Major components of orange oil inhibit Staphylococcus aureus growth and biofilms formation, and alter its virulence factors.

Major components of orange oil inhibit Staphylococcus aureus growth and biofilms formation, and alter its virulence factors. J Med Microbiol. 2016 Jun 3; Authors: Federman C, Ma C, Biswas D Abstract Bovine mastitis is a costly disease in the dairy industry that does not always respond to antibiotic treatment. The major components of terpeneless, cold-pressed Valencia orange oil, citral, linalool, decanal, and valencene, were examined as potential alternative treatments for Staphylococcus aureus associated mastitis. The minimum inhibitory concentration (MIC) of all four components against S. aureus was determined after 24 h incubation. Growth inhibition assay was performed for all effective components on S. aureus for either a 3 h or 72 h treatment. These components were tested for the ability to disrupt pre-formed S. aureus biofilms after 24 h of treatment by measuring absorbances at 540nm. Cytotoxicity against immortalized bovine mammary epithelial (MAC-T) cells was measured using MTT assay following a 1 h exposure. Only concentrations below the 50% cytostatic concentration (CC50) were used in an adherence and invasion assay of S. aureus on MAC-T cells and measurements of gene expression for virulence and biofilm genes via qPCR. The MICs of citral and linalool were 0.02% and 0.12%, respectively, but decanal and valencene were ineffective. Citral and linalool were capable of inhibiting growth of S. aureus after 24 h at their MIC valu...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research