ABSTRACT
This chapter discusses the mechanism of Enterotoxigenic Escherichia coli (ETEC) adherence, in particular the various types of fimbriae identified on enterotoxigenic strains. Escherichia coli is a normal inhabitant of the intestinal tract of man and domestic animals. Age-dependent susceptibility to animal ETEC infections is a well-known phenomenon. E. coli isolated from cases of travelers diarrhea or from the stools of piglets, lambs, calves, or children suffering from neonatal diarrhea possess a variety of different adhesion antigens or adhesins. The expression of the genetic determinants for biosynthesis of fimbriae is in general regulated by environmental factors. Important conditions affecting fimbriae production are the specific growth rate of the bacteria, the temperature, and in some cases the presence of particular nutrients. A mutant showing expression of the temperature-regulated pap operon both at high and low temperature is described. The mutation was located in the locus coding for the bacterial histone-like protein H-NS.
