Coumarins reduce biofilm formation and the virulence of Escherichia coli O157:H7.
E. coli O157:H7 is the most common cause of hemorrhagic colitis, and no effective therapy exists for E. coli O157:H7 infection. Biofilm formation is closely related to E. coli O157:H7 infection and constitutes a mechanism of antimicrobial resistance. Hence, the antibiofilm or antivirulence approach provides an alternative to antibiotic strategies. Coumarin and its derivatives have a broad range of biological effects, and in this study, the antibiofilm activities of nine coumarins were investigated against E. coli O157:H7. Coumarin or umbelliferone at 50μg/ml was found to inhibit biofilm E. coli O157:H7 formation by more than 80% without affecting bacterial growth. Transcriptional analysis showed that coumarins repressed curli genes and motility genes in E. coli O157:H7, and these findings were in-line with observed reductions in fimbriae production, swarming motility, and biofilm formation. In addition, esculetin repressed Shiga-like toxin gene stx2 in E. coli O157:H7 and attenuated its virulence in vivo in the nematode Caenorhabditis elegans. These findings show that coumarins have potential use in antivirulence strategies against persistent E. coli O157:H7 infection.
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
School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, Republic of Korea.
Hyun Seob
HS
Cho
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
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D017173:Caenorhabditis elegans / Q000187:drug effects; D003374:Coumarins / Q000494:pharmacology*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000472:pathogenicity / Q000502:physiology / Q000648:ultrastructure; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D014468:Umbelliferones / Q000494:pharmacology*; D014774:Virulence / Q000187:drug effects
D000900:Anti-Bacterial Agents; D003374:Coumarins; D014468:Umbelliferones; C031477:7-hydroxycoumarin; C030123:coumarin; C007628:esculetin
Biofilm formation; Coumarin; Escherichia coli O157:H7; Esculetin; Umbelliferone; Virulence