Effects of oregano, carvacrol and thymol on Staphylococcus aureus and Staphylococcus epidermidis biofilms

Abstract

The aim of this study was to evaluate the effect of oregano essential oil, carvacrol and thymol on biofilm-grown Staphylococcus aureus and Staphylococcus epidermidis strains, as well as the effects of the oils on biofilm formation. For most of the S. aureus (n56) and S. epidermidis (n56) strains tested, the biofilm inhibitory concentration (0.125-0.500 %, v/v, for oregano, and 0.031-0.125 %, v/v, for carvacrol and thymol) and biofilm eradication concentration (0.25-1.0 %, v/v, for oregano and 0.125-0.500 %, v/v, for carvacrol and thymol) values were twofold or fourfold greater than the concentration required to inhibit planktonic growth. Subinhibitory concentrations of the oils attenuated biofilm formation of S. aureus and S. epidermidis strains on polystyrene microtitre plates. INTRODUCTIONStaphylococci are important nosocomial pathogens. Eradication of these micro-organisms is not always successful due to their ability to form biofilms. Experimental evidence has shown that micro-organisms in biofilms are less susceptible to conventional treatment (Brown & Gilbert, 1993) than their planktonic counterparts. Many factors contribute to the lowered susceptibility of bacteria enclosed in a biofilm, and include the induction of a biofilm phenotype, the stress response and failure of the antimicrobial agents to penetrate the biofilm (Mah & O'Toole, 2001).As such, alternative strategies or more effective agents exhibiting activity against biofilm-producing micro-organisms are of great interest. Natural drugs could represent an interesting approach to limit the emergence and the spread of these organisms, which currently are difficult to treat. Recently, there has been considerable interest in the study of plant materials as sources of new compounds for processing into therapeutic agents. One approach may be the use of essential oils that have been shown to be potential agents in the treatment of infections, and are safe in terms of human and animal health. In this context, oregano oil and its major phenolic components, carvacrol [2-methyl-5-(1-methylethyl)phenol] and thymol (2-isopropyl-5-methylphenol), are known for their wide spectrum of antimicrobial activity, which has been the subject of several investigations in vitro (Dorman & Deans, 2000;Lambert et al., 2001) and in vivo (Adam et al., 1998;Manohar et al., 2001). They possess multiple biological properties such as anti-inflammatory, anti-leishmanial, antioxidant, hepatoprotective and anti-tumoral activities (Aeschbach et al., 1994; Alam et al., 1999; Robledo et al., 2005;Skold et al., 1998;Weber & de Bont, 1996;Zeytinoglu et al., 2003).Previously, we have shown the efficacy of oregano oil, carvacrol and thymol against planktonic Staphylococcus aureus and Staphylococcus epidermidis, including meticillinresistant strains (Nostro et al., 2004). The objective of this study was to extend the research to evaluate the activity of oregano oil, carvacrol and thymol on biofilm-grown S. aureus and S. epidermidis strains, as well as the effects of oils on biofilm formation....

Atividade antimicrobiana de óleos essenciais de condimentos frente a Staphylococcus spp isolados de mastite caprina

“…Destes transferiu-se uma alíquota de 10µl para a superfície do Ágar Muller-Hinton, o qual foi incubado Tabela 2 -Atividade antimicrobiana dos óleos essenciais de orégano, lípia, tomilho e das frações majoritárias carvacrol, timol e cinamaldeído frente à Staphylococcus spp isolados de mastite caprina. A maior concentração de carvacrol e timol nos OEs explicam a maior atividade antimicrobiana de alguns deles (NOSTRO et al, 2007). SARTORATTO et al (2004) Tabela 3 -Relações entre o perfil de resistência de Staphylococcus sp a antimicrobianos e a susceptibilidade a óleos essenciais e frações majoritárias.…”

Antibacterial and antibiofilm activity of Ammi majus seed against Gram-positive bacteria

“…The antibiofilm activity of the seed extracts against Streptococcal and Staphylococcal species may be an important tool for decrease microbial colonization on the surfaces and the epithelial mucosa which is main causes of infections by interrupting the release of the adhesion compound lipoteichoic acid from the cell surface, 24 or alteration of bacterial gene expression could be mediated the anti-biofilm action. 25 As a result concluded that the antibacterial and antibiofilm activity of Ammi majus seed due to their bioactive constituent present in it because phenolic acid, terpenes, tannin and flavonoids 10,[26][27][28][29] were found to exhibit marked antibacterial and antibiofilm activity.…”

“…8 Some plants have been reported to be able to prevent the formation of biofilm in some bacteria such as Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus auricularis, Streptococcus mitis, Streptococcus salivarius, Streptococcus pneumoniae. [9][10][11] Among plants of the Apiaceae, family Ammi majus native to northern Africa, southern Europe, western Asia and India. The fruit laterally compressed, oblong, mericarps of the cremocarp separated by a carpophore.…”

Phytochemical Screening and Evaluation of in-Vitro Antimicrobial Activity of Drosera Spatulata Var Bakoensis- an Indigenous Carnivorous Plant Against Respiratory Tract Infectious Microbes.

“…According to Johnson et al (2002) [17] and Nostro et al (2007) [18], effects of sub inhibitory concentrations of the all D. bakoensis plant extracts on established biofilms were evaluated. Bacteria and fungi cultures were grown in BHI in a polystyrene flat-bottomed microtiter plate to form biofilm after 24 hrs of incubation at 37°C.…”