title: Thermoresponsive oligomers reduce Escherichia coli O157:H7 biofouling and virulence.
abstract: Thermoresponsive polymers have potential biomedical applications for drug delivery and tissue engineering. Here, two thermoresponsive oligomers were synthesized, viz. oligo(N-isopropylacrylamide) (ONIPAM) and oligo(N-vinylcaprolactam) (OVCL), and their anti-biofouling abilities investigated against enterohemorrhagic E. coli O157:H7, which produces Shiga-like toxins and forms biofilms. Biofilm formation (biofouling) is closely related to E. coli O157:H7 infection and constitutes a major mechanism of antimicrobial resistance. The synthetic OVCL (MW 679) and three commercial OVCLs (up to MW 54,000) at 30 μg ml(-1) were found to inhibit biofouling by E. coli O157:H7 at 37 °C by more than 80% without adversely affecting bacterial growth. The anti-biofouling activity of ONIPAM was weaker than that of OVCL. However, at 25 °C, ONIPAM and OVCL did not affect E. coli O157:H7 biofouling. Transcriptional analysis showed that OVCL temperature-dependently downregulated curli genes in E. coli O157:H7, and this finding was in line with observed reductions in fimbriae production and biofouling. In addition, OVCL downregulated the Shiga-like toxin genes stx1 and stx2 in E. coli O157:H7 and attenuated its in vivo virulence in the nematode Caenorhabditis elegans. These results suggest that OVCL has potential use in antivirulence strategies against persistent E. coli O157:H7 infection.
authors.affiliation: a School of Chemical Engineering , Yeungnam University , Gyeongsan , Republic of Korea.
authors.forename: Jin-Hyung
authors.initials: JH
authors.lastname: Lee
authors.forename: Yong-Guy
authors.initials: YG
authors.lastname: Kim
authors.forename: Hyun Seob
authors.initials: HS
authors.lastname: Cho
authors.forename: Jintae
authors.initials: J
authors.lastname: Kim
authors.forename: Seong-Cheol
authors.initials: SC
authors.lastname: Kim
authors.forename: Moo Hwan
authors.initials: MH
authors.lastname: Cho
authors.forename: Jintae
authors.initials: J
authors.lastname: Lee
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry / Q000494:pharmacology*; D057219:Biofouling / Q000517:prevention & control*; D002209:Caprolactam / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D015536:Down-Regulation; D019453:Escherichia coli O157 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D013696:Temperature; D014774:Virulence
chemical_list: D000180:Acrylic Resins; D011108:Polymers; C052970:poly-N-isopropylacrylamide; C086861:poly-N-vinylcaprolactam; D002209:Caprolactam
keywords: Escherichia coli O157:H7; N-vinylcaprolactam; biofilm; biofouling; thermoresponsive polymer; virulence