Temperature-dependent transcriptional regulation of expression of fimbriae in an Escherichia coli strain isolated from a child with severe enteritis.

Escherichia coli 469-3 synthesizes fibrillar fimbriae at 37 degrees C, but not at 18 degrees C, which promote its adherence to human colonocytes. RNA homologous with a cloned fragment of the strain 469-3 chromosome necessary for normal expression of fimbriae was virtually undetectable in bacteria grown at 18 degrees C, indicating that environmental temperature affects expression by regulating transcription.