A Rare Case Report of Nosocomial Urosepsis due to Klebsiella pneumoniae in a Preterm Neonate Complicated by Acute Cystitis.

Late-onset sepsis secondary to urinary tract infection in preterm infants is frequently underdiagnosed and rarely reported. Establishing this diagnosis remains challenging, as clinical manifestations are often nonspecific, inflammatory markers may be inconclusive, and urinalysis is not routinely performed in many NICUs. We report a case of urosepsis originating from Klebsiella pneumoniae-associated cystitis in a 41-day-old preterm infant who had been admitted to our NICU since birth. The infant had multiple risk factors for sepsis, including prolonged mechanical ventilation and the presence of an indwelling central line. This case highlights the importance of maintaining a high suspicion index for urinary tract infection in preterm neonates with unexplained clinical deterioration and emphasizes the need for early urine evaluation as part of the sepsis workup.