Klebsiella pneumoniae UTI

Urinary tract infection (UTI) is common worldwide, with Klebsiella pneumoniae as the second most frequent cause. Emerging hypervirulent strains (hvKp) drive severe infections. Clinical evidence linking specific virulence traits or serotypes to UTI progression and mortality is limited. This study characterized clinical features, capsular serotypes, and virulence factors of K. pneumoniae and assessed whether hvKp and particular capsular serotypes independently predict bacteremia and 30-day mortality. A retrospective study of adults (≥19 years) with symptomatic K. pneumoniae UTI was conducted between January 2014 and December 2019. Patients were categorized as having UTI with vs. without bacteremia. Six capsular serotypes (K1, K2, K5, K20, K54, and K57) and 13 virulence genes (entB, ybtS, kfu, mrkD, allS, rmpA, rmpA2, iutA, iucA, iroB, peg344, peg589, and peg1631) were analyzed alongside clinical data.Among 408 patients, K1 serotype was the most common, and hvKp accounted for 26%. Bacteremia was independently associated with malignancy, shock, metastatic infection, fever, thrombocytopenia, elevated blood urea nitrogen, and increased procalcitonin, with hvKp (aOR 3.10, 95% CI 1.79-5.38), K1(aOR 4.58, 2.08-10.10), and K20 (aOR 11.31, 2.59-49.41) as risk factors. In our cohort of K. pneumoniae UTI, the 30-day mortality was 5.9% (24/408). Thirty-day mortality was independently associated with malignancy, metastatic infection, altered mental status, tachycardia, and elevated blood urea nitrogen, with hvKp, kfu, K1, and K20 as risk factors. hvKp and serotypes K1 and K20 are independent risk factors for progression of K. pneumoniae UTI to bacteremia and 30-day mortality.