pap genotype and P fimbrial expression in Escherichia coli causing bacteremic and nonbacteremic febrile urinary tract infection

Escherichia coli strains from patients with febrile urinary tract infection s were examined for pap (n = 73) genotype and P fimbrial expression in rela tion to bacteremia and patients' background variables. Most isolates were p ap(+) by DNA hybridization and 36 were papG(IA2)(+) and 18 prsG(J96)(+) by polymerase chain reaction. (n = 51). The pap and papG genotypes of the infe cting strain were shown to vary with host compromise, sex, and age. Bactere mia in noncompromised patients was caused by papG(IA2)(+) strains, but comp romised hosts carried a mixture of papG(IA2)(+), prsG(J96)(+), and pap(-) s trains. Women of all ages were infected with papG(IA2)(+) strains. Infected men carried prsG(J96)(+) or pap- strains and were older, and most had comp romising conditions. papG(IA2)(+) strains predominated among patients with medical illness, whereas prsG(J96)(+) strains predominated among patients w ith urinary tract abnormalities. These findings emphasize the strong influe nce of host factors on the selection of E. coli strains causing febrile uri nary tract infections.