title: Bactericidal Effect of Pterostilbene Alone and in Combination with Gentamicin against Human Pathogenic Bacteria.
abstract: The antibacterial activity of pterostilbene in combination with gentamicin against six strains of Gram-positive and Gram-negative bacteria were investigated. The minimum inhibitory concentration and minimum bactericidal concentration of pterostilbene were determined using microdilution technique whereas the synergistic antibacterial activities of pterostilbene in combination with gentamicin were assessed using checkerboard assay and time-kill kinetic study. Results of the present study showed that the combination effects of pterostilbene with gentamicin were synergistic (FIC index < 0.5) against three susceptible bacteria strains:Staphylococcus aureus ATCC 25923,Escherichia coli O157andPseudomonas aeruginosa 15442. However, the time-kill study showed that the interaction was indifference which did not significantly differ from the gentamicin treatment. Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 2 to 8 h treatment with 0.5 × MIC of pterostilbene and gentamicin. The identified combinations could be of effective therapeutic value against bacterial infections. These findings have potential implications in delaying the development of bacterial resistance as the antibacterial effect was achieved with the lower concentrations of antibacterial agents.
authors.affiliation: School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia. lee.wx@mckl.edu.my.
authors.forename: Wee Xian
authors.initials: WX
authors.lastname: Lee
authors.affiliation: School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia. dayang@ukm.edu.my.
authors.forename: Dayang Fredalina
authors.initials: DF
authors.lastname: Basri
authors.affiliation: School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia. rohi@ukm.edu.my.
authors.forename: Ahmad Rohi
authors.initials: AR
authors.lastname: Ghazali
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000648:ultrastructure; D004357:Drug Synergism; D005839:Gentamicins / Q000737:chemistry / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000648:ultrastructure; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D013267:Stilbenes / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D013267:Stilbenes; C107773:pterostilbene
keywords: antibiotic; bactericidal; pterostilbene; synergistic; time kill assay