title: Inhibitory effects of flavonoids on biofilm formation by Staphylococcus aureus that overexpresses efflux protein genes.
abstract: This study evaluated the efficacy of glycone (myricitrin, hesperidin and phloridzin) and aglycone flavonoids (myricetin, hesperetin and phloretin) in inhibiting biofilm formation by Staphylococcus aureus RN4220 and S. aureus SA1199B that overexpress the msrA and norA efflux protein genes, respectively. The minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC50- defined as the lowest concentration that resulted in ≥50% inhibition of biofilm formation) of flavonoids were determined using microdilution in broth procedures. The flavonoids showed MIC >1024 μg/mL against S. aureus RN4220 and S. aureus SA1199B; however, these compounds at lower concentrations (1-256 μg/mL) showed inhibitory effects on biofilm formation by these strains. Aglycone flavonoids showed lower MBIC50values than their respective glycone forms. The lowest MBIC50values (1 and 4 μg/mL) were observed against S. aureus RN4220. Myricetin, hesperetin and phloretin exhibited biofilm formation inhibition >70% for S. aureus RN4220, and lower biofilm formation inhibition against S. aureus SA1199B. These results indicate that sub-MICs of the tested flavonoids inhibit biofilm formation by S. aureus strains that overexpress efflux protein genes. These effects are more strongly established by aglycone flavonoids.
authors.affiliation: Laboratório de Genética de Microrganismos, Departamento de Biologia Molecular, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil.
authors.forename: Laênia Angélica Andrade
authors.initials: LAA
authors.lastname: Lopes
authors.affiliation: Laboratório de Processos Microbianos em Alimentos, Departamento de Engenharia de Alimentos, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil.
authors.forename: Jéssica Bezerra
authors.initials: JB
authors.lastname: Dos Santos Rodrigues
authors.affiliation: Laboratório de Processos Microbianos em Alimentos, Departamento de Engenharia de Alimentos, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil.
authors.forename: Marciane
authors.initials: M
authors.lastname: Magnani
authors.affiliation: Laboratório de Microbiologia de Alimentos, Departamento de Nutrição, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil. Electronic address: evandroleitesouza@ccs.ufpb.br.
authors.forename: Evandro Leite
authors.initials: EL
authors.lastname: de Souza
authors.affiliation: Laboratório de Genética de Microrganismos, Departamento de Biologia Molecular, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil.
authors.forename: José P
authors.initials: JP
authors.lastname: de Siqueira-Júnior
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D005419:Flavonoids / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D006031:Glycosylation / Q000187:drug effects; D006569:Hesperidin / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000737:chemistry; D026901:Membrane Transport Proteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics; D010693:Phloretin / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000737:chemistry; D010695:Phlorhizin / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D005419:Flavonoids; D006569:Hesperidin; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010693:Phloretin; D010695:Phlorhizin; C075040:NorA protein, Staphylococcus; C008577:myricitrin; C040015:myricetin; C013015:hesperetin
keywords: Biofilm; Flavonoids; Glycosylation; Inhibitory effect; Staphylococcus spp.