title: Temperature-dependent control of Staphylococcus aureus biofilms and virulence by thermoresponsive oligo(N-vinylcaprolactam).
abstract: Bacterial biofilms are associated with persistent infections because they are highly tolerant of antimicrobial agents, and in the case of Staphylococcus aureus, which is a leading cause of nosocomial infections because of its resistance to diverse antibiotics, biofilm formation is a known mechanism of drug resistance. In the present study, we investigated the ability of thermoresponsive oligo (N-vinylcaprolactam) (OVCL) to control biofilm formation by and the virulence of S. aureus. One synthetic and four commercial OVCLs (MW ≤ 240,000) at 50 µg/mL were found to increase S. aureus biofilm formation 7-fold at 25 °C, but to markedly inhibit S. aureus biofilm formation at 37 °C. Confocal and scanning electron microscopy confirmed the temperature-dependent effect of OVCL on S. aureus biofilms. It was found that the addition of OVCL to S. aureus culture caused cells to become dramatically more hydrophilic at 37 °C, which partially supports the biofilm reduction. Also, transcriptional analysis showed that OVCL temperature-dependently regulated biofilm-related genes (aur, agrA, and icaA) in S. aureus. In addition, it was found surface coatings containing OVCL effectively controlled S. aureus biofilm formation on solid glass surfaces. Furthermore, OVCL inhibited the hemolysis of human red blood cells by S. aureus at 37 °C and attenuated S. aureus virulence in the nematode Caenorhabditis elegans. These results suggest that OVCL has potential use for controlling bacterial biofilm formation and virulence.
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, 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: Kayeon
authors.initials: K
authors.lastname: Lee
authors.forename: Seong-Cheol
authors.initials: SC
authors.lastname: Kim
authors.forename: Jintae
authors.initials: J
authors.lastname: Lee
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects* / Q000528:radiation effects*; D017173:Caenorhabditis elegans / Q000382:microbiology; D002209:Caprolactam / Q000031:analogs & derivatives* / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000472:pathogenicity / Q000528:radiation effects*; D016019:Survival Analysis; D013696:Temperature; D014774:Virulence / Q000187:drug effects / Q000528:radiation effects
chemical_list: D011108:Polymers; C086861:poly-N-vinylcaprolactam; D002209:Caprolactam
keywords: N-vinylcaprolactam; Staphylococcus aureus; biofilm; hydrophilicity; thermoresponsive polymer