title: Eradication and Sensitization of Methicillin ResistantStaphylococcus aureusto Methicillin with Bioactive Extracts of Berry Pomace.
abstract: The therapeutic roles of phenolic blueberry (Vaccinium corymbosum) and blackberry (Rubus fruticosus) pomace (commercial byproduct) extracts (BPE) and their mechanism of actions were evaluated against methicillin resistantStaphylococcus aureus(MRSA). Five major phenolic acids of BPE, e.g., protocatechuic, p. coumaric, vanillic, caffeic, and gallic acids, as well as crude BPE completely inhibited the growth of vegetative MRSAin vitrowhile BPE+methicillin significantly reduced MRSA biofilm formation on plastic surface. In addition, BPE restored the effectiveness of methicillin against MRSA by down-regulating the expression of methicillin resistance (mecA) and efflux pump (norA,norB,norC,mdeA,sdrM, andsepA) genes. Antibiogram with broth microdilution method showed that MIC of methicillin reduced from 512 μg/mL to 4 μg/mL when combined with only 200 μg Gallic Acid Equivalent (GAE)/mL of BPE. Significant reduction in MRSA adherence to and invasion into human skin keratinocyte Hek001 cells were also noticed in the presence of BPE. BPE induced anti-apoptosis and anti-autophagy pathways through overexpression ofBcl-2gene and down-regulation ofTRADDandBaxgenes (inducers of apoptosis pathway) in Hek001 cells. In summary, novel and sustainable prophylactic therapy can be developed with BPE in combination with currently available antibiotics, especially methicillin, against skin and soft tissue infections with MRSA.
authors.affiliation: Department of Animal and Avian Sciences, University of Maryland College Park, MD, USA.
authors.forename: Serajus
authors.initials: S
authors.lastname: Salaheen
authors.affiliation: Department of Animal and Avian Sciences, University of MarylandCollege Park, MD, USA; Biological Sciences Program - Molecular and Cellular Biology, University of MarylandCollege Park, MD, USA.
authors.forename: Mengfei
authors.initials: M
authors.lastname: Peng
authors.affiliation: Department of Animal and Avian Sciences, University of Maryland College Park, MD, USA.
authors.forename: Jungsoo
authors.initials: J
authors.lastname: Joo
authors.affiliation: Department of Animal and Avian Sciences, University of Maryland College Park, MD, USA.
authors.forename: Hironori
authors.initials: H
authors.lastname: Teramoto
authors.affiliation: Department of Animal and Avian Sciences, University of MarylandCollege Park, MD, USA; Biological Sciences Program - Molecular and Cellular Biology, University of MarylandCollege Park, MD, USA; Center for Food Safety and Security Systems, University of MarylandCollege Park, MD, USA.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Biswas
keywords: Staphylococcus aureus; antibiotic resistance; antimicrobials; gene expression; phenolic compounds