U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Date of this Version

May 2001


Published in APPLIED AND ENVIRONMENTAL MICROBIOLOGY, May 2001, p. 2367–2370.


Single-base-pair csgD promoter mutations in human outbreak Escherichia coli O157:H7 strains ATCC 43894 and ATCC 43895 coincided with differential Congo red dye binding from curli fiber expression. Red phenotype csgD::lacZ promoter fusions had fourfold-greater expression than white promoter fusions. Cloning the red variant csgDEFG operon into white variants induced the red phenotype. Substrate utilization differed between red and white variants.