Gut E. coli profiles as prospective predictors of UTI risk and antibiotic susceptibility

Community-acquired UTI is the most common bacterial infection. We assessed whether gut Escherichia coli profiles are associated with UTI risk and pathogen antibiotic susceptibility in women aged ≥50, antibiotics-free for ≥1 year. In an 18-month prospective observational 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 is present in 90.8% of samples; 37.5% are resistant to one or more antibiotics. MDR strains are highly abundant in the gut, with ST131-H30 carriage increasing and ST1193 declining with age. During the 18-months follow-up, UTIs occur in 10.9% of E. coli carriers versus 3.3% of non-carriers (P = .003), with the highest risk of 37.8% observed among women ≥70 years old colonized with ST131-H30. Increased fecal abundance of strains resistant to the antibiotics is strongly associated with the UTI risk. In 95% of patients, susceptibility of E. coli to the tested antibiotics in the original fecal and follow-up urine sample is concordant, with 95–100% accuracy. These proof-of-concept findings support the feasibility of fecal E. coli profiling as a tool for individualized UTI risk stratification and empiric antibiotic guidance, particularly in at-risk populations. Tchesnokova1 et al., evaluates whether baseline fecal Escherichia coli abundance, antibiotic resistance, and clonal group carriage are associated with future UTI risk in antibiotic-free women aged ≥50 years. Gut E. coli, particularly antibiotic-resistant and ST131-H30 strains, is associated with increased UTI risk, and fecal resistance profiles accurately predict antibiotic susceptibility of urine isolates, supporting individualized risk stratification and empiric treatment guidance. Urinary tract infections (UTIs) are among the most common bacterial infections in women. This study looked at whether the E. coli bacteria naturally living in a person’s gut could predict their risk of getting a UTI and which antibiotics would work against it. We followed 1,804 women aged 50 and older for 18 months, starting with a stool sample test. Most carried E. coli in their gut, and a third carried strains resistant to commonly used antibiotics. People carrying gut E. coli were three times more likely to develop a UTI than those without it. Risk was especially high (up to 40%) in older women carrying multi-drug-resistant strains. Importantly, the antibiotic resistance pattern found in stool closely matched the pattern found later in urine during an actual infection, with up to 100% accuracy. This suggests a simple stool test could help doctors predict UTI risk and choose effective antibiotics well before infection even occurs.