MOLECULAR APPROACHES FOR THE IDENTIFICATION AND CHARACTERIZATION OF ANTIMICROBIAL RESISTANCE IN FOODBORNE PATHOGENS
Location: Bacterial Epidemiology and Antimicrobial Resistance
Title: Microarray analysis of Salmonella Enteritidis Phage Type 8 treated with subinhibitory concentrations of trans-cinnamaldehyde or eugenol
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 25, 2012
Publication Date: July 9, 2012
Citation: Kollanoor-Johny, A., Frye, J.G., Porwolik, S., Darre, M.J., Donoghue, A.M., Donoghue, D.J., Mcclelland, M., Venkitanarayanan, K. 2012. Microarray analysis of Salmonella Enteritidis Phage Type 8 treated with subinhibitory concentrations of trans-cinnamaldehyde or eugenol [abstract]. Poultry Science. 91(Suppl.1):76-77..
Salmonella Enteritidis phage type 8 (PT8) is a major poultry-associated Salmonella isolate implicated in foodborne outbreaks in the United States. We previously reported that the GRAS-status plant-derived compounds trans-cinnamaldehyde (TC) and eugenol (EG) significantly reduced S. Enteritidis colonization in broiler chickens. To elucidate the potential mechanisms by which TC and EG reduced S. Enteritidis colonization, a whole-genome microarray analysis of S. Enteritidis PT8 treated with TC and EG was conducted. The DNA array included PCR products representing more than 99% of the open reading frames of the sequenced S. Enteritidis PT4. S. Enteritidis PT8 was grown in Luria-Bertani broth at 37oC to an OD600 of ~0.5. Subinhibitory concentrations of TC (0.01%) or EG (0.04%) were then added to the culture. S. Enteritidis RNA was extracted before and 30 min after TC or EG addition. Labeled cDNA from triplicate biological replicates was subsequently hybridized to the microarray, and the hybridization signals were quantified. TC and EG down-regulated (P<0.005) S. Enteritidis genes required for expression of flagellar motility, regulation of Pathogenicity Island 1, invasion of intestinal cells, multiple transport systems and outer membrane proteins. Moreover, several metabolic and biosynthetic pathways in S. Enteritidis were down-regulated by the plant compounds. TC and EG up-regulated expression of heat shock genes, such as dnaK, dnaJ, ibpB and ibpA in S. Enteritidis (P<0.005). In conclusion, this study indicated that TC and EG exert antimicrobial effects on S. Enteritidis by multiple mechanisms, including those associated with bacterial virulence, cell membrane composition and transport.