Ginkgolic acids and Ginkgo biloba extract inhibit Escherichia coli O157:H7 and Staphylococcus aureus biofilm formation.
Infection by enterohemorrhagic Escherichia coli O157:H7 (EHEC) is a worldwide problem, and there is no effective therapy. Biofilm formation is closely related to EHEC infection and is also a mechanism of antimicrobial resistance. Antibiofilm screening of 560 purified phytochemicals against EHEC showed that ginkgolic acids C15:1 and C17:1 at 5μg/ml and Ginkgo biloba extract at 100μg/ml significantly inhibited EHEC biofilm formation on the surfaces of polystyrene and glass, and on nylon membranes. Importantly, at their working concentrations, ginkgolic acids and G. biloba extract did not affect bacterial growth. Transcriptional analyses showed that ginkgolic acid C15:1 repressed curli genes and prophage genes in EHEC, and these findings were in-line with reduced fimbriae production and biofilm reductions. Interestingly, ginkgolic acids and G. biloba extract did not inhibit the biofilm formation of a commensal E. coli K-12 strain. In addition, ginkgolic acids and G. biloba extract inhibited the biofilm formation of three Staphylococcus aureus strains. The findings of this study suggest that plant secondary metabolites represent an important resource for biofilm inhibitors.
School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
Jin-Hyung
JH
Lee
School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
Yong-Guy
YG
Kim
Korea Research Institute of Chemical Technology, Daejeon 305-606, Republic of Korea.
Shi Yong
SY
Ryu
School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
Moo Hwan
MH
Cho
School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea. Electronic address: jtlee@ynu.ac.kr.
Jintae
J
Lee
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D048168:Escherichia coli K12 / Q000187:drug effects; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D020441:Ginkgo biloba / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D012459:Salicylates / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology
D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D012459:Salicylates; C112485:ginkgolic acid
Biofilm formation; Escherichia coli O157:H7; Fimbria; Ginkgolic acids; Staphylococcus aureus; Swarming