Open AccessGrowth media and temperature effects on biofilm formation by serotype O157:H7 and non‐O157 Shiga toxin‐producing E scherichia coli
Author(s) -
Uhlich Gaylen A.,
Chen ChinYi,
Cottrell Bryan J.,
Nguyen LyHuong
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12439
Subject(s) - biofilm , congo red , microbiology and biotechnology , escherichia coli , agar , serotype , fimbria , strain (injury) , biology , shiga toxin , incubation , cellulose , pilus , toxin , bacteria , chemistry , gene , biochemistry , genetics , organic chemistry , adsorption , anatomy
Biofilm formation in most E scherichia coli strains is dependent on curli fimbriae and cellulose, and the production of both varies widely among pathogenic strains. Curli and cellulose production by colonies growing on agar are often identified by their affinity for Congo red dye (CR). However, media composition and incubation temperature can affect dye affinity and impose limitations on red phenotype detection by this method. In this study, we compared different Shiga toxin‐producing E . coli for CR affinity and biofilm formation under different media/temperature conditions. We found strain and serotype differences in CR affinities and biofilm formation, as well as temperature and media requirements for maximum CR binding. We also constructed strains with deletions of curli and/or cellulose genes to determine their contributions to the phenotypes and identified two O45 strains with a medium‐dependent induction of cellulose.