The lpf operon of invasive Escherichia coli

Extraintestinal pathogenic Escherichia coli (ExPEC) strains have been shown to code for several virulence factors involved in adherence to host tissues. Here we show the existence of an additional adherence gene cluster, coding for long polar fimbriae - LPF - in several strains of serotype O78 from septicemia and newborn meningitis. The complete gene cluster was sequenced in strain 789 (lpf789), where it is located between the genes glmS and pstS, and contains four ORFs, lpfA to lpfD. The lpf operon is expressed and is important for adherence to epithelial cells. The lpf operon was found only in four of the ExPEC strains tested and is likely to have been acquired by horizontal gene transfer.