Personalized prediction of UTI risk and antibiotic susceptibility based on gut E. coli.

Community-acquired UTI is the most common bacterial infection. We assessed whether gut Escherichia coli profiles predict UTI risk and pathogen antibiotic susceptibility in women aged ≥ 50, antibiotics-free for ≥1 year. In an 18-month prospective study, 1,804 participants provided a baseline fecal sample screened for E. coli abundance, resistance to trimethoprim/sulfamethoxazole, ciprofloxacin, and third-generation cephalosporins, and association with pandemic multidrug-resistant (MDR) clonal groups ST131- H30 and ST1193. E. coli was present in 90.8% of samples; 37.5% showed resistance to one or more antibiotics. MDR strains were highly abundant in the gut, with ST131- H30 carriage increasing and ST1193 declining with age. During follow-up, UTIs occurred in 10.9% of E. coli carriers versus 3.0% of non-carriers (P = .0013), with the highest risk of 37.8% observed among women ≥70 yo colonized with ST131- H30 . Increased fecal abundance of strains resistant to the antibiotics strongly associated with the UTI risk. Fecal E. coli resistance profiles predicted UTI antibiotic susceptibility with 95–100% (95% CI) accuracy in 95% of patients.