilms. Microbial biofilms are composed of microorganisms that adhere to each other and/or to surfaces or interfaces and are embedded in an extracellular polymeric matrix, which includes water and nutrient channels.[1]. Candida albicans is a commensal yeast from the oral cavity and is the most virulent species of the genus It is the main cause of oral candidiasis.[2] Escherichia coli is a transient colonizer of the oral cavity, and the endotoxin produced by this bacterium plays an important role in the onset and perpetuation of periapical lesions and inflammatory bone resorption.[3] Enterococcus faecalis is a normal inhabitant of the oral cavity

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