pap Genotype and P Fimbrial Expression in Escherichia coli Causing Bacteremic and Nonbacteremic Febrile Urinary Tract Infection

Abstract

Escherichia coli strains from patients with febrile urinary tract infections (n = 73) were examined for pap genotype and P fimbrial expression in relation to bacteremia and patients' background variables. Most isolates were pap⁺ by DNA hybridization (n = 51), and 36 were papG_IA2⁺ and 18 prsG_J96⁺ by polymerase chain reaction. The pap and pap G genotypes of the infecting strain were shown to vary with host compromise, sex, and age. Bacteremia in noncompromised patients was caused by papG_IA2⁺ strains, but compromised hosts carried a mixture of papG_IA2⁺, prsG_J96⁺, and pap⁻ strains. Women of all ages were infected with papG_IA2⁺ strains. Infected men carried prsG_J96⁺ or pap⁻ strains and were older, and most had compromising conditions. papG_IA2⁺ strains predominated among patients with medical illness, whereas prsG_J96⁺ strains predominated among patients with urinary tract abnormalities. These findings emphasize the strong influence of host factors on the selection of E. coli strains causing febrile urinary tract infections.