Effects of UVC Treatment on Biofilms of Escherichia coli Strains Formed at Different Temperatures and Maturation Periods

In the present study, the biofilm formation and ultraviolet-C (UVC) resistance characteris- tics of Escherichia coli isolated from an occluded biliary stent were compared with those of four E. coli O157:H7 strains (ATCC 35150, 43889, 43890, and 43895). To evaluate biofilm formation, the E. coli isolated from a stent and four E. coli O157:H7 strains were incubated at 37, 25, and 15 ◦C for 7 days, revealing that peak biofilm formation occurred at 37 ◦C (day 1), 25 ◦C (day 3), and 15 ◦C (day 5),...