title: The Effect ofFerula assa-foetidaL andCarum copticumHydroalcoholic Extract on the Expression Levels ofStaphylococcus aureusGenes Involved in Quorum Sensing.
abstract: BACKGROUND
  Quorum sensing is a microbial cell-to-cell communication process. Quorum sensing bacteria produce and release extracellular messenger molecules called autoinducers. Gram-positive and Gram-negative, homoserine lactones, and oligopeptides are autoinducers used to communicate and regulate gene expression.
  
  
  OBJECTIVE
  The goal of this study was to assess the impact of subinhibitory concentrations ofFerula assa-foetidal oleo-gum resin andCarum copticumfruit on the expression oftstandhldgenes of methicillin-resistantStaphylococcus aureus(MRSA) and methicillin-sensitiveS. aureus(MSSA) strains.
  
  
  METHODS
  This analytical study was performed using standard strains of MRSA (ATCC 33591) and MSSA (ATCC 29213). Suspensions of MRSA and MSSA bacteria were incubated at 37°C for 7 and 16 hours in the presence of ethanol extracts fromF. assa-foetidaandC. copticum. The expression of thehldandtstgenes was then assessed using the real-time PCR protocol and SYBR Green Master Mix. The data analysis was carried out using the 2-ΔΔCTmethod.
  
  
  RESULTS
  Thehldgene expression (RNAIII) of MRSA after 7 and 16 hours of exposure to the sMIC of theF. assa-foetidaextract showed a fold change of -1 and 0.08, respectively, in comparison with controls. After 7 and 16 hours of exposure to the sMIC of theC. copticumextract, the fold change was -0.23 and -0.27, respectively. After exposure to the sMIC of theC. copticumextract for 16 hours, the fold change in the expression of thetst(TSST-1) MSSA gene was 0.37 lower than that of the control sample.
  
  
  CONCLUSIONS
  The results indicate that sMICs of ethanol extracts fromF. assa-foetidaandC. copticumcan be used to control the expression of virulence genes in pathogenic bacteria, such as MRSA and MSSA.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran.
authors.forename: Najmeh
authors.initials: N
authors.lastname: Jomehpour
authors.affiliation: Research Center for Food Hygiene and Safety, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran; Department of Parasitology and Mycology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran.
authors.forename: Gilda
authors.initials: G
authors.lastname: Eslami
authors.affiliation: Department of Microbiology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran.
authors.forename: Mohammad Bagher
authors.initials: MB
authors.lastname: Khalili
keywords: Carum copticum; Ferula assa-foetida L; Methicillin-resistant Staphylococcus aureus; Methicillin-sensitive S. aureus