title: Synergistic Antibacterial Effect and Antibacterial Action Mode of Chitosan-Ferulic Acid Conjugate against Methicillin-Resistant Staphylococcus aureus.
abstract: We evaluated the synergistic antibacterial effect in combination with the chitosan-ferulic acid conjugate (CFA) and β-lactam antibiotics, such as ampicillin, penicillin, and oxacillin, against methicillin-resistant Staphylococcus aureus (MRSA) using fractional inhibitory concentration (FIC) indices. CFA clearly reversed the antibacterial activity of ampicillin, penicillin, and oxacillin against MRSA in the combination mode. Among these antibiotics, the combination of oxacillin-CFA resulted in a ∑FICmin range of 0.250 and ∑FICmax of 0.563, suggesting that the oxacillin-CFA combination resulted in an antibacterial synergy effect against MRSA. In addition, we determined that CFA inhibited the mRNA expression of gene mecA and the production of PBP2a, which is a key determinant for β-lactam antibiotic resistance, in a dosedependent manner. Thus, the results obtained in this study supported the idea on the antibacterial action mechanism that oxacillin will restore the antibacterial activity against MRSA through the suppression of PBP2a production by CFA.
authors.affiliation: Korea Food Research Institute, Sungnam 13539, Republic of Korea.
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Eom
authors.affiliation: Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea.
authors.forename: Shin-Kook
authors.initials: SK
authors.lastname: Kang
authors.affiliation: National Marine Biodiversity Institute of Korea, Seocheon 33662, Republic of Korea.
authors.forename: Dae-Sung
authors.initials: DS
authors.lastname: Lee
authors.affiliation: Aquaculture Management Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea.
authors.forename: Jeong-In
authors.initials: JI
authors.lastname: Myeong
authors.affiliation: Aquaculture Management Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea.
authors.forename: Jinhwan
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Marine Biology, Pukyong National University, Busan 48513, Republic of Korea.
authors.forename: Hyun-Woo
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Pukyong National University, Busan 48513, Republic of Korea.
authors.forename: Kyoung-Ho
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Marine-Bio Convergence Science, Pukyong National University, Busan 48513, Republic of Korea.
authors.forename: Jae-Young
authors.initials: JY
authors.lastname: Je
authors.affiliation: Department of Biomedical Engineering, Pukyong National University, Busan 48513, Republic of Korea.|Marine-Integrated Bionics Research Center, Pukyong National University, Busan 48513, Republic of Korea.
authors.forename: Won-Kyo
authors.initials: WK
authors.lastname: Jung
authors.affiliation: Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea.|Marine-Integrated Bionics Research Center, Pukyong National University, Busan 48513, Republic of Korea.
authors.forename: Young-Mog
authors.initials: YM
authors.lastname: Kim
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D048271:Chitosan / Q000494:pharmacology*; D003373:Coumaric Acids / Q000494:pharmacology*; D004357:Drug Synergism; D015870:Gene Expression / Q000187:drug effects; D008712:Methicillin / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D046915:Penicillin-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003373:Coumaric Acids; D046915:Penicillin-Binding Proteins; D047090:beta-Lactams; C487789:mecA protein, Staphylococcus aureus; D000667:Ampicillin; D048271:Chitosan; C004999:ferulic acid; D008712:Methicillin
keywords: Antibacterial activity; chitosan-ferulic acid conjugate; fractional inhibitory concentration; mecA gene; methicillin-resistant Staphylococcus aureus; synergy effect