Effect of cinnamaldehyde on biofilm formation and sarA expression by methicillin-resistant Staphylococcus aureus

Abstract

Aims: To investigate the antibiofilm effect of cinnamaldehyde on methicillin‐resistant Staphylococcus aureus (MRSA) and analyse the effect of subminimum inhibitory concentrations (MICs) of cinnamaldehyde on the expression of the biofilm‐related gene sarA. Methods and Results: The MICs and minimum bactericidal concentrations (MBCs) were determined using a microtitre broth dilution method. Biofilm susceptibility was determined using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) staining and colony forming unit (CFU) counting assays. Antibiofilm effects were studied with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). SarA expression was assessed by real‐time PCR. MICs and MBCs were in the range 0·0625–0·5% (v/v). The killing effects were concentration dependent. At a concentration of 5× MIC, all strains in biofilm were decreased to lower than 20% of the control groups. SEM and CLSM images indicated that a 5× MIC concentration of cinnamaldehyde was able to detach and kill existing biofilms. Apart from strain JB‐06, real‐time PCR showed that the expression of sarA of all other strains was decreased upon exposure to sub‐MICs of cinnamaldehyde. Conclusions: These data showed the strong killing effect of cinnamaldehyde against MRSA within biofilms. Significance and Impact of the Study: This study indicated the potential of cinnamaldehyde as an inhibitory agent for use in MRSA biofilm‐related infections.

Effect of cinnamon essential oil and cinnamaldehyde on Salmonella Saintpaul biofilm on a stainless steel surface

“…The effects of these compounds against Listeria monocytogenes, Escherichia coli, Pseudomonas spp., and Staphylococcus spp. biofilms on stainless steel and polystyrene have been demonstrated (Jia et al, 2011;Niu and Gilbert, 2004;Nuryastuti et al, 2009;Oliveira et al, 2012). However, to our knowledge, no studies have reported the effects of cinnamon EO or cinnamaldehyde on Salmonella spp.…”

“…The determination of biofilm metabolic activity was performed using a MTT staining assay according to Jia et al (2011) with some modifications. Briefly, overnight cultures of S. Saintpaul were diluted in Tryptic Soy Broth (TSB; Difco) to obtain 10 7 CFU/ml and added to a 96-well cell culture plate.…”

Selected Antimicrobial Essential Oils Eradicate Pseudomonas spp. and Staphylococcus aureus Biofilms

“…The strain used in this study, SC-01, is a biofilm-forming, oxacillin-and methicillin-resistant clinical isolate (26). Certain essential oils, such as tea tree, thyme, and peppermint, are effective against planktonic (5,18,20) and biofilm (3,12) MRSA. However, to our knowledge, essential oils from cassia, red thyme, and clove have not been tested against MRSA biofilms of any strain.…”

Anti Biofilm and Anti Plasmid Activites of Syzygium aromaticum and Kaempheria galanga against Pseudomonas aeruginosa

“…Phytochemicals or secondary metabolites, the bioactive principle of plants are established biofilm removing agents (Chirangini et al, 2005, Fu et al, 2007. S.aromaticum and K.galanga are found in Asia and Africa and are valued for their rich medicinal and culinary attributes (Jia et al, 2011). Further, the antimicrobial,anti-carminative (Shyamala et al, 2003) and antioxidant properties of these are well demonstrated.…”