title: Gallic acid conjugated with gold nanoparticles: antibacterial activity and mechanism of action on foodborne pathogens.
abstract: Foodborne pathogens, including Plesiomonas shigelloides and Shigella flexneri B, are the major cause of diarrheal endemics worldwide. Antibiotic drug resistance is increasing. Therefore, bioactive compounds with antibacterial activity, such as gallic acid (GA), are needed. Gold nanoparticles (AuNPs) are used as drug delivery agents. This study aimed to conjugate and characterize AuNP-GA and to evaluate the antibacterial activity. AuNP was conjugated with GA, and the core-shell structures were characterized by small-angle X-ray scattering and transmission electron microscopy. Antibacterial activity of AuNP-GA against P. shigelloides and S. flexneri B was evaluated by well diffusion method. AuNP-GA bactericidal mechanism was elucidated by Fourier transform infrared microspectroscopic analysis. The results of small-angle X-ray scattering showed that AuNP-GA conjugation was successful. Antibacterial activity of GA against both bacteria was improved by conjugation with AuNP because the minimum inhibitory concentration value of AuNP-GA was significantly decreased (P<0.0001) compared to that of GA. Fourier transform infrared analysis revealed that AuNP-GA resulted in alterations of lipids, proteins, and nucleic acids at the bacterial cell membrane. Our findings show that AuNP-GA has potential for further application in biomedical sciences.
authors.affiliation: Department of Biochemistry, Faculty of Science.
authors.forename: Narintorn
authors.initials: N
authors.lastname: Rattanata
authors.affiliation: Department of Biochemistry, Faculty of Science.
authors.forename: Sompong
authors.initials: S
authors.lastname: Klaynongsruang
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences.
authors.forename: Chanvit
authors.initials: C
authors.lastname: Leelayuwat
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences.
authors.forename: Temduang
authors.initials: T
authors.lastname: Limpaiboon
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences.
authors.forename: Aroonlug
authors.initials: A
authors.lastname: Lulitanond
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen.
authors.forename: Patcharee
authors.initials: P
authors.lastname: Boonsiri
authors.affiliation: Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand.
authors.forename: Sirinart
authors.initials: S
authors.lastname: Chio-Srichan
authors.affiliation: Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand.
authors.forename: Siriwat
authors.initials: S
authors.lastname: Soontaranon
authors.affiliation: Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand.
authors.forename: Supagorn
authors.initials: S
authors.lastname: Rugmai
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences.
authors.forename: Jureerut
authors.initials: J
authors.lastname: Daduang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D005517:Foodborne Diseases / Q000382:microbiology*; D005707:Gallic Acid / Q000737:chemistry / Q000494:pharmacology*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D053838:Scattering, Small Angle; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D005707:Gallic Acid; D006046:Gold
keywords: antibacterial activity; foodborne bacteria; gallic acid; gold nanoparticles; small-angle X-ray scattering (SAXS)